III International Conference

PP-II-106For the description of methanol dehydration into DME, a mechanistic scheme involvingsubstitution steps for strongly adsorbed species on the catalyst surface was used [1]. On thisbasis, a theoretical kinetic model was developed; computer simulation showed the results ofcalculations to be in good agreement with the experimental results. The average relativevariation between calculated and experimental points was 9.9 % for 105 experiments in therange t=220-300 o С, GHSV=1–112 h -1·10 3 , methanol partial pressure 0.3-1 MPa.Kinetics of direct DME synthesis from syngas was studied over a catalyst [2] at220-280 o C, 5–10 MPa in a broad GHSV range. Kinetic model of direct DME synthesis wasobtained on the basis of individual kinetic equations (1)-(3) constituting the process; newlyderived kinetic model of methanol dehydration coupled with those obtained earlier [3] formethanol synthesis and water gas shift reaction allowed satisfactory description of directDME synthesis from syngas (Fig. 2). As one of the more outstanding practical consequencesof this research, it was shown that syngas of any cоmposition is suitable for DME production,including "lean" gas (obtained by oxidation of natural gas with air) and gas with relativelylow H 2 content, CO/H 2 =1:1, for example.434darkened points - exp.hollow points - calc.DME conc., %2132Fig.2. Checkout of the direct DME synthesis1 kinetic model applicability – contact timedependence of DME concentration under 5 MPa at0different temperatures:0,0 0,2 0,4 0,61 – 220 o С; 2 - 240 0 С; 3 – 260 o С; 4 – 280 o С.Contact time, sInitial syngas composition: СО - 34.1; СО 2 -2.7;Н 2 - 56.3; N 2 – 2.7 (vol. %).AcknowledgmentThe authors would like to express their gratitude to INTAS for financing this work (Grant05-1000005-7663).Reference1. A.Ya. Rozovskii. Kinetics of Catalytic Reactions with the Participation of Strongly(“Irreversibly”) Chemisorbed Species. Kinet. Katal., 1989, 30 (3), 533.2. Russian Federation Patent 2218988. Catalyst and the Process of Dimethyl Ether and MethanolProduction from Syngas.3. A.Ya. Rozovskii, G.I. Lin. Fundamentals of Methanol Synthesis and Decomposition. Topics inCatal., 2003, 22 (3-4), 137.359