Optimization of bio-ethanol autothermal reforming and carbon monoxide removal processes

Abstract

Experimental investigation of bio-ethanol autothermal reforming (ATR) and water-gas shift (WGS) processes for hydrogen production and regression analysis of the data is performed in the study. The main goal was to obtain regression relations between the most critical dependent variables such as hydrogen, carbon monoxide and methane content in the reformate gas and independent factors such as air-to-fuel ratio (λ), steam-to-carbon ratio (S/C), inlet temperature of reactants into reforming process (TATRin), pressure (p) and temperature (TATR) in the ATR reactor from the experimental data. Purpose of the regression models is to provide optimum values of the process factors that give the maximum amount of hydrogen. The experimental ATR system consisted of an evaporator, an ATR reactor and a one-stage WGS reactor. Empirical relations between hydrogen, carbon monoxide, methane content and the controlling parameters downstream of the ATR reactor are shown in the work. The optimization results show that within the considered range of the process factors the maximum hydrogen concentration of 42 dry vol. % and yield of 3.8 mol mol−1 of ethanol downstream of the ATR reactor can be achieved at S/C = 2.5, λ = 0.20–0.23, p = 0.4 bar, TATRin = 230 °C, TATR = 640 °C.