On March 22, World Water Day is celebrated, which aims to raise awareness about its importance for the maintenance of ecosystems. In addition to encouraging its preservation, and as part of this commitment, industries have been increasingly adapting to this need in their activities.
Within these industries, a widely used process is water cooling, where the heat generated in production media is dissipated through thermal transfer. Cooling is essential to prevent equipment from overheating, maintain operational efficiency, and ensure the safety of operations.
There are several methods used for this purpose and each one has specific advantages and applicabilities. However, what all these methods have in common are energy efficiency, water reuse/circulation, and thermal control.
- Cooling towers stand out for their energy efficiency and extensive use in chemical and power industries;
- Chillers utilize vapor compression or absorption cycles to cool the water. They are ideal for pharmaceutical and electronic processes;
- Heat exchangers prove to be very efficient in processes that require fluid separation, such as in the food industry.
As an overview of these systems, the processes, for the most part, occur as follows:
- Water input: water is captured from an external source (rivers, lakes or wells) or can be reused from industrial processes;
- Circulation: water is pumped into cooling systems, such as cooling towers or heat exchangers;
- Heat transfer: heat from industrial equipment or processes is transferred to water, cooling the components or fluids involved;
- Evaporation or condensation: in cooling towers, part of the water evaporates, removing heat. In closed systems, heat is dissipated without significant water loss;
- Treatment: the water is treated to prevent corrosion, fouling and microbiological growth, ensuring efficiency and longevity of the system;
- Recirculation or disposal: Chilled water is recirculated into the system or disposed of in a controlled manner.
Sustainability in industrial cooling projects
In addition to the possible processes already mentioned, there are studies that suggest improvements and innovations in this area. A 2015 study by the University of São Paulo (USP) evaluated the feasibility of using electromagnetic treatment for cooling water in chemical industries. This technique can complement or replace conventional chemical treatments, reducing costs and environmental impacts.
In addition, the automation of these systems can also be a reality within industries. This is what the article presented to ConBRepro (Brazilian Congress of Production Engineering) in 2021 suggests. The UTFPR researchers presented the discussion on the applicability of software to optimize industrial cooling systems. Automation improves efficiency and worker safety, as well as reducing operational failures.
Another contribution to industries is the Mobile ETA project, entitled: “216m³/h in 18.5m²: the water revolution in 30 days“, carried out by the Technologist in Environmental Management, Paulo Alcino. Its implementation allows for the rapid restoration of treated water production, ensuring supply and minimizing damage.
“(…) It is the ideal solution for emergencies, urban expansions and temporary support to conventional WTPs. Its 93% faster deployment, simplified operation, accurate monitoring, mobility and costs reduced by 70%, in addition to environmental sustainability, make it a milestone of innovation”.
Cooling systems in different industrial sectors
In the documentary “The Bill Gates Code“, produced in 2019 and available on the Netflix platform, Bill Gates highlights the importance of sustainable solutions on several occasions. A striking example is when he mentions the basic sanitation crisis and the need for innovation to solve global problems, reflecting his commitment to using technology and its resources to create a positive impact on the planet.
In this sense, within industries, it is necessary to start from the same principle, especially in processes that involve high temperatures or that require strict thermal control, being able to use water consciously and sustainably for cooling processes. Some practical examples are:
- Chemical processes: in the production of plastics, glues or pharmaceutical products, cooling is necessary to maintain the ideal temperature and avoid unwanted reactions;
- Food production: cooling is used to control temperature in processes such as pasteurization, fermentation, and storage;
- Power generation: thermal and nuclear power plants use water-cooling systems to condense steam and improve energy efficiency;
- Metallurgy: in metal fabrication, cooling is used to solidify molten materials and control temperature in furnaces and rolling mills;
- Waste treatment: Cooling systems help control the temperature of gases and liquids generated in industrial waste treatment processes.
Adopting practices such as reusing water in cooling towers or using renewable sources, such as water from wells, not only reduces costs but also demonstrates a commitment to environmental goals, but also ESG (Environmental, Social and Governance) compliance.
Application of water cooling processes
According to data from the United Nations Food and Agriculture Fund (FAO), industrial activity accounts for approximately 20% of global water use. In Brazil, according to the National Water and Basic Sanitation Agency (ANA), it is estimated that the sector’s consumption will reach more than 215 m³/s in 2030, underscoring the importance of water preservation to ensure sustainability in the future.
In this context, efficiency in the use of water also includes continuity in the treatment of effluents for reuse. This allows treated waste to be destined for both non-potable uses, such as irrigation, and more demanding uses, such as in cooling towers and industrial processes. This approach reduces the demand for drinking water and ensures that effluents discharged into water bodies comply with established quality standards.
In addition, more initiatives aimed at promoting environmental sustainability in its production processes were taken. According to a survey by the National Confederation of Industry (CNI), in November 2023, 89% of industrial companies have already taken measures to minimize the generation of solid waste. In addition, 86% have developed actions to make energy consumption more efficient and 83% have implemented strategies to improve water management and use.
In the United States, many industries are adopting water reuse practices and renewable sources for cooling processes. For example, the electricity sector uses about 40% of the water withdrawn in the country for cooling systems in thermal power plants. Additionally, the reuse of treated water is becoming a common practice in industries such as manufacturing and energy production.
In Mexico, the Pacífico Mexinol project uses advanced technologies to reuse municipal wastewater in a closed-loop system. This approach avoids the use of freshwater sources, preserving natural resources and reducing environmental impact. In this way, it is considered one of the largest industrial water reuse applications in the world, avoiding the use of more than 8.5 million m³ of fresh water annually.
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