PROCESS FOR PRODUCING PURIFIED NATURAL GAS

摘要

The invention provides a process for producing purified natural gas, the process comprising the steps of : (a) expanding a pressurised natural gas stream comprising at least 4 ppmv of mercaptans and supplying the resulting de-pressurised natural gas stream to a first separation column, in which first separation column the natural gas stream is separated into a gaseous overhead stream enriched in methane and a first fraction enriched in mercaptans; (b) withdrawing the gaseous first separation column overhead stream enriched in methane from the separation column to obtain the purified natural gas; (c) withdrawing the fraction enriched in mercaptans from the separation column; (d) optionally supplying the withdrawn fraction comprising mercaptans to a second separation column, in which second separation column the fraction comprising mercaptans is separated into an overhead stream enriched in ethane and a second fraction enriched in mercaptans; (e) removing mercaptans either from the first fraction enriched in mercaptans or from the second fraction enriched in mercaptans.