Iranian Journal of Chemical Engineering (IJChE)

Abstract Nowadays, increasing demand for sustainable energy sources has led to a growing interest in using biomass as a renewable feedstock for producing hydrogen and methanol. The main objectives of this study involve simulation and economic analysis and evaluation of synthesis gas, hydrogen, and methanol production processes from various biomass sources using Aspen HYSYS software. Three lignocellulosic sources were waste wood biomass (WWB), thin hardwood chips biomass (THWCB), and almond shells biomass (ASB). In the first part of the simulation, the unrefined synthesis gas was produced through a multi-stage biomass gasification process. The outcomes reveal that the yield and composition of synthesis gas were increased by raising the steam-to-biomass ratio (SBR). Subsequently, an integrated model for hydrogen production from various biomass sources was examined through gasification in the presence of steam and oxygen through a water-gas shift (WGS) reaction and the separation and purification of the produced hydrogen using a pressure swing adsorption (PSA) unit. Finally, the hydrogen produced in the previous step was fed to the methanol synthesis unit. The results of the simulation of the gasification process of various lignocellulosic biomasses showed that the use of WWB, THWCB, and ASB can yield annual hydrogen production of 261,000, 349,344, and 361,656 kg, respectively. Consequently, the economic analyses indicated that hydrogen and methanol production from biomass is associated with significant efficiency and profitability. Furthermore, the comparison of synthesis gases' heating values derived from three biomasses revealed that the highest heating values were generated from ASB, THWCB, and WWB, respectively.

Abstract In this study we developed LaNixAl1-xO3 perovskite systems using a sol-gelmethod (with propionic acid as solvent) to use in methane-reforming reactions for producing synthesis gas. To understand the roles of the nature of the precursor and calcination conditions on the formation of LaNixAl1-xO3, we carried out identifications using NMR, FT-IR, XRD, SEM, and TEM. The precursor structure is a function of raw materials and calcination conditions. Nitrate salts of nickel, aluminium, and lanthanum, and calcinations at 750ºC for 4 h gave pure LaNixAl1-xO3 perovskite with good homogeneity, even at nanoscopic scales. These systems are highly efficient catalysts in steam and the dry reforming of methane. Various ratios of hydrogen to carbon monoxide in synthesis gas can be achieved by changing the feed type. We also investigated stabilization of these systems by studying the perovskite structure after reactivity tests. The optimum mixed perovskite for steam and dry reforming of methane is LaNi0.3Al0.7O3. The total conversion of CH4 is rapidly obtained at 750°C in steam reforming with a H2O/CH4 ratio = 3, the selectivity of CO is lower (55%) and the yield of hydrogen (98%) is higher compared to the ratio H2O/CH4 = 1. After 170 h of reaction, no deactivation had occurred, methane conversion remained higher than 90% at 750°C and in dry reforming, methane conversion and CO yield are about 98% and 95% respectively.