Sustainable Management of Forest and Building Wastes for Hydrogen- Rich Syngas from Catalytic Steam Gasification with Minimum CO2 Emissions

Abstract

The current study aimed to exploit forest residues and their industrial waste for biofuel production, together with the utilization of building demolition waste (BDW) for CO₂ capture from the gasification process. Selected materials were gasified by steam in a fixed-bed unit, using BDW as a sorbent and CeO₂ and K₂CO₃ as catalysts. The effects of the sorbent/biomass ratio, catalyst loading, and temperature on final conversion, product gas composition and heating value, syngas and hydrogen yields, and energy recovery were examined, and optimum conditions were determined. Gas analysis was performed using a thermogravimetric-mass spectrometric (TG-MS) system. At a Ca/C ratio of 1, the amount of CO₂ captured at 750 °C was 73.2-76%, the hydrogen concentration in the product gas was 56.2-59.3 mol%, and the higher heating value was 13.1 MJ/m3. An increase in catalyst loading up to 20 wt% resulted in higher conversion as well as increased syngas and hydrogen yields. The K₂CO₃ catalyst showed superior overall performance. In this case, conversion ranged between 80.7% and 84.8%, the molar fraction of hydrogen in the product gas was 67-80.5%, syngas yield varied from 1.9 m³/kg to 2.6 m³/kg, the heating value was 13.1-13.8 MJ/m³, and energy recovery was higher.