9.11 Gasifier

A gasifier needs to allow controlled airflow or introduce a limited supply of oxygen, aiding the conversion of biosolids into syngas. Compared to a pyrolysis unit (no air) and an incinerator (excess air), achieving optimal gasification conditions in a simple set-up is challenging. Consequently, simple gasifiers commonly lead to incomplete gasification or lower syngas quality.

The following setup can be used as a gasifier and a pyrolysis unit, depending on the operation.

The design uses a dual chamber (2 drums of different sizes) with adjustable air supply doors at the bottom of the outer drum. For pyrolysis, the air supply doors are eventually shut. For gasification, these doors continue to be regulated to achieve an air-starving environment within the drum.