Cogeneration Abstract

Abstract :Cogeneration, also known as combined heat and power (CHP), refers to a group of proven technologies that operate together for the concurrent generation of electricity and useful heat in a process that is generally much more energy-efficient than the separate generation of electricity and useful heat. The typical method of separate centralized electricity generation and on-site heat generation has a combined efficiency of about 45 percent whereas cogeneration systems can reach efficiency levels of 80 percent. Here we have sugar industry as an example for co-gen where Bagasse is main fuel used in cogeneration plant. When demand of heat and power is more coal is used as an alternate fuel. Boiler efficiency is more when coal is used as

Cogeneration is often called combined heat and power (CHP), since most cogeneration systems are used to supply electricity and useful heat. However, the heat energy from electricity production can also be used for cooling and other non-heating purposes, so the term cogeneration is more inclusive. Cogeneration is a form of local or distributed generation as heat and power production take place at or near the point of consumption. For the same output of useful energy, cogeneration uses far less fuel than does traditional separate heat and power production, which means lower greenhouse gas (GHG) emissions as fossil fuel use is

PRINCIPLE OF COGENERATION

Cogeneration or Combined Heat and Power (CHP) is defined as the sequential generation of two different forms of useful energy from a single primary energy source, typically mechanical energy and thermal energy. Mechanical energy may be used either to drive an alternator for producing electricity, or rotating equipment such as motor, compressor, pump or fan for delivering various services. Thermal energy can be used either for direct process applications or for indirectly producing steam, hot water, hot air for dryer or chilled water for process cooling.

Fig.1 Cogeneration

It produces two forms of energy from a single fuel source. One of the forms of energy must always be heat and the other may be electrical or mechanical energy. One of the common examples where this technology is used is sugar production. Almost all sugar mills in India are traditionally using cogeneration by using bagasse as a fuel. Sugar production process releases a valuable byproduct known as Bagasse. Basically it is a fibrous material that remains behind after the crushing of sugar cane. Bagasse has good calorific value and burns very easily. Sugar industry requires electricity and steam in the production process. Here bagasse is being burnt in boilers to produce steam for its use in the process and turbine generator for power generation. After self consumption, the surplus electricity will be available for sale to the