Low-temperature Methanol Synthesis Research Articles

Investigation of low-temperature methanol synthesis in a bubble column slurry reactor with a flash column

Reaction performance of a CuCr/CH 3ONa catalyst for the low-temperature methanol synthesis was examined in a bubble column slurry reactor with a flash column (BCSR/FC). The BCSR/FC was operated at 4.5 ± 0.2 MPa/110–120 °C for BCSR and 0.4 ± 0.1 MPa/80–90 °C for FC, although fluctuation of operation parameters was larger. Syngas conversion decreased from 71.0% to 19.8% during the operation test in 100 h, which was attributed to consumption of CH 3ONa and a negative effect of the emulsifier OP-10 used.

Catalytically active species in Ni-based catalytic systems for low-temperature methanol synthesis probed by in situ ATR/FTIR in combination with reaction kinetics

An in situ ATR/FTIR technique was employed to probe the transformation of the nickel precursor in a catalyst composed of Ni(OCOCH 3) 2 and CH 3OK for low-temperature methanol synthesis in a liquid medium. Homogeneous nickel species, Ni(CO) 4 and a hydridocarbonylnickel anion ([HNi(CO) 3] − and/or [HNi 2(CO) 6] −) were simultaneously derived from Ni(OCOCH 3) 2 during the reaction. Reaction kinetics in combination with in situ FTIR observation revealed that the ratio of the reaction rate between the catalysts with different nickel precursors, i.e. Ni(OCOCH 3) 2/CH 3OK and Ni(CO) 4/CH 3OK, agreed with the ratio of the infrared absorption assigned to the nickel anion. This supports the proposed reaction scheme in which methanol is formed through methyl formate and the nickel anion catalyzes the rate-determining hydrogenation step of methyl formate.

Influence of Zirconia Promoter on Catalytic Properties of Cu–Cr–Si Catalysts for Methanol Synthesis at High CO Conversion in Slurry Phase

The low-temperature methanol synthesis was studied using novel Cu-Cr-Si catalysts promoted by zirconia at 115 °C and 3.0 MPa in slurry phase. Zirconia addition improved significantly the catalytic performance. From the characteristic results, copper and chromium were enriched on the catalyst surface and more Cu + cations were stabilized by the zirconia promotion.

Spectroscopic and Kinetic Analysis of a New Low-Temperature Methanol Synthesis Reaction

The spectroscopy and kinetics of a new low-temperature methanol synthesis method were studied by using in situ DRIFTS on Cu/ZnO catalysts from syngas (CO/CO2/H2) using alcohol promoters. The adsorbed formate species easily reacted with ethanol or 2-propanol at 443 K and atmospheric pressure, and the reaction rate with 2-propanol was faster than that with ethanol. Alkyl formate was easily reduced to form methanol at 443 K and 1.0 MPa, and the hydrogenation rate of 2-propyl formate was found to be faster than that of ethyl formate. 2-Propanol used as promoter exhibited a higher activity than ethanol in the reaction of the low-temperature methanol synthesis.

A scale-up strategy for low-temperature methanol synthesis in a circulating slurry bubble reactor

Slurry bubble column reactors are being increasingly utilized in the large-scale conversion of coal or natural gas to liquid hydrocarbons and alcohols. A new suite of tools for developing low-temperature methanol synthesis in circulating slurry bubble reactors is explored in this study. The scale-up strategy consisting of hydrodynamics in cold flow units, catalyst performance evaluation in an autoclave, and process investigation in a pilot-scaled circulating slurry bubble reactor is presented. This methodology should be helpful for designing and scaling-up the low-temperature methanol synthesis and other related processes in slurry bubble column reactors, which will enhance and speed them towards commercial application.

Mechanistic study of a new low-temperature methanol synthesis on Cu/MgO catalysts

In situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) was used to clarify the reaction mechanism of a new methanol synthesis method on a Cu/MgO catalyst at 443 K from syngas containing CO 2 using an ethanol promoter. The adsorbed formate species were formed by exposing Cu/MgO catalyst to syngas (CO/CO 2/H 2), and it reacted easily with ethanol to form ethyl formate in two states: gas-phase species and physisorbed species, at low temperature. The ethyl formate was the reactive intermediate, and it was reduced easily by hydrogen atoms on Cu to form methanol at low temperature. The reaction temperature was significantly decreased due to the promotional catalytically active action of ethanol. This is a new reaction route, as ethanol used in this reaction was not consumed due to its self-regeneration by hydrogenation of ethyl formate. In order to accelerate this reaction, one must introduce a large amount of ethanol into the reaction system.

