Based on a typical gas composition from a methanol-to-propylene (MTP) reactor, and guided by a requirement to recover both propylene and ethylene, three separation strategies are studied and simulated by using PROI1 p...Based on a typical gas composition from a methanol-to-propylene (MTP) reactor, and guided by a requirement to recover both propylene and ethylene, three separation strategies are studied and simulated by using PROI1 package. These strategies are sequential separation, front-end dethanization, and front-end depropanization. The process does not involve an ethylene refrigeration system, using the separated stream as absorbent, and absorbing further the medium-pressure demethanization, and a proprietary technology by combining intercooling oil absorption and throttle expansio n. In fluences of different process streams as absorbent are studied on energy consumptions, propylene and ethylene recovery percentages, and other key-performance indicators of the separation strategies. Based on a commercial MTP plant with a methanol capacity of 1700 kt·a^-1, the simulated results show that the front-end dethanization using the C4 mixture as absorbent is the optimal separation strategy, in which the standard fuel oil consumption (a key-performance in dicator of energy con sumption) is 18.97 kt·h^-1, the total power consumption of two compressors is 22.4 MW, the propylene recovery percentage is 99.70%, and the ethylene recovery percentage is 99.70%. For a further improvement, the pre-dethanization and thermal coupling methods are applied. By using front-end pre-dethanization (partial cutting) with debutanizeroverhead, i.e. the C4 mixture, as absorbent, the power consumption of the compressors decreases to 19.9 MW, an 11% reduction compared with the clear-cutting method. The energy consumption for the dual compressors for crude gaseous product mixture and main product propylene refrigeration is 16.69 MW, 16.55% lower than that of the present MTP industrial plant with the same scale, and a total energy consumption of 20 MW for the triple compressors including product gas mixture compression, and ethylene and propylene refrigeration.展开更多
One type of ZSM-5 zeolite with large partical size was prepared and characterized by XRD, SEM, N2 adsorption-desorption, XRF, Py-IR and NH3-TPD techniques. Effects of ammonium exchange and SiO2/Al2O3 molar ratios on t...One type of ZSM-5 zeolite with large partical size was prepared and characterized by XRD, SEM, N2 adsorption-desorption, XRF, Py-IR and NH3-TPD techniques. Effects of ammonium exchange and SiO2/Al2O3 molar ratios on the reaction of methanol to propylene （MTP） over Na-ZSM-5 and H-ZSM-5 zeolites have been studied in a fixed-bed flow reactor under the operating conditions of T = 500 °C, P = 1 atm, and WHSV = 6 h-1. Ammonium exchange led to a rapid decrease in Na content for Na-ZSM-5 zeolite. The reaction results indicated that Na-ZSM-5 and H-ZSM-5 with different SiO2/Al2O3 molar ratios all exhibited high activity for methanol conversion. Ammonium exchange and the decreased SiO2/Al2O3 molar ratio of ZSM-5 zeolite led to an increase both in strong acid sites and weak acid sites. Na-ZSM-5 with high SiO2/Al2O3 molar ratio was favorable for the formation of propylene. The highest propylene selectivity （45.9%） was obtained over Na-ZSM-5 zeolite catalyst with SiO2/Al2O3 molar ratio of 220.展开更多
Fresh ZSM-5 zeolite catalysts were pretreated at 460 ℃and 500 ℃with various cumulative amount of water feed(CAWF) in a fixed bed reactor. The catalytic process was carried out under the following conditions: a tempe...Fresh ZSM-5 zeolite catalysts were pretreated at 460 ℃and 500 ℃with various cumulative amount of water feed(CAWF) in a fixed bed reactor. The catalytic process was carried out under the following conditions: a temperature of 480 ℃; a methanol WHSV of 3 h-1; a methanol partial pressure of 30 k Pa; and a time on stream of 12 h, 24 h and 48 h, respectively. The BET parameters of catalysts and diffusion coefficients of toluene showed that there were two types of mesopores generated under different hydrothermal conditions. Mild temperature and moderate CAWF conditions led to external open mesopores which could be entered from the external surface of the zeolite, while a high temperature or a high CAWF condition resulted in the generation of macropores or internal isolated mesopores, which were occluded in the microporous matrix. The TGA results showed that catalyst with external open mesopores had good ability to resist coke accumulation and good performance on propylene selectivity, while the internal isolated mesopores did no contribute to the increased diffusivity of reactants and products.展开更多
