"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.
(And, to beat the horse to death: Methanol can be manufactured from syngas derived from both coal and hydro-treated Carbon Dioxide, as well as materials noted in this report.)
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. (Synthesis gas should by now be familiar to all our readers.) This is usually accomplished by the catalytic reforming of feed gas and steam. (Here, again, is another process wherein water, in the form of steam, supplies the needed Hydrogen to hydrogenate, to convert into hydrocarbons, the essentially carbonaceous raw material as would be derived from coal, or, by extension, Carbon Dioxide.) 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).
(The last statement bears emphasis, with a rephrasing, since it confirms what much of the earlier research we've reported to you indicates: There are multiple ways through which Methanol, liquid fuel, can be derived from synthesis gas, which itself can be extracted from coal, or made from Carbon Dioxide, in multiple ways.)
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."
(The Hydrogen surplus results from the use of pure methane, as the original Carbon source, combined with water (as steam). Synthesis gas, syngas, derived solely from coal might exhibit a Hydrogen deficit, which could be easily resolved through more H2O in the form of additional reactive steam, and/or the collateral conversion of coal with other, Hydrogen-rich, raw materials, such as saw dust, crop wastes and scrapped auto tires.)
"If an external source of CO2 is available, the excess hydrogen can be consumed and converted to additional methanol. (In other words, if additional Carbon Dioxide can be obtained, such as from a coal power plant's flue gas, more Methanol can be made. That's a switch: More CO2 is actually wanted.)
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."
As we've earlier referenced, some components of the Methanol synthesis procedure are exothermic, as affirmed above, and can themselves provide a portion of the energy needed to drive the complete process of converting carbonaceous feed stocks, including coal and some renewable materials, such as Carbon Dioxide and Cellulose (waste wood, Intelligencers and News-Registers, sewage plant sludge, etc.) into liquid fuel.
In conclusion, we'll note once more that Methanol is itself a liquid fuel of high worth. However, it can also be converted into the gasoline we all know and love, and serve as the raw material for manufacturing some other very useful things, such as certain plastics.
Methanol production, as the basis for manufacturing fuels and plastics out of renewable resources, such as cellulose, municipal waste and CO2, is well-understood and viable. Coal is the raw material for methanol manufacture, aside from natural gas, which actually enables the scale of such an industry that would allow the economically meaningful inclusion of those environmentally beneficial resources.