| 摘要 |
Biogas is upgraded by stripping out carbon dioxide and hydrogen sulphide to leave about 98% methane using a counter-flow water scrubber. The raw biogas that has been freed of moisture and particulates is compressed to about 9 bar for introduction to the scrubber using a water flooded screw (WFS) compressor. The water introduced into the compressor with the raw gas has the effect of not only cooling and lubricating the compressor but also partially scrubbing the gas within the compressor prior to the scrubber operation and allowing the use of a single stage compressor. After scrubbing, the methane is flashed and recovered from the water, and at least some of the water from the scrubber is recycled to the compressor. |