At present, methanol to propylene(MTP) technology developed by Lurgi Company is adopted for commercial plants and refined methanol with the purity ≥99.85 wt% is required as the feed of MTP unit in Lurgi's technol...At present, methanol to propylene(MTP) technology developed by Lurgi Company is adopted for commercial plants and refined methanol with the purity ≥99.85 wt% is required as the feed of MTP unit in Lurgi's technology.Therefore, high energy cost for refined methanol production is one of the bottlenecks to improve the economy of MTP technology. Reducing the grade of feed refined methanol may be an effective method to save energy and reduce operation costs in MTP process. In this work, experiments and process simulation were carried out to investigate the influence and feasibility of degrading the methanol feed. Experiments were conducted to investigate the influence of crude methanol feed on conversion and selectivity of MTP reaction as well as the performance of ZSM-5 catalyst. The experimental results showed that degrading the methanol feed had no obvious influence on the conversion and selectivity of MTP reactions and the catalyst deactivation was caused by the carbon accumulation and metals deposition on the active sites. The process simulation results showed that the influence on the conversion and selectivity as well as the stream load of MTP process was negligible if 98 mol% methanol was used as feed. Finally, industrial experiments were conducted by adjusting the operation parameters to degrade of feed methanol of the commercial 500 kt·a^(-1) MTP unit of Ningmei Group in China. The results of industrial application illustrated that annually 180 kt fuel coal and 150 kt desalted water as well as 1770 MW·h^(-1) electricity would be saved when the water content increased from 0.01% to 0.4%. This work has identified the feasibility to improve MTP technology by degrading the methanol feed.展开更多
This paper describes the hydrogenation of impurities in the methanol-containing effluent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly spac...This paper describes the hydrogenation of impurities in the methanol-containing effluent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly space velocity(WHSV) and H2/methanol ratio on the concentration of various impurities in methanol solvent were investigated. It was found out that the aldehyde, hydrogen peroxide and nitro compounds in the methanol solvent could be completely hydrogenated over the Ni catalyst under proper reaction conditions. 90% of acetone and up to 50% of acetals(ketals) existing in the methanol solvent could be hydrogenated. No significant change was observed for the rest of the impurities that were present in the methanol solvent(i. e., 1-methoxy-2-propanol, 2-methoxy-1-propanol and 1,2-propanediol). The H2O2 decomposition reaction was enhanced using Ni catalyst, through the formation of NioOH, but no oxygen was found in the off-gas of hydrogenation reaction since NioH could react on NioOH formed via dissociative adsorption of hydrogen peroxide, or on NioO formed via adsorption of oxygen.展开更多
On September 14,2015 the 10 kt/a-class commercialized test project relating to the technology for methanolto-butene production with co-production of propylene(hereafter abbreviated as CMTX)has passed the scientific ac...On September 14,2015 the 10 kt/a-class commercialized test project relating to the technology for methanolto-butene production with co-production of propylene(hereafter abbreviated as CMTX)has passed the scientific achievement appraisal organized by the China Petroleum and Chemical Industries Federation(CPCIF).展开更多
A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.
基金Supported by Sinopec Group company commissioned development project(contract number:412101)
文摘Based on a typical gas composition from a methanol-to-propylene (MTP) reactor, and guided by a requirement to recover both propylene and ethylene, three separation strategies are studied and simulated by using PROI1 package. These strategies are sequential separation, front-end dethanization, and front-end depropanization. The process does not involve an ethylene refrigeration system, using the separated stream as absorbent, and absorbing further the medium-pressure demethanization, and a proprietary technology by combining intercooling oil absorption and throttle expansio n. In fluences of different process streams as absorbent are studied on energy consumptions, propylene and ethylene recovery percentages, and other key-performance indicators of the separation strategies. Based on a commercial MTP plant with a methanol capacity of 1700 kt·a^-1, the simulated results show that the front-end dethanization using the C4 mixture as absorbent is the optimal separation strategy, in which the standard fuel oil consumption (a key-performance in dicator of energy con sumption) is 18.97 kt·h^-1, the total power consumption of two compressors is 22.4 MW, the propylene recovery percentage is 99.70%, and the ethylene recovery percentage is 99.70%. For a further improvement, the pre-dethanization and thermal coupling methods are applied. By using front-end pre-dethanization (partial cutting) with debutanizeroverhead, i.e. the C4 mixture, as absorbent, the power consumption of the compressors decreases to 19.9 MW, an 11% reduction compared with the clear-cutting method. The energy consumption for the dual compressors for crude gaseous product mixture and main product propylene refrigeration is 16.69 MW, 16.55% lower than that of the present MTP industrial plant with the same scale, and a total energy consumption of 20 MW for the triple compressors including product gas mixture compression, and ethylene and propylene refrigeration.
