This section provides inputs on this trend – liquid diesel fuel from coal.

Deriving diesel from coal is not new.

During World War II, coal gasification and liquefaction produced more than 50 percent of the liquid fuel used by the German military. A worldwide oil embargo on South Africa's apartheid regime forced that nation to derive much of its transportation fuel from coal.

America has been recently in the forefront in the conversion technologies for coal to diesel. One of the reason is the coal reserves in the US. According to the U.S. Department of Energy, the US has 286 billion tons of coal reserves, which translates into energy reserves 40 times those of oil reserves in the US.

Recent developments appear to have made possible the deriving of diesel from coal in a more economical method, thus making it likely for many countries to reduce their dependence on foreign oil.

The process of converting coal to diesel involves:

(1) Feeding waste coal into a gasifier

(2) Where it is mixed with oxygen and water and heated to 2,500 degrees Fahrenheit to produce synthetic gas, or syngas

(3) The syngas undergoes another chemical reaction to become paraffin wax

(4) The wax is then refined into diesel

The countries that could benefit significantly from this invention are USA, India and China, each of which has large coal reserves, enough to produce many years’ equivalent of diesel. For coal reserves by country, see Living Landscapes, Survey of Coal Resources – World Energy Council

New Development in Coal to Diesel Process

(this technology development was announced in Apr 2006)

The process by which coal is converted into diesel is called the Fischer-Tropsch process. The new process uses a catalyst for a method known as Alkane Metathesis. This method, which is used along with the F-T process, converts previously-useless by-products of the Fischer-Tropsch process into useful synthetic materials. (see here)

The breakthrough technology employs a pair of catalytic chemical reactions that operate in tandem, one of which captured the 2005 Nobel Prize in Chemistry. These catalytic chemical reactions revamp the Fischer-Tropsch (FT) process for generating synthetic petroleum substitutes. The FT process invented in 1920 but never developed to the point of becoming commercially viable for coal conversion. The recent innovations eliminate shortcomings in the process that can finally make it a workable solution to dwindling domestic oil reserves.

The Fischer-Tropsch process yields a substantial quantity of medium-weight products (along with low-weight and high-weight products) that are not commercially useful. The low and high-weight products can be used – the light ones as gas and medium-heavy as diesel fuel. What the new technology does is to convert these medium-weight substances to the useful higher- and lower-weight products.

See the following links:

• Alkane Metathesis – from Wikipedia
• Olefin Metathesis – Big-deal Reaction
• Olefin Metathesis – Early Days
• New Chemistry Turns Coal into Clean Diesel (see also a Live Science article, original article from Rutgers University, a copy at Science Daily, Abstract of the invention at Science Mag)

Some Tidbits

• According to a research paper, coal-fueled diesel engines hold the promise of operating on a cheap, domestically abundant fuel in a wide range of applications. The technical challenges appear to be solvable by existing or near-term developments. The successful application of a coal-fueled diesel engine will require the simultaneous development of a fuel source, engine combustion, wear and emission control systems, and the support infrastructure in the operating environment

More Reference Links

• Rentech Announces Progress on Australian Coal-to-diesel Project – News Report
• The Unexamined Costs of Coal to Liquid – The Independent Online – describes some of the pitfalls involved in the Integrated Gasification Combined Cycle (IGCC) process, such as the massive amounts of carbon-di-oxide (a primary global warning gas) produced for which carbon sequestration needs to be done. The capture, compression and storage of CO2 in underground formations under intense pressure requires both considerable physical infrastructure, for instance
• Coal is Back – Time Magazine, Oct 2005 - Long dismissed as backwards and dirty, some new (and not-so-new) technologies are turning the rock into black gold, says this article.
• Clean Diesel from Coal – Technology Review, April 2006 - A novel catalytic method could let you fill up your tank with coal-derived diesel, cutting U.S. dependence on foreign oil, says this article
• Secret to Cheap Petrol is Coal – The Age, Australia, Sep 2006 - A $5 BILLION proposal to turn some of Victoria's abundant brown coal into diesel moved a step closer after the State Government revealed it was about to grant a mining licence to the company behind the project.
• Green Coal – Monga Bay, Apr 2006 - Green coal? Process converts coal into diesel fuel Coal-to-Diesel could reduced foreign dependence on oil University of North Carolina at Chapel Hill - Making alternative fuel becomes more efficient with dual-catalyst system: UNC-Rutgers study
• China to Promote Coal-derived Diesel Substitute – China Institute - China plans to promote the development of dimethyl ether (DME), a fuel created from coal, which is being touted as a cleaner substitute for diesel, the official Xinhua news agency reported. DME, currently used as a propellant in aerosol spray cans, can be made from biomass and some fossil fuels, including coal.