Dual fluidized bed based technologies for carbon dioxide reduction

Abstract

The dual fluidized bed technology offers a broad range of applications for the utilization of CO2 neutral energy carriers like biomass. This work provides an overview about dual fluidized bed technologies, which could contribute to a more sustainable future. The conventional biomass steam gasification is an already well-known technology. However, an advanced reactor design enables several further processes. These processes could be appropriate for a general CO2 reduction in the atmosphere. Based on this technology the sorption enhanced reforming process (SER) was developed and enables the in-situ removal of CO2 from the product gas. Consequently, the chemical equilibrium of the product gas is shifted and a high H2 content can be obtained in the product gas. Another variation of the DFB process is the gasification with CO2 instead of steam as gasification agent. This enables the utilization of a CO2 stream and the production of a product gas with high carbon content from biomass. Last but not least, a DFB reactor system can also be used for the so-called chemical looping combustion process of biomass (BioCLC), which has enormous potential for capturing CO2 due to its low energy demand. The principle is based on the use of a metal oxide as bed material and oxygen carrier. This oxygen carrier is used to burn the gas, which is produced by the gasification reactions of the biomass with steam.