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Direct Liquefaction Behaviors Of Shenhua Coal And Its Macerals

Posted on:2015-02-25Degree:MasterType:Thesis
Country:ChinaCandidate:K M HanFull Text:PDF
GTID:2181330467985670Subject:Chemical Engineering and Technology
Abstract/Summary:PDF Full Text Request
Macerals in coal can be divided into three parts:exinite, vitrinite and inertinite according to the characterristics of the microscope. Different components have different liquefaction behaviors. In this paper, liquefaction behaviors of Shenhua(SH) coal (SH-R) and its macerals (vitrinite-rich sample SH-V and inertinite-rich sample SH-I) obtained by hand-picking were investigated in a tubing-bomb micro-reactor.It is analyzed that the content of organic matter in SH coal and its macerals are more than95%, and vitrinite and inertinite are the main maceral compositions. The main mineral from SH coal and its macerals are clay and carbonate, and the maximum reflectance of vitrinite in samples is between0.4%and0.6%. The FT-IR analysis shows that the SH-V has more aliphatic hydrocarbon than SH-I and SH-R. The TG/DTG analyses show that the main weight loss of three samples are in the temperature range of350-600℃, and SH-V has more weight loss than SH-I and SH-R sample although the temperature with maximum weight loss rate of three samples is the same at about445℃.The liquefaction results showed that the conversion and oil yield of coal samples are in the order SH-V>SH-R>SH-I at same condition and SH-V releases more alkane gases (C1-C3) than SH-I. Moreover, the conversion and oil yield of SH-V in N2without catalyst is even higher than those of SH-R and SH-I samples in H2. These differences in liquefaction behaviors are mainly attributed to higher H/C ratio, higher volatile and lower average number of aromatic ring of SH-V than SH-I. The effects of catalyst and solvent on coal liquefaction are related with the atmosphere and properties of coal samples. Fe-based catalyst promotes the activation of H2and the formation of activated hydrogen, and is beneficial to hydrogenation of free radical fragments in H2. The conversion and oil yield of three samples with tetralin as solvent are as nearly twice as those with decalin as solvent in N2.The role of H2S in liquefaction process was studied. The results showed that the presence of H2S in the system increase oil yield, and the highest oil yield can be obtained with the volume content of H2S in H2S/H2atmosphere at4vol.%. H2S can accelerate the hydrogen transfer rate. It seems that H2S is beneficial to the oil yield of vitrinite, and Fe-based catalyst can promote the conversion and oil yield of inertinite. The presence of H2S in the system is also necessary to maintain a nonstoichiometric iron sulfide in catalyst and catalyze H2activation.
Keywords/Search Tags:Shenhua Coal, Coal Macerals, Direct Coal Liquefaction, H2S, HydrogenTransfer
PDF Full Text Request
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