Waste, agricultural

Electric power derived from present (ca 1992) technology via the combustion of wood and wood wastes, MSW, agricultural wastes, landfill and digester gas, and advanced digestion and turbine technology. 

G. T. Preston, in E. Ekman, ed.. Clean Fuelsfrom Biomass, Sewage, Urban Refuse, Agricultural Wastes, IGT, Chicago, 1976, pp. 89—114. 

Specific gravity is direcdy related to the bulk density of waste fuels prepared ia a variety of ways. Solid oven-dry (OD) wood, for example, has a typical bulk density of 48.1 kg/m (301b/ft ). In coarse hogged form, eg, <1.9-cm minor dimension, this bulk density declines to about24kg/m (151b/ft ). In pulverized form, at a particle size <0.16 cm, this bulk density declines to 16—19 kg/m (10—12 Ib/ft ). Similar relationships hold for municipal waste, agricultural wastes, and related fuels. 

Oxahc acid manufacture via the oxidation of carbohydrates is stiU actively pursued, especially in China (10—12). In India, processes which produce sihca and oxahc acid have been developed (13,14). The raw materials include agricultural wastes, such as rice husks, nut shell flour, com cobs, baggase, straw, etc. 

Includes wood, wood waste, peat, wood Hquors, railroad ties, pitch, wood sludge, municipal soHd waste, agricultural waste, straw, tires, landfill gases, fish oils, and/or other waste. 

In the United States, up to about 4 x 10 Btu/yr of biofuels ate consumed for electricity generation, raising process heat, and domestic heat. Eurthermore, much of the energy needs of many nations are met by biofuels, including wood and wood waste, spent pulping fiquors, bagasse, and municipal waste. Some use is also made of dried com cobs, rice hulls, and a wide variety of agricultural wastes used in niche appfications. 

Electric power generation using biomass as a fuel is economic in situations where the cost of the fuel is competitive with that of fossil fuels. The cost of a commercially available biomass steam—electric power plant is about 1500/kW for a wood-fired facility. If wood can be obtained at a cost of 2.00/GJ ( 2.10 X 10 /Btu), the total cost of power for base-load operation would be about 0.05/kWh. If wood or agricultural wastes are available at... 

Grain that is usable as food or feed is an expensive substrate for this fermentation process. A cheaper substrate might be some source of cellulose such as wood or agricultural waste. This, however, requires hydrolysis of cellulose to yield glucose. Such a process was used in Germany during World War II to produce yeast as a protein substitute. Another process for the hydrolysis of wood, developed by the U.S. Forest Products Laboratory, Madison, Wisconsin, uses mineral acid as a catalyst. This hydrolysis industry is very large in the former Soviet Union but it is not commercial elsewhere. 

Sliding separation Household refuse, agricultural wastes... 

A line of burning agricultural waste can be considered to be a finite line source 150 meters long. It is estimated that tlie total emission of orgmiics is a t a rate of 90 g/s. What is the 3- to 15-niinutc concentration of organics 400 meters directly downwind from the center of the line when tlie wind is blowing at 3 m/s perpendicular to the line Assmne a suiuiy fall afternoon. What is the concentration directly downwind from one end of tlie source ... 

This chapter discusses the present status of microbial SCP production from agricultural wastes and describes some of the technical and economical problems related to the production processes that must be overcome for large-scale application to be possible. 

Bacteria, yeast and algae are produced in massive quantities of protein sources as food for animals and humans.1 SCP is considered a major source of feed for animals. The production of valuable biological products from industrial and agricultural wastes is considered through the bioconversion of solid wastes to added-value fermented product, which is easily marketable as animal feedstock. The waste streams that otherwise would cause pollution and threaten the environment can be considered raw material for CSP production using suitable strains of microorganisms. 

The main carbon source for production of SCP is petroleum. It has been practised in many companies around the world. Other potential substrates for SCP include bagasse, citrus wastes, sulphite waste liquor from pulp and paper, molasses, animal manure, whey, starch, sewage and agricultural wastes. 

Table 14.1. Methods for conversion of cellulosic agricultural wastes into animal feed...

Several potential and mutant strains of T. viride have been identified in SCP production. Their capacity for amyloletic enzyme production was enhanced severalfold in SCP from lingnocellulosic resources. The process of bioconversion of agricultural wastes to SCP appeared to be too complex to find an economic application for agricultural waste. 

Large amounts of agricultural waste products, such as corn cobs, are continuously provided in several developing countries. Xylan is considered to be a green polymer that may play an essential role in the renewability of waste products due to its biodegradable and biocompatible nature. Furthermore, as shown in this chapter, xylan presents particular properties that allow a wide range of applications. 

The most studied system for agricultural waste recycling is their bioconversion into fiiels [1], such as ethanol production from sugarcane molasses, citrus peels [2] and whey [3],... 

On the other hand, agricultural wastes can be alternatively used as substrates for edible biomass production. Cotton plant stalks [8], maize residues [9], olive milling wastewater [10] have been tested for cultivation of Pleurotus sp. fruiting body. 

The European Economic Community have shown considerable interest in releasing ferulic acid from low value agricultural waste residues such as SBP, with subsequent bioconversion of the free acid to vanillin. Previous studies with commercial enzyme preparations have shown a high degree of solubilisation of ferulic acid from SBP is possible, giving rise to a mixture of free and esterified forms [9,10], However, it is not known which... 

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