JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2025
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IF 6.2
Juan Cai,Boyan Zhang,Jiatao Dang,Yunpeng Zhao,Dingcheng Liang,Qiang Xie,Jinchang Liu
The migration, transformation, and enrichment of strategic metal elements in coal in the process of coal processing and utilization are significant for their effective extraction and application. In this work, the migration, transformation, and enrichment of Li, Ga, Ge, In, and Re during coal pyrolysis were investigated by six-step sequential chemical extraction. The results showed that Li mainly exists in a residual state in raw coal and pyrolytic products under 500 ℃; however, the content of sulfide state Li increases largely when the pyrolysis temperature exceeds 500 ℃. Ga mainly enriches in residual form, and the content of Ga in the residual state rises with the pyrolysis temperature increasing. Ge mainly presents in the form of carbonate-binding state, sulfide state, and residual state. As the temperature rises to higher than 500 ℃, Ge combines with the carbon and oxygen compounds produced by pyrolysis to form a carbonate-binding state, resulting in a significant increase in its content. The content of Ge in the residual state also increases significantly. The ratio of carbonate-binding state and organic state In gradually decreases with the increase of pyrolysis temperature, while that of residual state In gradually increases. Due to the low content of Re, the reliability of the test results is poor. However, Re may exist in sulfide, organic, and residual states. With the pyrolysis temperature increasing, Li, Ga, Ge, In, and Re in pyrolysis products are more likely to combine with aluminosilicate than those in raw coal.
研究领域:
能源科学
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环境科学
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材料科学
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产品关联
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
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2012
·Vol. 8
·期 4
·567-577
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IF 0.758
Ying Gu,Xiaowei Liu,Bo Zhao,Wenqiang Liu,Minghou Xu
Nitrogen species distribution during coal pyrolysis with Ca addition in N 2 , CO 2 and Ar was studied at 1000 °C using a horizontal tube furnace. In particular, the effect of Ca on the distribution of nitrogen species in N 2 and CO 2 atmospheres, which were closer to pyrolysis processes of conversional air and oxy-fuel combustion in comparison with inert Ar environment, was investigated for the first time in this work. It was found that Ca has a great effect on nitrogen species distribution during both coal and demineralized coal pyrolysis; on the other hand, CO 2 causes the formation of NO. Demineralization increases the formation of HCN and char nitrogen, but there is little effect on NH 3 formation during pyrolysis in N 2 , in contrast to pyrolysis in Ar atmosphere, which decreases NH 3 formation. A significant reduction in char yield was found after char gasification in CO 2 at 1000 °C. With two different Ca-based additives, i.e., (CH 3 COO) 2 Ca and Ca(OH) 2 , char yield decreases with the increasing amount of Ca additives in both cases. The effect of Ca on HCN and NH 3 formation during pyrolysis depends on both the form of Ca and the amount of addition. In most cases, HCN and NH 3 formation decreases with Ca addition in Ar, but increases in N 2 . Ca addition slightly promotes HCN formation during pyrolysis in CO 2 . There is no NH 3 detected during pyrolysis in CO 2 because of the reaction of NH 3 and CO 2 in the background. In addition, NO concentration decreases sharply with increasing the amount of Ca addition in the atmosphere of CO 2 , which means that Ca has an effect not only on pyrolysis, but also on gasification of char in CO 2 . In most cases, char nitrogen increases with Ca addition in N 2 or Ar. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
研究领域:
能源科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
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2023
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IF 11.1
Bokun Chen,Caichun Zheng,Jicheng Bi,Xuan Qu,Rong Zhang,Xinbo Liu,Yanqi Yang
Coal pyrolysis wastewater pretreatment suffers from equipment fouling and inferior mass transfer efficiency brought by low emulsified oil removal efficiency. This paper comprehensively analyzed the properties of emulsified oil and found this inadequacies attribute to its high stability and penetrability derived from high ζ potential of −33.1 mV and tiny average particle size of 114.7 nm in initial condition. H 3 O + adjustment is developed to compress diffusion layer thickness and facilitate natural coalescence of emulsified oil droplets . Results of H 2 SO 4 acidification present the peaks of average particle size sustainably stabilized between 782.9 and 1009.0 nm and emulsified oil was mostly coagulated and subsequently settled/floated without further treatment. CO 2 was selected as a suitable donor of H 3 O + to improve application potential, and flocculants was coupled with pressurized dissolved CO 2 to intensify emulsified oil removal whose optimal efficiency achieved 93.82 wt% by changing flocculant types and operation conditions. Response surface analysis results introduced emulsified oil removal efficiency reached 95.17 wt% at PAC concentration of 1065 mg/L, CPAM concentration of 20 mg/L and operating pressure of 0.67 MPag. For renovation projects with limitations, the optimal emulsified oil removal efficiency achieved 94.33 wt% at PAC concentration of 1032 mg/L, CPAM concentration of 21 mg/L and operating pressure of 0.60 MPag. Process simulation of sour gas and ammonia stripper signified that CO 2 addition has little effect on current industrial process. By comparison, the proposed approach performs high efficiency, low impact to wastewater, strong feasibility, and great prospect in pretreatment.
