The Development of the PGL (Pyrolysis, Gasification, Liquefaction) Processes

[Gale]

This entry is to educate skeptics who think that these technologies are only done by backyard mechanics. PGL is not a new technology just one forgotten with the advent of cheap foreign oil. Thankfully with these high gas prices, stubborn consumers are looking to help out their pocketbooks while earth conscious people are looking for more sustainable technology to fit their energy needs.

In 1830, a developer successfully commercialized an early application of pyrolysis involving the production of liquid products from wood [2-3]. The production of coke from coal pyrolysis became the most common application of the technology; its use continues today.

Using wood pyrolysis to manufacture creosote oil expanded after the introduction of creosote as a wood preservative in 1838. Pyrolysis of coals and oil shales became common to produce oils in the United States and elsewhere in the mid-1800s (e.g., 55 to 60 plants in Kentucky, Ohio, and Pennsylvania; about 25 in Connecticut, Massachusetts, and New York). Pyrolysis plants to produce illuminating gas became common worldwide until the invention of the electric light bulb in 1879 ended further development [2-3].

The coal industry has applied liquefaction during the past five decades. Coal hydroliquefaction satisfied one third of the German petroleum needs during World War II.

By the early 1980s, only the South African Coal, Gas and Oil Company was condensing liquid fuels from coal [2-4]. In addition to coal, wood, and oil shake, feedstocks for PGL processes include municipal solid wastes and organic materials derived therefrom (e.g., plastics, tires, rubber, mixed paper, textiles, etc.); agricultural wastes (e.g., rice hulls, straw, etc.); and wastewater treatment sludges.

Previous Surveys of Tire PGL A survey of PGL, gasification, and liquefaction processes worldwide as of fall 1977 [2-5] revealed ten projects that had used tires as a feedstock:

1. Pyrotechnic Industries, Ltd., Calgary, AL, Canada - fixed bed shaft furnace, (C),3 mixed feedstock
2. DECO Energy Co., Irvine, CA - Agitated solids bed, (C), tires only
3. TOSCO Corp./Goodyear Tire and Rubber - Tumbling solids bed, (A), tires only
4. Thermex, Inc., Hayward, CA - Static solids bed, (A), tires only
5. Carbon Development Corporation, Walled Lake, MI - Static solids bed, (A), tires only
6. Firestone Tire and Rubber Co., Akron, OH - Electrically heated, (I), tires only
7. University of Tennessee, Knoxville, TN - Molten salt bath, (A), mixed feedstocks
8. Foster Wheeler, London, United Kingdom - Moving packed bed, (A), mixed feedstocks
9. Herko Pyrolyse GmbH & Co., Karlruhe, Germany - Tumbling solid bed, (C), tires only
10. Firma O. Herbold, Germany - Agitated solids bed, (A), tires only

Only one firm described in this early survey remains in business under the same name in 1993 (Thermex) [2-5].

In its 1983 study of tire PGL, the U.S. Department of Energy (DOE) concluded the following:

1. There were 31 existing plants, of which approximately one half were active.
2. Tire pyrolysis was technically feasible.
3. The economics appeared marginal at best except under special conditions:
- the cost of competing disposal was high,
- tax advantages accrued to the project, or
- high value products were produced.

This data is from the CalRecovery report of July 1995