In-house power generation

Captive power generators may be therefore installed in many chemical plants which are to be run by steam turbines. These can get the steam supply from coal-fired boilers or from waste heat recovery boilers operating on hot process gases. They can reduce dependence on supply of power from external grid. They 

The power generated in-house by the captive generators can be either more or less than the requirement for running the plant units and machinery. 

Excess power generated (more than own requirement) The additional power can be exported to external grid. This is not easy, however, due to conditions laid down by grid authorities for quantum of power and reliability of supply. 

This may be possible in case of an excess in-house power generation (from a large quantity of steam available from WHRBs and other units). Such plants can continue to run due to internal power generation even when the grid supply fails. 

However, it may be very difficult to supply power to the grid in case of a small chemical plant (even with WHRBs units) since enough steam may not be available steadily due to variations in process conditions. As a consequence, the turbines may not be able to generate steady and sufficient power for supplying to the grid. It may not be acceptable to grid authorities who generally want a steady supply. 

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