研究领域:
环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2020
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IF 4.982
Tiankai Zhang,Yongfa Zhang,Qi Wang,Xuemei Lv,Yunhuan Luo
In this paper, the changes in solid-phase carbon structure and the formation of carbon nanotubes in the process of K-catalyzed pyrolysis of bituminous coal were investigated. The results showed that the content of carbon nanotubes in K-catalyzed coal pyrolysis products increased with the extension of residence time. When the residence times were 0, 30 and 90 min, the yields of carbon nanotubes in the coal pyrolysis products were 1.98 wt%, 6.85 wt% and 10.16 wt%, respectively. It was found that the aromatic carbon C C, C H and ether carbon C-O-C structures in coal were the main carbon sources for the growth of carbon nanotubes. The probable growth mechanism of carbon nanotubes in the process of K-catalyzed coal pyrolysis was proposed to be as follows: aromatic C C and C H structures in coal convert K components such as K 2 CO 3 and K 2 O into metal K, and then metal K converts carbon atoms in the ether bond C-O-C structure into carbon atoms or clusters, which generate carbon nanotubes under the action of Fe catalyst particles in coal. This method provides a new strategy for the simultaneous high-value utilization of coal resources and macroscopic, low-cost preparation of carbon nanotubes.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2024
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IF 5.6
Shu-Ting Hu,Yue-Lun Wang,Qing-Gang Wang,Han-Bing Gao,Wen-Jie Gu,Wei-Hua Zhao,Yun-Peng Zhao,Jing-Pei Cao,Lin-Jun Zhu
The introduction of in situ hydrogen donors to obtain a high H/C eff ratio is an effective way to upgrade coal pyrolysis volatiles to light aromatics. In this study, the influence of different in-situ hydrogen suppliers in catalytic reforming of coal pyrolysis vapors was explored. The abilities of active hydrogen donation were greatly corresponded to structures of hydrogen donors. Isopropanol showed the best catalytic performance due to the release of a large amount of active α-H as a result of negative inductive effect of hydroxyl. Whereas tertbutanol showed the poorest catalytic performance owing to the lack of α-H. Meanwhile, the effect of in-situ hydrogen production via steam reforming with different alcohols on light aromatic yields was investigated. The highest BTEXN yield was obtained under in-situ hydrogen production from isopropanol steam reforming. Two circumstances of hydrogen supply were further compared. Relatively higher BTEXN yield was presented in the reaction of methanol steam reforming than that of using methanol solely. However, higher BTEXN yield was contrarily obtained from sole isopropanol as a hydrogen donor despite lower H 2 production was gained compared to the case of isopropanol steam reforming. The fact was probably ascribed that high electron-withdrawing effect of hydroxyl for isopropanol promoted the cleavage of α-C-H bond and favored the transfer of active hydrogen to reactants over acid sites.
研究领域:
化学工程
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能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2020
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IF 4.748
Mei Zhong,Da Zou,Yuebing Xu,Lijun Jin,Yue Pan
Acid treated kaolinites (KA) were successively loaded with Zr and Fe, Ni or Co component to control the product distribution and upgrade the tar quality in coal pyrolysis . The structure of the resultant catalysts was characterized and their catalytic performance in the pyrolysis of demineralized low-rank coal and benzyl phenyl ether (BPE), a model compound containing C al -O bridge bond, were investigated. Results show that the introducing of Zr into the KA can enlarge the hysteresis loop due to the stacking of ZrO 2 particles. The acidities, especially the strong ones, increase as the Zr content is below 8 wt% (KA-8Z). When adding Fe, Ni or Co metals into the KA-8Z, the number of Brønsted acid sites obviously decreases, but Lewis acid sites increase. The maximum BPE conversion of 94.0% occurs for the KA-8Z, further metal-loaded sample promotes the cleavage of C al -O bond in BPE and the formation of active H radicals from CH 3 OH, leading to the increase of BPE conversion. Besides, remarkable enhancement of target monomeric aromatics is observed for the Fe, Ni and Co-loaded samples. Compared with the pyrolysis without catalyst, the tar yield as well as pitch content decrease over the KA-8Z and its metal-modified catalysts. Wherein, Ni-KA-8Z has the highest activity for tar upgrading, leading to the largest increase in the contents of light oil and phenol oil. In-situ pyrolysis by time-of-flight mass spectrometry reveals the enhanced dissociation of weak covalent bonds linked in the coal skeleton over the KA-8Z and Fe, Ni and Co-modified catalysts, resulting in a decrease in the peak temperature for product release. A marked increase in phenols and diphenols confirms a promoted dissociation of ether bond in coal.
