A study of gasification behavior of residues from mild coal hydro-liquefaction

Yan, Jingchong; He, Jing; Yang, Qitong; Bai, Zongqing; Lei, Zhiping; Li, Zhan-Ku; Xue, Chao; Wang, Zhicai; Ren, Shibiao; Kang, Shigang; Shui, Hengfu

doi:10.1016/j.fuel.2021.120456

Cited by 5 publications

(11 citation statements)

References 35 publications

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“…The reactivity at 50 and 90% (R 0.5 and R 0.9 ) conversion was calculated using eqs 17 and 18, where t is the time at conversion in minutes. The fractional carbon conversions (X), initial reactivities (R i ), and average final reactivities (R fa ) were evaluated using eqs 19−21 7,13…”

Section: Characterization Of Feed Materials and Residues 241 Proximat...mentioning

confidence: 99%

“…Similar results were found by other authors. 7,26 The solid char residues (SR) reflect the structural compaction and enhanced graphitization (and recombination reactions) that occur during liquefaction, while the PAA fractions demonstrate the retention of structural order and crystallinity in the soluble components formed during the process. Furthermore, during coal maturation, molecular chains reconnect into larger macromolecular chains, leading to increased maturity and aromaticity in both VR and IR.…”

Section: Characterization Of Solid Fractions Obtained During Liquefac...mentioning

confidence: 99%

“…These free radicals then undergo hydrogenation, facilitated by the presence of hydrogen, leading to the formation of lighter products such as oil and gas. Conversely, under conditions where the availability of hydrogen for donation is insufficient, the larger radicals tend to condense through undesirable repolymerization and recombination reactions, resulting in the formation of unwanted residues such as tars and cokes containing large, unreactive polycyclic aromatic structures. ,, In addition to the solvent’s most crucial role in hydrogen donation, the solvent acts as a carrier for coal particles and facilitates heat transfer. , This transformation of the macromolecular network occurs at moderate temperature and pressure, typically within the range of 400–455 °C and at 69–172 bar, facilitated by the presence of a solvent. ,, High pressures in coal liquefaction processes are applied to accelerate reactions, enhance solubility, allow cracking of molecules, minimize gas production, increase yields, and improve the quality of the resulting liquid products . The solubilized products, which are predominantly comprised of aromatic compounds, can be further upgraded using conventional petroleum refining methods, such as hydrotreating, to meet the final specifications of liquid products. ,, …”

Section: Introductionmentioning

confidence: 99%

“…Coal liquefaction plays an important role in the production of liquid fuels and other petroleum products, particularly for countries lacking crude oil reserves like South Africa. Notably, liquefaction solid residues account for approximately one-third of the coal input, and their utilization is important in reducing the overall cost of the liquefaction process. , Managing the solid waste generated by the chemical industry has gained much attention, with coal liquefaction residues representing about 25–30% of the feed coal . The residues generated through liquefaction comprise not only unreacted coal macerals and intrinsic mineral components but also residual oil, as well as asphaltenes and preasphaltenes (PAAs) .…”

Section: Introductionmentioning

confidence: 99%

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Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines

Meyer,

Strydom,

Bunt

et al. 2024

ACS Omega

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In this investigation, coal fines enriched with inertinite were used for direct liquefaction experiments. For comparison, a vitrinite-rich coal typically utilized in coal-to-liquid processes was also employed. To assess the impact of mineral matter content, demineralization was used to remove most of the inorganic constituents. The findings revealed that the inertiniterich coal exhibited lower liquefaction conversions due to a reduced proportion of reactive macerals and elevated levels of inorganic mineral matter. These conversion values exhibited a strong correlation with the quantity of reactive macerals present in the parent coals. For the inertinite-rich coal, the presence of inorganic mineral matter impeded the liquefaction process but facilitated the CO 2 gasification reactions of the derived chars. To evaluate their potential in gasification processes, CO 2 gasification experiments were conducted and the reactivities and apparent gasification activation energies of both coal chars, liquefaction residue chars, and preasphaltene and asphaltene (PAA) chars were calculated. These calculations were carried out using the random pore model (RPM) and volumetric reaction model (VRM). The chemistry, reactivity, and kinetics of residue gasification conversion are not thoroughly understood, yet they hold significant importance in optimizing syngas production within gasification processes. The findings from this work highlight significant differences in liquefaction conversion values, product distribution, and composition. These differences are influenced by factors such as maceral composition, inorganic mineral matter content, hydrogen-donor capabilities of the solvent, and liquefaction reaction temperatures. Additionally, these variables affect the CO 2 gasification reactivity of liquefaction solid residue chars.

