The non-condensable gas treatment system (NCG) is used to control and minimize odors emerging from the biomass gasification plant chemical recovery processes.
In pulp plants using the kraft process, some odorous, toxic and explosive compounds are generated, called non-condensable gases (NCG), which need to be collected and eliminated to meet environmental and social requirements.
Inside a factory there are several CNG emissions. Some sources emit a small amount (volume) but highly concentrated (CNG – concentrated non-condensable gases), while others emit a large amount but at a low concentration (CNGD – diluted non-condensable gases).
Due to the upper and lower limits of explosivity of these gases, the collection must be done in a way to avoid that the concentration is between these limits. If the concentration is above the upper explosivity limit, the gases can be treated as GNCC.
A very important aspect concerning the treatment system, its safety and performance, is that typically the reduced sulfur compounds (TRS), to be removed at efficiency levels above 99%, must necessarily undergo thermal oxidation. Thermal oxidation is a process that requires oxygen consumption at a given temperature, and it is possible to ensure that the TRS concentration in the gases after thermal oxidation is below 10 ppm.