Crop by-products

Practical methods for reduction of residues (by washing, peeling, cooking, etc) Proposed tolerance (in each crop and crop by-product)... 

Biomass potentials are mainly determined by agricultural productivity and the amount of land accessible for energy crop production. The total area under energy crops in the EU was around 1.6 million hectares in 2004 (estimate for 2005 2.5 million hectares), which represents nearly 3% of the total arable land. AEBIOM (2007) estimated a total biomass supply of 220 MtOE for the year 2020, while 23 MtOE are covered by wood-based bioenergy (direct from forests) and 88 MtOE by agriculture-based energy crops (by-products not considered). The Commission has estimated that about 15% of the EU s arable land (17.5 million hectares) would be used to reach the targets for 2020. 

Cropping renewables explicitly for polymer production is environmentally disadvantageous. The use of crops as feedstock can only be advantageous if the crops by-products are used for producing polymers. Biotechnological production routes can potentially result in more environmentally friendly polymers. The assessment of renewable resources for use in polymers and other products has to be carried out in a case-specific manner [11]. 

Stanley E. Manahan is a professor emeritus of chemistry at the University of Missouri-Columbia, where he has been on the faculty since 1965. He earned his AB in chemistry from Emporia State University in Kansas in 1960 and his PhD in analytical chemistry from the University of Kansas in 1965. Since 1968, his primary research and professional activities have been in environmental chemistry, with recent emphasis on hazardous waste treatment. His latest research involves the gasification of wastes and sewage sludge and crop by-product biomass for energy production. 

Economic Aspects and Uses. Ammonium chloride is used as a nitrogen source for fertilization of rice, wheat, and other crops ia Japan, China, India, and Southeast Asia. Japan is a large producer, much of which is as by-product. 

Fig. 1. United States agricultural crop markets for manufactured controlled release fertilizers, 1990. (a) Total percentage ( 14 million) of market value by crop and (b) total percentage (6,800 t) of consumption by product type. IBDU is isobutyUdene diurea PCF, polymer-coated fertilizer UF,...

An additional quantity of product of lesser purity can be obtained as a second crop by evaporation of the pentane. 

Xanthan has some unique properties and high activity at low concentrations and is commercially the most important exopolysaccharide. Food products account for approximately 60% of xanthan use, 15% is accounted for by toothpaste, textiles and crop protection products, 10% in the oil industry and the remainder in miscellaneous industrial/consumer applications. 

Potential resources of xylans are by-products produced in forestry and the pulp and paper industries (forest chips, wood meal and shavings), where GX and AGX comprise 25-35% of the biomass as well as annual crops (straw, stalks, husk, hulls, bran, etc.), which consist of 25-50% AX, AGX, GAX, and CHX [4]. New results were reported for xylans isolated from flax fiber [16,68], abaca fiber [69], wheat straw [70,71], sugar beet pulp [21,72], sugarcane bagasse [73], rice straw [74], wheat bran [35,75], and jute bast fiber [18]. Recently, about 39% hemicelluloses were extracted from vetiver grasses [76]. 

The number of reports about hemicelluloses that have been covered by this review indicates the significantly increased importance of all types of hemicelluloses as plant constituents and isolated polymers during the last decade. Attention has been paid not only to known hemicelluloses but also to the primary structure, physicochemical, physical, and various functional properties of hemicelluloses isolated from hitherto uninvestigated plants. The efforts to exploit a variety of plant as potential sources of hemicelluloses were pointed out particularly for agricultural crops, wood wastes, as well as for by-products of pulp and rayon fiber technologies. Many studies were devoted to characterize seed-storage hemicelluloses from plants that have been traditionally applied in food and medicine of many underdeveloped countries to find substitutes for imported commercial food giuns. 

A gas chromatographic analysis by the checkers (see Note 10) on the material in the third crop from one run showed a major peak for 1-adamanttUiol and a second minor peak having an area ca. 12% of that of the major peak. In another run the area of the peak from this by-product in the third crop was less than 2% relative to that of 1-adamantanol. 

Tsao, R. and Yang, R., Lutein in selected Canadian crops and agri-food processing by-products and purification by high-speed counter-current chromatography, J. Chromatogr. A, 1112, 202, 2006. 

The recrystallization of the crude tryptophane is an extremely troublesome process. Not only must a less soluble by-product be removed, but the mother liquors contain a more soluble, gummy impurity in considerable proportion. After collecting each crop, the mother liquor must be evaporated to a small volume on the steam bath and treated with a double volume of alcohol. This process is repeated until no further crystals are obtained, but only a gum. 

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