PRACTICAL GUIDE FOR Improving Resource Efficiency in Red Meat Abattoirs in South Africa IN PARTNERSHIP WITH About IFC IFC – a member of the World Bank Group – is the largest global development institution focused on the private sector in emerging markets. We work in more than 100 countries, using our capital, expertise, and influence to create markets and opportunities in developing countries. In fiscal year 2020, we invested $22 billion in private companies and financial institutions in developing countries, leveraging the power of the private sector to end extreme poverty and boost shared prosperity. For more information, visit www.ifc.org. © International Finance Corporation [2020]. All rights reserved. 2121 Pennsylvania Avenue, N.W. Washington, D.C. 20433 Internet: www.ifc.org The material in this work is copyrighted. Copying and/or transmitting portions or all of this work without permission may be a violation of applicable law. IFC does not guarantee the accuracy, reliability or completeness of the content included in this work, nor the conclusions or judgments described herein, and accepts no responsibility or liability for any omissions or errors (including, without limitation, typographical errors and technical errors) in the content whatsoever, or for reliance thereon. Cover Image: ©depositphotos_dfuentesphotostock Contents 1. Executive Summary 5 2. Background 11 3. Monitoring Systems 13 Implement an Effective Metering and Monitoring System......................................................................... 13 4. Water 15 Water Supply.......................................................................................................................................... 17 Water Usage........................................................................................................................................... 18 Summary of Water Efficiency Recommendations......................................................................................25 5. Energy 27 Electrical Energy......................................................................................................................................28 Thermal Energy.......................................................................................................................................39 Summary of Energy Efficiency Recommendations.................................................................................... 49 6. Summary and Conclusions 51 References..............................................................................................................................................52 Figures Figure 1: Recommended metering programme........................................13 Figure 27: Typical demand on compressors with reduced plant load .......... 35 Figure 2: Water availability per person per year in selected countries.........15 Figure 28: Illustration of efficiency loss during unload cycle......................36 Figure 3: Overview of water use by area................................................ 16 Figure 29: Overview of heat recovery potential and applications ..............36 Figure 4: Water source and usage benchmark comparisons for: fully Figure 30: Overview of interventions for compressed air systems .............. 37 integrated facilities; slaughter, chill and bone facilities; Figure 31: New build life cycle cost on different power sources (2016 rates) .....38 and slaughter and chill facilities............................................. 16 Figure 32: Thermal energy savings potential for a typical abattoir............. 39 Figure 5: Water savings potential for a typical abattoir...........................17 Figure 33: Vapour compression cycle of a heat pump.............................. 40 Figure 6: Piping used for rinsing/manual cleaning ................................. 18 Figure 34: Illustration of heat recovery on a refrigeration system .............. 41 Figure 7: Manual cleaning low flow system........................................... 19 Figure 35: Solar irradiation map ...........................................................42 Figure 8: "Economiser" spray sanitation system.....................................20 Figure 36: Typical boiler efficiency curve................................................ 44 Figure 9: Illustration of a hot water/ultrasonic dip tank ..........................21 Figure 37: Anticipated generation efficiency of the boiler..........................45 Figure 10: Examples of hand wash basins with traditional rose fittings..... 22 Figure 38: Radiation loss pictures on steam lines.................................... 46 Figure 11: Example of an aerator and a touch fitting for conventional taps..... 22 Figure 39: Expected fuel saving through increased condensate return ....... 48 Figure 12: Example of a boot cleaning station......................................... 22 Figure 13: Mounted brush system for cleaning boots............................... 23 Figure 14: Examples of water reuse opportunities ...................................24 Figure 15: Overview of main energy users in an abattoir........................... 27 Tables Figure 16: Total energy source and usage benchmark comparisons for fully integrated facilities; slaughter, chill and bone facilities; Table 1: Summary of water saving recommendations................................ 25 and slaughter and chill facilities............................................. 27 Table 2: Overall steam system efficiency................................................. 44 Figure 17: Electrical energy savings potential for a typical abattoir...........28 Table 3: Radiation loss table for steam lines.............................................47 Figure 18: Time-of-use tariff overview ...................................................29 Table 4: Summary of energy saving recommendations..............................49 Figure 19: Demand management strategies............................................30 Figure 20: Live logging profile of a plant with a high refrigeration load.......30 Figure 21: Pump system curve illustrating the impact of throttling............31 Boxes Figure 22: Waste energy and potential savings illustrated by removing unnecessary head pressure and line throttling.......................... 32 Box 1: Best practice for manual cleaning and rinsing ................................ 19 Figure 23: The impact of running two pumps on a system designed for one..... 32 Box 2: Best practice for waste heat recovery on compressors ..................... 37 Figure 24: Pump curve of borehole pumps .............................................. 33 Box 3: Best practice for heat recovery on refrigeration units ....................... 41 Figure 25: Illustrations of the effect of refrigerant leaks............................34 Box 4: Combined heat and power biogas plant......................................... 43 Figure 26: Load matching strategies for air and cooling compressors ........34 Box 5: Best practice for steam piping – insulation for valves and flanges .....47 Glossary APRE Agri-Processing Resource Efficiency (Project in South Africa) CHP Combined Heat and Power CO2 Carbon Dioxide COP Coefficient of Performance DNI Direct Normal Irradiation GHG Greenhouse Gas IFC International Finance Corporation IRR Internal Rate of Return kg Kilogram kWh Kilowatt-hour kl Kilolitre KPI Key Performance Indicator Lairage Stock-holding pen where animals are held pre-slaughter at an abattoir. MAS Manufacturing, Agribusiness and Services m 3 Cubic metres mm Millimetre MWh Mega Watt hour NATSURV National Survey Offal The organs of a slaughtered animal, usually divided into: • Red offal – heart, liver, kidney, tongue • Rough offal – stomachs, intestines, other organs PPE Personal Protective Equipment QAC Quaternary Ammonium Compound R South African Rands Rendering Cooking and sterilising of animal waste products not fit for human consumption (i.e. “condemned”), as well as evaporation of moisture to produce a proteinaceous meal. Melted fat is normally recovered for further utilisation, such as tallow production. RMAA Red Meat Abattoir Association SECO Swiss State Secretariat for Economic Affairs Solar PV Solar Photovoltaic SU Slaughter Unit is the number of non-bovine species considered equivalent to one bovine animal for abattoir purposes, and is based on the South African standard whereby: • One cattle animal equals one SU • Two pigs equal one SU • Six sheep equal one SU • Six goats equal one SU • Six small-stock (mixed species) equal one SU TDS Total Dissolved Solids Tonnes Carcase Weight – the volume (metric tonnes) of carcase weight processed. CW (tCW) UV Ultraviolet VSD Variable Speed Drive WBG World Bank Group 2 PRACTICAL GUIDE Acknowledgements The Practical Guide for Improving Resource Efficiency in Red Meat Abattoirs in South Africa was produced as part of a broader International Finance Corporation (IFC) Agri-processing Resource Efficiency (APRE) project in South Africa, aimed to assist companies engaged in agricultural processing to transition to better water and resource efficiency practices. The project is expected to help mitigate water supply risks in the sector, resulting from the water scarcity challenge in South Africa and throughout the region. The project is implemented in partnership with the Swiss State Secretariat for Economic Affairs (SECO) and the Netherlands. The Practical Guide for Improving Resource Efficiency was developed as part of a resource efficiency benchmarking study for the red meat abattoir sector in South Africa. The study involved benchmarking of the water and energy usage of 21 abattoirs across the country against local and international best practices. The team would like to acknowledge the contribution from all red meat abattoir owners and managers, and other stakeholders who participated in the benchmarking study and provided input into the Best Practice Guide. The study was managed by Raymond Greig and Rong Chen (IFC). IFC commissioned Resource Innovations Africa (Pty) Ltd and ProAnd Associates Australia (Pty) Ltd to support the collection of information and the analysis, and to provide technical recommendations. We appreciate the effort of the key experts, Darrin McComb (Director, Resource Innovations Africa) and Jon Marlow (Director, ProAnd Associates Australia) and their teams. IFC has partnered with the Red Meat Abattoir Association (RMAA) to facilitate the implementation of the project, and is grateful to Gerhard Neethling (General Manager, RMAA) for coordinating stakeholder engagements and for providing inputs to the report. The team is also grateful to the World Bank Group (WBG) colleagues for supporting the assessment and providing feedback on the report. We would like to thank Alexander Larionov, Ivan Ivanov, Jerrard Müller, Nonhlanhla Halimana and Robert Peck. Also, many thanks to Bonny Jennings and the full team at ITL Communication and Design for the excellent production of the report. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 3 ©depositphotos_baronb 4 PRACTICAL GUIDE 1 Executive Summary South Africa’s red meat abattoir industry is a key driver of economic growth, as it contributes to value addition, job creation and exports. However, The South African red meat abattoir industry has the potential to reduce increasing water scarcity, combined with rising costs of energy and fuel, is water consumption by up to 28%, threatening the competitiveness and sustainability of the sector. The global resulting in national national savings of red meat industry will increasingly come under governmental and consumer up to 1.25 million cubic meters and R37 scrutiny for its climate footprint. South Africa has one of the lowest costs of million per annum. energy in the world; however, with increased power shortages, this will likely change. The APRE project in South Africa was established to address these challenges and help the industry transition to better water and resource efficiency practices. APRE, in partnership with the RMAA, has conducted a resource efficiency benchmarking study and developed this Practical Guide for Improving Resource Efficiency in Red Meat Abattoirs in South Africa, with the objective of identifying water and resource efficiency opportunities and proposing practical solutions that the abattoir industry can adopt. These measures will ultimately lead to improved competitiveness and sustainability of the industry. The red meat industry is a key sub-sector of the agri-processing sector, with 423 abattoirs processing a total of 5.1 million slaughter units (SUs) in 2019. The red meat abattoir industry is also a major water user in the agri-processing sector, utilising an estimated 4.5 million cubic metres of water per year, which amounts to approximately 10% of the water demand of the agri-processing sector (excluding pulp and paper). This study surveyed a sample of 21 abattoirs in South Africa of various sizes, species and geographical locations, and major water and energy saving opportunities were identified. It was determined that there is a potential to reduce water consumption by up to 28% in the industry, resulting in national savings of up to 1.25  million  cubic metres and R37  million per annum. Similarly, there is a potential to reduce energy consumption by up to 24% resulting in national savings of up to 92,000 MWh and R105 million per annum. The common resource efficiency opportunities are summarised below. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 5 Monitoring Systems Comprehensive metering and monitoring systems have not been commonly adopted by the industry. Without a metering and monitoring system in place, it is difficult to detect and quantify wastage, including water leaks and house-keeping-related wastage. Abattoirs should ideally be monitoring the areas depicted below with live logging meters on the water and electrical feeds to the plant. Detailed monitoring systems will typically see a 5% reduction in resource consumption. Metering Programme Water Energy Monthly Sampling Lairages Electrical main meter Effluent COD Main incoming meter Chiller compressors Effluent TDS Slaughter floor Air compressors Borehole water level Offal handling Boiler fuel (liquid) Borehole water quality (TDS/hardness) Post operative cleaning Cooling towers Boiler feed 6 PRACTICAL GUIDE Water Abattoirs predominantly utilise water from either municipal or ground water sources, with the bulk of the water used for cleaning and sanitation purposes. Whilst abattoirs within the municipal boundaries are faced with higher water costs, those in the rural areas have lower costs, yet their challenges are related to water availability. A typical abattoir could reduce its water consumption by 27.5% by implementing a number of water efficiencies measures. The graph below provides an indication of the expected savings in the respective areas. THE WATER EFFICIENCY MEASURES IDENTIFIED INCLUDE: • Implement a ground water strategy • Rainwater recovery • Optimise manual cleaning/rinse systems • Dry cleaning techniques • Optimise knife and hook sanitation systems • Optimise boot and hand washing • Water re-use opportunities 100 Improved 90 efficiency/ profitability 80 27.5% 70 60 50 % 40 30 20 10 0 Ave. Cost/ SU Pre-Slaughter Slaughter Offal Post- Other Potential Slaughter Cleaning Other Post-Slaughter Cleaning Offal Slaughter Pre-Slaughter Saving Improving Resource Efficiency in Red Meat Abattoirs in South Africa 7 THE ELECTRICAL ENERGY Electrical Energy EFFICIENCY AND RELATED Refrigeration and chiller plants typically account for up to 45% of the electrical COST-SAVING MEASURES demand of an abattoir and therefore offer the greatest electrical savings IDENTIFIED INCLUDE: opportunities. A typical abattoir could reduce its electrical energy consumption • Review electrical tariffs by an estimated 12% by implementing a number of energy efficiency measures. • Reduce peak electrical demand • Pump system optimisation • Chiller system coefficient Compressed air of performance (COP) 10% management and Other optimisation 25% • Compressed air system optimisation • Solar photovoltaic (PV) Pumping 10% Refrigeration 45% Lighting 10% ©depositphotos_temis1964 8 PRACTICAL GUIDE Thermal Energy The larger plants with on-site rendering would typically have steam systems utilising coal boilers. Smaller abattoirs without rendering capability would utilise either electrical heating elements or small liquid fuel-driven steam systems (flash steam generators). The fuel cost per kilowatt-hour (kWh) is relatively high in the smaller plants; however, their system efficiencies are significantly better, especially for point-of-use heating applications (heating elements at the sterilisers). There is significant scope for improving costs and efficiencies in the thermal heating systems, especially in the smaller plants that have relatively high heating costs per kWh. A typical abattoir could reduce its thermal energy consumed by an estimated 32% by implementing a number of thermal energy efficiency measures. THE THERMAL EFFICIENCY AND RELATED COST-SAVING MEASURES IDENTIFIED INCLUDE: • Renewables and waste heat recovery • Optimise steam system generation efficiency • Insulate steam lines, valves and flanges • Condensate recovery 100 Improved 90 efficiency/ profitability 80 31.8% 70 60 50 % 40 30 20 10 0 % Generation Radiation Leakage Wasteful Productive Potential Losses Losses Usage Work Productive Work Wasteful Usage Leakage Radiation Losses Generation Losses Saving Improving Resource Efficiency in Red Meat Abattoirs in South Africa 9 ©depositphotos_benedamiroslav 10 PRACTICAL GUIDE 2 Background South Africa is a water-scarce country. By 2030, South Africa’s water demand is expected to exceed its water supply by up to 17% (a deficit of 2.7-3.8 billion kl) and the forecasted growth in the agri-processing sector will contribute to this widening gap between water supply and demand1. South Africa’s agri-processing sector is a key driver for the economy as it contributes to value addition, job creation and exports. However, increasing water scarcity, combined with rising costs of energy and fuel, is threatening the competitiveness and sustainability of the sector. IFC’s Manufacturing, Agribusiness and Services (MAS) Advisory team, in partnership with SECO, launched the four-year APRE project in South Africa to address market challenges and help the industry transition to better water and resource efficiency practices. The programme aims to improve water use efficiency, reduce overall water consumption, and mitigate water supply risks in the sector. The red meat industry is a key sub-sector of the agri-processing sector, with 423 abattoirs of various sizes processing a total of 5.1 million SUs in 20192 3. The red meat abattoir industry is also a major water user in the agri-processing sector, utilising an estimated 4.5 million kl of water per year, which amount to approximately 10% of the water demand of the agri-processing sector (excluding pulp and paper)4. The sector possesses significant potential to reduce the use of water and other resources, which would improve its cost base and environmental footprint, and increase the competitiveness and DATA FOR THIS REPORT HAS sustainability of abattoirs and integrated operators, as well as enhance their BEEN COLLECTED FROM A VARIETY OF SOURCES, export potential. IFC has partnered with the RMAA to conduct a resource INCLUDING: efficiency benchmarking study and this Practical Guide for Improving Resource • Plant monitoring data Efficiency in Red Meat Abattoirs in South Africa, with the objective of identifying water and other resource efficiency opportunities and practical solutions that • In-plant surveys by the project abattoirs can adopt. team The Study surveyed 21 abattoirs (including single species abattoirs for cattle • Accounting documentation and pigs, and mixed species abattoirs for cattle, pigs and goats). The abattoirs • Energy and material audit tools were selected to be representative of the sector and therefore include high • Desk study of international throughput abattoirs (>20 SUs per day) as well as low throughput abattoirs (2- benchmarking. 20 SUs per day) which are geographically spread across the country. 