{"title":"Thermodynamic analysis of combined reforming process using Gibbs energy minimization method: In view of solid carbon formation","authors":"Behzad Nematollahi , Mehran Rezaei , Ebrahim Nemati Lay , Majid Khajenoori","doi":"10.1016/S1003-9953(11)60421-0","DOIUrl":"10.1016/S1003-9953(11)60421-0","url":null,"abstract":"<div><p>Thermodynamic analysis was applied to study combined partial oxidation and carbon dioxide reforming of methane in view of carbon formation. The equilibrium calculations employing the Gibbs energy minimization were performed upon wide ranges of pressure (1–25 atm), temperature (600–1300 K), carbon dioxide to methane ratio (0–2) and oxygen to methane ratio (0–1). The thermodynamic results were compared with the results obtained over a Ru supported catalyst. The results revealed that by increasing the reaction pressure methane conversion decreased. Also it was found that the atmospheric pressure is the preferable pressure for both dry reforming and partial oxidation of methane and increasing the temperature caused increases in both activity of carbon and conversion of methane. The results clearly showed that the addition of O<sub>2</sub> to the feed mixture could lead to a reduction of carbon deposition.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 694-702"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60421-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ruthenium promotion of Co/SBA-15 catalysts for Fischer-Tropsch synthesis in slurry-phase reactors","authors":"Jocielys Jovelino Rodrigues , Gina Pecchi , Fabiano André Narciso Fernandes , Meiry Gláucia Freire Rodrigues","doi":"10.1016/S1003-9953(11)60425-8","DOIUrl":"10.1016/S1003-9953(11)60425-8","url":null,"abstract":"<div><p>The aim of this work was to evaluate the catalytic properties of a Ru promoted Co/SBA-15 catalyst for Fischer-Tropsch synthesis (FTS). The Ru promoted Co/SBA-15 catalyst was prepared by wet impregnation method and was characterized by X-ray diffraction, X-ray energy dispersion spectrophotometer, N<sub>2</sub> adsorption-desorption, temperature-programmed reduction and transmission electron microscopy. The Fischer-Tropsch synthesis using the catalyst was carried out to evaluate the catalyst activity and its effect on FTS product distribution. The synthesis was carried out in a slurry reactor operating at 513 K, 20 atm, CO: H<sub>2</sub> molar ratio of 1: 1. X-ray diffraction showed that the calcined cobalt catalyst did not modify the structure of SBA-15, proving that Co was present in the form of Co<sub>3</sub>O<sub>4</sub> in the catalyst. The addition of cobalt in SBA-15 decreased the specific superficial area of the molecular sieve. Fischer-Tropsch synthesis activity and C<sub>5+</sub> hydrocarbon selectivity increased with the addition of Ru. The increases in activity and selectivity were attributed to the increased number of active sites resulting from higher reducibility and the synergetic effect of Ru and Co. Ru/Co/SBA-15 catalysts showed moderate conversion (40%) and high selectivity towards the production of C<sub>5+</sub> (80 wt%).</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 722-728"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60425-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wanjun Guo , Fei Feng , Guohui Song , Jun Xiao , Laihong Shen
{"title":"Simulation and energy performance assessment of CO2 removal from crude synthetic natural gas via physical absorption process","authors":"Wanjun Guo , Fei Feng , Guohui Song , Jun Xiao , Laihong Shen","doi":"10.1016/S1003-9953(11)60412-X","DOIUrl":"10.1016/S1003-9953(11)60412-X","url":null,"abstract":"<div><p>The paper presents an energy performance assessment of CO<sub>2</sub> removal for crude synthetic natural gas (SNG) upgrade by Selexol absorption process. A simplified process simulation of the Selexol process concerning power requirement and separation performance was developed. The assessment indicates that less pressure difference between crude SNG and absorption pressure favors the energy performance of CO<sub>2</sub> removal process. When both crude SNG and absorption pressures are 20 bar, CO<sub>2</sub> removal process has the best energy performance. The optimal specific power consumption of the CO<sub>2</sub> removal process is 566 kJ/kgCO<sub>2</sub>. The sensitivity analysis shows that the CO<sub>2</sub> removal efficiency would significantly influence the total power consumption of the removal process, as well as higher heating value (HHV) and CO<sub>2</sub> content in SNG. However, the specific power consumption excluding crude SNG and SNG compressions changes little with the variance of CO<sub>2</sub> removal efficiency. If by-product CO<sub>2</sub> is compressed for CO<sub>2</sub> capture, the process would turn into a CO<sub>2</sub>-sink for the atmosphere. Correspondingly, an increase of 281 kJ/kg<sub>CO2</sub> in specific power consumption is required for compressing the separated CO<sub>2</sub>.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 633-638"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60412-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jian Chen , Jinlin Li , Yanxi Zhao , Yuhua Zhang , Jingping Hong
