Quality Of Shale Oil Research Articles

Influence of original and additive AAEMs on the migration and transformation of N by pyrolysis in Fushun oil shale

Oil shale contains a large amount of nitrogen compounds during pyrolysis, which will lead to a decline in the quality of shale oil and produce a large number of PM2.5 precursors. To study the migration and transformation of N during the pyrolysis, fixed-bed pyrolysis experiments were conducted on oil shale with different pyrolysis temperatures (500 ℃、600 ℃、700 ℃、800 ℃) and residence times (20 min、40 min), meanwhile, the migration and transformation of single AAEMs on the N of oil shale pyrolysis, the acid-wash samples were loaded with the original and higher concentrations of metals (K2CO3, CaCO3, Na2CO3, MgCO3) according to the ICP results and subjected to experiments at 600 °C - 20 min, the obtained products were analyzed by XPS、GC-MS and solution absorption method. The results revealed that higher temperatures promoted the enrichment of nitrogen-containing molecules in tar, and longer residence durations also led to an increase. Some mineral components in oil shale facilitated the conversion of semi-coke nitrogen to oil-phase nitrogen. An elevated loading concentration caused the catalytic cleavage of macromolecular nitrides. With an increase in temperature, NH3 and HCN exhibited two distinct peaks, respectively. AAEMs encouraged the production of NH3 but limited the content of HCN, where Ca played a more important function than K. The N transformation route was identified by contrasting the effects of reaction temperatures、residence times and AAEMs on N distribution.

Investigating pilot test of oil shale pyrolysis and oil and gas upgrading by water vapor injection

The technology of oil shale pyrolysis by water vapor injection uses high-temperature steam as a heat carrier to heat oil shale. Water vapor not only plays the role of transferring and exchanging heat, but it also chemically reacts with organic matter and some oil and gas products, altering the generation characteristics of oil and gas products. In this paper, we developed a long reaction distance test system for oil shale pyrolysis by water vapor injection and obtained the effects of heat injection temperature and time on the quality of oil and gas products. First, the results showed that with increasing pyrolysis temperature, the hydrogen content in the gas components gradually increased and then tended to be stable. In the process of heat injection temperature, increasing from 330 °C to 475 °C, the hydrogen content increased from 1.05% to 66.64%. High hydrogen concentration was mainly due to the reaction of water vapor with carbon residues, water vapor conversion reactions, and steam gasification reactions of hydrocarbon gases. Then, for shale oil, when the injection temperature was higher than 500 °C, the content of light components in shale oil remained at high levels, but the content of heteroatomic compounds was very little and the quality of shale oil was good. Next, when the injection temperature was controlled to 555 °C and the pyrolysis time was increased from 0 h to 4 h, the hydrogen content in the gas products increased first and then decreased, but the heteroatomic contents in the shale oil products increased first and then decreased. When the pyrolysis time was 2.5 h, the hydrogen content peaked, reaching 87.6%. When the pyrolysis time was 2 h, the content of heteroatoms peaked and reached 8.22%. Overall, when the injection temperature was 555 °C and the injection time reached 3 h, the shale oil formed through oil shale cracking presented higher quality.

Oil shale pyrolysis in indirectly heated fixed bed with metallic plates of heating enhancement

This study is devoted to improving the heating to oil shale particles and in turn the yield and quality of shale oil in fixed bed reactors indirectly heated through use of internals. Metallic heating plates were vertically welded on the reactor wall as heating enhancement internals to provide extra heating surfaces inside the oil shale bed and to increase the high-temperature heating surface area by 35% to 210%. Comparison of heating rate to particles and shale oil yield was made between the reactors without and with the plate internals. Utilizing internals evidently enhanced the heating to oil shale particles and shortened pyrolysis time by 30% to 50%. The shale oil yield increased by 7% to reach 90% of the Fischer Assay oil yield (8.98wt.%, dry base) when the heating surface area was increased by 70–110%. With increased heating surface area above 110%, the shale oil yield manifested conversely a slight decrease. Nonetheless, the fraction of light oil (boiling point <350°C by analysis in simulation GC) was increased to about 66wt.% from 60.94wt.% for the reactor without any heating plate. Characterizing the char samples at different lateral positions of the oil shale bed justified that the flow of gaseous pyrolysis product in the reactor was guided to the vicinity of heat transfer plates to speed up gas exhaust and selective cracking. Consequently, adding heat transfer plates into an indirectly heated reactor would obviously intensify the heating to the oil shale bed and also elevate the pyrolysis oil yield and quality.

A Study on the Denitrogenation of Fushun Shale Oil

Removal of nitrogen compounds, especially basic nitrogen compounds, from Fushun shale oil was investigated. Different acidic reagents were chosen as the extraction reagent. The results showed that phosphoric acid-sulfuric acid complex reagent had the best nitrogen removal effect. The removal rate of basic nitrogen compounds increased with the increasing mass ratio of agent to oil, reaction temperature, reaction time, and settling time, respectively. When mass ratio of agent to oil was 1:1, reaction temperature was 60°C, reaction time was 20 min and settling time was 4 h with acidic reagent AB, removal rate of basic nitrogen compounds was up to 97.43%, and that of total nitrogen compounds was up to 38.25%, the yield of shale oil was 97.18%. The quality of shale oil had been significantly improved through this method.

Effects of retorting factors on combustion properties of shale char. 3. Distribution of residual organic matters

Shale char, formed in retort furnaces of oil shale, is classified as a dangerous waste containing several toxic compounds. In order to retort oil shale to produce shale oil as well as treat shale char efficiently and in an environmentally friendly way, a novel kind of comprehensive utilization system was developed to use oil shale for shale oil production, electricity generation (shale char fired) and the extensive application of oil shale ash. For exploring the combustion properties of shale char further, in this paper organic matters within shale chars obtained under different retorting conditions were extracted and identified using a gas chromatography-mass spectrometry (GC-MS) method. Subsequently, the effects of retorting factors, including retorting temperature, residence time, particle size and heating rate, were analyzed in detail. As a result, a retorting condition with a retorting temperature of 460-490 degrees C, residence time of <40 min and a middle particle size was recommended for both keeping nitrogenous organic matters and aromatic hydrocarbons in shale char and improving the yield and quality of shale oil. In addition, shale char obtained under such retorting condition can also be treated efficiently using a circulating fluidized bed technology with fractional combustion.