Hydrogen-rich gas production with CO2 capture from steam gasification of pine needle using calcium oxide: Experimental and modeling study

A research-scale bubbling fluidized bed reactor (BFBR) has been assembled and used to study the steam gasification of pine needles with calcium oxide (CaO) as sorbent and catalyst. The output parameters such as syngas composition, higher heating value, lower heating value, and cold gas efficiency, have been analyzed at the operating conditions of a temperature of 650°C to 850°C, steam/biomass (S/B) ratio of 0.4 to 1.6, and CaO/biomass ratio of 0.3 to 1.5. Furthermore, an ASPEN PLUS model of BFBR has been developed using Gibbs free energy minimization technique and model values have been compared with experimental values. From the experimental results, it is analyzed that the concentration of H₂ is increased from 37.02 vol% to 68.36 vol% with an increase in temperature from 650°C to 750°C at the S/B ratio of 1 and CaO/biomass ratio of 0.9 and after that, it decreased slightly. Furthermore, the concentration of CO₂ in syngas captured from 5.49 vol% to 0 vol%, when the CaO/biomass ratio is varied from 0.3 to 1.5. From the result analysis, it is concluded that higher temperature and higher CaO/biomass ratio has a significant impact on H₂ production while excess S/B ratio has a negative impact.