Methanol distributed production

Figure 5.3.4 Effect of space velocity on 14C distribution in methanol synthesis products, from [20],...

When quinoxaline is treated with potassium cyanide and benzoyl chloride in water (Reissert reaction) or methanol, the products are chlorine- and cyano-substituted quinoxaline derivatives. The relative product distribution depends on the reaction conditions. 

Methanol and Wood Conversion Product Classes. Methanol has been used in this screening work to ascertain catalyst activity. The methanol relative product distribution on an active, pure catalyst is shown in Figure lA. (Table II gives the identification of the ions observed). No methanol (m/z 31 and 32) breakthrough was observed, and the first formed product, dimethyl ether (m/z 45 and 46), has been consumed to form a mixture of C2 to Cg olefins and toluene, xylene, and trimethyl-benzene. Note the lack of benzene and alkanes. With lower space velocities and higher methanol partial pressure, the alkenes are known to disproportionate to branched alkanes and to form more aromatics (11). The absence of products above m/z 120 indicates the well-known shape selectivity of the catalyst. 

The alcoholysis reaction may be carried out either batchwise or continuously by treating the triglyceride with an excess of methanol for 30—60 min in a well-agitated reactor. The reactants are then allowed to settle and the glycerol [56-81-5] is recovered in methanol solution in the lower layer. The sodium methoxide and excess methanol are removed from the methyl ester, which then maybe fed directiy to the hydrogenolysis process. Alternatively, the ester may be distilled to remove unreacted material and other impurities, or fractionated into different cuts. Practionation of either the methyl ester or of the product following hydrogenolysis provides alcohols that have narrow carbon-chain distributions. 

Extraction from Aqueous Solutions Critical Fluid Technologies, Inc. has developed a continuous countercurrent extraction process based on a 0.5-oy 10-m column to extract residual organic solvents such as trichloroethylene, methylene chloride, benzene, and chloroform from industrial wastewater streams. Typical solvents include supercritical CO9 and near-critical propane. The economics of these processes are largely driven by the hydrophihcity of the product, which has a large influence on the distribution coefficient. For example, at 16°C, the partition coefficient between liquid CO9 and water is 0.4 for methanol, 1.8 for /i-butanol, and 31 for /i-heptanol. 

The crude product is distributed between equal parts of petroleum ether and 70% methanol. From the petroleum ether layer 5.6 grams of A -17a-ethyl-17(3-hydroxy-19-nor-androstene with a melting point of about 50°C are obtained. 

However, there are several issues with widespread methanol usage. Methanol production from natural gas is relatively inefficient ( 67%), and this largely offsets the vehicular improvement in efficiency and carbon dioxide reduction (since gasoline can be made with "85% efficiency from oil). Additionally, the PEM fuel cell demands very pure methanol, which is difficult to deliver using existing oil pipelines and may require a new fuel distribution infrastructure. 

Other energy sector concerns are methane emissions from unburned fuel, and from natural gas leaks at various stages of natural gas production, transmission and distribution. The curtailment of venting and flaring stranded gas (remotely located natural gas sources that are not economical to produce liquefied natural gas or methanol), and more efficient use of natural gas have significantly reduced atmospheric release. But growth in natural gas production and consumption may reverse this trend. Methane has... 

Table 5-4 shows the product distribution, when methanol was reacted over different catalysts for maximizing olefin yield. 

The electrocatalytic oxidation of methanol has been thoroughly investigated during the past three decades (see reviews in Refs. 21-27), particularly in regard to the possible development of DMFCs. The oxidation of methanol, the electrocatalytic reaction, consists of several steps, which also include adsorbed species. The determination of the mechanism of this reaction needs two kinds of information (1) the electrode kinetics of the formation of partially oxidized and completely oxidized products (main and side products) and (2) the nature and the distribution of intermediates adsorbed at the electrode surface. 

The catalytic reaction was carried out at 270°C and 101.3 kPa in a stainless steel tubular fixed-bed reactor. The premixed reaction solution, with a molar ratio catechol. methanol water of 1 1 6, was fed into the reactor using a micro-feed pump. To change the residence time in the reactor, the catechol molar inlet flow (Fio) and the catalyst mass (met) were varied in the range 10 < Fio <10 mol-h and 2-10 < met < 310 kg. The products were condensed at the reactor outlet and collected for analysis. The products distribution was determined quantitatively by HPLC (column Nucleosil 5Ci8, flow rate, 1 ml-min, operating pressure, 18 MPa, mobile phase, CH3CN H2O =1 9 molar ratio). 

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