(424j) Simulation and experiments of biomass pyrolysis for fuel gas with calcium oxide

Authors: 
Zhao, B., Energy Research Institute of Shandong Academy of Sciences
Zhang, X., Energy Research Institute of Shandong Academy of Sciences
Chen, L., Energy Research Institute of Shandong Academy of Sciences
Sun, L., Energy Research Institute of Shandong Academy of Sciences
Si, H., Energy Research Institute of Shandong Academy of Sciences
Yi, X., Energy Research Institute of Shandong Academy of Sciences

In this study, the technical route of biomass pyrolysis in-situ CO2 absorption with CaO has been proposed in order to get high-quality fuel gas. The optimum operation parameters were investigated with combination of experiments and simulating calculations, which will be the foundation of the large-scale application of this technology.

Through the simulations of thermodynamic equilibrium, the effects of temperature, pressure, mass ratio of CaO to sawdust (Ca/B) on the products distribution of the biomass pyrolysis in-situ CO2 absorption were investigated. It indicated that atmospheric pressure, 700 ℃ and Ca/B of 0.65 would be the suitable operating conditions to produce the high quality fuel gas with good economic prospects. Based on the results of calculation, one system of a moving bed pyrolyzer coupled with a fluid bed combustor (MFS) has been used to produce high quality fuel gas. With the operating conditions of pyrolysis temperature of 700℃, 0.65 of Ca/B and atmospheric pressure, the experiments were carried out in MFS system. The average contents of H2 and CH4 were about 40 vol.% and 26 vol.%, while those of CO and CO2 were about 17 vol.% and 4 vol.%, respectively. LHV of the produced fuel gas was above 16 MJ/Nm3. Cold gas efficiency of the system reached 51.2% through the analysis of system energy. Therefore, with high efficiency and simple operation, this technology may be a promising route to achieve high quality fuel gas for biomass utilization.