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

Abstract

The current study aimed at the exploitation of forest residues and their industrial waste for biofuel production, together with the exploitation of building demolition wastes (BDW) for CO₂ capture from the gasification process. Selected materials were gasified by steam in a fixed bed unit, using BDW as sorbent and CeO₂ and K₂CO₃ as catalysts. The effects of sorbent/biomass ratio, catalyst loading and temperature on final conversion, product gas composition and heating value, syngas and hydrogen yield and energy recovery were examined and optimum conditions were determined. Analysis of gases was performed in a thermogravimetric-mass spectrometric (TG-MS) system. At a ratio of Ca/C = 1, the amount of CO₂ captured at 750 °C was 73.2-76%, the concentration of hydrogen in the product gas was 56.2-59.3% mol and the higher heating value was 13.1 MJ/m³. An increase of catalyst loading up to 20% wt resulted in higher conversion and syngas and hydrogen yields. K₂CO₃ catalyst showed a better 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, with a heating value of 13.1-13.8 MJ/m³ and energy recovery was higher.