5 Gas SPECIFICATIONS
Specifications for biosyngas and product gas are defined by the final gas application and comprise acceptable levels for the concentration of impurities and the required main gas composition.
5.1 Producer Gas Compositions
The producer gas composition is mainly dependent on the type and operation conditions of the gasifier. The main parameters are the gasification agent, operation temperature, operation pressure, and type of reactor. Tab. 2 gives an impression about the typical ranges of three selected reactor types. Allothermal atmospheric steam blown gasifiers lead to a practically nitrogen free producer gas and as further advantage a high hydrogen content can be observed. In case of oxygen blown pressurrized fluidized bed and entrained flow gasification the producer gas contains a lower content of hydrogen. At low temperatures (800 - 900̊C) the methane content is high which can be beneficial for SNG (synthetic natural gas) production. High temperature operation (>1200̊C) leads to low methane contents. This gas is well suited for e.g. Fischer-Tropsch biofuel production.