1 World Bank Group, 2020 2 Red Meat Levy Admin, 2019 3 IFC, 2020 4 IFC, 2019 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 11 Details of the Study are included in IFC’s Benchmarking Study: Resource Efficiency in Red Meat Abattoirs in South Africa. This document has been specifically prepared for South African red meat abattoirs and therefore focuses on the most prominent opportunities for the sector, taking into account the existing operating environment. To have a comprehensive list of resource efficiency best practices and opportunities, this document should be read in conjunction with other reputable and complementary South African and international publications such as the Water Research Commission’s NATSURV 7 on Water and Wastewater Management in the Red Meat Abattoir Industry (2017). The sections to follow describe a number of resource efficiency opportunities and best practices that have been identified during the study. First, a metering and monitoring system is recommended which is applicable to both water and energy consumption. This is followed by water efficiency measures, electrical energy efficiency measures and finally thermal energy efficiency measures. For each of these sections, current practices are described, opportunities are identified, recommended actions are outlined, potential problems are raised, and an indicative cost-benefit analysis is provided based on 2020 costs. 12 PRACTICAL GUIDE 3 RECOMMENDED ACTION 1. Install live logging meters on the water and electrical feed to Monitoring Systems the plant. 2. Develop a monitoring programme with targets for key consumption areas. Implement an Effective Metering 3. Implement a leak detection and Monitoring System and repair programme. Observation Detailed water balances were compiled at abattoirs during the assessment, which showed that roughly 10% of the water utilised was lost to observable leaks, while a further 15-25% of the water utilised could not be accounted for and was likely lost to underground leaks. On ageing production facilities with piping systems underground, it is possible INDICATIVE COST-BENEFIT for water leaks to go undetected for long periods of time. In addition, if effective ANALYSIS metering and monitoring is not conducted, it is difficult to detect and quantify house-keeping-related wastage. Live monitoring systems are effective in not Detailed monitoring systems will typically see a 5% reduction in only quantifying water and energy consumption but also in understanding resource consumption. usage patterns. Tracking downtime readings (over holidays or weekends) often provides a clear indication of potential leaks and avoidable losses. Abattoirs should ideally be monitoring the following areas: FIGURE 1: RECOMMENDED METERING PROGRAMME Metering Programme Water Energy Monthly Sampling Lairages Electrical main meter Effluent COD Main incoming meter Chiller compressors Effluent TDS Slaughter floor Air compressors Borehole water level Offal handling Boiler fuel (liquid) Borehole water quality (TDS/hardness) Post operative cleaning Cooling towers Boiler feed Improving Resource Efficiency in Red Meat Abattoirs in South Africa 13 ©depositphotos_dfuentesphotostock 14 PRACTICAL GUIDE 4 Water South Africa is considered a water-scarce country with average annual rainfall of just under 500 mm and just 843 m3 per capita per annum water availability. Figure 2 provides an indication of how South Africa compares against other countries. FIGURE 2: WATER AVAILABILITY PER PERSON PER YEAR IN SELECTED COUNTRIES5 28 254 21 272 1 761 1 543 13 331 1 083 8 914 867 715 534 495 3 033 2 674 416 285 1 155 1 187 843 South Africa India Botswana Namibia France USA DRC Australia Brazil Water per capita per annum (m3) Average annual rainfall (mm) The red meat sector is a significant water user and has been identified as one of the sectors that could benefit from optimisation studies. Abattoirs utilise water predominantly from either municipal or ground water sources. Abattoirs based in a metropolitan area would typically purchase water at a rate of between R20-R40/kl and discharge at a cost which would range between R20–R80/kl, depending on the quality of the water discharged. Abattoirs in rural areas would typically extract from boreholes and discharge the water to irrigation or evaporation ponds. The costs involved in these instances would be for pumping (~R1-R2/kl) and chemical treatment (chlorination). Abattoirs that irrigate their effluent invariably make use of biological treatment ponds prior to spraying the water to reduce the organic loading. 5 World Wildlife Fund, 2016 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 15 FIGURE 3: OVERVIEW OF WATER USE BY AREA Pre-Slaughter Other 15% 20% The bulk of the water used in a typical abattoir would be for cleaning and sanitation purposes. Figure 3 provides an indication of the distribution of water consumption in these facilities. Post-Slaughter Slaughter Cleaning 30% 20% Offal 15% Abattoirs’ water consumption and specific water usage is provided in Figure 4 below. FIGURE 4: WATER SOURCE AND USAGE BENCHMARK COMPARISONS FOR: FULLY INTEGRATED FACILITIES; SLAUGHTER, CHILL AND BONE FACILITIES; AND SLAUGHTER AND CHILL FACILITIES SLAUGHTER UNIT BASIS FULLY INTEGRATED SLAUGHTER, CHILL & BONE SLAUGHTER, CHILL Water Source Water Usage Water Source Water Usage Water Source Water Usage 1 200 (Litre/SU) (Litre/SU) 1 200 (Litre/SU) (Litre/SU) 1 200 (Litre/SU) (Litre/SU) 1 000 1 000 1 000 800 800 800 600 600 600 400 400 400 200 200 200 0 0 0 South African Median South African Median South African Median Benchmark Benchmark Benchmark Municipal Borehole Recycled Pre-Slaughter Slaughter Post-Slaughter Cleaning Rainwater River Offal Other The water usage South African benchmarks for fully integrated facilities; slaughter, chill and bone facilities; and slaughter and chill facilities were determined to be 1 000 l/SU, 950 l/SU and 800 l/SU, respectively. While the pressure on abattoirs within municipal boundaries relate to cost, the pressure on those in the rural areas relate to water availability. A typical abattoir could reduce its water consumption by 27.5% by implementing water efficiencies measures. Figure 5 provides an indication of the expected savings in the respective areas. 16 PRACTICAL GUIDE FIGURE 5: WATER SAVINGS POTENTIAL FOR A TYPICAL ABATTOIR 100 Improved 90 efficiency/ profitability 80 27.5% 70 60 50 % 40 30 20 10 0 Ave. Cost/ SU Pre-Slaughter Slaughter Offal Post-Slaughter Other Potential Cleaning Other Post-Slaughter Cleaning Offal Slaughter Pre-Slaughter Saving The following sections focus on these water minimisation opportunities. Water Supply Ground Water Strategy RECOMMENDED ACTION Observation 1. Install pressure probes None of the abattoirs utilising ground water monitored the levels on an ongoing basis. on each borehole at the A few abattoirs had issues with limited yield in the boreholes, which necessitated discharge point. drilling additional wells. 2. Monitor ground water reserve levels using pressure sensors Ground water is a limited resource and extensive extraction will lead to resource on borehole pump supply. constraints. Organisations should develop strategies that look at minimising the use of or replenish the reserves they are depleting. International best practice considers 3. Develop a drought event replenishment of ground water reserves at a rate of 200% of extraction as sustainable. strategy which requires the plant to reduce its extraction Water levels on ground reserves should be monitored routinely to understand what by 60%. the reserves are and whether they are depleting. Rainwater Recovery RECOMMENDED ACTION Observation 1. Install lined dams to recover South Africa is a water-scarce region with average annual rainfall of under 600 mm rainwater from the site. and increasingly limited supply due to current and recurring drought conditions. 2. Recover rainwater from Rainwater in general is fairly clean, with low hardness levels, making it suitable for rooftops. cooling tower and boiler systems. 3. Re-use water in lairage washdown or as make-up for Potential Issues/Problems cooling condensers. Rainwater may contain microbial and chemical impurities and may need to be treated prior to inclusion in the plant. Rainwater should be bacteriologically tested before use. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 17 Water Usage Optimize Manual Cleaning/Rinse System RECOMMENDED ACTION Observation 1. Fit directional restriction nozzles. Extensive use of hoses for manual cleaning as well as personal rinsing was 2. Locate hose points close to the noted during the site visits, specifically in the slaughter areas. Many pipes had point of use. no directional nozzles or shut-off valves, with flow rates between 15-30  l/min. Water for personal cleaning (apron rinsing), floor washing and post-slaughter 3. Install automatic shut-off processes often exceeded 50% of the water used in the abattoir. These volumes valves on the end of the hoses. could be reduced by 30-50% by installing directional nozzles and automatic shut- off valves. Some examples of pipes without valves left running or used for apron rinsing are provided in Figure 6. FIGURE 6: PIPING USED FOR RINSING/MANUAL CLEANING Manual cleaning (personal and floor cleaning) systems can be optimised using restriction orifices and shut-off valves on the end of the pipe. An example of a low flow, low pressure fan spray is illustrated in Figure 7. These systems reduce water utilisation for cleaning by approximately 50% while increasing the cleaning efficacy. 18 PRACTICAL GUIDE FIGURE 7: MANUAL CLEANING LOW FLOW SYSTEM Potential Issues/Problems BOX 1: The correct nozzles for the boosted pressure systems are often stolen or BEST PRACTICE FOR MANUAL CLEANING AND RINSING removed. Consideration should be given to issuing nozzles to staff as a part of their personal protective equipment (PPE). The picture below is of abattoirs with point-of-use water pipe dropdowns, Indicative Cost-benefit Analysis with both an auto shut-off valve and a manual shut-off valve and It is conservatively estimated that a 50% reduction in water usage (a reduced directional nozzle. flow from 20  l/min to 10  l/min) could be achieved for the above processes using restriction orifices. The couplings can be installed cost effectively, with a cost of R1 000 per point budgeted for. