The Thermal Conversion Of Oil Shale Utilization

Oil shale is an important substitute energy resource, which can be converted into shale oil by retorting. In addition, it can be used in the fields of generation, chemical industry, pharmaceutical industry, construction industry, agriculture, etc. China has rich oil shale resource, which has tremendous developmental potentiality.Both Fushun oil shale and Shandong oil shale have high oil contents that are 9.40 % and 15.87 %, respectively, so they have great values in utilization.The affecting factors on oil shale retorting were studied by Fischer Assay analysis. Under the conditions of 510℃final temperature, 20 min persistence, the heating rate of 10℃/min and particle size of less than 3 mm, Fushun oil shale got the maximum shale oil yield, the main stage of producing shale oil was between 390℃and 490℃. Under the conditions of 490℃final temperature, 20 min persistence, the heating rate of 10℃/min and particle size of less than 3 mm, Shandong oil shale got the maximum shale oil yield; the main stage of producing shale oil was between 350℃and 450℃.The affecting factors of heating rate, particle size and mineral on oil shale pyrolysis were investigated by thermogravi metric analysis. The pyrolysis process was divided into three stages. Below 200℃, the oil shale lost its moisture; between 200℃and 600℃, hydrocarbon materials released, the two-step cracking of Fushun oil shale can be observed at this stage; exceeding 600℃, carbonates started to decompose. The starting temperature, maximum decomposition rate and ending temperature increased with the increasing of heating rate, and the cracking temperature range became wider. However, heating rate had little effect on conversion. Particle size had limited effect on pyrolysis. Mineral materials had catalytic effect, the conversion of Fushun and Shandong oil shale relatively increased 15.6 %, 17.8%, respectively. It was found that mineral had important catalytic effect on the pyrolysis of Fushun oil shale between 450℃and 600℃.The affecting factors of coking methods and mineral on oil shale gasification were investigated by thermogravimetric analysis. The gasification reactivity of char made by fixed bed decreased with the increasing of coking temperature. However, The gasification reactivity of char made by thermogravimetric analyzer first decreased then increased with the increasing of coking temperature. The gasification reactivity of char made by thermogravimetric analyzer was better than that of char made by fixed bed. More pores would be got by coking, that were benefit to gasification. The gasification ratios of chars made by fixed bed of Fushun and Shandong at 400°C coking temperature were 13.1 % and 4.9 %, respectively higher than those of the raw oil shales. Mineral materials had catalytic effect on the gasification. But the decrease of the catalytic effect at high temperature was inferior to the enlargement of the surface area causing the increase of the gasification reactivity.Kinetic parameters in pyrolysis were researched by DAEM, mineral promoting two-step cracking was found. Kinetic parameters in gasification were obtained by Coats-Redfern. The parameters conformed to the experimental phenomena and conclusions.