05/00588 Development of a new low-temperature methanol synthesis process

05/00588 Development of a new low-temperature methanol synthesis process

Low temperature methanol synthesis from carbon monoxide and hydrogen over ceria supported copper catalyst

High catalytic activity in the methanol synthesis from carbon monoxide and hydrogen can be produced with ceria supported copper catalysts prepared by a coprecipitation method at a reaction temperature below 200 °C. In comparison with commercial copper–zinc catalysts, the equivalent activity is obtained at a lower reaction temperature by 60 °C, while it is still unstable. Although the reaction atmosphere is reductive, metallic copper particles formed in the pretreatment with hydrogen are oxidized and the catalyst is highly activated. The size of the copper oxide species produced is significantly small, showing dispersion of copper on cerium oxide during the reaction. Hence, the interaction between copper and cerium oxide is probably indispensable for the appearance of the high catalytic activity.

In situ DRIFT study of low-temperature methanol synthesis mechanism on Cu/ZnO catalysts from CO 2-containing syngas using ethanol promoter

In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to study the reaction mechanism of a new methanol synthesis method on Cu/ZnO at low temperatures from syngas (CO/CO 2/H 2) using ethanol promoter. The adsorbed formate species were formed by exposing Cu/ZnO catalysts to syngas (CO/CO 2/H 2), and it reacted easily with ethanol in the gas phase to form ethyl formate in two states of species, gas phase and physisorbed, at low temperatures. Ethyl formate was the reactive intermediate, and it was reduced easily by hydrogen atoms on Cu to form gas-phase methanol. The reaction temperature was significantly decreased due to the catalytic action of ethanol and a new reaction route. In order to accelerate this reaction, a large amount of ethanol must be introduced into the reaction system. When there was no ethanol or little ethanol in the reaction system, this reaction was difficult to complete at a temperature as low as 443 K.

Novel Anion Exchange Resin-based Catalyst for Liquid-phase Methanol Synthesis at 373–393 K

Abstract A thermo-stable anion exchange resin–Raney Cu system was found as the most effective solid catalyst for low-temperature liquid-phase methanol synthesis at 373 to 393 K under 5.0 MPa of syngas (2H2/CO). With the catalyst (20 mL of the resin and 2.0 g of Cu) suspended in methanol solution 72% of CO was converted to methanol (70%) and methyl formate (HCOOCH3) (30%) in 4 h.

Development of a new low-temperature methanol synthesis process

A new reaction route of methanol synthesis at low temperature from CO 2-containing syngas with Cu/ZnO catalyst and the aid of alcohols has been developed in a batch and a flow-type semi-batch reactors. The use of alcohols as catalytic solvents realized methanol synthesis at 443 K with formate as an intermediate. The activity of methanol synthesis depends on types and structures of alcohols. Among all alcohols, 2-alcohol exhibited the highest activity. With the aid of 2-butanol, the one-pass 47.0% conversion and 98.9% selectivity were achieved at a mild condition, 443 K and 50 bar. The new reaction route of methanol synthesis is a practical method for near future technology.

03/01695 Low-temperature methanol synthesis in a circulating slurry bubble reactor: Zhang, K. et al. Fuel, 2003, 82, (2), 233–239

03/01695 Low-temperature methanol synthesis in a circulating slurry bubble reactor: Zhang, K. et al. Fuel, 2003, 82, (2), 233–239

Integrating low-temperature methanol synthesis and CO 2 sequestration technologies: application to IGCC plants

Coupling a low-temperature once-through methanol synthesis process with CO 2 separation technology would provide an option for integrated gasification combined cycle (IGCC) power plants to address the CO 2 mitigation issue and also create the capability to utilize methanol as a peak-shaving fuel. Data are presented that show that several nickel complexes activated by alkoxide bases catalyze facile synthesis of methanol from synthesis gas (primarily a mixture of CO and H 2) in homogeneous liquid phase under mild conditions of temperature (<150 °C) and pressure (<5 MPa). Under these mild conditions, batch-mode productivity of up to 20 g mol MeOH/l cat. h is achieved and more importantly, per pass gas conversion and methanol selectivity exceed 90 and 95%, respectively. The overall synthesis gas to methanol process has built-in waste-minimization and minimum by-product formation features and thus achieves CO 2 mitigation. The potential of this low-temperature methanol synthesis approach is considered in light of the recent advances in CO 2 sequestration technologies. A successful development of this technology may also provide an atom-economical pathway to transport remote natural gas in the form of methanol, a liquid energy-carrier.