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 19 Dry Cleaning Techniques RECOMMENDED ACTION Observation 1. Develop an organics weighing system for cleaning and shift The norm for cleaning staff is to rinse excess organics/product down the drain. staff to quantify organic Much of this will be recovered on the effluent static screen, but in the process debris on the floor. suspended solids will be degraded and ultimately contribute to the organic load 2. Develop key performance that has to be treated by the effluent treatment system. indicators (KPIs) to ensure process staff keep product Dry cleaning systems should be adopted to reduce water usage and ingress of spillages to a minimum. organics into the effluent treatment systems. Specific objectives and targets should be incorporated for production staff and incentives used to encourage 3. Employ dry cleaning good habits/behaviour. techniques as a primary method for managing organics in all areas prior Potential Issues/Problems to post-slaughter cleaning (especially in the lairages Managing staff efficacy and culture is normally difficult and will require a where most problems occur). concerted effort by management. Indicative Cost-benefit Analysis The cost savings would be in terms of improved yield on the processing and by- products lines. FIGURE 8: "ECONOMISER" SPRAY Optimise Knife and Hook Sanitation Systems SANITATION SYSTEM Observation All of the abattoirs surveyed utilised overflow hot water systems for knife sterilisation. Invariably, these are boosted to the required temperature with electrical elements at the point of use, or steam is used to maintain the temperature. Conventional hot water overflow knife sterilisation systems and hook spray systems use significant amounts of energy and water. The aim of the process is to effectively sanitise the equipment by exposing it to elevated temperatures for a set period. New systems of sanitation, including dry (UV sterilisation) and on-demand “spray” systems significantly reduce the amount of hot water/steam used while improving the cleaning and sanitation efficacy. An electrically heated spray system is depicted in Figure 9. The unit supplies 120 ml of hot water per sterilisation cycle, which is a significant saving on the 0.5-2 l/min of conventional overflow systems. Should overflow systems be prescribed, consideration should be given to installing double-skin or otherwise insulated sterilisers which will reduce the hot water flow rate required to maintain temperatures. Spray-type hook and viscera sanitation systems may not achieve the desired microbiological outcome; alternative dip tank systems may be a solution for hooks, skids and other conveyor systems. 20 PRACTICAL GUIDE FIGURE 9: ILLUSTRATION OF A HOT WATER/ULTRASONIC DIP TANK 6 Should spray systems be used for the hook cleaning and viscera table, these RECOMMENDED ACTION should be interlocked to ensure turning off when the line is not operating. 1. Introduce spray sterilisation, Potential Issues/Problems double-skin (insulated) systems or low flow hot water Hygiene inspectors may not approve of the application of this technology; it sprays. would therefore be a sound strategy to address approval from the relevant 2. Use an immersion tank for authorities. Consideration should be given to providing a visual temperature hook sanitation. display to prove the required temperatures are being met while sterilising. 3. Interlock sprays to ensure they are not operating while the Indicative Cost-benefit Analysis line is not running. The cost of the water used at this step would vary between R50-R140/kl depending on the heating system and the cost of water. A knife steriliser would use between 2-5 l/min which equates to 250-600 kl/annum. Each knife steriliser therefore costs in the vicinity of R12 500-R35 000/annum to operate, depending on the flow rate setting, the cost of water and the cost of energy. This cost could be reduced by over 80% through implementing spray sterilisers, low flow insulated sterilisers or alternate technologies. There would be a two- to three- year payback period on implementing alternative sanitation systems for knife and hook sterilisers. 6 Christeyns, 2017 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 21 FIGURE 10: EXAMPLES OF HAND WASH Optimise Boot and Hand Washing BASINS WITH TRADITIONAL ROSE FITTINGS Observation Effective hand, boot and apron washing is important for hygiene requirements but is often an area that sees significant water losses. Hand and boot wash stations utilise conventional water faucets and hoses, and account for roughly 5-10% of the facility’s water consumption. Typically, the water is heated to 45°C, with the cost in the vicinity of R40-R80/kl depending on the cost of water and energy for the plant. Plants typically utilise conventional shower head fittings for hand and boot washing as depicted in Figure 11. Hand wash station usage can be significantly reduced by fitting low flow restriction nozzles that would also improve the cleaning efficacy of the handwashing process by ensuring staff members take longer to rinse the soap off their hands. The atomisation spray also requires staff members to rub the RECOMMENDED ACTION soap off their hands, which further improves cleaning efficacy. 1. Install low flow/mist taps and A cheaper alternative to a mist nozzle is a touch-demand nozzle with aerator as boot brush stations. shown in Figure 12. In addition, the conventional boot washing process does not adequately address the bottom of boots, as this would require standing on one leg while trying to clean. FIGURE 11: EXAMPLE OF AN AERATOR AND A TOUCH FIGURE 12: EXAMPLE OF A BOOT FITTING FOR CONVENTIONAL TAPS CLEANING STATION One-touch tap - Neoperl Cascade Aerator 90% H2O saving - 84% H2O saving Boots can be more effectively cleaned using a system as shown in Figure 14 where the staff member holds the rail and pushes the boot through the brush system. A quaternary ammonium compound (QAC) or chlorine sanitiser can be sprayed onto the brush system periodically. 22 PRACTICAL GUIDE FIGURE 13: MOUNTED BRUSH SYSTEM FOR CLEANING BOOTS Potential Issues/Problems Thin mist sprays may block up due to particles/sediment in the water system. This can be averted by installing a serviceable filter ahead of the hand wash station. Indicative Cost-benefit Analysis There could be a 60-80% reduction in warm water consumption in these areas. Water Reuse Opportunities 20 Observation Some wastewater streams are relatively clean and may be used elsewhere in the plant for activities that do not require high quality water. The key to water reuse is the ability to segregate suitable wastewater streams from the main wastewater drainage system, and to ensure that the reused water is bacteria free. 5 To determine the best opportunities for water reuse, the quantities and the quality of water available for each reuse stream should be estimated and matched up with the quantities required for each potential application, as shown in Figure 15. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 23 FIGURE 14: EXAMPLES OF WATER REUSE OPPORTUNITIES 7 AVAILABLE VOLUME VOLUME REQUIRED POTENTIAL SOURCES OF WATER (KL/DAY) POTENTIAL AREA OF REUSE (KL/DAY) Freezer Defrost 5 Cooling tower makeup 45 Pig scald tanks Knife and equipment sterilisers 120 Stock washing (initial rinse only for some plants) 100 Cooling water from pig singeing oven 20 Pig dehairing, scraping and brushing 20 Rendering material conveyance chutes Handwash basins 75 Sprays on trommel screens 60 Hand wash 5 Gut washing 60 Many abattoirs utilise evaporative condensers which account for roughly 10-15% RECOMMENDED ACTION of the water usage on the plant. The bleed rate on these condensers, depending Recover evaporative condenser on the water quality, would range between 20-30%. This water could be bleed and use for cleaning in the recovered and reused for lairage washdown. lairages. Additional reuse opportunities are outlined in Figure 15, but these should be Consider reusing steriliser and considered in close consultation with the health inspectorate. water in the scald tanks in abattoirs processing pigs. Potential Issues/Problems Ensure reused water is bacteriologically tested before use Current red meat hygiene standards in South Africa typically do not allow for the and periodically during use. reuse of water on edible products or in a process where the water could come into contact with edible products, and therefore reuse opportunities are limited. 7 Meat and Livestock Australia Ltd, 2002 24 PRACTICAL GUIDE Summary of Water Efficiency Recommendations The expected savings through the implementation of the described measures is in the vicinity of 25-35%. The main savings relate to manual cleaning in the pre-slaughter and slaughter processes. A summary of the recommendations is provided in Table 1. TABLE 1: SUMMARY OF WATER SAVING RECOMMENDATIONS SECTION RECOMMENDED ACTIONS POTENTIAL SAVINGS Ground water strategy 1. Install pressure probes on each borehole at the discharge n/a point. 2. Monitor ground water reserve levels using pressure sensors on borehole pump supply. 3. Develop a drought event strategy which requires the plant to reduce its extraction by 60%. Rainwater recovery 1. Install lined dams to recover rainwater from the site. n/a 2. Recover rainwater from rooftops. 3. Reuse water in lairage washdown or as make-up for cooling condensers. Optimise manual 1. Fit directional restriction nozzles. 50% of water usage for cleaning/rinse system these processes. 2. Locate hose points close to the point of use. 3. Install automatic shut-off valves on the end of hoses. Dry cleaning techniques 1. Develop an organics weighing system for cleaning and The cost savings would be shift staff to quantify organic debris on the floor. in terms of improved yield on the processing and by- 2. Develop KPIs to ensure that process staff keep product products lines. spillages to a minimum. 3. Employ dry cleaning techniques as a primary method for managing organics in all areas prior to post-slaughter cleaning (especially in the lairages where most problems occur). Optimise knife and hook 1. Introduce spray sterilisation, double-skin (insulated) Up to 80% of water sanitation systems systems or low flow hot water sprays. used by knife and hook sanitation systems. 