scholarly journals Effect of Pressure and Syngas Composition on Direct Synthesis of Dimethyl Ether using Dual Bed Catalyst

2019 ◽  
Vol 19 (1) ◽  
pp. 38
Author(s):  
Aisyah Ardy ◽  
Jenny Rizkiana ◽  
Melia Laniwati Gunawan ◽  
Herri Susanto
Keyword(s):  
Dimethyl Ether ◽  
Direct Synthesis ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Commercial Catalyst ◽  
Fixed Temperature ◽  
Effect Of Pressure ◽  
Co Conversion ◽  
Dual Bed ◽  
Synthesis Of Dimethyl Ether

National General Energy Plan of Indonesia 2017 (RUEN 2017) stated that dimethyl ether (DME) is appointed as a blending of LPG to reduce LPG imports. DME can be made with two reaction pathways, namely direct synthesis and indirect synthesis. The objective of this study was to determine the effect of pressure and syngas composition on the direct synthesis of DME using dual fixed bed catalyst. The research was carried out with two types of catalyst: M-xxx as a commercial catalyst for methanol synthesis and γ-Al2O3 as catalyst for dehydration of methanol to DME. The later was prepared in our Laboratory of Chemical Reaction Engineering and Catalysis, ITB. The dual catalyst experiment was carried out at 5 and 7 bars, and a fixed temperature of 240oC. The mass ratio of the M-xxx to γ-Al2O3, so-called M/D ratios, were varied from 1/9 to 9/1. Two type of syngas were used, i.e. SA containing only H2 and CO with a SN of 2,3 and SB containing 4% CO2 with SN of 1,8. The dual bed with a M/D ratio of 1/4 gave a CO conversion up to 62% at 5 bars and 240oC (SA). As pressure increased, the conversion of CO and H2 increases to 85% and 83% at 7 bar and 240oC (SA). The presence of CO2 (SB) decreases catalyst activity, as indicated by the decrease in conversion of CO and H2 to 56% and 54%, at 7 bar and 240oC.

scholarly journals FORMULASI KATALIS BIFUNGSIONAL SINTESA DME SATU TAHAP

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Ade Syafrinaldy ◽  
Zulaicha Dwi Hastuti
Keyword(s):  
Methanol Synthesis ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Methanol Dehydration ◽  
Commercial Catalyst ◽  
Methanol Synthesis Catalyst ◽  
Co Conversion ◽  
The Right

This research is aiming to formulate the most appropriate catalyst which is expected to be able to directthe reaction to form Dimethyl Ether (DME) in direct synthesis process using dual catalyst. It iscommonly known that DME can be formulated from synthetic gasses reaction, H2 and CO. Theprocess might be gone through indirect synthesis, methanol synthesis and dehydration, or directsynthesis in which both rections take place in one reactor. Both processes, indirect or direct synthesis,each would be needed the right catalyst. Dual catalyst is prepared by mixing physically methanolsynthesis catalyst and methanol dehydration to form DME.As methanol dehydration catalyst, we makeuse of HZSM-5 with Si/Al ratio of 25 and 90. This HZSM-5 is firstly calcined for 6 hours at 500°C. Thetemperature is raised to 500°C from ambient with pace of 5°C/min. The methanol synthesis catalyst isbased on CuZnAl, made by copresipitation method from Cu(NO3)2.3H2O; Zn(NO3)2.4H2O andAl(NO3)2.9H2O. The catalyst was then calcined at 350 ° C for 6 hours, then reduced by hydrogen 10 ml /minute and nitrogen 90 ml / min at 240 ° C, atmospheric pressure for 10 hours to remove the Ocomponent in the catalyst. The catalyst that has been prepared is CuZnAl with a ratio of 4: 3: 1; 5: 3: 1and 6: 3: 1. The ratio of the two catalysts is 2: 1 for Cu / Zn / Al2O3: HZSM-5. The catalytic activity test iscarried out using a continuous tubular fixed-bed microactivity reactor. The reaction is carried out at apressure between 3 - 4 MPa and a temperature in the range of 200 - 300 ° C. T The flow rate of thereactant gas is controlled by a mass flow controller, with a mass of 1 g of catalyst. Through the catalyticactivity test, the best methanol synthesis was given by CuZnAl catalyst with a 5: 3: 1 molar ratio, whichresulted in a CO conversion of 19.66% greater than the commercial catalyst of CZA-Sudchemie of15.62%. As for dehydration of methanol, the best result was given by Sudchemie-ZSM-5 catalyst withSi /Al 25 ratio resulting in higher DME concentration (0.90%) than Si /Al 90 ratio (0.45%).Keywords : direct synthesis, methanol synthesis, methanol dehydration, dual catalyst, CO conversion

A CuZnAl-Based Hybrid Material for the Direct Synthesis of Dimethyl Ether from Syngas

2012 ◽  
Vol 457-458 ◽  
pp. 261-264 ◽  
Author(s):  
Zhuo Li ◽  
Cheng Yang ◽  
Jian Qing Li ◽  
Jin Hu Wu
Keyword(s):  
Dimethyl Ether ◽  
Hybrid Material ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Synthesis Process ◽  
Impregnation Method ◽  
Active Components ◽  
Co Precipitation ◽  
Synthesis Of Dimethyl Ether

A CuZnAl-based hybrid material was prepared by co-precipitation impregnation method using the active components of methanol synthesis material and pseudo-boehmite as the precursors. The as-prepared material was evaluated for the direct synthesis of dimethyl ether (DME) from syngas in a pressurized continuous flow fixed-bed reactor system. It was revealed that the hybrid material showed high activity and selectivity after an induced period, i.e. the CO conversion and DME selectivity reached as high as 81% and 67%, respectively. Moreover, it was observed that there was only slight carbon which could be eliminated rather than graphite carbon deposited on the material after run for 150 h, indicating its good stability for the direct synthesis process .

scholarly journals Temperature-programmed surface reactions of methanol and dimethyl ether on bifunctional catalysts for the direct synthesis of dimethyl ether from syngas

2018 ◽  
Vol 243 ◽  
pp. 00002
Author(s):  
Olga Vodorezova ◽  
Pavel Musich ◽  
Natalia Karakchieva ◽  
Lothar Heinrich ◽  
Irina Kurzina
Keyword(s):  
Dimethyl Ether ◽  
Direct Synthesis ◽  
Bifunctional Catalyst ◽  
Bifunctional Catalysts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physical Mixing ◽  
Stage Synthesis ◽  
Temperature Programmed ◽  
Synthesis Of Dimethyl Ether

Dimethyl ether (DME) can be used as a replacement for diesel fuel in transportation. The catalytic effectiveness of bifunctional catalysts for DME one-stage synthesis from carbon monoxide and hydrogen was estimated in the paper. Bifunctional catalysts CuZnAl/HZSM-5, CuZnAlCr/HZSM-5, and CuZnAlZr/HZSM-5 were obtained by physical mixing of CuZnAl(Cr/Zr)– Ох and HZSM-5 components and were characterized by BET, X-ray diffraction, and temperatureprogrammed surface reaction methods. Based on the TPSR results, the mechanism of the interaction of methanol and DME with the surface of the bifunctional catalyst was studied. It was found that the temperature range of the greatest catalytic activity was 240–260 °С.

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