High efficiency gasifier with recycle system

摘要

A high efficiency gasifier employs a rotary kiln having an indirect fired gasifier and a recycle system. The rotary kiln provides an essentially oxygen-free gasifying chamber into which raw feed material is introduced. Radiant tubes within the chamber transfer heat to the incoming raw feed material to pyrolyze it and convert it to char and product gas as the material advances toward the outlet end. The recycle system within the chamber returns both product gas and hot char to a receiving end of the kiln to aid in heat transfer to the raw feed material. The feed is thus heated more rapidly, and less heat input is required. Efficiency is further aided by providing additional residence time and gasification of the char.