文摘One type of ZSM-5 zeolite with large partical size was prepared and characterized by XRD, SEM, N2 adsorption-desorption, XRF, Py-IR and NH3-TPD techniques. Effects of ammonium exchange and SiO2/Al2O3 molar ratios on the reaction of methanol to propylene （MTP） over Na-ZSM-5 and H-ZSM-5 zeolites have been studied in a fixed-bed flow reactor under the operating conditions of T = 500 °C, P = 1 atm, and WHSV = 6 h-1. Ammonium exchange led to a rapid decrease in Na content for Na-ZSM-5 zeolite. The reaction results indicated that Na-ZSM-5 and H-ZSM-5 with different SiO2/Al2O3 molar ratios all exhibited high activity for methanol conversion. Ammonium exchange and the decreased SiO2/Al2O3 molar ratio of ZSM-5 zeolite led to an increase both in strong acid sites and weak acid sites. Na-ZSM-5 with high SiO2/Al2O3 molar ratio was favorable for the formation of propylene. The highest propylene selectivity （45.9%） was obtained over Na-ZSM-5 zeolite catalyst with SiO2/Al2O3 molar ratio of 220.
基金supported by the National Natural Science Foundation of China(Grant 21176208&61590925)the National High-Tech R&D Program of China(Grant 2012AA030304)+1 种基金the International S&T Cooperation Projects of China(2015DFA40660)the Fundamental Research Funds for the Central Universities(Grant2015QNA4033)
文摘Fresh ZSM-5 zeolite catalysts were pretreated at 460 ℃and 500 ℃with various cumulative amount of water feed(CAWF) in a fixed bed reactor. The catalytic process was carried out under the following conditions: a temperature of 480 ℃; a methanol WHSV of 3 h-1; a methanol partial pressure of 30 k Pa; and a time on stream of 12 h, 24 h and 48 h, respectively. The BET parameters of catalysts and diffusion coefficients of toluene showed that there were two types of mesopores generated under different hydrothermal conditions. Mild temperature and moderate CAWF conditions led to external open mesopores which could be entered from the external surface of the zeolite, while a high temperature or a high CAWF condition resulted in the generation of macropores or internal isolated mesopores, which were occluded in the microporous matrix. The TGA results showed that catalyst with external open mesopores had good ability to resist coke accumulation and good performance on propylene selectivity, while the internal isolated mesopores did no contribute to the increased diffusivity of reactants and products.
基金Supported by the National Key R&D Program of China(2017YFB0601902)
文摘At present, methanol to propylene(MTP) technology developed by Lurgi Company is adopted for commercial plants and refined methanol with the purity ≥99.85 wt% is required as the feed of MTP unit in Lurgi's technology.Therefore, high energy cost for refined methanol production is one of the bottlenecks to improve the economy of MTP technology. Reducing the grade of feed refined methanol may be an effective method to save energy and reduce operation costs in MTP process. In this work, experiments and process simulation were carried out to investigate the influence and feasibility of degrading the methanol feed. Experiments were conducted to investigate the influence of crude methanol feed on conversion and selectivity of MTP reaction as well as the performance of ZSM-5 catalyst. The experimental results showed that degrading the methanol feed had no obvious influence on the conversion and selectivity of MTP reactions and the catalyst deactivation was caused by the carbon accumulation and metals deposition on the active sites. The process simulation results showed that the influence on the conversion and selectivity as well as the stream load of MTP process was negligible if 98 mol% methanol was used as feed. Finally, industrial experiments were conducted by adjusting the operation parameters to degrade of feed methanol of the commercial 500 kt·a^(-1) MTP unit of Ningmei Group in China. The results of industrial application illustrated that annually 180 kt fuel coal and 150 kt desalted water as well as 1770 MW·h^(-1) electricity would be saved when the water content increased from 0.01% to 0.4%. This work has identified the feasibility to improve MTP technology by degrading the methanol feed.
文摘This paper describes the hydrogenation of impurities in the methanol-containing effluent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly space velocity(WHSV) and H2/methanol ratio on the concentration of various impurities in methanol solvent were investigated. It was found out that the aldehyde, hydrogen peroxide and nitro compounds in the methanol solvent could be completely hydrogenated over the Ni catalyst under proper reaction conditions. 90% of acetone and up to 50% of acetals(ketals) existing in the methanol solvent could be hydrogenated. No significant change was observed for the rest of the impurities that were present in the methanol solvent(i. e., 1-methoxy-2-propanol, 2-methoxy-1-propanol and 1,2-propanediol). The H2O2 decomposition reaction was enhanced using Ni catalyst, through the formation of NioOH, but no oxygen was found in the off-gas of hydrogenation reaction since NioH could react on NioOH formed via dissociative adsorption of hydrogen peroxide, or on NioO formed via adsorption of oxygen.
文摘On September 14,2015 the 10 kt/a-class commercialized test project relating to the technology for methanolto-butene production with co-production of propylene(hereafter abbreviated as CMTX)has passed the scientific achievement appraisal organized by the China Petroleum and Chemical Industries Federation(CPCIF).
文摘A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.
