Oil Yield Losses Research Articles

EMPIRICAL APPROACH FOR THE DIAGNOSTIC ANALYSIS OF CHEMICALLY RELATED OIL YIELD LOSSES DURING THE RETORTING OF OIL SHALE

The analysis of chemically related oil yield losses during the retorting of oil shale is important for understanding the chemistry of a process, supplying data for modeling efforts and process control of a production facility. Previously developed gas chromatographic correlations for evaluating oil yield losses were duplicated using combined gas chromatograph/mass spectrometric data. Evaluation of these results through calculation of local oil yields indicated that they were higher than expected when compared to material balance oil yields. A new correlation was developed to estimate the fraction of oil lost by cracking plus combustion. The approach to the new correlation was based on selection of steranes and pentacyclic triterpanes as the species in shale oil which would undergo cracking and combustion to yield selected aromatic compounds. Evaluation of the results from this correlation for determination of local oil yields was found to produce acceptable results. The two approaches for estimating the fraction of oil lost by cracking plus combustion are compared. The differences appear to be that the earlier approach is dependent upon severe cracking and combustion conditions. The new approach for determining the fraction of oil lost by cracking plus combustion appears to be applicable to a wider range ofmore » process conditions and therefore is more useful in research.« less

Model Capabilities for In-Situ Oil Shale Recovery

The extensive oil shale reserves of the United States are now under development as an energy source. One of the approaches for extracting oil from shale is the so-called modified in-situ retort. The operation of such retorts for maximum yield requires an understanding of oil loss mechanisms so that operating strategies that minimize these losses can be developed. The present modeling capabilities for describing the behavior and yield from a modified in-situ retort are discussed. Two models that have been subject to comparison with laboratory retorts are described. The first is a one-dimensional model that treats the retort as a packed bed reactor; the second is a quasi-two-dimensional examination of block retorting. Both models are capable of predicting retorting rates, off-gas composition and oil yield losses to coking and combustion. The major need for modeling now is expansion to multi-dimensional simulation.

Effects of simulated rust epidemics on the growth and yield of sunflower

Oil yield losses in sunflower (cv. Peredovic) caused by rust infection (Puccinia helianthi) were greatly influenced by the growth stage of the plant when infection occurred and by the intensity of infection. Simulated epidemics produced under greenhouse conditions, where plants were first inoculated at the vegetative, budding, anthesis or seed development stages of growth and thereafter at 10 day intervals, resulted in reductions in oil yield of 85, 73, 38 and 13% respectively relative to those in uninoculated controls. In contrast, plants inoculated once only at each of these growth stages showed reductions in 011 yield of 13, 42, 35 and 10% respectively. When plants were inoculated at the vegetative stage and thereafter at 10, 20 and 40 day intervals, the reductions in oil yield were 85, 79 and 64% respectively relative to uninoculated controls. The reduction in oil yield of infected plants was caused by a reduction in the number of seeds produced per head, the weight of individual seeds and the percentage oil content of seeds. The effects of rust infection on other parameters showed similar trends to that on oil yield.