The raw products of biomass gasification contain contaminants, including particles, organic impurities (tar) alkali metals, chlorine, nitrogen, and sulfur compounds (such as H2S, CS2, COS, AsH3, PH3, HCl, NH3, and HCN). These contaminations can block the downstream units, such as gas coolers and engines, and also interfere with the catalyst used in the production of synthetic fuels. Therefore, they have to be completely removed or significantly reduced before utilizing the gas depending on the application of interest. Also, the purpose of the conditioning system is to adjust the components to the appropriate ratio. Depending on the type of feedstock, its composition, and the type of gasification product application, there are different types of gas cleaning and conditioning that can be categorized as physical cleaning, such as cyclone, filters, and wet scrubbers’ application, or chemical cleaning, such as catalytic cracking, thermal reforming, shift hydrolysis, and hydrogenation.