Reciprocating Compressors – Fugitive Emissions Control
One of the growing environmental concerns for both new and existing reciprocating compressor installations is fugitive emissions. Fugitive emissions are the leakage of volatile organic compounds (VOCs) into the atmosphere. The local environmental regulations should be checked at the beginning of the compression project to avoid delays and field modifications.
The major source of fugitive emissions from a gas compressor cylinder is the piston rod packing. Other sources of fugitive emissions are around the cylinder valve covers, unloader covers, unloader actuator packing, and clearance pocket gasket and actuator packing.
Fugitive emissions can be reduced by supplying improved O-ring seal designs along with piston rod packing cases and actuator stem seal . designs that utilize an inert buffer gas purge. The purge gas and VOCs can then be collected and sent to either a flare or vapor recovery system. The compressor manufacturer must advise the maximum allowable back-pressure on the compressor components. A typical compressor cylinder inert buffer gas arrangement is shown in Figure 11-25.