CFD modeling of methanol to light olefins process in a sodalite membrane reactor on SAPO-34 catalyst with in situ steam removal

Author(s):  
Abbas Aghaeinejad-Meybodi ◽  
Seyed Mahdi Mousavi ◽  
Ali Asghar Shahabi ◽  
Mohammad Rostampour Kakroudi

Aims and Objective: In this work, the performance of sodalite membrane reactor (MR) in methanol to olefins (MTO) process was evaluated for ethylene and propylene production with in situ steam removal using 3-dimensional CFD (computational fluid dynamic) technique. Methods: The local information of component concentration for methanol, ethylene, propylene, and water was obtained by the proposed CFD model. Literature data were applied to validate model results, and between experimental data and predicted results using CFD model, a good agreement was attained. In the sodalite MR model, a commercial SAPO-34 catalyst in the reaction zone was selected. The influence of key operation parameters including pressure and temperature on methanol con-version, water recovery, and yields of ethylene, propylene, and water was studied to evaluate the performance of sodalite MR. Permeation flux through the sodalite membrane was increased by an increase of reaction temperature which led to enhance-ment of water stream recovered in the permeate side. Result and Conclusion: The CFD modeling results showed that the sodalite MR in MTO process has higher performance regarding methanol conversion compared to the fixed-bed reactor (methanol conversion of 97% and 89% at 733 K for sodalite MR and fixed-bed reactor, respectively).

Author(s):  
Mohammad Farsi ◽  
Abdolhossein Jahanmiri

Dimethyl ether is a colorless gas at the ambient condition that is easily liquefied under light pressure. Currently, DME as a green fuel has been suggested as one of the most promising candidates for substitution of LPG and diesel fuel. In this paper, a water cooled membrane fixed bed reactor is proposed and modeled heterogeneously for large scale production of DME from methanol dehydration. The proposed reactor is modeled one-dimensionally based on mass and energy conservation laws at steady state condition. Also, the efficacy of the proposed membrane reactor is investigated and the results of the proposed reactor are compared with an isothermal and commercial adiabatic reactor. The simulation results of the proposed membrane reactor indicate that the methanol conversion is improved about 6.2 percent compared to the conventional industrial reactor. Also, water vapor removal from reaction zone in the membrane reactor yields lower water concentration over the catalyst pellets and higher quality of outlet product. These can lead to higher catalyst lifetime and lower cost in purification stage.


2011 ◽  
Vol 347-353 ◽  
pp. 3681-3684 ◽  
Author(s):  
Young Ho Kim ◽  
Su Gyung Lee ◽  
Byoung Kwan Yoo ◽  
Han Sol Je ◽  
Chu Sik Park

A SAPO-34 catalyst is well known to be one of the best catalysts for DME to olefins (DTO) reaction. Main products of the reaction were light olefins such as ethylene, propylene and butenes. However, the main problem is rapid deactivation of the SAPO-34 catalyst due to coke deposition during DTO reaction. In this study, various SAPO-34/ZrO2 catalysts added with ZrO2 were prepared for improving the lifetime and their physicochemical properties have been characterized by XRD and SEM. The DTO reaction over various SAPO-34/ZrO2 catalysts was carried out using a fixed bed reactor. All SAPO-34/ZrO2 catalysts showed similar activity and selectivity in the DTO reaction. The SAPO-34(9wt%)/ZrO2 catalyst was showed the best performance for the catalyst lifetime.


2007 ◽  
Vol 46 (28) ◽  
pp. 5412-5416 ◽  
Author(s):  
Simona M. Bennici ◽  
Bas M. Vogelaar ◽  
T. Alexander Nijhuis ◽  
Bert M. Weckhuysen

2022 ◽  
Vol 9 ◽  
Author(s):  
Sichao Cheng ◽  
Su Cheun Oh ◽  
Mann Sakbodin ◽  
Limei Qiu ◽  
Yuxia Diao ◽  
...  

Direct non-oxidative methane conversion (DNMC) converts methane (CH4) in one step to olefin and aromatic hydrocarbons and hydrogen (H2) co-product. Membrane reactors comprising methane activation catalysts and H2-permeable membranes can enhance methane conversion by in situ H2 removal via Le Chatelier's principle. Rigorous description of H2 kinetic effects on both membrane and catalyst materials in the membrane reactor, however, has been rarely studied. In this work, we report the impact of hydrogen activation by hydrogen-permeable SrCe0.8Zr0.2O3−δ (SCZO) perovskite oxide material on DNMC over an iron/silica catalyst. The SCZO oxide has mixed ionic and electronic conductivity and is capable of H2 activation into protons and electrons for H2 permeation. In the fixed-bed reactor packed with a mixture of SCZO oxide and iron/silica catalyst, stable and high methane conversion and low coke selectivity in DNMC was achieved by co-feeding of H2 in methane stream. The characterizations show that SCZO activates H2 to favor “soft coke” formation on the catalyst. The SCZO could absorb H2in situ to lower its local concentration to mitigate the reverse reaction of DNMC in the tested conditions. The co-existence of H2 co-feed, SCZO oxide, and DNMC catalyst in the present study mimics the conditions of DNMC in the H2-permeable SCZO membrane reactor. The findings in this work offer the mechanistic understanding of and guidance for the design of H2-permeable membrane reactors for DNMC and other alkane dehydrogenation reactions.


