Annual percentage yield

AISE Association of Iron and Steel Engineers APY annual percentage yield... 

From coal tar by distillation there are obtained a number of aromatic compounds. Upon coking, a ton of soft coal may yield about 120 pounds of coal tar. From this 120 pounds the following aromatic compounds can be separated benzene, 2 pounds toluene, 0.5 pound xylenes, 0.1 pound phenol, 0.5 pound cresols, 2 pounds naphthalene, 5 pounds. Two pounds of benzene from a ton of coal does not represent a very high percentage yield, yet so much coal is coked every year that the annual production of benzene from coal tar is enormous. 

A realistic assessment of biomass as an energy resource is made by calculating average surface areas needed to produce sufficient biomass at different annual yields to meet certain percentages of fuel demand for a particular country (Table 2). These required areas are then compared with surface areas available. The conditions of biomass production and conversion used in Table 2 are either within the range of 1993 technology and agricultural practice, or are believed to be attainable in the future. 

The burning of fossil fuels in the United States has been calculated to yield 8,000,000 pounds of selenium annually as a pollutant to the atmosphere. However, in the industrial northeastern United States where a large percentage of these fuels are burned, 65% of the forage crops analyzed by Kubota and his associates (28) contained insuflBcient selenium for the growth of healthy animals. 

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