We developed an original gas chromatographic procedure for determining the products and reagents for the catalytic synthesis of dimethyl ether (DME) from synthesis gas, which enables the simultaneous detection of СН 3 ОН, DME, СО, СО 2 , Н 2 , Н 2 О, N 2 , and hydrocarbons to С 6 . The gas circuit includes four detectors, three packed columns, two precolumns (to prevent water and organic compounds from entering molecular sieve columns) in combination with two relief valves and two pressure regulators for the implementation of the back purging of precolumns. The system is assembled based on a Khromatek-Kristall 5000 chromatograph. The determination is carried out at a constant temperature of 140°C. The duration of analysis is not more than 12 min. Because of the presence of a flame ionization detector, it is possible to detect trace amounts of hydrocarbons, as well as ethane in the presence of large amounts of CO 2 .

Several bifunctional catalysts for dimethyl ether (DME) synthesis from syngas are prepared on the basis of commercial methanol-synthesis Megamax 507 catalyst. Commercial HZSM-5 zeolites with a SiО2/Al2О3 ratios of 23, 80, and 307 and γ-alumina were used as dehydration components. Physicochemical characteristics of zeolites and alumina are studied: temperature-programmed desorption of ammonia, the porosity, and the specific surface area. The activity of catalyst in DME synthesis is studied in a microcatalytic flow-type setup at a pressure of 3 MPa in a temperature range of 200–260°С with a productivity based on syngas of up to 30000 L $${\text{kg}}_{{{\text{cat}}}}^{{ - 1}}$$ h–1. The composition of syngas was (vol %): CO, 21; CO2, 6; Н2, 67; N2, 6 . It is shown that zeolites, especially with silica/alumina ratios of 23 and 80, are more active than alumina in methanol dehydration to DME, but in the presence of these zeolites, traces of hydrocarbons were detected at 260°С. The zeolite with a silica/alumina ratio of 307 is the most interesting of the studied zeolites. Hydrocarbons are almost not formed on it, and its activity in methanol dehydration is somewhat higher than that of alumina. The behavior of the methanol-synthesis component of the bifunctional catalyst is studied: the apparent activation energy of methanol synthesis and the degree of approaching to equilibrium are estimated depending on the catalyst load.