Dimethyl Ether Synthesis Research Articles

CFD modeling of DME synthesis based on methanol dehydration process by an adiabatic reactor: Characterization

Today, Dimethyl ether (DME) can be used as a fuel in various applications, including as a substitute for diesel fuel. Despite its advantages, there are some challenges associated with DME as a fuel. One of the main challenges is the limited availability of DME refueling stations and the need for dedicated storage facilities due to their different properties compared to traditional fuels. DME shows promise as a clean-burning alternative fuel with the potential to reduce emissions and dependence on fossil fuels, especially in the transportation and power generation sectors. Ongoing research and development efforts are focused on improving production methods, expanding infrastructure, and exploring new applications for DME as a fuel. DME is a colorless gas that can be used as a fuel or as a precursor for the production of other chemicals. The most common method for DME synthesis involves the dehydration of methanol. Methanol is first converted to dimethyl ether by removing a molecule of water. This reaction is typically catalyzed by acidic materials such as alumina or zeolites. In this work, to study the physical properties of the methanol dehydration reaction, CFD modeling of the adiabatic reactor has been accomplished. The researchers showed that the use of an alumina catalyst, which has selective mechanical properties and unique surface properties, is a suitable choice as a catalyst for DME synthesis. The results of this study indicate that laboratory data such as pressure, energy, and velocity in the adiabatic reactor satisfy the reaction conditions well. Also, temperature profile diagrams with changes in temperature, pressure, and velocity show that the reaction of methanol dehydration is strongly dependent on environmental factors and presents different results under the influence of other conditions.

Assessment of Hazards in the High‐Pressure Continuous Flow Reactor for Dimethyl Ether (DME) Synthesis

AbstractThe objective of this study is to conduct a thorough hazard analysis specifically tailored to identify hazards and suggest precautions associated with the intricate process of dimethyl ether (DME) production. This exothermic nature of DME production introduces the critical concern of thermal runaway. Furthermore, the DME synthesis process demands precise control over both pressure and flow rate. These parameters are important for increasing DME selectivity and CO conversion. Inadequate monitoring of these values may not only prevent the synthesis from proceeding but may also lead to major risks to health and safety. For this reason, proactive measures must be implemented to eliminate or minimize the risks. The significance of such measures cannot be overstated, as they serve to safeguard not only the integrity of the synthesis process but also the surrounding environment and human health. To delve deeper into the hazard evaluation, a comprehensive Hazard and Operability (HAZOP) analysis has been carried out, focusing specifically on the reactor within the DME process. This methodical examination involves a systematic review of potential deviations, identifying the associated hazards, and proposing effective preventive measures. The HAZOP analysis serves as a pivotal tool in ensuring the overall safety and reliability of the DME process.

Synthesis of dimethyl ether from biomass gasification: A simulation and techno-economic analysis

Synthesis of dimethyl ether from biomass gasification: A simulation and techno-economic analysis

Kinetic and Thermodynamic Requirements for Polyoxymethylene Dimethyl Ether Synthesis Catalyzed by Ion-Exchange Resin

Kinetic and Thermodynamic Requirements for Polyoxymethylene Dimethyl Ether Synthesis Catalyzed by Ion-Exchange Resin

Effect of TiO2 on Acidity and Dispersion of H3PW12O40 in Bifunctional Cu-ZnO(Al)-H3PW12O40/TiO2 Catalysts for Direct Dimethyl Ether Synthesis

The performance of bifunctional hybrid catalysts based on phosphotungstic acid (H3PW12O40, HPW) supported on TiO2 combined with a Cu-ZnO(Al) catalyst in the direct synthesis of dimethyl ether (DME) from syngas has been investigated. In this work, different types of TiO2 were used as a support to study the effect of changes in the structure of the TiO2 support on the acidity and dispersion of HPW. Various TiO2 supports with different structural and surface characteristics have been studied and the results indicate that: (i) the crystallinity and crystallite size of the primary particles of the HPW units depend on the TiO2 support; (ii) the pore size distribution of the TiO2 support affects the surface segregation of the heteropolyacids; and (iii) changes in the supported HPW acid catalysts do not significantly alter the crystal structure of the CuO and ZnO phases after contact with CZA in bifunctional catalysts. The activity results indicate that the variation in the intrinsic activity of the Cu-ZnOx centers in the bifunctional catalysts for direct DME synthesis is minimal due to the limited alteration of the crystal structure of the centers.

