Comparison of a commercial water-gas shift catalyst and La modified Cu-based catalysts prepared by deposition-precipitation in methanol steam reforming.

Herein, a performance analysis of La-doped copper-based catalysts (CuO/ZrO2/La-Al2O3) in methanol steam reforming (MSR) was conducted and compared with a commercial low temperature water-gas shift catalyst (HiFUEL W220) to produce H2 with low CO selectivity. The physicochemical properties of as-obtained catalysts were characterized by N2 adsorption, XRD, and ICP-OES. Effect of calcination temperature (750 °C and 1000 °C) on the properties of mixed oxide support (La-Al2O3) were discussed based on catalytic activity. The optimum conditions of H2O/CH3OH ratio (1.0-3.0), space-time ratio (WFA0) (40-120 kg s mol-1), and reaction temperature (180-310 °C) were evaluated by a parametric study using the commercial catalyst (HF220). Additionally, thermodynamic equilibrium calculations of experimentally identified components by using Aspen HYSYS process simulation software were also performed to analyze MSR process. The results were indicated that the calcination temperature significantly affected the structural properties and the activity with respect to CO selectivity. An increasing trend in CO selectivity for catalysts with supports calcined at 750 °C and a decreasing trend for catalysts with supports calcined at 1000 °C were observed. Hence, CZ30LA750 and CZ30LA1000 catalysts were selected to attain low CO selectivity and comparable activity when compared to other catalysts and the simulated thermodynamic calculation results.

Investigation of glycerol electrooxidation activity of carbon supported PdCu bimetallic electrocatalyst.

In this study, Pd/C, Cu/C, and a series of PdCu/C bimetallic electrocatalysts were prepared by microwave-assisted modified polyol method to determine glycerol electrooxidation reaction (GOR) activities. The effect of microwave duration on catalyst structure and GOR activity was investigated on PdCu/C bimetallic catalysts. Also, a commercial Pd/C (com-Pd/C) was used to compare catalytic activities with prepared samples. Electrocatalysts were characterized by using X-ray Diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and Transmission Electron Microscopy (TEM) analyses. In addition, the activity and stability of electrocatalysts for GOR were examined by using cyclic voltammetry (CV) and chronoamperometry (CA). In XRD results, the formation of PdCu alloy structure was observed successfully in all bimetallic catalysts. It was found that the PdCu electrocatalyst with microwave duration of 150 s (PdCu150) was exhibited homogeneous dispersion in TEM images. The particle size of 6.45 nm for PdCu150 was identified from TEM. Furthermore, the performance results were indicated that PdCu150 has the highest activity (36.02 mA/cm2) and stability compared to Pd/C (8.56 mA/cm2), and com-Pd/C (10.23 mA/cm2) in glycerol electrooxidation.

Thermodynamic modelling and optimization of oxy-reforming and oxy-steam reforming of biogas by RSM.

In this study, a comparative thermodynamic equilibrium calculation of biogas oxy-reforming and oxy-steam reforming processes to produce syngas has been conducted by Aspen Plus simulation software. The effects of temperature (600-800°C), pressure (1-20 atm), and inlet O2/CH4 (0-1.0), H2O/CH4 (0-3.0), and CO2/CH4 (0.3-1.0) mole ratios on the equilibrium compositions of products were determined. The operation of the process was optimized using Gibbs free energy minimization method and statistical approach: response surface methodology (RSM). Optimum operating conditions CH4/CO2/O2 = 1:0.51:0.12 at 788°C and 1 atm for oxy-reforming and CH4/CO2/H2O/O2 = 1:0.63:0.19:0.07 at 780°C and 1 atm for oxy-steam reforming were obtained to reach maximum H2 yield, CH4 and CO2 conversions by minimizing carbon selectivity to produce syngas for methanol production.

A novel process for CO2 capture by using sodium metaborate. Part I: effects of calcination.

This paper presents a comprehensive study on the carbonation of sodium metaborate (NaBO2) and the synthesis of high added value chemicals via NaBO2 and carbon dioxide (CO2). Carbon dioxide (CO2) is a greenhouse gas and NaBO2 is a by-product of sodium borohydride (NaBH4) hydrolysis reaction to produce H2. Therefore their transformation into commercial chemicals is quite important in order to provide a mutual benefit to global warming issue and hydrogen economy. In the presented study, reaction parameters such as hydration factor, furnace type, calcination temperature, and environment are investigated at different levels and optimized. The effects of those key parameters on CO2 fixation yield are discussed. It is found that 400 °C is a key temperature for dehydration and reaction steps. Both dehydrated NaBO2 is obtained and maximum carbonation conversion is reached at 400 °C. Moreover, at relatively low temperatures (below 400 °C), a new reaction pathway is proposed and proved by thermodynamic calculations. Structural properties of NaBO2 are exhibited differences regard to thermal exposure and the conversion is strictly related to the structural properties.