Energy Recovery eBook
12 March, 2024
Using energy recovery is always the smart choice when you own and operate a compressor. Lear more on compressor heat recovery, its benefits, and its impressively wide range of applications.
What is waste heat in industrial processes?
Various industrial processes generate waste heat as a byproduct, which refers to underutilized energy. Equipment, machinery, or industrial systems release excess heat during their operation. Within this article, you will find a wide range of topics related to the above question.
Industrial waste heat specifically refers to the residual heat generated by industrial processes, such as manufacturing, power generation, chemical production, and refining, among others. These processes often involve the conversion of energy or the use of heat to carry out specific operations. Processes do not use all the energy put in; some release heat and are not useful.
The laws of thermodynamics
To understand excess heat, we must turn to the laws of thermodynamics. The second law says that when turning temperature difference into energy, like in a heat engine, waste heat is made. In other words, no energy conversion process can be perfectly efficient—some heat will always escape.
Various industrial processes produce a significant amount of heat as a byproduct. Cooling systems or exhausts release this extra heat into the air, and it is not utilized for any useful purpose.
While surplus heat is considered a "waste" because it is not directly used for its original purpose, it can still hold significant amounts of energy. Many industries use waste heat recovery systems to capture and use heat, improving energy efficiency, reducing costs, and lowering carbon footprint.
Where does your factory lose heat?
In a compressor room, waste heat refers to the excess heat generated by the operation of the compressors and associated equipment. Processes use compressors to increase the pressure of a gas or air. This process typically involves the conversion of electrical or mechanical energy into heat.
When compressing gas, compressors use energy and produce heat as a byproduct. The equipment releases heat into the surroundings, which contributes to the overall temperature increase in the compressor room.
Identifying the specific sources of waste heat in your factory may require an on-site assessment and an understanding of your factory's processes and equipment.
To find waste heat sources and determine if they can be used more efficiently, you should conduct an energy audit. Also, consulting with energy specialists is a good idea. They can analyze your factory's energy usage and processes to pinpoint specific areas where waste heat is generated. Also, you can receive recommendations for heat recovery and utilization, helping you reduce energy and reduce environmental impact.
Industrial processes change energy from one form to another, like burning fuel for electricity or making steam for heating.
During these energy conversion processes, the system releases a significant amount of heat as a byproduct.
Common sources of waste heat
- Compressors: increase gas pressure and produce waste heat during operation.
- Process water: Industrial processes that require heating or cooling of water can result in waste heat. In places like refineries, chemical plants, and power plants, waste heat is in the water that comes out of cooling systems.
- Industrial boilers and furnaces: used for heating or steam generation can produce waste heat as a byproduct.
- Exhaust gases: Many industrial processes produce hot exhaust gases as a byproduct. This includes combustion processes in power plants, furnaces, boilers, and engines. The waste gases hold a substantial quantity of heat energy that can be utilized.
- Cooling systems: Industrial processes often use cooling systems to remove excess heat generated during operations. Cooling towers, condensers, refrigeration units, and air conditioning systems generate waste heat that we can recover.
- Industrial ovens and furnaces: are used in various industries such as food processing, ceramics, and metallurgy. They are used for heat-intensive processes like drying, baking, and heat treatment. These machines produce waste heat that can be recycled and used again. They produce waste heat that can be recycled.
- Engines and Turbines : Power generation units, such as engines and turbines, produce waste heat during their combustion process.
- Industrial processes: like steelmaking and glass production create waste heat as a byproduct. Chemical reactions also generate heat during manufacturing.
- Many industries widely use steam in steam systems for purposes like heating, sterilization, and power generation. The condensate and low-pressure steam from these systems can be sources of waste heat.
- Industrial equipment: like machinery, motors, and transformers can produce waste heat during operation in industrial processes. You can recover and repurpose this heat.
- Heat exchangers: Industries frequently use thermal exchangers to transfer heat from one medium to another in various industrial processes. If they do not optimize the heat transfer, they can generate waste heat.
Waste heat is hard to avoid, but we can use it in new ways to make energy practices more sustainable. Learn more about waste heat technologies. As we continue to develop cleaner technologies, let’s also consider how we can make the most of every joule of energy, even the seemingly “wasted” ones.