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[Display omitted] • 82 methanogenic strain were screened for methane production from carbon dioxide sequestration. • The isolate Methanobacterium sp. M11, efficiently produced 7.90 mol of methane from 8.34 mol of CO 2. • Integration of methanogenic bioreactor with methanotrophic reactor for methanol production. • Maximum methanol productivity was obtained from Methyloceanibacter sp. M31 was 0.470 mol in 24 h. Carbon dioxide (CO 2) poses a significant threat, contributing to global warming and climate change. This study focused on isolating efficient CO 2 -reducing methanogens and methanotrophs for converting methane into methanol. Samples from diverse regions in India were collected and processed, yielding 82 methanogenic and 48 methylotrophic isolates. Methanogenic isolate M11 produced a higher amount of methane, reaching 2.9 mol L−1 on the sixth day of incubation at 35 °C, pH 7.0, and CO 2 :H 2 (80:20) as feeding rates. Under optimized conditions, isolate M11 effectively converted 8.3 mol CO 2 to 7.9 mol methane in 24 h. Methylotrophic isolate M31 demonstrated significant soluble methane monooxygenase activity (450 nmol/ml) and produced 0.4 mol methanol in 24 h. 16S rRNA analysis identified Methanobacterium sp. and Methyloceanibacter sp. among the isolates, elucidating their taxonomic diversity. This study offers valuable insights into methanogens' potential in CO 2 sequestration and methane conversion to methanol through methanotrophism, a promising sustainable biofuel production. [ABSTRACT FROM AUTHOR]

This paper includes a cradle-to-gate life cycle impact evaluation of gasoline blends in India. The potential environmental impacts of gasoline blends with three major components, i.e., methanol, ethanol, and n-butanol are assessed. The production of methanol from the natural gas reforming process, ethanol from hydrogenation with nitric acid, and n-butanol from the oxo process are considered in the current study. The results show that the gasoline blending with methanol has the lowest impact (11 categories) and is nearly constant from 5 to 15%. For gasoline with ethanol as an additive, the global warming potential, ozone depletion potential, and abiotic depletion potential rise with increasing ethanol addition. Meanwhile, increasing ethanol addition reduces the acidification potential and terrestric ecotoxicity potential impact of gasoline blends. Similarly, gasoline with n-butanol as an additive has higher acidification potential, eutrophication potential, human toxicity potential, terrestric ecotoxicity potential, marine aquatic ecotoxicity potential, and photochemical ozone creation potential compared to methanol and ethanol. [ABSTRACT FROM AUTHOR]

The present study reports the modeling and simulation of methanol production through the gasification of freshly mined three coal samples having different wt.% of ash, viz., low-ash coal (LAC), medium-ash coal (MAC), and high-ash coal (HAC), collected from three different locations in India. The effect of the input parameters such as steam-to-coal mass ratio and gasification temperature on process performance parameters such as stoichiometric number, syngas yield, green house gas emissions from the process stream or net stream carbon dioxide equivalent, and methanol yield was studied through process sensitivity analysis and input parameters are optimized for the maximum methanol yield and minimum green house gas emission. Primary economic investigation at optimized conditions revealed that an internal rate of return of 5.93% is achieved for HAC at minimum plant scale and setting the methanol selling price of 400 USD/ton whereas IRR obtained as 3.20% and 5.87% for LAC and MAC, respectively, at this condition. The coal sample, HAC, performed better due to a high internal rate of return (i.e., 7.53% at base case) and subsequently low production cost. The present study's findings can be decisive for the countries with substantial low-grade high-ash coal reserves concerning coal diversification for its sustainable consumption in methanol production. [Display omitted] • Equilibrium thermodynamic modelling of steam-coal gasification process. • Kinetic modelling of methanol synthesis process utilizing low-rank Indian coal. • Sensitivity analysis to study the influence of operating parameters. • Detailed comparative techno-economic analysis for methanol production. • Environmental analysis for coal to methanol production. [ABSTRACT FROM AUTHOR]