On 'Unconventional' Sources Of Petroleum Hydrocarbons
Authors: Berkowi N. , Chakrabartty S.K. 
Published: March 2010

Abstract
As well as being recoverable from oil sands and oil shales, "petroleum hydrocarbon" (i.e. liquid fuels, industrial solvents, lubricating oils and greases, waxes, etc.) can be produced from a variety of other feedstocks. Examples are coal, coal tar, cellulosic wastes, carbon monoxide + hydrogen, and carbon monoxide + water.
This paper outlines the methods by which liquid fuels can be made from non-petroleum hydrocarbon, and note that, in several instances, a fairly highly developed technology for such "fuel conversation" is already available.

Introduction
As THE MORE easily accessible indigenous oil reserves are depleted, and oil prices rise beyond a nominal $5–6 per barrel, the alternatives that offer themselves as replacements or supplementary sources of petroleum hydrocarbons include raw materials and processes which, although occasionally used in times of emergency, could so far otherwise not compete against conventional petroleum and petroleum refining.
Having regard to the extent of projected North American oil demands, and to the enormous potentials represented by offshore and "frontier" oil accumulations, oil sands and oil shales, it can perhaps be taken for granted that future oil supplies will, for the most part, be drawn from these resources. This said however, it is also important to observe that fuel conversion technology and hydrocarbon synthesis have reached a stage of development where it becomes possible to all but disregard classical distinctions between solid, liquid and gaseous fuels, and to consider almost any form of carbon as a potential source of "petroleum hydrocarbons". In the decade ending with the second world war, Germany thus met the greatest part, and Britain some, of their respective needs of automotive and aviation fuels, industrial solvents and other petrochemicals by hydrogenation of coal and coal tars. South Africa is now covering 20–25 percent of her gasoline and petrochemical requirements by Fischer-Tropsch syntheses, using a coal-derived syngas as feedstock for this purpose. Several other countries, the U.S. among them, are now also manufacturing ammonia, methanol and certain plastics precursors by similar methods.
This paper is therefore intended to summarize what has been and could, technically, now be done to exploit non-petroleum hydrocarbons as sources of liquid fuels. What makes this timely is the fact that several of the relevant technologies are now clearly moving into the realm of the economically feasible and emerging as vital components in the United States' drive toward energy self-sufficiency. There are indeed already some indications that updated conversion processes, partly being developed in the U.S. from earlier British and German techniques, may on occasion prove preferable to the recovery of conventional oil and gas from the geographically more remote reservoirs that would otherwise have to be brought into play*.

The Principles of Synthetic Liquid Fuels Production
In principle, the distinction between solid, liquid and gaseous fossil fuels lies ultimately in their hydrogen contents.