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Electrocatalytic CO2-reduction technology can convert CO2 into methanol and other chemicals using renewable electricity, but the techno-economic prospects of the large-scale electrocatalytic reduction in CO2 into methanol are not clear. This paper conducted sensitivity analysis to confirm the key parameters affecting the cost of methanol production from an alkaline flow cell and a neutral MEA electrolyzer, compared the cost of the two electrolyzers under laboratory data and optimized data scenarios, and analyzed the key parameter requirements of the two electrocatalytic systems to achieve profitable methanol production. The results show that electricity price, Faradaic efficiency, cell voltage, and crossover/carbonate formation ratio are the most sensitive parameters affecting the cost of methanol production. The alkaline flow cell had higher energy efficiency than the MEA cell, but the saving cost of electricity and the eletrolyzer cannot cover the cost of the regeneration of the electrolyte and CO2 lost to carbonate/bicarbonate, resulting in higher methanol production costs than the MEA cell. When the crossover/carbonate formation ratio is zero, the cost of methanol production in an alkaline flow cell and a neutral MEA cell can reach under 400 USD/tonne in the cases of energy efficiency more than 70% and 50%, respectively. Therefore, enhancing energy efficiency and ensuring a low crossover/carbonate formation ratio is important for improving the economy of electrocatalytic methanol production from CO2 reduction. Finally, suggestions on the development of electrocatalytic CO2 reduction into methanol in the future were proposed. [ABSTRACT FROM AUTHOR]

CaO is efficient in catalyzing transesterification for biodiesel production, but its industrial application is inherently restricted by active sites leaching. To address this drawback, CaO is decorated into wollastonite to prepare the stable Ca/wollastonite catalyst. Microwave-assisted transesterification is used to produce biodiesel from palm oil, which effectively accelerates the reaction rate and improves the conversion efficiency. The Ca/wollastonite-0.8 catalyst with the mass ratio of CaO to wollastonite of 0.8 performs well with the fatty acid methyl ester (FAME) yield of 97.59%. Also, this catalyst is highly stable, where the FAME yield of 87.30% could be obtained for the fifth reused cycle. CaO is evenly dispersed on the wollastonite surface and the total basicity is high to 0.281 mmol g−1. Meanwhile, transesterification parameters are optimized by response surface methodology with central composite design (RSM-CCD) and the maximum FAME yield of 98.46% is achieved at reaction temperature of 64.2 °C, molar ratio of methanol to palm oil of 15.54 and mass ratio of catalyst to palm oil of 9.21 wt % for 3 h. Besides, the mass ratio of catalyst to palm oil is the primary variable. Wollastonite is demonstrated to be feasible to enhance the stability of CaO in catalyzing transesterification. Image 1 • Wollastonite is decorated with CaO to prepare transesterification catalyst. • CaO is evenly dispersed on wollastonite surface without agglomeration. • Ca/wollastonite-0.8 shows strong stability in catalyzing transesterification. • Transesterification parameters are optimized by RSM-CCD. • Mass ratio of catalyst to palm oil is the primary variable affecting FAME yield. [ABSTRACT FROM AUTHOR]

With the accelerated process of industrial modernization, the continuous emission of CO 2 seriously disrupts the natural carbon balance and contributes to global warming. To reverse this effect, CO 2 photocatalytic reduction has received increasing attention. Among various value-added products converted from CO 2 , methanol has been regarded as an excellent fuel alternative and desired energy storage form. This review summarizes the different catalytic materials explored for CO 2 photocatalytic conversion to methanol, and briefly describes the primary designing strategies for photocatalysts. Meanwhile, the fundamentals and mechanism of CO 2 photocatalytic reduction to methanol are briefly discussed. And the development course of CO 2 photocatalytic reduction to methanol has been attempted to organize. Furthermore, the paper tries to sort out the basic types of photocatalytic reaction systems with methanol as the product, and compares photocatalysis with other technologies that target CO 2 conversion to methanol. Finally, this work ends with the conclusions of the CO 2 photocatalytic reduction to methanol, and makes prospects for future development. [Display omitted] • Recent progress of CO 2 photocatalytic reduction to methanol was reviewed. • Primary photocatalytic materials for methanol production were discussed. • Design strategies of photocatalysts for methanol production were summarized. • Various reactors of CO 2 photocatalytic reduction to methanol were described. • Future perspectives of CO 2 photocatalytic reduction to methanol were presented. [ABSTRACT FROM AUTHOR]

• Ca-Zn-Ce/Al 2 O 3 catalysts are synthesized to be used for biodiesel production. • The biodiesel yield of 87.37% is achieved for the fifth reused cycle. • The maximum biodiesel yield of 99.41% could be obtained through optimization. • Physicochemical properties of produced biodiesel are accordance with ASTM D6751. The calcium modified Zn-Ce/Al 2 O 3 heterogeneous base catalysts are synthesized by the hydrothermal method, impregnation method and co-precipitation method, respectively. Further, they are applied to catalyze transesterification of palm oil with methanol for the biodiesel production. The hydrothermal method with the Ca: Zn: Ce: Al molar ratio of 5: 4: 1: 1 is preferred to synthesize the catalyst due to the best catalytic performance. The catalyst shows strong reusability, where the biodiesel yield of 87.37% is obtained for the fifth reused cycle and the weakened catalytic capability is mainly ascribed to the leaching out of the active sites. The response surface methodology with the central composite design (RSM-CCD) is employed to optimize the transesterification parameters and predict the biodiesel yield. The predicted maximum biodiesel yield of 99.44% is achieved at the reaction temperature of 66.12 °C, methanol to oil molar ratio of 18.53 and catalyst amount of 8.19 wt. % with 3 h, which is consistent with the experimental result of 99.41%. Also, the physical properties of the produced biodiesel meet the ASTM D 6751 standard. This study reveals the Ca-Ce-Zn/Al 2 O 3 catalyst gains a good application prospect in the biodiesel production and the response surface methodology is effective in optimizing the transesterification parameters and predicting the optimal values. [ABSTRACT FROM AUTHOR]

Stability of the calcined dolomite in catalyzing transesterification during the reused cycles is poor due to the leaching out of the calcium active sites and dolomite is incorporated with cerium to overcome the drawback in this study. Three different methods of the wet impregnation, direct wet impregnation and solid mixing are used for the cerium incorporation, where the wet impregnation method with the cerium to calcium molar ratio of 0.6 is preferred for the best catalytic performance. The maximum biodiesel yield of 97.21% is achieved with the catalyst to oil mass ratio of 0.05 and methanol to oil molar ratio of 15 at 65 °C for 2 h. Attributed to the strong synergistic effect between CaO and CeO 2 , the leaching out of the calcium active sites from the cerium incorporated dolomite catalyst into the liquid transesterification products is greatly reduced and the biodiesel yield of 88.63% is obtained for the fifth reused cycle. The physical properties of the produced biodiesel are in accordance with the ASTM D 6751 or EN 14214 standard to guarantee its industrial application. Image 1093 • Dolomite is incorporated with cerium to enhance the catalytic stability. • Wet impregnation method is preferred for cerium incorporation. • The catalytic capability is closely relevant to the basicity density. • The maximum biodiesel yield of 97.21% could be achieved. • Calcium leaching is greatly reduced through cerium incorporation. [ABSTRACT FROM AUTHOR]