The effect of natural waste filter on dimethyl ether production from low calorific coal gasification

In Indonesia, rapid population growth has increased energy demand, especially in the transportation and power generation sectors. The Indonesian government has been active in promoting the use of renewable energy, but the transition from fossil energy is still faced with various challenges, including limited technology and adequate infrastructure. Apart from that, Indonesia's large potential in coal is the main factor slowing down this energy transition. One promising alternative is to convert coal into Dimethyl Ether (DME) through the gasification process, which is a thermochemical process for converting solid fuel into gas, producing syngas containing H2, CO, and CH4. Synthesis purification is essential to produce high-purity DME. This process involves the use of filter materials such as zeolite and rice husk charcoal to remove contaminants such as sulfur. Zeolite, with its chemical absorption properties and regular pore structure, is effective in absorbing H2S from syngas. Meanwhile, rice husk charcoal, which is an agricultural waste rich in silica and has a porous structure, has shown potential as an absorbent material to reduce H2S content in gas. In research on the use of various filter material compositions in the up-draft type coal gasification process with CuO–ZnO–Al2O3 and ZSM-5 catalysts, it was found that a 3:7 ratio for zeolite and rice husk charcoal provided optimal performance. This ratio not only increases CH4 and CO levels in syngas, but is also effective in reducing H2S content. The research results showed that the highest DME production reached 90.10% at a ratio of 3:7, while at a ratio of 2:8 and 5:5, production was 81.61% and 73.64% respectively. These findings emphasize the importance of using diverse filter materials in improving syngas quality and DME synthesis efficiency, strengthening steps to accelerate the energy transition towards more sustainable solutions in Indonesia.

Reducing Energy Consumption in the Synthesis of Dimethyl Ether (DME) from Methanol Dehydration by Modifying Heat Transfer Unit Using Aspen HYSYS

In the pursuit of a transport sector free from fossil fuels, the incorporation of Dimethyl ether (DME) emerges as a commendable ecological substitute. The DME is a synthetically produced serves as a viable alternative to conventional fuels such as diesel and liquified petroleum gas (LPG). The Dimethyl Ether (DME) production is carried out by catalytic dehydration of methanol over an acidic zeolite-based catalyst. The technological process for the DME synthesis was simulated using Aspen HYSYS based on the combined operating parameters of the reaction dynamic model for the methanol dehydration reaction. This paper attempts to evaluate a modification in dehydration of methanol process to reducing energy consumption by modifying heat transfer unit. The heater and cooler heat transfer units were converted into heat exchangers (HE) by utilizing the output of the process that can be used for other processes so that energy consumption is reduced. The temperature of reaction and the heat transfer unit are modified to reduce energy consumption from 11.850 MMBtu/h to 7.6291 MMBtu/h by changing one heater and one cooler with two heat exchangers. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Improving Net Energy Efficiency of Dimethyl Ether Production Process by Methanol Dehydration

Dimethyl ether (DME) is a source of fuel that produces clean energy for the future. Methanol can be used as a raw material for the manufacture of DME as a natural gas that is treated for synthesis. This paper evaluates how to improve net energy efficiency in DME production and how to review the net energy efficiency calculations in DME production. Methods used for production of DME are methanol dehydration, thermodynamics examination, also improving the net energy efficiency of DME with the addition of the heat exchanger (E-100), the addition of a heater (E-104) before entering a column (T-102), and moved the mixer position before the heater (E-100). By modifying the addition of a heat exchanger (E-100), heater (E-104), and changing the position of the mixer in DME production, it has been proven that it can reduce energy requirements in the dimethyl ether synthesis process from methanol and increase net energy efficiency by up to 98.83%. The results of the case study indicate that the addition heat exchanger (E-100) able to reduce the heater load after the creation process and remove the cooler (E-101) that existed before creation, then the addition of the heater (E-104) serves to reduce the load of Qcond2 and Qreb2 on columns (T-102), also the position of the mixer for the methanol recycling flow is moved before the heater (E-100) is intended to remove the heaters (E-103). Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Does Direct Dimethyl Ether Synthesis from Carbon Dioxide and Hydrogen Yield More Valuable Products than the Equivalent Methanol Production? A Review on Recent Work

AbstractDimethyl ether (DME) has promising properties as e‐fuel and platform chemical. Its direct synthesis from CO2 and hydrogen, which is thermodynamically more favorable than the indirect route over methanol, is reviewed. Systematic thermodynamic equilibrium calculations are evaluated and compared to bifunctional catalysis experiments performed with Cu/ZnO/ZrO2 methanol catalyst and ferrierite or heteropolyacid‐coated dehydration catalysts under thermodynamic and kinetic conditions. In the thermodynamic region, the methyl yield of direct DME synthesis is superior over sole methanol synthesis. Significant differences among the solid acids used are absent. However, under kinetic conditions, the heteropolyacid‐coated catalysts show superior performance for dehydration over zeolites.

