What about CO2?
Biomass CHP and the implications for CO2 enrichment in the glasshouse.
Gas-fired CHP also produces CO2, from which contaminants such as NOx and CO are easily removed, so it can be utilised to enrich levels in the glasshouse. The ready availability of usable CO2 has been a significant driver for the uptake of CHP, particularly in the intensive edible crops sector.
However, biomass systems have a very different flue-gas composition. This means that the usual catalytic flue-gas cleaning system, used for natural-gas CHP installations, is unsuitable for cleaning the flue gas in a biomass CHP. The absence of an affordable flue-gas cleaning system for biomass has been a significant bottleneck for uptake by growers of some crops, until now.
There have been systems developed in Canada and Europe which use an amine scrubber to separate the CO2 from the rest of the flue gas.