Reaction Kinetics Study on the Heating Stage of the Shenhua Direct Coal Liquefaction Process

Shan, Xiangen; Li, Kejian; Zhang, Xuwen; Jiang, Hongbo; Weng, Han‐Rong

doi:10.1021/ef502874p

Cited by 14 publications

(17 citation statements)

References 11 publications

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“…This may be attributed to the thermal decomposition of some substances in the compounds. The percentage of compounds represented by peak 1 of NS showed a maximum value, and its M w also increased during this interval, which indicates the migration of components of BS and TS to NS and the further decomposition of some of the thermosensitive substances present therein.…”

Section: Resultsmentioning

confidence: 84%

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H₂O–CO Systems

et al. 2019

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A new method for the alkali catalytic modification of lignite in subcritical H2O–CO systems is presented, which can greatly improve its caking properties (caking index, >90). Soxhlet extraction technology coupled with GPC (gel permeation chromatography), FTIR (Fourier transform infrared spectroscopy), and 13C-NMR (carbon-13 nuclear magnetic resonance) analysis methods were used to investigate the structural evolution and formation mechanisms of solutes of n-hexane, benzene, and tetrahydrofuran in modified coal (denoted as NS, BS, and TS, respectively), which were the main caking components in the modified lignite. The results showed that the solutes were composed of four kinds of compounds with weight-average molecular weights in the range of 1170–2900, 300–550, 190–300, and 100–150, respectively. Oxygen-containing functional groups appeared in many forms, such as phenolic OH, aliphatic OH, ether bonds, and carbonyl and carboxyl groups, but mainly existed as C–O. When the temperature was <320 °C, NS consisted of aliphatic ring compounds, while BS and TS contained some aromatics, with an average of two aromatic rings per cluster in both. The appearance of monocyclic aromatic structures in the solutes occurred in the 320–330 °C temperature range, with one to three aromatic rings in the BS clusters, while polycyclic aromatic structures with more than five rings appeared in TS. The statistical structural models of the solutes all contained polycyclic aliphatic/aromatic structures as their main bodies, connected with substituents such as monocyclic aromatic structures, aliphatic side chains, and oxygen-containing functional groups. They are consistent with the structure of caking components in caking coal. The formation of caking components in modified lignite therefore underwent four distinct stages: separation of primary solutes, formation of pyrolysis solutes, formation of hydrogenated solutes, and formation of polycondensation solutes. This study provides valuable insights into the caking transition of modified coal and a basis for the high-added value utilization of lignite.

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Section: Resultsmentioning

confidence: 84%

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H₂O–CO Systems

et al. 2019

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“…Cugini [25] reported that liquefaction feed coal not only promoted the generation of ultrafine FeOOH but also assisted in dispersing the Fe1−xS that was generated in situ during DCL. It is worth noting that ultrafine γ-FeOOH catalysts supported on coal have been successfully applied in the first megaton DCL industrial demonstration plant, operated by the Shenhua Group [26][27][28].…”

Section: Introductionmentioning

confidence: 99%

The relationship between the microstructures and catalytic behaviors of iron–oxygen precursors during direct coal liquefaction

Xie

Shu

et al. 2018

Chinese Journal of Catalysis

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A series of both unsupported and coal-supported iron-oxygen compounds with gradual changes in microstructure were synthesized by a precipitation-oxidation process at 20 to 70 °C. The relationship between the microstructures and catalytic activities of these precursors during direct coal liquefaction was studied. The results show that the microstructure could be controlled through adjusting the synthesis temperature during the precipitation-oxidation procedure, and that compounds synthesized at lower temperatures exhibit higher catalytic activity. As a result of their higher proportions of γ-FeOOH or α-FeOOH crystalline phases, the unsupported iron-oxygen compounds synthesized at 20-30 °C, which also had high specific surface areas and moisture levels, generate oil yields 4.5%-4.6% higher than those obtained with precursors synthesized at 70 °C. It was also determined that higher oil yields were obtained when the catalytically-active phase formed by the precursors during liquefaction (pyrrhotite, Fe1−xS) had smaller crystallites. Feed coal added as a carrier was found to efficiently disperse the active precursors, which in turn significantly improved the catalytic activity during coal liquefaction.

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“…A coal‐to‐liquids company in China has the first direct coal liquefaction production line for commercial operation in the world, which was put into operation at 2009 . As the commencement, the corrosion on the internal bottom plate of various tanks for liquid hydrocarbon storage occurred frequently, which has resulted in the leakage of flammable materials .…”

Section: Introductionmentioning

confidence: 99%

Corrosion of sedimentary liquids on internal bottom plate of tanks among coal liquefaction process

Wang

Jiang

et al. 2018

Process Safety Progress

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The leakage accidents due to the corrosion on the internal bottom plates occurred frequently in the tanks which are involved in the first commercial direct coal liquefaction production line. For comprehending the corrosion, the compositions of the sedimentary liquids from diesel, hydro‐upgrading feed oil, heavy solvent oil, thick condensed oil and hydro‐stabilizing feed oil are surveyed in the first place, the results show that all the sedimentary liquids are almost neutral; the cations and anions in all sedimentary liquids are the same; the majority of ions are Ca2+, Cl−, and SO42− in these five sedimentary liquids. Then the immersion and electrochemical tests are implemented, it is represented that corrosion of same sedimentary liquid on Q235 steel coupon is severer than that on 16MnR steel coupon; the sedimentary liquid from hydro‐stabilizing feed oil has the most violent causticity; all the corrosives may hold the Fe2CO3 and Fe2O3; the polarization behavior of Q235 steel in the sedimentary liquid from hydro‐stabilizing feed oil is similar to that of 16MnR steel. Finally, the influences of different ions on the corrosivity of sedimentary liquids are also investigated, it can be concluded that the 672‐h general corrosion rates of Q235 and 16MnR steel coupons in all sedimentary liquids increase with improve of Cl‐ content but decrease with rising of SO42− content; in the sedimentary liquids containing large numbers of Cl‐ and Ca2+, the Ca2+ is the definitely vital ion which deeply influences the corrosivity of sedimentary liquids. The achievement of this research work also can be applied in the prevention for corrosion formed on the internal bottom plates of tanks referred to the direct coal liquefaction process. © 2018 American Institute of Chemical Engineers Process Saf Prog 37: 506–517, 2018

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Reaction Kinetics Study on the Heating Stage of the Shenhua Direct Coal Liquefaction Process

Cited by 14 publications

References 11 publications

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H₂O–CO Systems

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H₂O–CO Systems

The relationship between the microstructures and catalytic behaviors of iron–oxygen precursors during direct coal liquefaction

Corrosion of sedimentary liquids on internal bottom plate of tanks among coal liquefaction process

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Reaction Kinetics Study on the Heating Stage of the Shenhua Direct Coal Liquefaction Process

Cited by 14 publications

References 11 publications

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H2O–CO Systems

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H2O–CO Systems

The relationship between the microstructures and catalytic behaviors of iron–oxygen precursors during direct coal liquefaction

Corrosion of sedimentary liquids on internal bottom plate of tanks among coal liquefaction process

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Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H₂O–CO Systems

Structural Evolution and Formation Mechanisms of Caking Components of Modified Lignite in Subcritical H₂O–CO Systems