The absorption column novel 3:1 height to width ratio is likely to
reduce CO2 absorption efficiency compared to commercial upgrading
plants but this could be at least partially offset by increasing
absorption water flow. Biggest obstacle for acquiring higher CH4
content in upgraded gas was N2 present in the MSW landfill gas,
however N2 concentration can be reduced by intensive control of
the landfill gas collection systems.
Water absorption with water recycling removes siloxanes on
average 16.6% from the studied landfill gas but the removal percentage
depends on which siloxane component is most common
in the gas. From studied siloxanes, there was a high degree of removal
of TMS and (90.8%) and D5 (76.2%) and significant enrichment
of L2 and L3 (67% and 108% respectively). D5 was the most
common siloxane component in the studied landfill gas. The
absorption pressure did not affect the removal or enrichment percentage
but water flow speed did.
It was observed that a commercial gas drying system can be
effective in removing siloxane components from upgraded landfill
gas. On average 99.1% of all studied siloxanes were removed by the
gas drying system but the removal efficiency can diminish at different
pace for different siloxane component