2. Utilise an immersion tank for hook sanitation. 3. Interlock sprays to ensure they are not operating while the line is not running. Optimise boot and hand 1. Install low flow/mist taps and boot brush stations. 60-80% reduction washing in warm water consumption in these areas. Water reuse 1. Recover evaporative condenser bleed and use for n/a opportunities cleaning in the lairages. 2. Consider reusing steriliser and water in the scald tanks in abattoirs processing pigs. 3. Ensure reused water is bacteriologically tested before use and periodically during use. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 25 26 PRACTICAL GUIDE 5 Energy FIGURE 15: OVERVIEW OF MAIN ENERGY USERS IN AN ABATTOIR Compressed Air Abattoirs typically utilise both electrical Other 10% and thermal energy. The main users of 25% electrical energy are the refrigeration and chiller plants (~45%), the air compressors and pumps (~10% each) and heating elements (sterilisers and geysers ~20%). Where electrical heating elements are not used, thermal energy is used to heat water for cleaning and sterilisers. The specific energy use for abattoirs is Pumping provided in Figure 16. 10% Refrigeration 45% Lighting 10% FIGURE 16: TOTAL ENERGY SOURCE AND USAGE BENCHMARK COMPARISONS FOR FULLY INTEGRATED FACILITIES; SLAUGHTER, CHILL AND BONE FACILITIES; AND SLAUGHTER AND CHILL FACILITIES SLAUGHTER UNIT BASIS FULLY INTEGRATED SLAUGHTER, CHILL & BONE SLAUGHTER, CHILL 140 Energy Source Energy Usage 140 Energy Source Energy Usage 140 Energy Source Energy Usage (kWh/SU) (kWh/SU) (kWh/SU) (kWh/SU) (kWh/SU) (kWh/SU) 120 120 120 100 100 100 80 80 80 60 60 60 40 40 40 20 20 20 0 0 0 South African Median Benchmark South African Median Benchmark South African Median Benchmark Supplied Electricity Other Fossil Fuels Refrigeration Solar PV Hot Water / Steam Improving Resource Efficiency in Red Meat Abattoirs in South Africa 27 The total energy usage South African benchmarks for fully integrated facilities; slaughter, chill and bone facilities; and slaughter and chill facilities were determined to be 120 kWh/SU, 75 kWh/SU and 55 kWh/SU, respectively. The following sections are split by electrical and thermal energy, and review common recommendations made as well as the indicative savings. Electrical Energy A typical abattoir could reduce the electrical energy it consumes by an estimated 12% by implementing a number of energy efficiency measures. Figure 18 provides an indication of the expected savings in the respective areas. FIGURE 17: ELECTRICAL ENERGY SAVINGS POTENTIAL FOR A TYPICAL ABATTOIR 100 Improved efficiency/ 90 profitability 11.5% 80 70 60 50 % 40 30 20 10 0 % Compressed Refrigeration Lighting Pumping Other Potential Air Other Post-Slaughter Cleaning Offal Slaughter Pre-Slaughter Saving The following sections focus on these electrical energy minimisation opportunities. Review Electrical Tariff Observation Abattoirs based in metropoles typically purchase their electricity from the municipality and are charged on a demand tariff basis where electrical usage is covered at a set rate ranging between R0.80-R1.00/kWh and the demand charges at rates of R200-R250/kVA. The peak demand would account for between 40-50% of the total bill. The average electrical cost (total cost of electrical energy divided by the electrical energy kWh consumption) would be in the vicinity of R1.40-R1.65/kWh on this tariff. Abattoirs based in rural areas usually purchase electricity on the Eskom rural time-of-use tariff which is the cheapest available option and their electrical costs would range between R1.00–R1.30/kWh. The time-of-use tariffs are summarised in Figure 19. The high demand season coincides with the winter months June to August and the rates increase in proportion to the increased grid demand. 28 PRACTICAL GUIDE FIGURE 18: TIME-OF-USE TARIFF OVERVIEW 8 Low Demand Season High Demand Season 23 24 1 23 24 1 22 2 22 2 Weekdays Weekdays 21 3 21 3 20 4 20 4 Saturday Saturday ê 19 5 19 5 18 Sunday 6 18 Sunday 6 17 7 17 7 16 8 16 8 15 9 15 9 14 10 14 10 13 11 13 11 12 12 Off-peak Standard Peak Abattoirs’ main energy user would be the refrigeration plant which would draw power on a 24-hour basis. A time-of-use tariff would usually be favourable RECOMMENDED ACTION for companies that have a fixed constant demand. As a rule of thumb, if the 1. Request a tariff review from blended cost for electrical power purchase (total cost divided by the total kWh) the local authority or Eskom. exceeds R1.50/kWh, it would be prudent to review the available tariffs. Typically, municipalities and Eskom will do the tariff comparison for the abattoir, but this comparison would have to be requested formally. Potential Issues/Problems Tariff changes can typically only be done once a year. Indicative Cost-benefit Analysis Tariff changes can result in savings of between 10-20% of the cost of electricity. Reduce Peak Electrical Demand Observation Abattoirs are either on a time-of-use tariff or a peak demand tariff. Both tariffs will typically contain a peak demand cost (the highest draw in power over a 30-minute period in the month). This cost would account for 20-40% of the bill. Demand is the average rate at which energy is used during a 30-minute time period called the demand interval and the “peak demand” is the highest average load (kVA) reached over all the demand intervals within a given billing period. One half-hour period will determine the rate for the entire month. These costs can be reduced by either conserving power (e.g. reducing compressed air leaks), clipping the peak (e.g. turning off equipment during peak times) or shifting the load outside of peak times (e.g. utilising a timer on a heat pump). 8 Eskom, 2019 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 29 FIGURE 19: DEMAND MANAGEMENT STRATEGIES Peak Clipping Strategic Conservation Load Shifting The example below shows logging at a facility with a high base load requirement (refrigeration). Based on live historical electrical readings, a pattern in the occurrence of peak demand was noted. The peak demand seemed to occur between 11:30am and 12:30pm. On two occasions, the spike in demand accounted for more than 50 kVA. This coincided with the canteen preparing for lunch. The 50 kVA cost the company more than R14 000/ month and could easily be averted by employing load lopping/shifting strategies. FIGURE 20: LIVE LOGGING PROFILE OF A PLANT WITH A HIGH REFRIGERATION LOAD 30 PRACTICAL GUIDE Live logging will reveal when the peak demand is incurred, and strategies could RECOMMENDED ACTION be employed to reduce or shift this demand. 1. Install live logging on the main Potential Issues/Problems feed. Care should be taken to avoid implementing timed shutdown events that would 2. Implement a demand management programme. disrupt the process. Indicative Cost-benefit Analysis An aggressive peak demand management programme could see a 10% reduction in a facility’s costs. Pump System Optimisation Observation Pump systems frequently operate against unnecessary head pressure introduced either by system components (dynamic head) or by elevating the liquid to unnecessary height (static head). Unnecessary increases in head pressure result in a loss in efficiency, as the pump is pushed back on its curve away from its operating point, resulting in lower flow rates. Figure 22 illustrates the impact of increased head pressure through the installation of a tight bend or throttle valve. FIGURE 21: PUMP SYSTEM CURVE ILLUSTRATING THE IMPACT OF THROTTLING9 Pump curve System curve (determined by (determined by pump used) valves, pipes etc.) HB B HA A Pressure loss across Head throttle valve HC C Head needed by system to produce flow Power Efficiency QB QA Flow This loss can be avoided by installing pumps that are correctly sized or by fitting variable speed drives (VSDs). Figure 23 provides an indication of the impact of reducing the size of the pump. 9 ETSU, 1998 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 31 FIGURE 22: WASTE ENERGY AND POTENTIAL SAVINGS ILLUSTRATED BY REMOVING UNNECESSARY HEAD PRESSURE AND LINE THROTTLING 1. FLOW RATE AND PRESSURE CONTROL WITH VALVE THROTTLING 2. OPTION WITH SMALLER AND SLOWED DOWN PUMP Head Head Operating point Design point Design point Wasted Saved energy energy Useful Useful Operating point energy energy Required flow Flow Valve losses are eliminated Required flow Flow Companies sometimes operate two pumps on a system designed for one to boost RECOMMENDED ACTION pressure and flow, or just to reduce pipework. Figure 24 indicates the impact of this 1. Install decentralised tanks type of strategy. While there is a marginal increase in pressure and flow, it results in close to the borehole and an increased cost per kl pumped (usually around 30-40% higher) with reduced overall then use booster pumps to flow rate compared to the scenario where the pumps operate on their own system. feed to the plant. FIGURE 23: THE IMPACT OF RUNNING TWO PUMPS ON A SYSTEM DESIGNED 2. Install level controls to shut FOR ONE off the feed pumps if the tanks are full. A 3. Install above-ground piping B to ensure that inspections 2 Pumps can be done regularly. Head 1 Pump 4. Install timers on the pumps to turn off during peak electrical Power tariff periods. (of each pump) Efficiency (of each pump) Q2/2 Q1 Q2 Flow Rural abattoirs are heavily dependent on ground water reserves and may not have sufficient yield on existing boreholes to supply the plant demand. Existing boreholes typically range between 50-100  m deep and then need to elevate further to the storage tanks. If multiple borehole pumps are installed, they would invariably feed into a common line before feeding into the storage tank. Additional head is introduced through this configuration, resulting in significantly reduced flow rates. From the pump curve shown in Figure 25, the additional head introduced by lifting the water an additional 20 m would result in a 20-60% reduction in flow rate, depending on the borehole depth. 