PRINCIPAL USES OF METHANOL
What do reformulated gasoline, PET plastic bottles, paints, plywood panels, bleached paper, Spandex clothing, polyester carpets and windshield wiper fluid have in common? The answer is methanol, made from clean natural gas. Methanol is a liquid chemical that can be made from renewable resources such as municipal solid waste and biomass crops. Today, methanol is primarily made from steam reformed natural gas and carbon dioxide.
The methanol industry generates approximately $12 billion dollars in economic activity a year worldwide. As one of the largest distributors, SCC imports over 3 million tons of the total 5.4 million tons of methanol per year into the U.S. Eight percent of methanol supplied to the U.S. is produced in Trinidad.
METHANOL FUEL AND CHEMICAL USES
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 fibers, methylcellulose and silicone compounds and can be used to manufacture the antiknock petrol additive M.T.B.E.
Methanol can be found in a wide array of products used in our homes, cars and businesses:
• Formaldehyde resins are used in engineered wood products like particleboard made from waste wood, and in products like seat cushions and Spandex fibers.
• Methanol-based acetic acid is used in making PET plastic, used to package beverages and household products and polyester fiber in clothing and carpets.
• MTBE as a gasoline additive to replace lead and as an oxygenate to help reduce emmissions.
• Methanol is one of the principal ingredients in windshield wiper fluid*, and is used in chlorine-free bleaches, paints, solvents, refrigerants, and disinfectants.
• As an alternative fuel, methanol is used in cars, trucks and buses to reduce tailpipe emissions and our dependence on imported oil.
*Windshield wiper fluid is 10-20% Methanol
More than 90 world-scale methanol plants have the capacity to produce over 11 billion gallons of methanol annually. The global methanol industry generates $12 billion in economic activity each year, while creating nearly 100,000 jobs.
The typical feedstock used in the production of methanol is natural gas. Methanol can also be made from renewable resources such as wood, municipal solid wastes and sewage. The production of methanol also offers an important market for the use of flared natural gas.
In a typical plant, methanol production is carried out in two steps. The first step is to convert the feedstock natural gas into a synthesis gas stream consisting of CO, CO2, H2O and hydrogen. This is usually accomplished by the catalytic reforming of feed gas and steam. Partial oxidation is another possible route. The second step is the catalytic synthesis of methanol from the synthesis gas. Each of these steps can be carried out in a number of ways, and various technologies offer a spectrum of possibilities to suit most any desired application(s).
Conventional steam reforming is the simplest and most widely practiced route to synthesis gas production:
2 CH4 + 3 H2O -> CO + CO2 + 7 H2 (Synthesis Gas)
CO + CO2 + 7 H2 -> 2 CH3OH + 2 H2 + H2O
This process results in a considerable hydrogen surplus, as can be seen in the formula above.
If an external source of CO2 is available, the excess hydrogen can be consumed and converted to additional methanol. The most favorable gasification processes are those in which the surplus hydrogen is “burnt” to water, during which steam reforming is accomplished through the following partial oxidation reaction:
CH4 + _O2 -> CO + 2 H2 -> CH3OH
CH4 + O2 -> CO2 + 2 H2
The carbon dioxide and hydrogen produced in the last equation would then react with an additional hydrogen from the top set of reactions to produce additional methanol. This gives the highest efficiency, but may be at additional capital cost.
Unlike the reforming process, the synthesis of methanol is highly exothermic, taking place over a catalyst bed at moderate temperatures. Most plant designs make use of this extra energy to generate electricity needed in the process. By employing even its by-products, methanol production proves its efficiency over other fossil fuels used in the world today.
For technical information regarding methanol, click here.