Pyrolytic oil

Pyrolysis Of the many alternative chemical conversion processes that have been investigated, pyrolysis has received the most attention. Pyrolysis has been tested in countless pilot plants, and many full-scale demonstration systems have been operated. Few attained any longterm commercial use. Major issues were lack of market for the unstable and acidic pyrolytic oils and the char. 

F. Cataldo, Evaluation of pyrolytic oil from scrap tires as plasticizer of mbber compounds. Progress in Rubber, Plastics and Recycling Technology, 22(4), 243, 2006. 

In liquefaction systems wood and wood wastes are the most common fuelstocks. They are reacted with steam or hydrogen and carbon monoxide to produce liquids and chemicals. The chemical reactions that take place are similar to gasification but lower temperatures and higher pressure are used. Liquefaction processes can be direct or indirect. The product from liquefaction is pyrolytic oil which has a high oxygen content. It can be converted to diesel fuel, gasoline or methanol. 

Vitelo, S., Seggiana, M., Frediani, P., Ambrosini, G., Poloti, L., Catalytic upgrading of pyrolytic oils over different zeolites, Fuel, 1999, 78, 1147. 

Chantal, P.D., Kaliaguine, S., Grand-maissen, J.L., Mahay, A., Production of hydrocarbons from Aspen Poplar pyrolytic oils over HZMS-5, Appl. Catal., 1984, 10, 317. 

The process is used on petroleum sludges, used tires, biomedical waste, automobile shredder residues, bark residues and municipal solid wastes. It is limited to treating organic wastes and contaminated soil. For soil contaminated by polychlorinated biphenyls (PCBs), vacuum pyrolysis cannot destroy the PCBs but will concentrate them in the pyrolytic oils. The process cannot be used to treat mine tailings. 

For as long as it has been known that waste tires harbor mosquitoes, it has been known they pose a fire hazard. Tire fires are particularly bad because of the difficulty in extinguishing them. This is because of the 75 percent void space present in a whole waste tire, which makes it difficult to either quench the fire with water or cut off the oxygen supply. Water on tire fires often increases the production of pyrolytic oil and provides a mode of transportation to carry the oils off-site and speed up contamination of soils and water. 

Although pyrolytic oil contains significant quantities of benzene and toluene that have high value in the pure form, removal of these compounds from the pyrolytic oil requires expensive fractional distillation equipment. Pyrolysis operators have been reluctant to make the capital investment in distillation equipment because the risk is too high and the return on investment is too low. As a result, the pyrolytic oil must be sold as a replacement for Number Six (low priced grade) fuel oil. The oils generated at Conrad s Centralia facility contain a maximum of 1.5 percent sulfur, and have a potential market as blender oils for commercial fuel.1... 

Tipping fee, credit received for tire disposal, /tire b Selling price of pyrolytic oil, /gallon... 

Williams PT, Horne PA. Analysis of aromatic hydrocarbons in pyrolytic oil derived from biomass. J Anal Appl Pyrolysis. 1995 31 15-37. 

The liquid product obtained from thermal cracking can be either catalytically cracked/ hydrocracked or co-processed with a refinery feed. Since the catalytic cracking of oil derived from MWP is more or less problematic, any cracking catalyst can be applied to oil derived from pyrolysis of plastics. But the yield and the quality of gasohne obtained from cracking step vary with the type of catalyst and the properties of the pyrolytic oil derivated from waste plastics. 

P. T. Williams S. Besler and D. T. Taylor, The batch pyrolysis of tyre waste - fuel properties of the derived pyrolytic oil and overall plant economics. Proceedings of the Institution of Mechanical Engineers Part A. Journal of Power and Energy, 207, 55-63 (1993). 

Epstein, Kostrin, and Alpert (1978). The feedstock was pyrolyzed in a 0.5-m ID fluid-bed reactor containing sand and an inert gas generated from compressed air-natural gas combustion with a slight excess of air (about 0.2 to 0.6%). The fluidizing velocities were 0.3 to 1 m/s. The products were low-energy gas (3.89-11.78 MJ/m- (n)), pyrolytic oil (23.3-27.9 MJ/kg), and charcoal. Feed rates were 50-200 kg/h. The moisture contents of the feedstocks were not specified. The balance of the yield for each feedstock is water. 

Williams, PT and PA Home (1995) Analysis of Aromatic Hydrocarbons on Pyrolytic Oil Derived from Biomass, J. Anal. andAppl. Pyrolysis 31 15-37. 

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