32 PRACTICAL GUIDE FIGURE 24: PUMP CURVE OF BOREHOLE PUMPS10 300 250 200 HEAD (M) 150 100 50 0 0 20 40 60 80 100 120 140 160 180 FLOW RATE (L/MIN) Potential Issues/Problems Additional booster pumps will result in increased maintenance requirements. Chiller System COP Management and Optimisation Observation Conventional decentralised freon-based chiller systems are used at many abattoirs, with many of the compressors operating at low loads. Considerable scope for optimisation exists through monitoring and managing the overall plant performance. The refrigeration plants typically contribute to 45-50% of a plant’s electrical energy consumption and costs. Monitoring individual chiller COP and energy load profiles is essential to understanding the plant demand requirements and the system’s ability to cost-effectively meet the demand. All cooling systems realise low levels of leakage of the refrigerant. If the refrigerant levels are not topped up timeously, the system will be more inefficient and the potential for breakdowns and lost production will increase. Figure 26 displays the effects of diminishing refrigerant levels in a chiller system11. 10 Hurricane Pumps, 2020 11 Energy Technology Support Unit, Didcot, UK (1997) Improving Resource Efficiency in Red Meat Abattoirs in South Africa 33 FIGURE 25: ILLUSTRATIONS OF THE EFFECT OF REFRIGERANT LEAKS System consumption breakdown Stock and kWh/day Wasted quality Power energy losses Cost of repairs Cost (cumulative) Time (parts and Nominal Efficiency Capacity labour) capacity kW and shorfall Cooling Minimum capacity starts requirement Lost start to Lost cooling Leak fall refrigerant capacity starts here A B C D E Time Wasted Refrigerant replaced energy Fault reported No more spare capacity Time 'Buffer' used up Leak Starts Trending chiller COP will predict system issues (e.g. low refrigerant levels) and allow for predictive mainte- nance. Optimal load strategies can only be determined if the demand of the plant is known. Figure 27 provides an indication of the types of load matching strategies. FIGURE 26: LOAD MATCHING STRATEGIES FOR AIR AND COOLING COMPRESSORS12 12 Energy Technology Support Unit, Didcot, UK (2000) 34 PRACTICAL GUIDE RECOMMENDED ACTION Potential Issues/Problems 1. Install dedicated electrical Additional information without clear lines of responsibility or automatic energy logging equipment to interpretation of the data will not realise savings. Investment in appropriate data monitor plant loads. management tools is required. 2. Install flow meters and temperature sensors to Indicative Cost-benefit Analysis determine individual chiller COP. A 20-30% reduction in energy consumption on the compressors can be expected 3. Operate the most efficient through actively monitoring the chiller COP and selecting the most efficient chillers as base load. compressors for baseload operation. 4. Trend COPs to pre-empt maintenance cycles (e.g. Compressed Air System Optimisation refrigerant leaks). Observation 5. Measure overall system COP and set objectives and targets Compressed air accounts for roughly 10% of an abattoir’s electrical energy to increase overall COP. consumption and the overall efficiency of the system is less than 15% once heat 6. Implement a leak detection loss and line leaks are taken into account. program to ensure optimal refrigerant levels are Compressor efficiencies vary with regard to their individual components and the maintained. load factor on the compressors. This can be seen in Figure 28; while a VSD will result in savings for a varying load pattern, these savings diminish if compressors 7. Turn off or slow down radiator are operated consistently at full or low load. fans when areas are not in use. FIGURE 27: TYPICAL DEMAND ON COMPRESSORS WITH REDUCED PLANT LOAD13 100 90 l ing contro POWER (% OF FULL LOAD) 80 Modulat 70 60 /off l tro ry on /off con Rota on ed 50 ting spe ipro ca iable Rec Var 40 30 20 10 0 10 20 30 40 50 60 70 80 90 100 DEMAND (% OF RATED CAPACITY) It is important when using load/unload control mechanisms to keep the number of cycles to a minimum, as there is energy lost between the unload point and the load point. In addition to power being drawn with no productive air being produced, there is a space between the unload point and the steady state where the motor draws close to the full rated power. This is illustrated by the area highlighted in red in Figure 29. 13 Energy Research Institute, 2000 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 35 FIGURE 28: ILLUSTRATION OF EFFICIENCY LOSS DURING UNLOAD CYCLE 130 120 110 100 90 System Pressure 80 Inefficiency due to sump pressurization/ blowdown 70 PSI A Compressor Power 60 50 40 30 20 Inefficiency due to unloaded 10 operation 0 Even with optimal control strategies, over 78% of the input energy into air compressors is lost to waste heat. Most of this heat (~94%) can be recovered to pre-heat air or to heat water. FIGURE 29: OVERVIEW OF HEAT RECOVERY POTENTIAL AND APPLICATIONS 14 Shaft power 100% Cooling water and its usage t oC 90o Radiant losses 2% Remain in compressed air 4% 80o Heating of 51% boiler return 70o Heating of buildings 60o via the shunt circuits 29% 50o Hot tap water Preheating of tap 40o water, process water, supply air, 14% maintain ground 30o heat Recoverable energy 94% Significant losses are also incurred through distribution line leakage. Most facilities that actively monitor their leakage will target a leakage rate of 10% of system capacity. Facilities that do not actively manage their leakage will typically experience leakage rates as high as 20-30% of system capacity. 14 Atlas Copco Airpower, 2010 36 PRACTICAL GUIDE RECOMMENDED ACTION In addition to optimising the load FIGURE 30: OVERVIEW OF INTERVENTIONS FOR COMPRESSED AIR SYSTEMS15 controls, Figure 31 provides some common savings interventions, which include: 1. Reduce compressed air leaks 2. Use outside air for 2. Utilise cooler outside air compressor intakes 3. Reduce system pressure 4. Utilise waste heat productively. 4. Recover waste heat BOX 2: 3. Reduce BEST PRACTICE FOR WASTE HEAT pressure RECOVERY ON COMPRESSORS 1. Air leaks Some companies in the food sector have installed economisers on their air compressors to recover low- grade heat. This type of intervention Indicative Cost-benefit Analysis will realise an overall system efficiency of 50% as opposed to 15% The following rules of thumb apply to compressed air systems: typically experienced in compressed • Optimising compressor controls can save 5-10% of the energy utilised air facilities. by the compressed air system by more closely matching the load requirement. • Reducing air compressor pressure by 2 psi can reduce compressor energy use by 1% (at 100 psi) 16 • There will be a 1% reduction in compressor electrical energy utilisation for every 2.2oC reduction in intake gas17 . Solar PV Observation Abattoirs’ electrical energy costs range between R1.20/kWh and R1.60/kWh (including demand costs), depending on the tariff regime assigned to the abattoir. Solar companies are currently offering solar PV power purchase agreements at rates below R1.10/kWh, and the levelised cost of energy for a system owned by the abattoir will likely be cheaper. On a utility scale, the life-cycle cost of renewables are significantly more effective than that of conventional coal-based systems (see Figure 33). 15 Energy Research Institute, 2000 16 Oregon State University, 1997 17 Council for Scientific and Industrial Research, 2017 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 37 FIGURE 31: NEW BUILD LIFE CYCLE COST ON DIFFERENT POWER SOURCES (2016 RATES) 18 LIFETIME COST PER ENERGY UNIT IN R/KWH April 2016 Rand 2011 3.69 As per South African IRP 2016 Fixed 2.89 (Capital, O&M) 2011 1.41 1.41 Variable 1.00 1.09 (Fuel) 0.62 0.62 Solar PV Wind Baseload Nuclear Gas (CCGT) Mid-merit Gas (OCGT) Diesel Coal(PF) Coal (OCGT) Baseload operation Mid-merit operation Peaking operation Abattoirs have fairly constant energy demand as a result of their high RECOMMENDED ACTION refrigeration and chilling requirements, which make the industry an excellent Review solar PV as a potential prospect for solar PV systems. energy source. Potential Issues/Problems Power purchase agreements may be enticing, but care should be taken to properly interrogate the proposed annual cost escalations (if any). Indicative Cost-benefit Analysis There would typically be a four- to five-year payback on solar PV installations. Financing is also more easily attained for these systems than general business financing. 18 Council for Scientific and Industrial Research, 2017 38 PRACTICAL GUIDE Thermal Energy Larger plants with on-site rendering typically have steam systems utilising coal boilers. The fuel purchase cost of coal equates to roughly R0.30/kWh at the point of use. The operating and maintenance costs of these systems will add an additional R0.30-R0.50/kWh to the cost. Smaller abattoirs without rendering capability use either electrical heating elements or small liquid fuel-driven steam systems (flash steam generators) and their point- of-use cost will be in the vicinity of R1.10-R1.50/kWh. Their operating and maintenance costs (~R0.10/kWh) will be significantly lower than that of coal systems. It is important to note that while the fuel cost per kWh is relatively high on the smaller plants, their system efficiencies are significantly better, especially for point-of- use heating applications (heating elements at the sterilisers). Steam systems’ overall thermal efficiencies for supplying heated water range between 40-75%, whereas electrical heating systems at the point of use exceed 95%. There is significant scope for improving costs and efficiencies in thermal heating systems, especially on smaller plants that have relatively high heating costs per kWh. A typical abattoir could reduce its thermal energy consumed by an estimated 32% by implementing a number of thermal energy efficiency measures. Figure 34 provides an indication of the expected savings in the respective areas. FIGURE 32: THERMAL ENERGY SAVINGS POTENTIAL FOR A TYPICAL ABATTOIR 100 Improved 90 efficiency/ profitability 80 31.8% 70 60 50 % 40 30 20 10 0 % Generation Radiation Leakage Wasteful Productive Potential Losses Losses Usage Work Productive Work Wasteful Usage Leakage Radiation Losses Generation Losses Saving The following sections focus on these thermal energy minimisation opportunities. