Experimental Study On Biological Methanation Of Lignite

Conventional natural gas resources can not meet its growing demand, the development of unconventional natural gas is an important means to ensure our country energy security. In this issue, the proposers put forward a new approach to settle the problems in high efficiency and cleaner soft lignite-using processes and to reduce the phase of unrich natural gas source in our country. The approach can translate soft lignite into methane using the microorganism under ground, on the basis of the soft lignite source predominance in Inner Mongolia and the characteristics of soft lignite from East Inner Mongolia, such as shallow carbonization processing, high water-containing, and high ash content.Firstly, the structure and composition of the lignite samples were analyzed and results showed that humic maceral to the main group, and high moisture and volatile content result in a relatively large hydrocarbon potential; at the same time a large specific surface area provides more attachment sites for methanogens living.Secondly, Research has acquired consortia in anthracite with highly methanogenic capacity throughout enrichment and domestication. The research was carry out for lignite bio-degradation by the consortia in anthracite, which investigated thet influence of pH value, temperature, particle size of lignite, the amount of lignite and the ratio of the culture on methane yield. The results demonstrated the best condition was the pH value of 7.0, the temperature of 35 ℃, a particle size of 200 mesh or more, 2g lignite and the 100% culture for lignite bio-degradation and the total gas production was 49.27 mL in the system of 50 m L medium and inoculum 4%.Finally, the anaerobic bacteria’s metabolic processes of soft lignite will be discussed, and the microbe degradation limit and mechanism of chemical structure and composition of soft brown coals will be proved up. This research confirmed that it was observed the lignite after degradation surface morphology changed, detritus group is main gas matrix, and carbon content of lignite samples decreased compared with raw lignite, which based on the use of scanning electron microscopy, X-ray diffraction, infrared spectroscopy, pyrolysis, and the reaction supernatant.In summary, this paper domesticated anaerobic methane-producing bacteria capable of degrading achieve lignite. Based on project, the proposers will develop a new approach for the low-cost high efficiency and cleaner soft brown coal-using Technology in east Inner Mongolia.