| Dimethyl Ether (DME) is not only an important chemical, but also can be converted into liquefied petroleum gas. Furthermore, DME is also an ideal substitute for diesel or liquefied petroleum gas. So, the application prospect of DME becomes wider. In recent years, the synthesis process of DME has attracted much attention in research fields and industrial field.The syngas, which is produced commercially by steam reforming of natural gas or coal can be converted into DME. As well known, coal resource in China is very rich, production of DME from coal is an important option for the efficient conversion of coal into clean fuel.The conventional process of DME production, named two-step method, has become more and more insufficient with the growing demand for DME as fuels for new applications. Lately, an original technique named one-step method was developed for the direct synthesis of DME from synthesis gas in a single reactor. Compared with the conventional method, the one-step method is attracting more and more industrial attention from industry because of its dramatically economic values and theoretical significance.The synthesis gas directly convert into dimethyl ether by using fixed - bed and high - pressure flow apparatus. In this paper, the catalyst and process of dimethyl ether from syngas were studied.Firstly, a series of catalysts were prepared with mechanical mixing method. These catalysts were investigated by means of XRD, BET and NH3-TPD. The methanol synthesis catalyst and methanol dehydration catalyst were tested, which resulted in the conclusion that the optimal catalyst is C207/HZSM-5=4:1 (weigh ratio), and the ratio of Si/Al of HZSM-5 is 50.Secondly, the effect of temperature, pressure, space velocity and reduction temperature were discussed, then the optimal reaction conditions were optained: T=275℃, P=5.0MPa, SV=1600h-1, reduced temperature is 300℃. The conversion of the CO is above 90%, the yield of the DME is above 70%.
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