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 39 Renewables and waste heat recovery Observation Implementing renewable and heat recovery systems on the rendering plant, the compressed systems and refrigeration systems could reduce the need for thermal heating for the hot water systems entirely in facilities with rendering plants, and by over 40% in facilities without rendering plants. Heat pumps can also significantly reduce the cost of heating water up to 50°C. The heat load could be met with: 1. Refrigeration plant: ~10% of refrigeration plant load 2. Compressed air system: ~65% of air compressor load 3. Rendering plant heat recovery system 4. Solar hot water system/heat pumps. Heat Pumps Heat pumps are far more efficient than conventional electrical resistance heating applications within the optimal temperature bands (45-55°C). Typically, at ambient temperatures of around 20-25°C, a heat pump will produce 3-4 kW thermal energy for every 1 kW of electrical energy input (see Figure 35). Electric heating requires around 1  kW to produce approximately 1  kW thermal energy. The heat pump effectively produces cool air or water as a “waste product”, which can be used beneficially in the process (see Figure 35)19. FIGURE 33: VAPOUR COMPRESSION CYCLE OF A HEAT PUMP Hot reservoir Heat sink Qhot 4 500 W vapor liquid Condenser 2 3 1 500 W Wnet Compressor Expansion valve 1 4 Evaporator liquid + vapor vapor Qcold 3 000 W Cold reservoir Heat source 19 Nuclear Power, 2020 40 PRACTICAL GUIDE Applications able to utilise the “cool” output from the heat pump include: • Fresh air intake into the plant • Compressed air intake. Refrigeration systems generate “cold air” and reject the heat from the system through condensers. It is possible to safely recover around 10% of this heat through a heat recovery system and a control valve on the hot flue gas as depicted in Figure 36. FIGURE 34: ILLUSTRATION OF HEAT RECOVERY ON A REFRIGERATION SYSTEM 20 Hot water out Cold water in Water out Water in Condenser De-superheater Expansion valve Oil separator Compressor Evaporator Water out Water in BOX 3: BEST PRACTICE FOR HEAT RECOVERY The recovered heat could be used for hand and boot washing or as a make-up ON REFRIGERATION UNITS for the 45°C, 65°C and 82°C lines. Some abattoirs have already installed heat recovery refrigeration units or Solar systems like the units depicted below, South Africa boasts some of the best solar intensities in the world. This is where the heat from condensing is illustrated by Figure 38 which illustrates the “direct normal irradiation” (DNI) recovered by a water loop which can then be used for heating, thereby levels. resulting in improved efficiencies. 20 Carbon Trust, 2020 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 41 RECOMMENDED ACTION FIGURE 35: SOLAR IRRADIATION MAP 21 1. Investigate the option of installing a de-superheater system on the chillers. 2. Install compressed air heat recovery system. 3. Investigate installing heat recovery on the rendering plant. 4. Investigate installing solar heating panels. Solar heating is therefore a logical choice, especially for applications that draw warm water during the day (e.g. hand washing and other warm water applications). Potential Issues/Problems Detailed engineering would be required to implement these systems, which may prove to be cost prohibitive. Care should be taken to utilise softened water in the heating systems to prevent scale and corrosion on the hot water lines and tanks. Indicative Cost-benefit Analysis There will typically be a one- to two-year payback on heat recovery installations. 21 World Bank Group, 2020 42 PRACTICAL GUIDE BOX 4: COMBINED HEAT AND POWER BIOGAS PLANT Biogas plants basically rely on the anaerobic digestion of wastewater. During this process, methane is produced, and this could be captured for use in various applications such as pre-heating of process water, generation of electricity, etc. The technology has not been widely adopted by the red meat abattoir industry, and various pitfalls may occur along the way. Certain elements, such as the uncontrolled release of large volumes of blood, chlorine and biocides used for cleaning purposes could have a disastrous effect on the biomass population required for methane gas production. Advanced technology is available for biogas plants in the red meat abattoir industry, but effective operation of the facility will be crucial. A 75 kW combined heat and power (CHP) biogas plant has been successfully installed at a pig abattoir which uses pig manure as the feedstock from the adjacent piggery. The plant produces 834 MWh electrical and 1 075 MWh thermal energy per year, and there are plans to increase the capacity to 125 kW. Optimise Steam System Generation Efficiency Observation Most boiler systems have no live load monitoring in place and would typically operate on very low loads at some point during the day. The boiler loss in efficiency in low load conditions is illustrated in Figure 40 and Table 2. Lower efficiencies as a result of ignition losses and cooling through the “chimney effect” when the boilers are not in fire mode can be expected. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 43 FIGURE 36: TYPICAL BOILER EFFICIENCY CURVE 100 90 80 BOILER EFFICIENCY (%) 70 60 50 40 30 y= 0.0004x3 - 0.0706x2 + 4.1378x + 2.5843 20 R2 = 0.9634 10 0 0 10 20 30 40 50 60 70 80 90 BOILER LOAD (% OF RATED CAPACITY) The overall system efficiency, once distribution losses are taken into account, can be calculated – an example is provided in Table 2. In this instance, radiation and condensate losses result in an overall system efficiency of 47%. TABLE 2: OVERALL STEAM SYSTEM EFFICIENCY THEORETICAL AREA BOILER TARGET Boiler Losses  Radiation loss/boiler design* 0.5% 1.0% Flue gas loss 15.0% 14.8% Unaccounted-for loss 1.0% 8.3% Bleed* 0.5% 0.4% Generation efficiency 83.0% 75.5% Distribution Losses  Radiation loss 1.0% 29.4% Leakage 0.1% 1.2% Condensate return loss 0.0% 5.2% Flash steam loss 1.0% 1.8% Subtotal 3.1% 37.6% Overall Thermal Efficiency 80.4% 47.1% KPIs Generation cost / tonne steam 162.46 172.19 Distribution cost / tonne steam 5.20 103.81 Point of use cost / tonne steam 167.66 276.00 Tonne steam / tonne fuel 8.3 7.8 44 PRACTICAL GUIDE Combustion systems require sufficient air to ensure that there is excess oxygen IN SUMMARY, THE BOILER available for complete combustion. A lack of oxygen will result in incomplete SYSTEM’S GENERATION combustion of the burner fuel which will in turn result in significant safety risks EFFICIENCY CAN BE due to the potentially explosive nature of the flue gas that contains volatile DETERMINED THROUGH hydrocarbons still capable of combusting. To this extent, burners are set to ensure MONITORING THE FOLLOWING: excess air (which can be measured by the percentage of oxygen in the stack). Stack • Feed water temperature and temperatures of around 200°C with oxygen levels of between 4-6% are typical. metering Supplying too much air, however, would result in unnecessary heat loss to the stack, as there would be an inadvertent cooling of the boiler. This condition can be • Make-up water metering identified through elevated oxygen content and lower stack temperatures (see the • Boiler feed and blow-down TDS. measurements below). Fouled heat exchange surfaces (i.e. fire side fouling) would result in elevated stack temperatures as a result of poor heat exchange, even if the oxygen set points were in the optimal range. The steam generation and distribution losses can be calculated utilising first principles and a mass balance approach. The amount of steam produced can be indirectly calculated through estimating the amount of water discharged to blow-down (utilising the total dissolved solids [TDS] to calculate cycles of concentration). The steam energy content and the fuel energy content is known which with the volumes allows one to calculate the generation efficiency. Typically, generation efficiencies should be in the vicinity of 80% once the various losses have been taken into account. An example of a typical plant’s generation efficiency and associated losses is provided in Figure 40. FIGURE 37: ANTICIPATED GENERATION EFFICIENCY OF THE BOILER Direct Stream Application Condensate return 205.9 tonne Flash steam 10.9 tonne Direct steam Heat 121.3 tonne Exchange Applications Generation efficiency 75.5% Steam 458.1 tonne Hotwell Boiler feed 495.0 kl Boiler Make-up 300.0 kl Blowdown 9.9 tonne Cycles 50.0 Bleed rate 2.0% Improving Resource Efficiency in Red Meat Abattoirs in South Africa 45 Indicative Cost-benefit Analysis RECOMMENDED ACTION 1. Use the mass balance method A 2.5-5% improvement in generation efficiency through improved operating for determining efficiency in practices could be realised by focusing on improving generation efficiencies. addition to flue gas analyses. 2. Install live loggers on the water Insulate Steam Lines, Valves and Flanges feed. Observation 3. Calculate the overall system efficiency and set appropriate The total amount of uninsulated piping and components can be determined for KPIs for staff. the steam lines as well as the uninsulated condensate lines and the radiation 4. Reduce oxygen setpoints to loss can result in 10-30% losses in steam energy generated. Uninsulated lines, between 4-6%. valves and flanges will experience radiation losses which can be quantified by determining the process / surface temperatures, the type of metal and the external temperatures. FIGURE 38: RADIATION LOSS PICTURES ON STEAM LINES RECOMMENDED ACTION Potential Issues/Problems 1. Insulate all exposed piping Insulation can often hide leaks or inhibit maintenance. Insulation installed and install jacket covers on flanges and valves. should take into account the requirement to service components. 2. Insulate the bodies of the expansion joints. 3. Insulate condensate return piping. 