{"title":"Effects of Ru nanoparticle sizes confined in cavities of SBA-16 on the catalytic performance of Fischer-Tropsch synthesis reaction","authors":"Jian Chen , Jinlin Li , Yanxi Zhao , Yuhua Zhang , Jingping Hong","doi":"10.1016/S1003-9953(11)60418-0","DOIUrl":"10.1016/S1003-9953(11)60418-0","url":null,"abstract":"<div><p>Ru nanoparticles with different sizes confined in the cavities of mesoporous SBA-16 have been successfully synthesized by incipient wetness impregnation method with a Ru loading of 4 wt%. The catalysts were characterized by XRD, N<sub>2</sub> adsorption-desorption, H<sub>2</sub>-TPR, H<sub>2</sub>-TPD, O<sub>2</sub>-titration and TEM. The catalytic performance of Fischer-Tropsch synthesis over the catalyst was tested in a fixed-bed reactor. The addition of citric acid in the impregnation procedure shows a significant influence on the size of Ru nanoparticles. The selectivity to C<sub>5+</sub> increases, while the selectivities to methane and C<sub>2</sub>–C<sub>4</sub> light hydrocarbons decrease with Ru average particles size from 2.0 nm to 9.3 nm,. The Ru catalyst confined in the SBA-16 with average nanoparticle size of 5.3 nm gives the best activity.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 673-679"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60418-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fengsi Liu , Wei Chu , Wenjing Sun , Ying Xue , Qian Jiang
{"title":"A DFT study of methane activation on graphite surfaces with vacancy defects","authors":"Fengsi Liu , Wei Chu , Wenjing Sun , Ying Xue , Qian Jiang","doi":"10.1016/S1003-9953(11)60423-4","DOIUrl":"10.1016/S1003-9953(11)60423-4","url":null,"abstract":"<div><p>The activation of methane on graphite surfaces with monovacancies and 5-8-5 vacancies have been investigated using density functional theory. Sixteen different initial adsorption configurations were investigated to identify the most favorable activation site. It is found that methane tends to be activated on the defective graphite surfaces, and the most stable configuration is that methane activation happened in the center hole of the monovacancy site, with a reaction energy of 1.13 eV. Electron transfer and weaker electrostatic potential of the vacancy region indicate that carbon atom of methane tends to fill the vacancy and makes the system more stable.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 708-712"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60423-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A high-surface-area silicoaluminophosphate material rich in Brönsted acid sites as a matrix in catalytic cracking","authors":"Shaojun Xu , Qiang Zhang , Zhaoxuan Feng , Xiaojing Meng , Tongyu Zhao , Chunyi Li , Chaohe Yang , Honghong Shan","doi":"10.1016/S1003-9953(11)60420-9","DOIUrl":"10.1016/S1003-9953(11)60420-9","url":null,"abstract":"<div><p>A transparent gel-like mesoporous silicoaluminophosphate material (SAP) with a Si/Al molar ratio of 20 was synthesized by hydrothermal method. The physicochemical features of SAP were characterized by XRD, XRF, BET, SEM and FT-IR spectroscopy of pyridine adsorption techniques. The results indicated that incorporation of phosphorus (P) into aluminasilica system altered the basic textural characteristics of aluminasilica. Especially after hydrothermal treatment, the material with large special surface area (up to 492 m<sup>2</sup>/g) exhibited a good performance on hydrothermal stability. Moreover, the phosphorus modifier can not only increase the amount of Brönsted acidic sites (up to 48.44 μmol/g) and the percentage of weak acidic sites in total acidic sites, but also regulate the acid type, such as the ratio of B/L (Brönsted acid/Lewis acid) increases to 1.15. The performances of samples as matrices for the catalytic cracking of heavy vacuum gas oil (VGO) were investigated. At 520 °C, the catalysts showed much higher gasoline and diesel oil yields achieving to 45.59 wt% and 19.20 wt%, respectively, and lower coke selectivity (2.86%) than conventional FCC matrices, such as kaolin and amorphous silica-alumina.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 685-693"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60420-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of CeO2 addition on Ni/Al2O3 catalysts for methanation of carbon dioxide with hydrogen","authors":"Hezhi Liu, Xiujing Zou, Xueguang Wang, Xionggang Lu, Weizhong Ding","doi":"10.1016/S1003-9953(11)60422-2","DOIUrl":"10.1016/S1003-9953(11)60422-2","url":null,"abstract":"<div><p>The Ni-CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> catalysts with a nickel content of 15 wt% prepared via impregnating boehmite were found to be highly active and stable for methanation of carbon dioxide with hydrogen at a H<sub>2</sub>/CO<sub>2</sub> molar ratio of 4. The effects of CeO<sub>2</sub> content and reaction temperature on the performance of the Ni-CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> catalysts were studied in detail. The results showed that the catalytic performance was strongly dependent on the CeO<sub>2</sub> content in Ni-CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> catalysts and that the catalysts with 2 wt% CeO<sub>2</sub> had the highest catalytic activity among the tested ones at 350 °C. The XRD and H<sub>2</sub>-TPR characterizations revealed that the addition of CeO<sub>2</sub> decreased the reduction temperature by altering the interaction between Ni and Al<sub>2</sub>O<sub>3</sub>, and improved the reducibility of the catalyst. Preliminary stability test of 120 h on stream over the Ni-2CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> catalyst at 350 °C revealed that the catalyst was much better than the unpromoted one.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 703-707"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60422-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haiyang Wang , Zhenhua Li , Erdong Wang , Can Lin , Yuguang Shang , Guozhong Ding , Xinbin Ma , Shaodong Qin , Qi Sun
