In this paper. the influences of particle size, grade and pyrolysis temperature on the oil yield have been evaluated in a laboratory scale reactor. Five categories of particle sizes from two different oil shale samples were pyrolysed by employing a fixed bed retorting system. The reactor and the 011 shale sample were heated at a constant rate and nitrogen gas was used to purge the sample. continuously, in order to remove the pyrolysis products from the reactor as well as to reduce secondary reactions. The liquid products were condensed and collected in a series of cold glass-traps and the off-gases analysed for their hydrocarbon and non-hydrocarbon species. Subsequent experiments were conducted, employing a thermogravimetric analyser. using only the four smallest particle sizes under similar conditions as applied to the fixed bed retort. The activation energy was determined hy using the integral method. The pyrolysis of the investigated shales was found to comply with first-order kinetics within the limits of experimental error. Increasing the particle size resulted in a small rise in the liquid oil yield, however. the total gaseous production was simultaneously decreased.
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Fuel economy rebound effect for U.S. household vehicles Greene. D. L. et N/. The Emzrgy Jownal. 1999, 20, (3). S-31. This paper presents an econometric estimation of the 'rebound effect' for household vehicle travel in the United States based on analysis of survey data collected by the Energy Information Administration (EIA) at approximately three-year intervals over a 15-year period. The rebound effect measures the tendency to 'take back' potential energy savings from fuel economy improvements as increased travel. Vehicle use models were estimated for one-. two-, three-, four-and five-vehicle households. The results confirm recent estimates based on national or state-level data: a long-run 'take hack' of about 20% of potential energy savings. Consumer responses to changes in fuel economy or fuel price per gallon appear to be equal and opposite in sign. Recognizing the interdependencies among miles of travel. fuel economy and price is key to obtaining meaningful results.