4. Insulate condensate return tank 46 PRACTICAL GUIDE BOX 5: BEST PRACTICE FOR STEAM PIPING – INSULATION FOR VALVES AND FLANGES 22 The pictures below provide an indication of insulation best practice, with flanges and valves insulated with removable steam jackets. Indicative Cost-benefit Analysis Table 3 outlines the losses experienced through poor insulation. An 80% reduction in radiation losses is viable through the installation of insulation. The table provides an indication of heat losses for different applications and how these can be calculated. TABLE 3: RADIATION LOSS TABLE FOR STEAM LINES LOSS TOTAL LOSS STEAM TONNE UNINSULATED LINES (M) COST / ANNUM W/M KW / ANNUM 50mm line (2’’) 500.0 0.0 0.0 R0 75mm line (3’’) 5 650.0 3.3 22.0 R6 185 100mm line (4’’) 6 800.0 4.8 32.4 R9 134 150mm line (6’’) 7 1 200.0 8.4 56.8 R15 985 Uninsulated condensate / feed (m) 50mm line (2’’) 100 230.0 23.0 155.4 R43 768 75mm line (3’’) 300.0 0.0 0.0 R0 Uninsulated items (0.5m per item) 75mm line (3’’) 5 650.0 1.6 11.0 R3 092 100mm line (4’’) 5 800.0 2.0 13.5 R3 806 150mm line (6’’) 5 1 200.0 3.0 20.3 R5 709 Uninsulated Application  Hot well 80 453.0 36.2 244.9 R87 679  Total 76 511 R162 000 22 Flextra Engineering Products (Pty) Ltd, 2020 Improving Resource Efficiency in Red Meat Abattoirs in South Africa 47 RECOMMENDED ACTION Condensate Recovery Implement an aggressive Observation condensate return and condensate line insulation programme. A number of condensate leaks were noted during the site visits, as well as applications that utilised direct steam injection instead of heat exchangers. These would result in a 5% reduction in overall system efficiency. Condensate is the ideal boiler feed water due to its heat content and chemical suitability. The higher the temperature of the boiler feed water, due to a high level in condensate return, the less work the boiler has to do in converting water into steam. Potential Issues/Problems Some of the condensate discharged to drain may not have enough pressure to be incorporated back into the condensate lines. Indicative Cost-benefit Analysis The indicative cost-benefit analysis is illustrated in Figure 43. FIGURE 39: EXPECTED FUEL SAVING THROUGH INCREASED CONDENSATE RETURN 23 14 % Condensate return 100 12 % BOILER FUEL SAVED 10 75 8 50 6 4 25 2 20 30 40 50 60 70 80 90 100 CONDENSATE TEMPERATURE OC 23 Envirowise Best Practice Programme, 1999 48 PRACTICAL GUIDE Summary of Energy Efficiency Recommendations The electrical and thermal energy consumption and cost can conservatively be reduced by between 12-32% through the implementation of the interventions described in the previous sections. A summary of all the energy saving recommendations is provided in the table below. TABLE 4: SUMMARY OF ENERGY SAVING RECOMMENDATIONS SECTION RECOMMENDED ACTIONS POTENTIAL SAVINGS Electrical Energy Review electrical tariff 1. Request a tariff review from the local authority Tariff changes can result in savings or Eskom. of between 10-20% of the cost of electricity. Reduce peak electrical 1. Install live logging on the main feed. An aggressive peak demand demand 2. Implement a demand management program. management program could see a 10% reduction in the facility’s costs. Pump system 1. Install decentralised tanks close to the borehole n/a optimisation and then use booster pumps to feed to the plant. 2. Install level controls to shut off the feed pumps if the tanks are full. 3. Install above-ground piping to ensure that inspections can be done regularly. 4. Install timers on the pumps to turn off during peak electrical tariff periods. Chiller system COP 1. Install dedicated electrical energy logging A 20-30% reduction in energy management and equipment to monitor the plant loads. consumption on the compressors optimisation 2. Install flow meters and temperature sensors in could be expected through actively order to determine individual chiller COP. monitoring the chiller COP and selecting the most efficient 3. Operate the most efficient chillers as base load. compressors for baseload operation. 4. Trend COPs to pre-empt maintenance cycles (e.g. refrigerant leaks). 5. Measure overall system COP and set objectives and targets to increase overall COP. 6. Implement a leak detection program to ensure optimal refrigerant levels are maintained. 7. Turn off or slow down radiator fans when areas are not in use. Compressed air system 1. Reduce compressed air leaks. Optimising compressor controls can optimisation 2. Utilise cooler outside air. save 5-10% of the energy utilised by the compressed air system by closely 3. Reduce system pressure. matching the load requirement. 4. Utilise waste heat productively. Reducing air compressor pressure by 2 psi can reduce compressor energy use by 1% (at 100 psi). There would be a 1% reduction in compressor electrical energy utilisation for every 2.2°C reduction in intake gas. Solar PV 1. Review solar PV as a potential energy source. Typically there would be a 4-5-year payback on solar PV installations. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 49 SECTION RECOMMENDED ACTIONS POTENTIAL SAVINGS Thermal Energy Renewables and waste 1. Investigate the option of installing a de- There would typically be a 1-2-year heat recovery superheater system on the chillers. payback on heat recovery installations. 2. Install a compressed air heat recovery system. 3. Investigate installing heat recovery on the rendering plant. 4. Investigate installing solar heating panels. Optimise steam 1. Use the mass balance method for determining A 2.5-5% improvement in generation system generation efficiency in addition to flue gas analyses. efficiency through improved operating efficiency practices could be realised by focusing 2. Install live loggers on the water feed. on improving generation efficiencies. 3. Calculate the overall system efficiency and set appropriate KPIs for staff. 4. Reduce oxygen setpoints to between 4-6%. Insulate steam lines, 1. Insulate all exposed piping and install jacket An 80% reduction in radiation losses valves and flanges covers on flanges and valves. is viable through the installation of insulation. 2. Insulate the bodies of the expansion joints. 3. Insulate condensate return piping. 4. Insulate condensate return tank. Condensate recovery 1. Implement an aggressive condensate return 2-4% of boiler fuel and condensate line insulation programme. 50 PRACTICAL GUIDE 6 Summary and Conclusions The Resource Efficiency Benchmarking Study and the Practical Guide for Improving Resource Efficiency in Red Meat Abattoirs in South Africa have identified a number of energy and water efficiency opportunities and outline practical measures to improving resource efficiency. The red meat abattoir industry is a major water user in South Africa, utilising an estimated 4.5 million kl of water per year. The Study found that a typical abattoir could reduce its water consumption by 27.5% by implementing a number of water efficiencies measures, a potential saving of up to 243l/SU in South Africa. Similarly, a typical abattoir could reduce its electrical energy consumption by an estimated 12% and thermal energy consumption by 32%. The industry is encouraged to adopt appropriate metering and monitoring practices to assist in identifying opportunities, track progress and enable continuous improvement. The resource efficiency measures detailed in this report will assist South Africa to reduce the widening gap between water supply and demand, as well as alleviate pressures on the electrical supply grid and the country’s natural resources. Improving Resource Efficiency in Red Meat Abattoirs in South Africa 51 References • Atlas Copco Airpower. (2010). Compressed air manual. 7th edition. • Carbon Trust. (2020). How to implement heat recovery in refrigeration. Retrieved 11 February 2020, from https://www.carbontrust.com/media/147189/j8088_ctl056_heat_recovery_in_refrigeration_aw.pdf. • Christeyns. (2017). Hygiene through cavitation: ultrasonic cleaning in the food industry. Retrieved 10 February 2020, from https://www.christeyns.com/en/news/hygiene-through-cavitation-ultrasonic- cleaning-food-industry • Council for Scientific and Industrial Research. (2017). The case for renewable energy to provide base load energy in South Africa. • Energy Research Institute. (2000). How to save energy and money in compressed air systems. • Energy Technology Support Unit (ETSU) 1998. Energy Savings in Industrial Water Pumping Systems on behalf of Envirowise (UK) Good Practice Guide 249 (no longer in print). • Energy Technology Support Unit. (2000). Designing energy efficient refrigeration plants. Good Practice Guide 278. • Envirowise Best Practice Programme. (1999). Energy efficient operation of industrial boiler plant. Good Practice Guide 30. • Eskom. (2019). Schedule of standard prices for Eskom tariffs 1 April 2019 to 31 March 2020 for non-local authority supplies. • Flextra Engineering Products (Pty) Ltd. Removable insulation jackets / covers. Retrieved 3 June 2020, from https://www.flextra.co.za/products/removable-insulation/. • Hurricane Pumps. (2020). Retrieved 23 April 2020, from http://hurricanepumps.co.za/. • International Finance Corporation. (2019). South African agri-processing resource efficiency: Opportunities, challenges and outlook. • International Finance Corporation. (2020). Benchmarking study: Resource efficiency in red meat abattoirs in South Africa. • Meat and Livestock Australia Ltd. (2002). Eco-efficiency manual for meat processing. • National Cleaner Production Centre South Africa. (2019). Advanced steam training course. • Nuclear Power. Retrieved 11 February 2020, from https://www.nuclear-power.net/wp-content/ uploads/2017/06/vapor-compression-cycle-heat-pump.png • Oregon State University. (1997). How to take a self-guided tour of your compressed air system. • Red Meat Levy Admin. (2019). MSMS Data November 2018 to October 2019. • Rutgers University. Office of Industrial Productivity & Energy Assessment. (1995). Modern industrial assessments: A training manual. • World Bank Group. (2020). 2030 Water Resources Group • World Bank Group. (2020). Global solar atlas. Retrieved from https://globalsolaratlas.info. • World Wildlife Fund. (2016). Water facts & futures: Rethinking South Africa’s water future 52 PRACTICAL GUIDE For More Information visit www.ifc.org IN PARTNERSHIP WITH