研究领域:
化学工程
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能源科学
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
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2022
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IF 7.34
Qian Zhou,Bingxiao Feng,Lining Hao,Chao Pan,Hongbing Song,Hengjun Gai,Quanhong Zhu,Meng Xiao,Tingting Huang
The removal of oil from coal pyrolysis wastewater persists to be a challenging problem. Thus, this study proposes a new scheme that integrates the adsorption of oil using fibers and subsequent centrifugation or elution to achieve efficient oil–water separation. Based on their stable chemical property, PP and were selected as the substrates for drawing the fibers. In addition, PVDF and PTFE were explored to modify the wettability of PP and PE. The performances of as-prepared fibers were tested for removing oil from wastewater in both batch and continuous modes. Among all the fibers, the PVDF-modified PP fibers exhibited the best performance. For PP-based fibers with 5 wt% PVDF, the saturated oil-removal efficiency reached 92.24 % in case of the simulated wastewater and 81.10 % for the actual wastewater. Given that the oil content in coal pyrolysis wastewater was ~2000 ppm, the residual oil content in the outlet water would be ~380 ppm, which satisfies the requirement of the subsequent treatment process. Furthermore, the PVDF-modified PP fibers exhibited excellent reusability and stability to defy various environmental corrosions. The separation of oil and water based on the adsorption by fibers offers promising prospect to remove oil from coal pyrolysis wastewater. In addition, we derived a formula to calculate the oil contact angle under water based on Young's equation using several measurable parameters. As the calculation results were consistent with real scenarios, this derived formula can provide quantitative guidance for material modification in coal wastewater treatment .
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
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2022
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IF 8.035
Chenyao Bi,Zhuangzhuang Zhang,Daizong Han,Chengan Wang,Jianbo Zhang,Ming Sun,Qingqing Hao,Huiyong Chen,Xiaoxun Ma
Quality improvement of pyrolysis tar with yield increasing of high value-added components is highly desired for coal utilization. Herein, Ga-impregnated mesoporous ZSM-5 (Ga/MZ5) directed by organosilane surfactant of [3-(trimethoxysilyl) propyl] octadecyldimethylammonium chloride (TPOAC) is used as a catalyst for the catalytic upgrading of coal pyrolysis volatiles. Effective regulation by reduction and reduction/reoxidation promotes a secondary dispersion of gallium species from external surface deposition to micropore permeation. The comprehensive evaluation of catalytic upgrading performance indicates that the designedly regulated gallium species (mainly Ga + , GaH 2 + and GaO + ), feasible balance of Brønsted and Lewis active sites and mesopore diffusion superiority effectively contribute the yield increasing of both light-fraction ( M LF / M Tar ) and target products of BTEXN (benzene, toluene, ethylbenzene, xylene and naphthalene). The optimal catalyst of Ga/MZ5_R/O exhibited the highest value of M LF / M Tar (88 %) and highest yield of BTEXN (31.84 mg.g −1 ), which are 173 and 589 % higher than non-catalytic single pyrolysis and 133 and 280 % higher than those over the conventional Ga-impregnated ZSM-5 (Ga/Z5). Moreover, the possible reaction networks towards high value-added products of BTEXN based on the positive conversion of polycyclic aromatic hydrocarbons (PAHs), phenols, and other oxygen-containing compounds (abbreviated as PPO) is further proposed.