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Section: Characterization Of Feed Materials and Residues 241 Proximat...mentioning

confidence: 99%

Section: Characterization Of Solid Fractions Obtained During Liquefac...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines

Meyer,

Strydom,

Bunt

et al. 2024

ACS Omega

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“…[ 6 , 7 ]. At present, the research on liquefaction residue mainly focuses on the gasification [ 5 , 8 , 9 , 10 ], pyrolysis [ 11 , 12 , 13 ], combustion [ 14 ] and preparation of functional carbon materials [ 15 , 16 , 17 ]. However, it is not hard to find a common feature in applied research in these fields.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Electrochemical Desulfurization of Coal Liquefaction Residue

Jiang

Zhang

et al. 2023

Molecules

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The occurrence of sulfur in coal direct liquefaction residue affects its further high quality and high value utilization. Electrochemical desulfurization is characterized by mild reaction conditions, simple operation, easy separation of sulfur conversion products and little influence on the properties of the liquefied residue. An anodic electrolytic oxidation desulphurization experiment was carried out on the liquefaction residue of the by-product of a coal-to-liquid enterprise in the slurry state. An electrochemical test and material characterization of raw materials before and after electrolysis showed that electrolytic oxidation can desulfurize the liquefaction residue under an alkaline condition. Linear sweep voltammetry (LSV) was used for the electrolysis experiments to obtain the optimal slurry concentration of 60 g/L. On this basis, the reaction kinetics were calculated, and the minimum activation energy in the interval at 0.9 (V vs. Hg/HgO) was 19.71 kJ/mol. The relationship between the electrolytic desulfurization of the liquefied residue and energy consumption was studied by the potentiostatic method. The influence of anodic potential and electrolytic temperature on the current density, cell voltage, desulfurization rate and energy consumption was investigated. The experimental results showed that the desulfurization rate and total energy consumption increase positively with the increase in reaction temperature and electrolytic potential in a certain range. The influence of the reaction temperature on the desulfurization rate and total energy consumption is more prominent than that of electrolytic potential, but the energy consumption of sulfur removal per unit mass does not show a positive correlation. Therefore, with the energy consumption per unit mass of sulfur removal as the efficiency index, the optimal experimental results were obtained: under the conditions of 0.8 (V vs. Hg/HgO) anode potential, 50 °C electrolytic temperature, 60 g/L slurry concentration and 14,400 s electrolytic time, the desulfurization rate was 18.85%, and the power consumption per unit mass of sulfur removal was 5585.74 W·s/g. The results of XPS, SEM, BET and IC showed that both inorganic and organic sulfur were removed by electrolytic oxidation, and the morphology, pore structure and chemical bond of the liquefied residue were affected by electrolytic oxidation. The research method provides a new idea and reference for the efficiency evaluation of desulfurization and hydrogen production from coal liquefaction residue.

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Boosting chemical looping combustion performances of red mud with transition metal oxides

Yan

Zhang

et al. 2022

Carbon Resources Conversion

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A study of gasification behavior of residues from mild coal hydro-liquefaction

Cited by 5 publications

References 35 publications

Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines

Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines

Experimental Study on Electrochemical Desulfurization of Coal Liquefaction Residue

Boosting chemical looping combustion performances of red mud with transition metal oxides

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