Non‐Oxidative Conversion of Methanol to Dimethyl Ether, Methyl Formate and Dimethoxymethane over Cu/Hβ Catalyst: Tailoring Product Selectivity

AbstractHerein, we present the production of either dimethyl ether (DME), methyl formate (MF) or dimethoxymethane (DMM), representing pivotal molecules for the green transformation of fuels and chemical industry, by the non‐oxidative gas‐phase conversion of methanol under the same reaction conditions. The product selectivity is optimized by tailoring the acidic and dehydrogenative sites of the bifunctional Cu/Hβ catalyst system by varying the SiO2/Al2O3 ratio of the Hβ zeolite (25 and 520) and the Cu loading (0.5 and 20 wt %). At 240 °C, >99 % (DME), 74.5 % (MF), and 77.3 % (DMM) selectivity is achieved with the respective catalysts 0.5 %Cu/Hβ(25), 20 %Cu/Hβ(520), and 0.5 %Cu/Hβ(520). High acidic site concentration catalyzes DME formation, while the presence of Cu+ species is crucial for DMM formation, and Cu0 species mainly catalyze MF formation. A highly dynamic reaction behaviour is observed, when the dehydrogenative functionality is dominant (i. e., in the production of MF or DMM), presumably due to the dynamic nature of the Cu oxidation state, which is in turn influenced by possible by‐products (H2 and H2O). While the catalytic activity in DME synthesis over 0.5 %Cu/Hβ(25) is remarkably stable over 1500 min TOS, the activity in MF and DMM production over 20 %Cu/Hβ(520) and 0.5 %Cu/Hβ(520), respectively, can be successfully regenerated.

Comparative well-to-tank life cycle assessment of methanol, dimethyl ether, and oxymethylene dimethyl ethers via the power-to-liquid pathway

Energy systems are currently transforming into configurations with a significant share of renewable energies to reduce greenhouse gas (GHG) emissions. One frequently discussed option to reduce CO2 and simultaneously provide temporary storage for fluctuating renewable energy is coupling the energy and the transport sector in a Power-to-Liquid (PtL) approach by producing synthetic fuels. The syntheses for methanol, 1-step and 2-step dimethyl ether and oxymethylene dimethyl ethers (OME3–5) are modeled using captured CO2 and hydrogen. Hydrogen is produced by electrolysis using German electricity mixes (2021, 2030) and wind power. To evaluate the environmental impacts of the different PtL pathways, a comparative well-to-tank Life Cycle Assessment (LCA) is conducted. Aspen process simulations are performed to provide material and energy balances for the LCA. The results show that the production of all PtL fuels is highly emission intensive, when using the current electricity mix and is – from an environmental point of view – not a viable option today. The GHG emissions are estimated to be between 9.3 – 16 kg CO2 equivalents/l diesel equivalent which is five to eight times that of a conventional diesel system. But already the electricity mix 2030 can drastically reduce the GHG emissions to 2.5 – 6 CO2 equivalents/l diesel equivalent. Wind will decrease these values further to 0.6 – 3.6 CO2 equivalents/l diesel equivalent. Dimethyl ether and methanol generate considerably lower impacts than OME3–5 as their production is less energy intensive. The conventional 2-step dimethyl ether synthesis and the more innovative 1-step process hardly differ.

Biomass-derived activated carbon catalysts for the direct dimethyl ether synthesis from syngas

The direct DME synthesis from syngas was studied by using activated carbon-based bifunctional catalytic beds. Two kinds of activated carbons, prepared by physical (by CO2 partial gasification) and chemical (with phosphoric acid) activation of olive stones, were used as supports for the preparation of the catalysts. The chemically activated carbon presented a considerable amount of thermally and chemically stable surface phosphorus complexes, which played an important role on the catalytic performance of the prepared catalysts. A Zr-loaded P-containing activated carbon presented a relatively high activity, selectivity and stability for the production of DME from methanol and was used as methanol dehydration catalyst. On the other hand, Cu-Zn was loaded on both P-containing and P-free activated carbon supports for the preparation of methanol synthesis catalysts. The presence of surface-phosphorus on the carbon support resulted in a strong metal-support interaction, hindering the catalytic activity for the hydrogenation of CO to methanol. However, the catalyst that did not contain phosphorus showed noticeable activity for this reaction. The physical mixing of the methanol synthesis and methanol dehydration catalysts resulted in the preparation of carbon-based bifunctional catalytic beds, which performed very efficiently in the direct DME synthesis from syngas in a fixed-bed reactor. Different mass ratios of the individual (metallic and acid) catalysts were studied. An acid/metallic catalyst mass ratio of 2 provided the catalytic bed with enough acid sites to promote methanol dehydration to its maximum extent and make the overall product distribution controlled by the methanol synthesis reaction on the metallic phase.

