Methanol or ethanol produced from woody biomass: which is more advantageous?

Effect of selenium and tungsten on cell growth and metabolite production in syngas fermentation using "Clostridium autoethanogenum"

The effect of tungsten and selenium on cell growth and production of metabolites such as acetic acid and ethanol when fermenting syngas using "Clostridium autoethanogenum" was investigated to improve the process efficiency. General concentrations of selenium and tungsten in the medium are 0.01µM during acetogenic syngas fermentation. We conducted culture experiments at concentrations of 0, 0.001, 0.01 and 0.1µM for each heavy metal. The effect of selenium on cell growth and total metabolite production was greater than that of tungsten as the effect of selenium on formate dehydrogenase, an important enzyme of the Wood-Ljungdahl pathway, is greater than that of tungsten. Although an increase in tungsten had a marginal effect on total metabolite production, the ethanol/acetic acid production ratio increased significantly due to a decrease in acetic acid and an increase in ethanol production. Thus, tungsten plays a key role in activating aldehyde:ferredoxin oxidoreductase, a key enzyme in the reduction of acetate to ethanol. A specific ethanol productivity of 0.462g ethanol/g DCW∙d was obtained in a culture using 0.01µM selenium and 0.1µM tungsten, which was 2.18 times higher than when using 0.01µM of both selenium and tungsten.

Influence of Short Carbon-Chain Alcohol (Ethanol and 1-Propanol)/Diesel Fuel Blends over Diesel Engine Emissions

Oxygenated fuels, in this case short carbon-chain alcohols, have been investigated as alternative fuels to power compression ignition engines. A major advantage of short-chain alcohols is that they can be produced from renewable resources, i.e., cultivated commodities or biomass-based biorefineries. However, before entering the market, the effects of short-chain alcohols on engine performance, exhaust emissions, noise and sound quality need to be understood. This work sheds light on the relationship between the physicochemical properties of the alcohol/diesel fuel blends (ethanol and 1-propanol) on engine performance, exhaust emissions and, for the first time, on noise and sound quality. It has been demonstrated that when the content of alcohol in blends increased, soot and soluble organic material emissions drastically decreased, mainly due to the increase of oxygen content in the fuel. Reduction in soot emissions combined with higher thermodynamic efficiency of alcohol fuels, with respect to diesel fuel, enable their utilization on compression ignition engines. There is also an improvement in the soot-NOx trade off, leading to large reductions on soot with a small effect on NOx emissions. The oxygen content within the fuel reduces CO and THC emissions at extra-urban driving operation conditions. However, hydrocarbons and CO emissions increased at urban driving conditions, due to the high heat of vaporization of the alcohol fuels which reduces cylinder temperature worsening fuel atomization, vaporization and mixing with air being more significant at lower cylinder temperature conditions (low engine loads and speeds). Similarly, the higher the presence of alcohol in the blend, the higher the noise emitted by the engine due to their low tendency to auto-ignition. The optimization of alcohol quantity and the calibration of engine control parameters (e.g., injection settings) which is out of the scope of this work, will be required to overcome noise emission penalty. Furthermore, under similar alcohol content in the blend (10% v/v), the use of propanol is preferred over ethanol, as it exhibits lower exhaust emissions and better sound quality than ethanol.

An aluminium fluorosensor for the early detection of micro-level alcoholate corrosion

The detection of the dry alcoholate corrosion of aluminium is vital to design a corrosion resistive aluminium alloy for the storage and transportation of biofuel (methanol or ethanol). By synthesizing an Al3+ fluorescent probe operable in an alcoholic medium, we quantified the alcoholate corrosion in terms of the fluorometrically estimated soluble alkoxide (Al(OR)3) generation under nitrogen atmosphere. With time, a linear increase in corrosion with specific aluminium dissolution rate constants ∼2.0 and 0.9 μg per day per cm2 were estimated for aluminium and Al-7075 alloy, respectively. During open atmosphere monitoring, the adsorbed moisture converted small extent of Al(OR)3 to the insoluble Al(OH)3 at the alloy surface which retarded the alcoholate corrosion appreciably.

New reduction mechanism of CO dimer by hydrogenation to C2H4 on a Cu(100) surface: theoretical insight into the kinetics of the elementary steps

An alternative reaction pathway for the production of C₂H₄ through the OCCO* intermediate from CO dimerization is provided in this mechanistic study.

Chemical and electrochemical hydrogenation of CO2 to hydrocarbons on Cu single crystal surfaces: insights into the mechanism and selectivity from DFT calculations

The research results have great significance for the in depth understanding of the selectivity of the CO₂ electrochemical reduction process and the sensitivity of the Cu surface structure.

Production of methanol from biomass waste via pyrolysis

The production of methanol from agricultural, forestry, livestock, poultry, and fishery waste via pyrolysis was investigated. Pyrolysis was conducted in a tube furnace at 450-500 °C. Sugarcane bagasse showed the methanol production (5.93 wt.%), followed by roots and sawdust with 4.36 and 4.22 wt.%, respectively. Animal waste offered the lowest content of methanol, as only 0.46, 0.80, and 0.61 wt.% were obtained from fishery, goat, and cow waste, respectively. It was also observed that the percentage of methanol increased with an increase in volatile compounds while the percentage of ethanol increased with the percentage of ash and fix carbon. The data indicate that, pyrolysis is a means for production of methanol and ethanol after further optimization of the process and sample treatment.