On the basis of its properties, ethanol has been identified as the most used biofuel because of its remarkable contribution in reducing emissions of carbon dioxide which are the source of greenhouse gas and prompt climate change or global warming worldwide. The use of ethanol as a new source of biofuel reduces the dependence on conventional gasoline, thus showing a decreasing pattern of production every year. This article contains an updated overview of recent developments in the new technologies and operations in ethanol production, such as the hydration of ethylene, biomass residue, lignocellulosic materials, fermentation, electrochemical reduction, dimethyl ether, reverse water gas shift, and catalytic hydrogenation reaction. An improvement in the catalytic hydrogenation of CO₂ into ethanol needs extensive research to address the properties that need modification, such as physical, catalytic, and chemical upgrading. Overall, this assessment provides basic suggestions for improving ethanol synthesis as a source of renewable energy in the future.

Utilisation and conversion of carbon dioxide into valuable chemicals and fuels are the promising ways to reduce carbon dioxide concentration in the atmosphere. In addition, the conversion of carbon dioxide into fuels, such as methane, methanol and formic acid has been proven a good method for hydrogen storage. In this work, the catalyst structure plays an important role in the production of formic acid and acetic acid at low temperature. Nickel oxide supported alumina catalysts were synthesised by using the solid-state fusion method at 550 °C and 700 °C. Calcined catalysts were characterised by X-ray diffraction, Brunauer-Emmett-Teller surface area, high-resolution field emission scanning electron microscopy, Auger electron spectroscopy with X-ray photoelectron spectrometer and transmission electron microscopy. Carbon dioxide hydrogenation was performed in the batch reactor. The products obtained were analysed by using high-performance liquid chromatography and gas chromatography with a thermal conductivity detector. The highest levels of formic acid and acetic acid production were 4.08 and 1.58 mmol/L, respectively.