Kinetic Modeling of the Direct Dimethyl Ether (DME) Synthesis over Hybrid Multi-Site Catalysts

This paper deals with the proposition of a kinetic model for the direct synthesis of DME via CO2 hydrogenation in view of the necessary optimization of the catalytic system, reactor design, and process strategy. Despite the fact that DME synthesis is typically treated as a mere combination of two separated catalytic steps (i.e., methanol synthesis and methanol dehydration), the model analysis is now proposed by taking into account the improvements related to the process running over a hybrid catalyst in a rational integration of the two catalytic steps, with boundary conditions properly assumed from the thermodynamics of direct DME synthesis. Specifically, the CO2 activation step at the metal–oxide interface in the presence of ZrO2 has been described for the first time through the introduction of an ad hoc mechanism based on solid assumptions from inherent studies in the literature. The kinetic modeling was investigated in a tubular fixed-bed reactor operating from 200 to 260 °C between 1 and 50 bar as a function of a gas hourly space velocity ranging from 2500 to 60,000 NL/kgcat/h, in a stoichiometric CO2/H2 feed mixture of 1:3 v/v. A well-detailed elementary mechanism was used to predict the CO2 conversion rate and identify the key reaction pathways, starting with the analysis of the implicated reactions and corresponding kinetic mechanisms and expressions, and finally estimating the main parameters based on an appropriate modeling of test conditions.

Bifunctional catalysts based on PdZn/ZnO and hierarchical zeolites in the direct synthesis of dimethyl ether from CO-rich syngas: influence of the support and the Zn/Pd molar ratio

Pd/Zn-nanoparticles were used as precursors to study the influence of the molar Zn/Pd ratio and hierarchical HZSM-5 zeolites in the syngas-to-dimethyl ether process.

A Review of DME Manufacturing: Process and Catalyst Studies

Consumption of fossil-based energy is increasing every year which has an impact on air, water and soil pollution. Therefore, alternative energy is needed to replace fossil fuels. Dimethyl Ether (DME) is considered suitable to replace LPG because of its better physical and chemical properties than LPG. This review article discusses the differences between direct and indirect DME synthesis methods and studies their reaction mechanisms. In addition, the types of promoter addition and their effects on the characteristics and performance of the catalyst are also studied in this article. The final part of this article discusses the effect of operating conditions (temperature, pressure, time on stream (TOS), room velocity, and H2/CO ratio) on catalyst performance, which is sourced from several literatures. It is hoped that this article can obtain an effective DME manufacturing method both in terms of process and catalytic

CFD Simulation of Methanol Dehydration Step through an Adiabatic Fixed-bed Reactor of DME Synthesis

Today, dimethyl ether (DME) is changing to ordinarily worn as a superb aerosol propellant and refrigerant for its eco-friendly characteristics. Lately, with the development of novel chemical energy in the coal industries, it has become a fascinating field of research as an alternative green fuel for diesel machines due to the high cetane number. The DME synthesis processes include catalytic dehydrating methanol in an adiabatic fixed-bed reactor. In this study, to investigate the chemical conditions of the methanol dehydration reaction, CFD simulations of the adiabatic reactor have been assessed. The advantage of the work is a sensitivity analysis was run to find the effect of pressure, kinetics, and velocity on the reactor performance. The results showed that using a γ-Al2O3 catalyst with selective mechanical properties and unique surface properties is a convenient choice for DME synthesis. The CFD simulation results also show that the laboratory data such as pressure, energy, and velocity in the adiabatic reactor meet the reaction requirements well, and deliberated a major vision of what happened in the reactor. Also, the graphs of the temperature profile with changes in physical properties pomp that methanol dehydration reaction strongly depends on environmental factors and gives different results under the influence of other conditions.

