Producer gas cooling and cleaning

The result of the biomass gasification  with steam is an virtually nitrogen-free product gas, which is, according to prevailing equilibriums, rate,  and time spent, composed of mainly components H2, CO, CO2, CH4 and higher hydro-carbons.

Before going to the gas engine the gas needs to be cooled and cleaned.

Withdrawn from the gasifier at approximately 850°C it is cooled down to about 150°C in the subsequent product gas cooler. The heat obtained is used for district heating. Constructive design ensures high gas velocities and pipe wall temperatures and in this way reduces the tendency to pollution. The in-fabric filter-secluded dust is guided back into the combustion chamber due to its high carbon content. The following scrubber reduces the concentrations of tar, ammonia and acid gas components. As the producer gas is further cooled to provide an optimal inlet temperature for the gas engine, water and tars are condensed. An organic solvent is used as a washing medium. Condensate loaded with tars is continuously channelled out from the scrubber system and replaced by a fresh one. The discharged washing liquid is disposed in the combustion chamber, the resulting condensate is used for the production of steam needed in the gasifier.

Because of this special procedure, virtually all residues in the process can be recycled, which leads to a gas-cleaning process that is free of waste or waste water.