A Downdraft Fixed-Bed Biomass Gasification System with Integrated Products of Electricity, Heat, and Biochar: The Key Features and Initial Commercial Performance

Biomass, as a renewable and clean energy resource, plays a vital role in energy security and greenhouse gas reduction across the world. This paper reports on our newly established technology: a downdraft fixed-bed biomass gasification system using nut shells (mainly apricot kernel shells) for electricity generation, heating and partially activated carbon production at the same time. Particularly, the key features of the gasification reactor will be presented in detail. In the commercial plant (3 MW scale) located in Hebei province, China, the typical energy conversion from apricot kernel shell gasification is as follows: 47% syngas, 44% char (partially activated carbon), 5% hot water, and 4% energy loss. The main gasification temperature is 600-800 degrees C, while the activation zone is 850-900 degrees C. The commercial system has currently been in operation for 4 years. Considering the partially activated carbon as a stable carbon carrier, the whole system features negative CO2 emissions.