Methanol
Methanol Manufacture:
Methanol is synthesised from what is known as synthesis gas, a mixture of carbon monoxide (CO) and hydrogen. Synthesis gas can be produced from a number of hydrocarbon feedstocks, including coal and naphtha.
In New Zealand’s case, natural gas, whose principal component is methane (CH4), is the feedstock, and the production process is that developed by ICI in the late 1960’s, and utilised in most of the plants built since then.
Methanol (wood alcohol) had first been produced by the destructive distillation of wood. In the early decades of the twentieth century, new technology for making it was developed in concert with that for producing ammonia, which has the same starting point; synthesis gas. Chromium-based catalysts were used but these were of low activity, and required the use of high pressures and temperatures.
After World War II, reforming processes were developed which could produce a very pure synthesis gas. ICI recognised that this would allow the use of copper catalysts of high activity and product specificity that previously could not be used because they were poisoned by sulphur impurities in the synthesis gas.
By combining these catalysts with the use of efficient high-speed centrifugal compressors and with fully integrated heat recovery systems, ICI were able to develop their process.
Uses of Methanol
Methanol occupies a key position in the chemical industry, being mainly used to make wood adhesives and plastics. About 20% of production goes into making dyes and perspex and 15% into solvents for paints and dyes. It is also used for polyester fibres, methyl cellulose and silicone compounds and can be used to manufacture the antiknock petrol additive M.T.B.E.
When the interdepartmental Petrochemicals Project Group reported in June 1976 it said an export-based chemical methanol plant would be in the national interest. It also suggested that methanol be used as a gasoline extender but said that additional technical research was needed before the economic viability of doing this could be assessed.
Subsequently DSIR and the University of Canterbury started investigations into the use of gasoline/methanol mixtures in motor vehicles.
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