H2-rich gas production from steam gasification of a winery waste and its blends with industrial wastes. Effect of operating parameters on gas quality and efficiency

Abstract

A winery waste and its blends with industrial wastes were gasified by steam via a two-step process, employing a fixed bed reactor and a thermal analysis-mass spectrometer unit. Solid materials were characterized in terms of elemental analysis, heating value, internal structure and chemical functional groups, whereas bio-oil, pyrolysis gas and syngas were quantitatively analysed. The effect of temperature, steam-to-biomass ratio and fuel composition on carbon conversion, cold gas efficiency, energy recovery, reaction rate, gas composition and quality were determined and kinetic analysis was performed. When industrial wastes waste wood shavings and refused derived fuel were blended with grape husks and curls at ratios 30:70, upgraded fuels were produced. At 850 °C organic matter was almost completely converted to syngas upon steam gasification. A first-order kinetic model fitted the experimental results successfully, with activation energy values ranging between 54.3 kJ/mol and 143.5 kJ/mol. An increase in steam-to-biomass ratio from 0.5 to 3 resulted in a higher concentration of hydrogen in product gas, while excess steam enhanced hydrogen yield up to 74%. Energy recovery from all fuels was high, cold gas efficiency reached a value of 66% and the higher heating value of syngas ranged between 9.6 and 11.4 MJ/m3.