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Moving bed gasifier: In a moving bed gasifier, oxidants (steam and O2) are blown in at the bottom of the gasifier. The resulting crude fuel gas moves upward through the solid fuel bed, and as the feed at the bottom of the bed is consumed, the solid material gradually moves downward. Therefore, the defining characteristic of a moving bed is counterflow. As the coarse fuel gas flows through the bed, it is cooled by the incoming feed, while the feed is dried and of its volatiles are removed. Therefore, the temperatures at the upper and lower parts of the gasifier differ significantly, with the bottom temperature being 1000°C or higher, and the top temperature around 500°C. The removal of volatiles from the fuel during gasification means that the resulting fuel gas contains a large amount of coal tar components and methane. Therefore, the crude fuel gas is washed with water at the outlet to remove tar. As a result, the fuel gas does not need to be cooled at high temperatures in the syngas cooler; however, if it comes from a gas flow reactor, it does require cooling. The moving bed gasifier is designed for gasifying coal, but it can also accept other solid fuels, such as waste. In a moving-bed gasifier, oxidants (steam and O2) are blown in at the bottom of the gasifier. The resulting crude fuel gas moves upward through the solid fuel bed, and as the feed at the bottom of the bed is consumed, the solid material gradually moves downward. Therefore, the defining characteristic of a moving bed is counterflow. As the coarse fuel gas flows through the bed, it is cooled by the incoming feed, while the feed is dried and of its volatiles are removed. Therefore, the temperatures at the upper and lower parts of the gasifier differ significantly, with the bottom temperature being 1000°C or higher, and the top temperature around 500°C. The removal of volatiles from the fuel during gasification means that the resulting fuel gas contains a large amount of coal tar components and methane. Therefore, the crude fuel gas is washed with water at the outlet to remove tar. As a result, the fuel gas does not need to be cooled at high temperatures in the syngas cooler; however, if it comes from a gas flow reactor, it does require cooling. The moving bed gasifier is designed for gasifying coal, but it can also accept other solid fuels, such as waste.