期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
Selective conversion of methanol to propylene over highly dealuminated mordenite:Al location and crystal morphology effects 被引量:2
1
作者 Li Ren Bowen Wang +5 位作者 Kun Lu Rusi Peng Yejun Guan Jin‐gang Jiang Hao Xu Peng Wu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第7期1147-1159,共13页
The growing consumption of light olefins has stimulated intensive researches on methanol to olefin(MTO)process which possesses great advantages for coal conversion to value‐added chemicals in an environmentally benig... The growing consumption of light olefins has stimulated intensive researches on methanol to olefin(MTO)process which possesses great advantages for coal conversion to value‐added chemicals in an environmentally benign way.The catalysts commonly used for MTO process faces several challenges such as poor selectivity control,low hydrothermal stability and short lifetime.In the present study,we prepared a series of mordenite zeolites with variable Al contents(Si/Al molar ratios of 51−436)by a sequential dealumination treatment of air‐calcination and acid leaching.The textural properties,acidity and Al location before and after the dealumination treatment have been systematically studied and their effect on MTO especially the methanol to propylene(MTP)performance was thoroughly investigated.The mordenite zeolites with the Si/Al ratios over 150 selectively catalyzed methanol conversion in the MTP pathway,providing a high propylene selectivity of 63%and propylene/ethylene ratio of>10.Compared to the low‐silica MOR catalysts,highly dealuminated MOR showed much higher stability and longer lifetime,which can be further enhanced via harsh hydrothermal pretreatment.Furthermore,the lifetime was highly related to the crystal size along c‐axis.The excellent performance of highly dealuminated MOR is likely ascribed to the mesopores formed upon dealumination and the scarce Al sites located in the T sites shared by the 8‐member ring(MR)side pockets and 12‐MR pore channels. 展开更多
关键词 MORDENITE methanol to propylene DEALUMINATION Al location Crystal size
下载PDF
Conversion of methanol to propylene over SAPO-14:Reaction mechanism and deactivation
2
作者 Ye Wang Jingfeng Han +7 位作者 Nan Wang Bing Li Miao Yang Yimo Wu Zixiao Jiang Yingxu Wei Peng Tian Zhongmin Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第8期2259-2269,共11页
Methanol to olefins(MTO)reaction as an important non-oil route to produce light olefins has been industrialized,and received over 80% ethylene plus propylene selectivity.However,to achieve high single ethylene or prop... Methanol to olefins(MTO)reaction as an important non-oil route to produce light olefins has been industrialized,and received over 80% ethylene plus propylene selectivity.However,to achieve high single ethylene or propylene selectivity towards the fluctuated market demand is still full of challenge.Small-pore SAPO-14 molecular sieve is a rare MTO catalyst exhibiting extra-high propylene selectivity.It provides us a valuable clue for further understanding of the relationship between molecular sieve structure and MTO catalytic performance.In this work,a seconds-level sampling fixed-bed reactor was used to capture real-time product distributions,which help to achieve more selectivity data in response to very short catalytic life of SAPO-14.Changes in product distribution,especially during the low activity stage,reflect valuable information on the reaction pathway.Combined with in situ diffuse reflectance infrared Fourier-transform spectroscopy,in situ ultraviolet Raman measurements and ^(12)C/^(13)C isotopic switch experiments,a reaction pathway evolution from dual cycle to olefins-based cycle dominant was revealed.In addition,the deactivation behaviors of SAPO-14 were also investigated,which revealed that polymethylbenzenes have been the deactivated species in such a situation.This work provides helpful hints on the development of characteristic methanol to propylene(MTP)catalysts. 展开更多
关键词 methanol to propylene SAPO-14 molecular sieve UV Raman spectroscopy Dual-cycle mechanism DEACTIVATION
下载PDF
In-situ Synthesis of ZSM-5 Zeolite from Metakaolin/Spinel and Its Catalytic Performance on Methanol Conversion 被引量:4
3
作者 Liu Ye Yu Xianbo +2 位作者 Qin Lei Wang Jingdai Yang Yongrong (Department of Chemical and Biochemical Engineering,Zhejiang University,Hangzhou 310027) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2010年第1期23-28,共6页
ZSM-5 zeolite was in-situ synthesized from metakaolin or s alumina sources, respectively. The ZSM-5 zeolite was characterized pinel by incorporating additional silica and by X-ray diffractometry (XRD), scanning elec... ZSM-5 zeolite was in-situ synthesized from metakaolin or s alumina sources, respectively. The ZSM-5 zeolite was characterized pinel by incorporating additional silica and by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and N2 adsorption measurement. This supported zeolite was tested on the methanol to propylene (MTP) processes. Experimental results showed that the ZSM-5 zeolite exhibited high selectivity for propylene. The yield of propylene on ZSM-5 zeolite made from metakaolin was increased by 17.73%, while that on ZSM-5 zeolite made from spinel was raised by 9.90%, compared to that achieved with the commercial ZSM-5 zeolite. The significant increase in propylene production is probably due to the distinctive morphology of the ZSM-5 zeolite, which possessed a rough external surface covered with sphere-like particles and distribution of small crystals sized at around 400--500 nm. This morphology could help to generate more crystal defects so that more active centers could be exposed to the reaction mixture. In addition, the zeolite product had a gradient pore distribution and many medium Brǒnsted acid sites, both of which might also contribute to the increased propylene production. 展开更多
关键词 METAKAOLIN SPINEL in-situ synthesis of ZSM-5 methanol to propylene (MTP)
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部