Methods of gasification and crude gas composition
A comparison of the gases produced by standard gasification methods shows that only staged gasifiers are able to consistently stay below the limit values without additional detarring. The tar content after pyrolysis should not exceed a maximum value of 50 mg/Nm3. The evaluation of crude tar content is essential because this product gas then has to pass through the whole facility between the gasifier and the gas motor, and this represents a critical point in terms of facility availability and economy.
Overview of condensable hydrocarbons (tars) in product gases produced by standard biomass gasification methods.
Combined power and heat production based on biomass gasification in decentralized, small output ranges (< 500 kWel) therefore requires processes with highest possible product gas purity after the first gasification stage.