Syngas Generation from Methanol

Monodentate phosphites performed superior to bidentate diphosphites or PPhg as ligands. A large excess of the ligand retarded the reaction. Noteworthy, the phosphite-modified Ru catalyst remained stable also in a second run. An increase of the H2 partial pressure in comparison to the partial pressure of CO2 led to the hydrogenation of the olefinic substrate. Under all conditions, the aldehyde was formed in minor quantities. Based on this protocol, some other cyclic or acyclic olefins were converted into the corresponding alcohols with yields of 45-88%. 

The generation of syngas from CO2 can be coupled with a hydroaminomethyla-tion reaction, as shown by Srivastava and Eilbracht [34]. Several amines could be obtained in up to 98% yield. 

The high concentration of MeOH at this side inhibited the CO hydrogenation. On the other hand, the high concentration at the Pt-Si02 interface side was beneficial for the hydroformylation. The activity for the hydrogenation of propene was much slower than that for the hydroformylation. 

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Thermodynamically, the carbonylation of methyl acetate (AG298 -10 kJ/mol) is considerably less favourable than that of methanol (AG298 -74 kJ/mol). This means that the reaction does not reach completion but attains an equilibrium which is dependent on the temperature and the CO pressure. Two variants are currently practised commercially that developed by Tennessee Eastman, based on a Halcon process, and a BP process in which acetic acid and the anhydride are co-produced in proportions which can be varied according to demand. Syngas for the Eastman process is made from coal which is mined close to the plant in Tennessee and the acetic anhydride produced is used to make cellulose acetate for film production. The BP process uses syngas generated from North Sea gas which is piped directly to the BP plant in EIull. [Acetic anhydride manufacture M. J. Eloward, M. D. Jones, M. S. Roberts, S. A. Taylor, Catalysis Today, 1993, 18, 325]. 

Where acetic is the starting acid (eq. 1), homologation selectively yields the corresponding C3+ aliphatic carboxylic acids. Since acetic acid is itself a "syngas" chemical derived from methanol via carbonylation (2,3), this means the higher MW carboxylic acids generated by this technique could also be built exclusively from C0/H2 and would thereby be in-depent of any petroleum-derived coreactant. 

Methanol and ethanol have been considered as promising fuels for generating H2, especially for on-board fuel cell applications due to their easy availability, ability to transport, and reaction simplicity.52 121 159 169 For example, both alcohols have high H2-to-carbon ratio (H/C) of 4 and 3, respectively (Table 2.1). They could be synthesized from renewable sources such as biomass and thus the ability to close the carbon cycle.161 166 Unlike hydrocarbon fuels, methanol and ethanol are free from sulfur, and this avoids additional sulfur removal step in the fuel processing. In addition, methanol can be reformed at a lower temperature, around 300 °C, and this makes the fuel processing relatively simple and less complicated. Furthermore, unlike natural gas, which produces primarily syngas, reforming of methanol and ethanol can in principle produce a mixture of H2 and C02, and this would also simplify the downstream CO cleanup for fuel cells such as PEMFCs where CO is a poison. 

In the water-gas process, hydrogen and carbon monoxide are generated from the reaction between steam and high-temperature coke in a two-step process. In the first step, the coal bed is heated to about 1300 °C with upward blown air. The reactant gas is then switched to steam, creating the syngas and cooling the coal bed. To make optimum use of the heat in the system, steam is blown first upward then downward. When the bed temperature drops to about 900 °C, the steam is stopped and the next cycle is started. The product from the water-gas process can be used for ammonia or methanol synthesis. 

Syngas produced from gasification of coal, biomass, petroleum coke, and other types of feedstock can be used to generate electricity or to produce hydrogen and other liquid fuels or chemicals (ammonia, methanol, dimethyl ether, and diesel fuel) by... 

Davy Process Technology, UK/Johnson Matthey Catalysts Methanol Natural gas or associated gas The process produces methanol from natural gas or associated gas via a reforming step or from syngas generated by gasification of coal, coke or biomass. The reforming/gasification step is followed by compression, methanol synthesis and distillation 87 2010... 

The conversion of methanol to hydrocarbons is the most studied reaction of oxygenates over microporous solids, for both commercial and academic reasons. Methanol can be generated from syngas over copper- and zinc-based catalysts using the ICI process, and syngas can be prepared from methane, which is a readily available resource. Under the correct economic conditions, methanol conversion reactions can provide an important route to higher... 

Methanol is an important multipurpose intermediate traditionally used for production of various chemicals [57], It is currently produced from syngas, which is industrially generated via catalytic steam or autothermal reforming of methane [13-15]. Figure 23.7 schematically illustrates commercial and alternative routes for methanol formation from methane. Despite the fact that syngas production and methanol synthesis are highly optimized processes, strong economic and environmental interests exist in direct oxidative conversion of methane to methanol. 

Whereas near-term appHcation of coal gasification is expected to be in the production of electricity through combined cycle power generation systems, longer term appHcations show considerable potential for producing chemicals from coal using syngas chemistry (45). Products could include ammonia, methanol, synthetic natural gas, and conventional transportation fuels. 

Dynamic smdies of the alloy system in CO and H2 demonstrate that the morphology and chemical surfaces differ in the different gases and they influence chemisorption properties. Subnanometre layers of Pd observed in CO and in the synthesis gas have been confirmed by EDX analyses. The surfaces are primarily Pd-rich (100) surfaces generated during the syngas reaction and may be active structures in the methanol synthesis. Diffuse scattering is observed in perfect B2 catalyst particles. This is attributed to directional lattice vibrations, with the diffuse streaks resulting primarily from the intersections of 111 reciprocal lattice (rel) walls and (110) rel rods with the Ewald sphere. 

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