15 Mar 2021 |
Research article |
Improving Sustainability in the Brewery Industry with Slight Changes
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The brewery industry has grown in popularity in recent years, and there is an increasing need to improve operations by making it both more efficient and environmentally friendly. Here, a simple action plan was developed to reduce the overall environmental footprint of a brewery and to enhance its economic efficiency, by targeting operations optimization at multiple levels, such as water usage, process waste (wastewater, beer, grains), energy efficiency and CO2 emissions.
To improve brewing operations, making them more efficient and eco-friendly, we need to consider the whole supply chain including logistics, transportation, and production processes. However, here, we will only be focusing on the production process. Generally, there are three dimensions of sustainability—(i) economic, related to cost; (ii) environmental, related to emission and pollution; and (iii) social, related to human rights and social equity—from which both environmental and economic aspects are considered. To develop an action plan, we need to consider a trade off between cost efficiency and environmental issues and take both objectives into account.
Cutting Down on Water Usage
In the brewing industry, the most significant environmental issues in the operation phase include water consumption, wastewater, solid waste and by-products, energy usage, and emissions . The main ingredients required in beer production include water, barley, hops, and yeast . The brewing process uses large volumes of water [1, 2] to produce the beer, and for heating, cooling, brewing, rinsing and sterilizing purposes. It is estimated that for each litre of beer, ten litres of water is used, from which a large amount is discharged in the drains. Discharging untreated wastewater in surface waters can cause pollution .
There are several measures to cut down on the level of water usage :
- installing and monitoring water meters at various stages,
- dry milling of malted barley,
- installing low-flow nozzles and reducing water pressure on equipment spray nozzles,
- installing automatic valves to stop water supply in the event of interruptions,
- using a closed system for cleanup,
- removing attached solids prior to wash down, to reduce pollutant loadings,
- mixing water jet with compressed air stream and using compressed air instead of water whenever possible,
- using preventative maintenance to avoid water loss. Moreover, the wastewater can be recycled through physical treatment by removing solids and large materials, chemical treatment by removing toxic materials, and biological treatment .
Cutting Down on Process Waste
Reductions in process waste (beer, grains, etc.) can help decrease purchasing costs, raw material consumption, and environmental impacts. To do so, the following can be implemented :
- improving brewhouse yield through process optimization,
- selecting better quality malt,
- installing well-designed storage and transfer equipment,
- providing longer storage periods.
Packaging modification can also decrease resource consumption by substituting glass bottles with recyclable polyethylene terephthalate (PET) bottles and using waterproof labels. Brewery waste and by-products can be recycled and sold as fertilizers, animal feed and food flavouring .
Cutting Down on Energy Consumption
On the other side of the spectrum, the brewing process is a relatively intensive consumer of electrical and thermal energy . Thermal energy is used to raise steam in boilers, while the refrigeration process, brewhouse, bottling hall, and wastewater treatment plant consume electrical energy. By reengineering the processes and development of new technical solutions, a considerable reduction could be achieved . Moreover, energy usage can be optimized by:
- improving energy efficiency, e.g. using fluorescent lights, low watt lamps, and more efficient technologies; implementing regular equipment maintenance for motors, pumps and compressors to reveal leakages;
- implementing energy recovery, e.g. using waste heat to provide heat energy in the brewery;
- developing additional energy sources, e.g. biofuel and solar energy, and also using anaerobic fermentation of brewery wastewater and biogas production. The combustion of spent grains can generate thermal heat and electrical power . The steam produced in the boiling process could be used to heat the water for washing purposes . Furthermore, improving insulation on heating/cooling systems—as a low-cost and effective way to reduce energy usage—may lower thermal energy consumption . Preventative maintenance is another measure that could reduce steam leakage. For instance, a leaking steam valve may lead to emissions of about 1 kg of steam per hour, which equals the fuel consumption of approximately 700 kg of oil per year .
Cutting Down on Greenhouse Gas Emissions
In addition to cost efficiency, improving fossil fuel consumption will reduce greenhouse gas (GHG) emissions and the potential climate changes due to these emissions. Several greenhouse gases including CO2, NOx, Sox, CH4, N2O, O3, etc., may be produced during brewery operations. It is estimated that for each hectolitre (equal to 100 litres) of beer, approximately 16 kg of CO2 is generated in boilers that consume fossil fuel . The carbon footprint of a brewery can be optimized using clean sources like solar thermal energy. The technology of biomass combustion needs to be developed in this industry . CO2 produced as a by-product of fermentation and maturation processes can be recovered, stored, and used in several brewery processes .
In general, beer production should lean toward sustainability by adopting new brewing technologies and solutions with efficient energy consumption, reductions in GHG emissions, efficient water consumption especially for cleaning and cooling purposes, prevention of leakage and loss, and reuse of brewery waste and treated wastewater .
Asefeh Hassani Goodarzi
Asefeh Hassani Goodarzi is a PhD student in System Engineering at ÉTS. She recently was a visitor at Grenoble INP University, Grenoble, France. She earned her MSc at the Department of Industrial Engineering at University of Tehran, Iran.
Program : Operations and Logistics Engineering