Gas compression

A method of compressing a gas for a gas sequestration process, said method using a compressor train having a plurality of discrete portions and comprising at least an upstream portion, a mid-stream portion and a downstream portion arranged successively in flow series, the method comprising:

• (i) performing a first compression step by directing a flow of said gas into the upstream compressor portion and driving the upstream compressor portion to compress the gas;
• (ii) performing a second compression step by directing the compressed flow from the upstream compressor portion into the mid-stream compressor portion and driving the mid-stream compressor portion to further compress the gas;
• and (iii) performing a third compression step by directing the compressed flow from the mid-stream compressor portion into the downstream compressor portion and driving the downstream compressor portion to further compress the gas;
• the method being characterised by driving the discrete compressor portions independently of one another.