Advantages And Disadvantages Of Methanol

Methanol production

Methanol is a major raw material for petrochemical production and is currently under consideration as a liquid fuel. It is used to be called as “wood Alcohol” or “wood spirit” as the production route was the destructive distillation of wood, the first widespread method for producing methanol. The wide application of methanol motivates its large scale production which is ever increasing. [1]

The annual production of methanol exceeds 40 million tons and continues to grow by 4% per year. The production of methanol from coal is increasing in locations where natural gas is not available or expensive such as in China. However, most methanol is produced from natural gas. Several new plants have been constructed in areas where

It is often produced in a two-step process where methanol is first generated from syngas followed by methanol dehydration over a solid acid catalyst, to produce DME. Alternatively, in a single-step conversion, DME is produced directly from syngas over a bi-functional or hybrid catalyst system employing both a methanol synthesis function and a methanol dehydration function.[9,10] Producing DME directly from syngas has many economic and technical advantages, provided suitable catalyst(s)

The overall reaction is exothermic and the reaction heat at methanol synthesis step is dominant.

Since both reaction (1.4) and (1.5) generate two molecules of products from six molecules of syn-gas, the higher reaction pressure gives higher syn-gas con- version.

In addition, thermodynamically, DME production from syngas is favoured over methanol. Direct DME synthesis involves several competing reaction pathways. One can infer from the reactions, 1 step is preferred over 2 step process as the hybrid catalyst used in one step process allows synergy between the reactions which results into higher syngas conversion per pass or greater productivity by consuming methanol as soon as it forms. The synergy between the reactions works in the following way : Methanol produced in reaction (1.1) get consumed in reaction (1.2) immediate after its formation, water produced in reaction (1.2) favours the product formation of reaction (1.3) according to Le Châtelier's principle and finally H2 produced in reaction (1.3) again used in reaction (1.1), therefore increasing its rate of