Over the years, there had been continues improvement in energy efficiency related to the industry and its processes. Energy efficiency is one of the mitigation options for climate change in the industry sector. The potential for industrial energy efficiency rises in some undeveloped countries since the industrialization development opens the opportunity for the installation of new plants which have materials and processes with highly energy efficiency. Energy efficiency is the second technology more used (after fuel switching) among all the technologies identified in the Industrial sector which are fuel switching, mining, high efficiency motors, cement production and energy efficiency.
The industrial sector requires energy to drive reactions, to create heat, and to obtain mechanical energy (work). However, these reactions have thermodynamic limits.
It is estimated than the technical potential of energy efficiency in industry is around the range of up to 25%. By means of innovation in technologies, reductions of roughly up to 20% in energy intensity could be achieved. The development of thermal systems that make a efficient use of non renewable resources such as oil, natural gas or coal is very important nowadays due to the high demand for goods and services.
Cogeneration allows to the plant obtaining electricity and useful thermal energy at the same time. This useful thermal energy is the steam and domestic hot water. Cogeneration helps to increase the energy efficiency since heat and energy are used instead of using a conventional power plant or a conventional boiler for the heat needs. By using cogeneration, changes in tension and transport are also avoided. These represent energy losses between 25 and 30%. When electricity is generated the use of the chemical energy of the fuel is not complet. The use ranges between 25% and 46%. The rest is lost in the form of heat. Cogeneration uses the heat losses that in other way, will produce air or water pollution. Cogeneration can be used in a large scale in industries but it can also be utilized in huge buildings where the heat is used for heating, cooling and hot water generation.
Micro Cogeneration is the use of cogeneration but in small spacial scales such as particular homes. However, cogeneration is more dessirable to be used at large scales.
Trigeneration allows to obtainning heat, energy and cold thanks to the use of the heat losses. Cold is obtained by means of a heat source thanks to the absorption process. As a result, a higher energy efficiency is obtained.
There are other ways to increase the energy efficiency in relation to the cogeneration process. There are processes that in addition to produce the three products of trigeneration process, produce useful mechanical energy to generate compressed air.