Process for vapor emission control

A process for controlling vapor emissions comprising:

• passing a hydrocarbon containing vapor stream through first stage carbon beds to adsorb heavier hydrocarbons onto the beds and produce a partially extracted hydrocarbon stream,
• applying a vacuum to the first stage carbon beds to remove hydrocarbons as a gaseous hydrocarbon stream from the first stage carbon beds,
• converting the gaseous hydrocarbon stream into a liquid hydrocarbon product,
• passing the partially extracted hydrocarbon stream through second stage carbon beds to adsorb lighter hydrocarbons onto the beds and venting the fully extracted hydrocarbon stream to atmosphere,
• applying a vacuum to the second stage carbon beds to remove hydrocarbons as a second gaseous hydrocarbon stream from the second stage carbon beds, and
• discharging the second gaseous hydrocarbon stream which can be used for fuel gas.

A process for controlling vapor emissions comprising:

• passing a hydrocarbon containing vapor stream through first stage carbon beds to adsorb heavier hydrocarbons onto the beds and produce a partially extracted hydrocarbon stream,
• applying a vacuum to the first stage carbon beds to remove hydrocarbons as a gaseous hydrocarbon stream from the first stage carbon beds,
• converting the gaseous hydrocarbon stream into a liquid hydrocarbon product,
• passing the partially extracted hydrocarbon stream through second stage carbon beds to adsorb lighter hydrocarbons onto the beds and venting the fully extracted hydrocarbon stream to atmosphere,
• applying a vacuum to the second stage carbon beds to remove hydrocarbons as a gaseous hydrocarbon stream from the second stage carbon beds which can be used for fuel,
• recycling to the other first stage carbon bed a first portion of lean gaseous hydrocarbon stream initially removed when applying vacuum to one of the first stage carbon beds, and
• recycling to the other second stage carbon bed a first portion of lean gaseous hydrocarbon stream initially removed when applying vacuum to one of the second stage carbon beds.