Experimental study and comprehensive kinetic modeling of the direct dimethyl ether synthesis on Cu/ZnO/ZrO2 and H-FER-20

In the direct dimethyl ether (DME) synthesis, the combination of Cu/ZnO/ZrO2 (CZZ) and H-FER-20 (FER) has shown high selectivity and productivity for a broad range of CO2/COX ratio. Aiming to understand the behavior of the studied catalyst system under distinct operating conditions, we developed a new 9-parameter kinetic model. The parameters were estimated based on 815 steady-state experiments carried out at several values of pressure (30–54 bar), temperature (190–250 ℃), space-velocity (0.79–4.34 s−1) and inlet gas composition. This broad database was used in the development and validation of a new 9-parameter kinetic model for the direct DME synthesis. The model adequately simulates experiments in several process conditions, with 95% of the simulated points presenting a deviation lower than 20% with respect to the experimental results for outlet DME molar percentage. In addition, it correctly predicts the trends with respect to variations in H2 inlet fraction, which is of high relevance for processes using fluctuating renewable power sources for H2 production. In comparison to state-of-the-art models with more parameters, the new model is significantly more accurate. It benefits from the broad range of validity and elevated number of experimental points, which makes it a reliable model that can be applied for process optimization and scale-up.

A novel power, DME, and ammonia polygeneration system using Aspen plus based on the integration of biomass gasification and syngas chemical looping

To solve the problems of fossil energy shortage and environmental pollution, a novel polygeneration system based on corn straw gasification was developed using Aspen Plus. The system consists of gasification, the supercritical CO2 cycle, syngas chemical looping, ammonia synthesis, methanol synthesis, and dimethyl ether (DME) synthesis subsystems. This system can simultaneously generate power, DME, and ammonia. Sensitivity, energy, and exergy analyses were conducted on the system. The results showed that the thermal and exergy efficiencies of the system are 60.15% and 46.70%, respectively. The system can recover the initial investment cost in 8 years, and within a 20-year life cycle, the net present value of this new solution can reach 1566.61 k$. The sustainability index (SI) value of the entire system is 1.88.

Polymer-based solid acids with adjustable textural and hydrophobic properties for polyoxymethylene dimethyl ethers synthesis from formaldehyde and methanol

Cation exchange resins are widely utilized in polyoxymethylene dimethyl ethers (PODEn) synthesis due to considerable catalytic performance. However, low specific surface area and strong hydrophilicity hinder the generation of long-chain PODEn and industrial applications. Herein, polymer-based solid acids with adjustable textural and hydrophobic properties were prepared by hydrothermal method. Results indicated that the use of tetrahydrofuran and water as solvents in the preparation process resulted in a significant increase in the specific surface area and pore size distribution of the catalysts. Meanwhile, hydrophobic catalysts prepared by copolymerization under optimal solvent exhibited superior performance over commercial resins. Moreover, two reaction pathways for the reaction of hemiformal (HF1, CH3OCH2OH) with formaldehyde and methanol were investigated by DFT calculations. The intermediate formed by combining sulfonic acid group with carbocation is favorable for embedding formaldehyde in HF1 to promote chain growth, while the direct attack of methanol on HF1 is conducive to chain termination.

Life cycle water footprint and carbon footprint analysis of coal gasification to clean fuel dimethyl ether

Dimethyl ether is an ideal clean fuel that can replace diesel and liquefied petroleum gas, and has broad application prospects. The work analyzed the life cycle water footprint and carbon footprint of dimethyl ether production from coal gasification. The research results reveal that the water footprint of coal-to-dimethyl ether under the basic scenario is 11.2667 L H2O/MJ, and the carbon footprint is 0.2716 kgCO2-eq/MJ. In the whole production process, the synthesis of dimethyl ether is the main water consumption unit, occupying 99.70% of the whole water footprint. At the same time, this unit is also the major carbon emission unit, occupying 95.26% of the total carbon footprint. By studying and analyzing the distribution of water consumption and carbon emissions in the production process of dimethyl ether, it is found that power utilization is the major contributor to water footprint, accounting for 68.44% of the total water footprint. Although direct carbon emissions are the main impact on the carbon footprint, with electricity usage accounting for 6.33% of the total carbon footprint, they cannot be ignored. Based on this, the water footprint and carbon footprint of 31 provinces under the influence of power structures are studied. In addition, sensitivity analysis was conducted to study water consumption and carbon emissions under 24 different scenarios. This study introduced the relevant water consumption and carbon emissions in the process of producing dimethyl ether from coal gasification within a certain range, and emphasized the impact of regional differences in power structure on the results. The research results provide important references for reducing resource consumption in the production process of dimethyl ether and formulating environmental investment plans.