{"title":"Effect of composite supports on the methanation activity of Co-Mo-based sulphur-resistant catalysts","authors":"Haiyang Wang , Zhenhua Li , Erdong Wang , Can Lin , Yuguang Shang , Guozhong Ding , Xinbin Ma , Shaodong Qin , Qi Sun","doi":"10.1016/S1003-9953(11)60430-1","DOIUrl":"10.1016/S1003-9953(11)60430-1","url":null,"abstract":"<div><p>The effects of composite supports of CeO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>, MgO-Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> or ZrO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> on the methanation activity of supported Co-Mo-based sulphur-resistant catalysts were investigated. The catalysts were further characterized by nitrogen adsorption measurement, X-ray diffraction and X-ray photoelectron spectroscopy. The catalyst of 5%CoO-15%MoO<sub>3</sub> supported on CeO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>, MgO-Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> or ZrO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> composite oxides, respectively, showed different catalytic performances of syngas methanation in the presence of hydrogen sulphide as compared with that of the 5%CoO-15%MoO<sub>3</sub>/Al<sub>2</sub>O<sub>3</sub> catalyst. The Co-Mo/CeO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> catalyst shows the highest methanation activity among the tested catalysts. The enhanced methanation activity may be attributed to the improvement of the dispersion of active metal species and the inhibition of the formation of S<sup>6+</sup>.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 767-773"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60430-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56795950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoyu Zhang, Qing Ma, Bibo Cheng, Jun Wang, Jinshan Li, Fude Nie
{"title":"Research on KOH/La-Ba-Al2O3 catalysts for biodiesel production via transesterification from microalgae oil","authors":"Xiaoyu Zhang, Qing Ma, Bibo Cheng, Jun Wang, Jinshan Li, Fude Nie","doi":"10.1016/S1003-9953(11)60431-3","DOIUrl":"10.1016/S1003-9953(11)60431-3","url":null,"abstract":"<div><p>Alumina supports modified by lanthanum (La) and barium (Ba) were prepared by peptization. Catalysts with different KOH contents supported on modified alumina were prepared by impregnation method. Various techniques, including N<sub>2</sub> adsorption-desorption (Brunauer-Emmet-Teller method, BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), and fourier transform infrared absorption spectroscopy (FT-IR). Catalytic activity for microalgae oil conversion to methyl ester via transesterification was evaluated and analyzed by GC-MS and GC. BET results showed that the support possessed high specific surface area, suitable pore volume and pore size distribution. Activity results indicated that the catalyst with 25 wt% KOH showed the best activity for microalgae oil conversion. XRD and SEM results revealed that Al–O–K compound was the active phase for microalgae oil conversion. The agglomeration and changing of pore structure should be the main reasons for the catalyst deactivation when KOH content was higher than 30 wt%.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 774-779"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60431-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56796017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Preparation of mesoporous activated carbons from coal liquefaction residue for methane decomposition","authors":"Jianbo Zhang, Lijun Jin, Shengwei Zhu, Haoquan Hu","doi":"10.1016/S1003-9953(11)60429-5","DOIUrl":"10.1016/S1003-9953(11)60429-5","url":null,"abstract":"<div><p>Mesoporous activated carbons were prepared from direct coal liquefaction residue (CLR) by KOH activation method, and the experiments were carried out to investigate the effects of KOH/CLR ratio, solvent for mixing the CLR and KOH, and carbonization procedure on the resultant carbon texture and catalytic activity for catalytic methane decomposition (CMD). The results showed that optimal KOH/CLR ratio of 2: 1; solvent with higher solubility to KOH or the CLR, and an appropriate carbonization procedure are conductive to improving the carbon pore structure and catalytic activity for CMD. The resultant mesoporous carbons show higher and more stable activity than microporous carbons. Additionally, the relationship between the carbon textural properties and the catalytic activity for CMD was also discussed.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 6","pages":"Pages 759-766"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60429-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56796314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}