研究领域:
化学工程
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能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Jinxin Li,Dan Zhong,Feiyu Li,Kefei Li,Wencheng Ma,Jun Ma,Jingna Zhang,Aoshuang Sun
A bifunctional electro-Fenton (EF) cathode with Fe 3 O 4 -LaFeO 3 /C embedded graphite felt (GF) was synthesized through a hydrothermal process, which was used for in situ electrochemical formation of active oxygen species (ROS) for coal pyrolysis wastewater (CPW) removal. Experimental results illustrated that the mineralization efficiency of dimethylphenol (DMP) was achieved at 90.7 % within 150 min reaction. On the basis of quenching test and free radical detection, the ∙OH and ∙O 2 − were the detectable ROS in the hetero-EF system for DMP removal. Meanwhile, the formed oxygen vacancies (OVs) and the redox of Fe 2+ /Fe 3+ promoted the oxygen adsorption and H 2 O 2 activation. Density functional theory (DFT) calculations further discussed that the Fe 3 O 4 -LaFeO 3 interface possessed more downward spin density of states in the conduction band, resulting in a higher total density of states (DOS) value near the Fermi level. Moreover, the Fe 3 O 4 -LaFeO 3 /C/GF cathode displayed good recyclability with low metal ion dissolution for 5 times (99.5 % DMP removal and 78.6 % TOC removal) and underlying actual CPW application potential (80.2 % of COD removal and 100 % of total phenol (Tph) removal). Overall, this work invented a novel and stable bifunctional cathode for the efficient removal of refractory CPW in the hetero-EF system.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2022
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IF 6.437
Xin Jin,Lunjing Yan,Beibei Cui,Jiao Kong,Meijun Wang,Liping Chang,Frederik Ronsse,Weiren Bao
The carbon material prepared by co-pyrolysis of biochar and caking coal has been proved that it acts in catalytic conversion of volatiles and could be used in a granular bed duster as filter medium due to its high abrasive resistance in the coal pyrolysis technology. In this work, inactive carbon material loaded by nickel (Ni/ICM) was prepared by pyrolysis of the blend of biochar ion exchanged with nickel and caking coal, and then was steam activated obtaining activated carbon material loaded by nickel (Ni/ACM). The study investigated the in-situ catalytic conversion process of coal pyrolysis volatiles over Ni/ICM and Ni/ACM in a continuous pyrolysis downer-bed reactor. The physical and chemical properties of Ni/ICM and Ni/ACM, pyrolysis product distribution and the component of tar were analyzed, especially, the coke suspended in tar (Coke-S) was separated from tar and characterized in detail. Results show that the crystallite size of Ni and NiO in Ni/ICM is about 5–7 nm, and that is slightly larger in Ni/ACM. Compared to Ni/ICM, more nickel species, pores, acid sites, oxygen-containing functional groups and carbon defects are contained in Ni/ACM. The yields of tar and light tar (boiling point below 360 °C) are higher over Ni/ICM than over Ni/ACM. Ni/ICM further improves the tar quality compared to ICM, and the content of light oil in tar increases from 22.0 wt% over ICM to 30.6 wt% over Ni 3.2 /ICM. The highest light oil yield is obtained over Ni 1.9 /ICM as 3.6 wt% and the lowest pitch yield is obtained over Ni 3.2 /ICM as 3.5 wt%. The characterization of Coke-S shows that it is composed of large aromatic clusters crosslinked by oxygen and fine ash particles. The large aromatic clusters, as heavy component in tar, are found that its H/C molar ratio increases and condensation degree decreases over Ni/ICM and Ni/ACM in comparison with ICM and ACM, respectively, which also means that the quality of tar is improved. Besides, the oxygen in the tar may have been transferred to the coke.
研究领域:
能源化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
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IF 4.908
Yang Zhou,Lu Li,Lijun Jin,Jian Zhou,Zhiwei Shi,Yang Li,Haoquan Hu
Coal pyrolysis is generally considered to initiate by cleavage of weak covalent bonds bridged between aromatic rings. The C–C covalent bonds are predominant bridged linkages among the framework of coal, which have a critical influence on coal pyrolysis reaction but lack of direct online observation. Five representative coal-related model compounds containing C–C bridged bonds, polypropylene (PP), polyvinylpyrrolidone (PVP), poly-4-vinylpyridine (P4VP), polystyrene (PS) and poly-4-vinylphenol, were selected to pyrolyze in an in-situ pyrolysis vacuum ultraviolet photoionization mass spectrometry (Py-VUV-PIMS). The soft ionized mass spectral detection can provide product distribution and evolved information of original products and intermediates, which are the key evidence to understand the initiation, recombination and reaction routes during pyrolysis process. Online analysis of pyrolysis reaction was found to be priority with cracking of C–C bond in the five polymer samples, and homologous free radicals and original products, which mainly include monomers, dimers and their alkyl and alkenyl radicals, were detected. The results reveal the cleavage temperature of C–C covalent bond is deeply related to its chemical environment, and obvious conjugation effect and steric effect for the bridged linkage were observed. In addition, the effect of hydrogen bond was also observed during the pyrolysis of model compounds containing hydroxyl groups, and intramolecular or intermolecular hydrogen bonding reduced the temperature at which C–C bridged bonds break. The analogous fracture mode and pyrolysis behavior of coal-related model compounds, which are beneficial to understand the reaction route and mechanism of coal pyrolysis, were discussed based on the experimental observations and theoretical calculation.
研究领域:
化学工程
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分析化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）