[Gasification] Compression question

[Zietsman, Rex]

William, Doug and Listers,

Biogas has a substantial amount of CO2 as well as Methane. When
compressing biogas, if you use say a three stage compressor, you can
send the biogas from the first stage to a pressurized water column where
the gas is allowed to bubble up through water. As the gas is under
pressure, say 5 bar, CO2 is absorbed into the water just like soda water
and other carbonated drinks. The CO2 removal is remarkably good. The now
much more concentrated methane gas leaving the top of the column can be
compressed to end pressure. Meanwhile, water from the water column is
flashed down to atmosphere in a holding tank. The lower pressure causes
the CO2 to come out of solution and go vent to atmosphere. The water is
pumped back to the top of the column. 

Besides some clever water trapping of the compressed gas, the system is
as simple as it sounds -> no membranes, etc and is fast. I don't know
how well this would work with CO but someone could come up with some
data I am sure. I have an article that details this system very well.
For those that want it, you will have to mail me as we cannot post
attachments to the forum.

Rex