Microbial Desulfurization of Coals in a Slurry Pipeline Reactor Using. Thiobacillus ferrooxidans

Mapping the knowledge domain of microbial desulfurization application in fuels and ores for sustainable industry

Direct application of high-sulfur fuels and ores can cause environmental pollution (such as air pollution and acid rain) and, in serious cases, endanger human health and contribute to property damage. In the background of preserving the environment, microbial desulfurization technologies for high-sulfur fuels and ores are rapidly developed. This paper aims to reveal the progress of microbial desulfurization research on fuels and ores using bibliometric analysis. 910 publications on microbial desulfurization of fuels and ores from web core databases were collected in this work, spanning 39 years. Through 910 retrieved documents, collaborative networks of authors, institutions and countries were mapped by this work, the sources of highly cited articles and cited documents were statistically analyzed, and keyword development from different perspectives was discussed. The results of the study provide a reference for microbial desulfurization research and benefit environmental protection and energy green applications.

Acidithiobacillus ferrooxidans and its potential application

The widely distributed Acidithiobacillus ferrooxidans (A. ferrooxidans) lives in extremely acidic conditions by fixing CO₂ and nitrogen, and by obtaining energy from Fe²⁺ oxidation with either downhill or uphill electron transfer pathway and from reduced sulfur oxidation. A. ferrooxidans exists as different genomovars and its genome size is 2.89-4.18 Mb. The chemotactic movement of A. ferrooxidans is regulated by quorum sensing. A. ferrooxidans shows weak magnetotaxis due to formation of 15-70 nm magnetite magnetosomes with surface functional groups. The room- and low-temperature magnetic features of A. ferrooxidans are different from other magnetotactic bacteria. A. ferrooxidans has potential for removing sulfur from solids and gases, metals recycling from metal-bearing ores, electric wastes and sludge, biochemical production synthesizing, and metal workpiece machining.

Biodesulphurization of coal: mechanism and rate limiting factors

The pyrite sulphur removal from coal by Thiobacillus ferrooxidans was studied in batch reactor. A combination of SEM, IR and XRD was used to study the presence of superficial phases and the changes in solid surface during biodesulphurization. Biodesulphurization was found to be a three-step process. In the first step (0-4 days), direct oxidation of pyrite by bacteria brought about 28% pyritic sulphur removal. Both direct and indirect oxidation contributed to the second step (4-10 days) resulting in 51% pyrite removal. The deposition of elemental sulphur, jarosite and ferric sulphate precipitates in the third step reduced the pyrite availability and ferric iron concentration in the leachate and brought the process of biodesulphurization to an end.