Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry

The food manufacturing sector is one of the most dominant consumers of energy across the globe. Food processing methods such as drying, baking, frying, malting, roasting, etc. rely heavily on the heat released from burning fossil fuels, mainly natural gas or propane. Less than half of this heat cont...

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Main Authors: Sanjay Mukherjee, Abhishek Asthana, Martin Howarth, Jahedul Islam Chowdhury
Format: Article
Language:English
Published: MDPI AG 2020-12-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/13/23/6446
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author Sanjay Mukherjee
Abhishek Asthana
Martin Howarth
Jahedul Islam Chowdhury
author_facet Sanjay Mukherjee
Abhishek Asthana
Martin Howarth
Jahedul Islam Chowdhury
author_sort Sanjay Mukherjee
collection DOAJ
description The food manufacturing sector is one of the most dominant consumers of energy across the globe. Food processing methods such as drying, baking, frying, malting, roasting, etc. rely heavily on the heat released from burning fossil fuels, mainly natural gas or propane. Less than half of this heat contributes to the actual processing of the product and the remaining is released to the surroundings as waste heat, primarily through exhaust gases at 150 to 250 °C. Recovering this waste heat can deliver significant fuel, cost and CO<sub>2</sub> savings. However, selecting an appropriate sink for this waste heat is challenging due to the relatively low source temperature. This study investigates a novel application of gas-to-air low temperature waste heat recovery technology for a confectionary manufacturing process, through a range of experiments. The recovered heat is used to preheat a baking oven’s combustion air at inlet before it enters the fuel-air mixture. The investigated technology is compared with other waste heat recovery schemes involving Regenerative Organic Rankine Cycles (RORC), Vapour Absorption Refrigeration (VAR) and hot water production. The findings indicate that utilising an oven’s exhaust gases to preheat combustion air can deliver up to 33% fuel savings, provided a sufficiently large heat sink in the form of oven combustion air is available. Due to a lower investment cost, the technology also offers a payback period of only 1.57 years, which makes it financially attractive when compared to others. The studied waste heat recovery technologies can deliver a CO<sub>2</sub> savings of 28–356 tonnes per year from a single manufacturing site. The modelling and comparison methodology, observations and outcomes of this study can be extended to a variety of low temperature food manufacturing processes.
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spelling doaj.art-089214c84e2c483a987448093bd0ce7c2023-11-20T23:39:05ZengMDPI AGEnergies1996-10732020-12-011323644610.3390/en13236446Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing IndustrySanjay Mukherjee0Abhishek Asthana1Martin Howarth2Jahedul Islam Chowdhury3National Centre of Excellence for Food Engineering, Sheffield Hallam University, Sheffield S9 2AA, UKNational Centre of Excellence for Food Engineering, Sheffield Hallam University, Sheffield S9 2AA, UKNational Centre of Excellence for Food Engineering, Sheffield Hallam University, Sheffield S9 2AA, UKSchool of Aerospace, Transport and Manufacturing, Cranfield University, Bedford MK43 0AL, UKThe food manufacturing sector is one of the most dominant consumers of energy across the globe. Food processing methods such as drying, baking, frying, malting, roasting, etc. rely heavily on the heat released from burning fossil fuels, mainly natural gas or propane. Less than half of this heat contributes to the actual processing of the product and the remaining is released to the surroundings as waste heat, primarily through exhaust gases at 150 to 250 °C. Recovering this waste heat can deliver significant fuel, cost and CO<sub>2</sub> savings. However, selecting an appropriate sink for this waste heat is challenging due to the relatively low source temperature. This study investigates a novel application of gas-to-air low temperature waste heat recovery technology for a confectionary manufacturing process, through a range of experiments. The recovered heat is used to preheat a baking oven’s combustion air at inlet before it enters the fuel-air mixture. The investigated technology is compared with other waste heat recovery schemes involving Regenerative Organic Rankine Cycles (RORC), Vapour Absorption Refrigeration (VAR) and hot water production. The findings indicate that utilising an oven’s exhaust gases to preheat combustion air can deliver up to 33% fuel savings, provided a sufficiently large heat sink in the form of oven combustion air is available. Due to a lower investment cost, the technology also offers a payback period of only 1.57 years, which makes it financially attractive when compared to others. The studied waste heat recovery technologies can deliver a CO<sub>2</sub> savings of 28–356 tonnes per year from a single manufacturing site. The modelling and comparison methodology, observations and outcomes of this study can be extended to a variety of low temperature food manufacturing processes.https://www.mdpi.com/1996-1073/13/23/6446waste heat recoverybakingenergy efficiencyfood manufacturingorganic rankine cyclevapour absorption cooling
spellingShingle Sanjay Mukherjee
Abhishek Asthana
Martin Howarth
Jahedul Islam Chowdhury
Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry
Energies
waste heat recovery
baking
energy efficiency
food manufacturing
organic rankine cycle
vapour absorption cooling
title Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry
title_full Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry
title_fullStr Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry
title_full_unstemmed Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry
title_short Techno-Economic Assessment of Waste Heat Recovery Technologies for the Food Processing Industry
title_sort techno economic assessment of waste heat recovery technologies for the food processing industry
topic waste heat recovery
baking
energy efficiency
food manufacturing
organic rankine cycle
vapour absorption cooling
url https://www.mdpi.com/1996-1073/13/23/6446
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AT jahedulislamchowdhury technoeconomicassessmentofwasteheatrecoverytechnologiesforthefoodprocessingindustry