Carbon Negative Biomass Chemical Looping (BCL) Process – Reactor Design and Life Cycle Analysis

The Biomass Chemical Looping (BCL) process utilizes iron oxide as the oxygen carrier to produce hydrogen and electricity from cellulosic biomass, lignin-rich non-fermentable residues, and agricultural residues with 100% CO₂ capture. Preliminary experimental results indicate that the BCL process concept is feasible. In this paper, the design of the BCL reactors is proposed. Studies on the hydrodynamic behaviors of the BCL reactors using the proposed design are performed with a cold flow model. An ASPEN Plus® model is developed to evaluate the performance of the BCL process. Life cycle analysis (LCA) on the BCL process is also conducted. Process analyses show that close to 70% process efficiency (HHV basis) can potentially be achieved for hydrogen and electricity co-production from cellulosic biomass using the BCL process. Moreover, the process is carbon negative with a net CO₂ emission of less than -1.3 tons per ton of biomass converted. The high energy conversion efficiency and carbon negative nature of the BCL process results from the process intensification, energy management optimization, and in-situ CO₂ separation.