Continuous Low-Temperature Methanol Synthesis from Syngas Using Alcohol Promoters

Continuous low-temperature methanol synthesis from syngas containing CO2 on various Cu/ZnO catalysts was investigated by using a semibatch autoclave reactor. Methanol was easily produced at a temperature as low as 443 K and with a pressure of 50 bar with the aid of 2-butanol, which showed a very high efficiency with a one-pass yield of 47.0% and a selectivity of 98.9%. Methanol itself used as alcohol promoter exhibited a higher activity than other 1-alcohols because it has the lowest spatial effect. 2-Alcohols, however, exhibited the highest conversion among the same carbon number because of its well-balanced effects produced by their of electronic and spatial factors. The one-pass conversion was improved by increasing the catalyst weight because no thermodynamic limitations existed at low temperatures. The continuous low-temperature methanol synthesis is a very promising process because completely purified syngas is not necessary.

Low-Temperature Methanol Synthesis in Catalytic Systems Composed of Copper-Based Oxides and Alkali Alkoxides in Liquid Media: Effects of Reaction Variables on Catalytic Performance

Catalytic systems composed of copper-based oxides and alkali alkoxides are tested for low-temperature methanol synthesis in liquid phases, which involves carbonylation of methanol to methyl formate and consecutive hydrogenation of methyl formate to methanol. The effects of reaction variables on the catalytic performance are investigated under the conditions of 373-423K temperature and 1.5-5.0 Mpa pressure. The combined catalytic systems of copper chromite and potassium methoxide exhibit excellent activities for the production of methanol. Higher values of reaction temperature, initial pressure, catalyst loading, and H2/CO ratio of the feed gas lead to higher methanol productivity. In particular, the reaction temperatures and the feed gas compositions strongly influence the catalytic performance. No methanol is formed when employing a feed gas containing 2% CO2. The catalytic systems are deactivated in a short period even in a CO2-free feed gas, due to the consumption of the alkoxide component. Alkali alkoxides are consumed through reactions with trace amounts of CO2 and H2O which are formed as by-products during the course of the runs. The results also suggest that the hydrogenation step of methyl formate over copper chromite is greatly accelerated in the presence of the alkali alkoxide.

Low-temperature methanol synthesis in a circulating slurry bubble reactor

A circulating slurry bubble reactor was developed to synthesise methanol via methyl formate from the gas mixture of carbon monoxide and hydrogen at low temperature. The strategy for designing and scaling up the bubble reactor involved a preliminary understanding of fluid dynamics in a cold model, continuous operations under industrial conditions and a parallel experiment in an autoclave. Per-pass syngas conversion was investigated during 100-h operations. The axial profile of solid catalyst concentration was measured just before the shutdown and the composition of liquid product was analysed after the shutdown. These results show that the circulating slurry bubble column will become a potential reactor for the commercial process of low-temperature methanol synthesis after the catalyst system has been improved.

Mathematical modeling of low temperature methanol synthesis in a bubble slurry reactor

Mathematical modeling of low temperature methanol synthesis in a bubble slurry reactor

Low-temperature methanol synthesis (LTMS) in liquid phase on novel copper-based catalysts

Novel Cu-Cr based catalysts with alumina promotion have been prepared and studied in low-temperature methanol synthesis (LTMS) in a slurry reactor. The new method of co-precipitation from the sol state gave better results than those of three other preparation methods. From the results of temperature programmed desorption and XRD, there were more active sites in the presence of alumina.

New process of low-temperature methanol synthesis from CO/CO2/H2 based on dual-catalysis

A new process of low-temperature methanol synthesis from CO/CO2/H2 based on dual-catalysis has been developed. Some alcohols, especially 2-alcohol, were found to have high catalytic promoting effect on the synthesis of methanol from CO hydrogenation. At 443 K and 5 MPa, the synthesis of methanol could process high effectively, resulting from the synergic catalysis of Cu/ZnO solid catalyst and 2-alcohol solvent catalyst. The primary results showed that when 2-butanol was used as reaction solvent, the one-pass average yield and the selectivity of methanol, in 40 h continuous reaction at temperature as low as 443 K and 5 MPa, were high up to 46.51% and 98.94% respectively. The catalytic activity was stable and the reaction temperature was 80 K or so lower than that in current industry synthesis process. This new process hopefully will become a practical method for methanol synthesis at low temperature.

A New Low-Temperature Synthesis Route of Methanol: Catalytic Effect of the Alcoholic Solvent

The effects of different alcohols as reaction solvent on the synthesis of methanol from CO/CO2/H2 on solid Cu/ZnO catalyst were investigated. In the presence of some alcohol, especially 2-alcohol, as reaction medium, the reaction of methanol synthesis proceeded with high activity at temperatures as low as 423−443 K, much lower than the temperature in the present industrial methanol production process. This method is very promising to become a new technology for low-temperature synthesis of methanol where complete purification of syngas is not necessary.