Radiation treatment of solid wastes

Solid waste is now generally recognized as both a major problem and an underutilized renewable resource for materials and energy recovery. Current methods for dealing with solid wastes are admittedly inadequate for cost effective utilization of the latest material and energy values, especially of cellulose and other organics. Processes for production of energy from organic wastes including incineration, pyrolysis and biodegradation, are receiving considerable attention even though the heating value of dried organic wastes is substantially less than that of fossil fuels. An attractive alternative approach is conversion into chemical feedstocks for use as fuels, intermediates for plastics, rubbers, fibers etc., and in the preparation of foods. Radiation treatment of solid wastes offers attractive possibilities for upgrading the value of such organic waste components as cellulose and putrescible matter. The latter can be cold sterilized by radiation treatments for the production of animal feed supplements. The wide availability of cellulosic wastes warrants their consideration as an alternate feedstock to petrochemicals for fuels, intermediates and synthesis of single cell protein. The crucial step in this developing technology is optimizing the conversion of cellulose to its monomer glucose which can be accomplished by either acid or enzymatic hydrolysis. A combination pretreatment consisting of radiation of hydropulped cellulosic wastes has shown considerable promise in improving the yields of glucose for acid hydrolysis reactions at substantially lower cost than presently used methods such as grinding. Data are presented to compare the effectiveness of this pretreatment with other techniques which have been investigated.