2013 ◽  
Author(s):  
Saeed Danaei Kenarsari ◽  
Yuan Zheng

A lab-scale CO2 capture system is designed, fabricated, and tested for performing CO2 capture via carbonation of very fine calcium oxide (CaO) with particle size in micrometers. This system includes a fixed-bed reactor made of stainless steel (12.7 mm in diameter and 76.2 mm long) packed with calcium oxide particles dispersed in sand particles; heated and maintained at a certain temperature (500–550°C) during each experiment. The pressure along the reactor can be kept constant using a back pressure regulator. The conditions of the tests are relevant to separation of CO2 from combustion/gasification flue gases and in-situ CO2 capture process. The inlet flow, 1% CO2 and 99% N2, goes through the reactor at the flow rate of 150 mL/min (at standard conditions). The CO2 percentage of the outlet gas is monitored and recorded by a portable CO2 analyzer. Using the outlet composition, the conversion of calcium oxide is figured and employed to develop the kinetics model. The results indicate that the rates of carbonation reactions considerably increase with raising the temperature from 500°C to 550°C. The conversion rates of CaO-carbonation are well fitted to a shrinking core model which combines chemical reaction controlled and diffusion controlled models.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Asghari ◽  
Mohammadreza Khanmohammadi Khorrami ◽  
Sayed Habib Kazemi

AbstractThe present work introduces a good prospect for the development of hierarchical catalysts with excellent catalytic performance in the methanol to aromatic hydrocarbons conversion (MTA) process. Hierarchical H-ZSM5 zeolites, with a tailored pore size and different Si/Al ratios, were synthesized directly using natural kaolin clay as a low-cost silica and aluminium resource. Further explored for the direct synthesis of hierarchical HZSM-5 structures was the steam assisted conversion (SAC) with a cost-effective and green affordable saccharide source of high fructose corn syrup (HFCS), as a secondary mesopore agent. The fabricated zeolites exhibiting good crystallinity, 2D and 3D nanostructures, high specific surface area, tailored pore size, and tunable acidity. Finally, the catalyst performance in the conversion of methanol to aromatic hydrocarbons was tested in a fixed bed reactor. The synthesized H-ZSM5 catalysts exhibited superior methanol conversion (over 100 h up to 90%) and selectivity (over 85%) in the methanol conversion to aromatic hydrocarbon products.


2007 ◽  
Vol 119 (28) ◽  
pp. 5508-5512 ◽  
Author(s):  
Simona M. Bennici ◽  
Bas M. Vogelaar ◽  
T. Alexander Nijhuis ◽  
Bert M. Weckhuysen

2013 ◽  
Vol 743-744 ◽  
pp. 449-454 ◽  
Author(s):  
Zhi Juan Gao ◽  
Wei Ren Bao ◽  
Li Ping Chang ◽  
Jian Cheng Wang

A Cu-SAPO-34/cordierite monolithic catalyst was prepared by in-situ hydrothermal method. The effects of ultrasonic treatment were mainly investigated during the preparing process. The removal of NOX was evaluated using a fixed-bed reactor. X-ray diffraction, scanning electron microscopy were used to characterize the samples showing that the crystallinity of Cu-SAPO-34 molecular sieve have increased after ultrasonic treatment. The Cu-SAPO-34/cordierite prepared by ultrasonic treatment showed higher de-NOx activity and stronger anti-aging property. NOx conversion could reach more than 80% between 440 and 560°C over the fresh Cu-SAPO-34/cordierite catalyst with ultrasonic treatment (600 W, 2 h) and the highest conversion was 86%, however, the highest conversion was only 76% over the Cu-SAPO-34/cordierite catalyst without ultrasonic treatment. After aging (treated for 15 h at 720 °C in the presence of 200 ppm SO2 and 10% vapor), NOx conversion reached more than 45% between 400 and 520 °C over the catalyst with ultrasonic treatment and the highest conversion was 57%, however, the highest conversion was only 43% over the catalyst without ultrasonic treatment. The XRD and SEM results indicated that the structure and morphology of Cu-SAPO-34/cordierite monolithic catalyst kept in good condition after aging.


2011 ◽  
Vol 233-235 ◽  
pp. 3036-3039
Author(s):  
Yun Bo Jiang ◽  
Ke Zheng Zhang

Discrete and Multi-tube Pass Number Inorganic Membrane Reactor offers supplements to single-tube membrane reactor, referencing heat exchanger can provide larger transmission area and plate column can realize multi-stage separation. It realizes the reaction and separation occurs simultaneously many times, and can change the membrane area according to the need, so that reaction and separation process can be matched better. Discrete and multi-tube membrane reactor and fixed bed reactor was experimented in sec-butyl alcohol dehydrogenation system at 150-225, the result shows the new membrane reactor structure is reasonable.


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