Predicted Costs of Environmental Controls for a Commercial Oil Shale Industry. Volume II. A Subjective Self-Assessment of Uncertainty in the Predicted Costs

摘要

The uncertainties in Volume I without extensive additional engineering effort were identified and quantified. Substantial uncertainty was found in several critical variables, allowing a broad range of possible values. Calculations of the cost impact associated with such broad ranges, however, did not always result in significant differences. Seven major areas of pollution control activity were judged to warrant the assessment effort. Three of these areas were found to contain significant uncertainty and additional research is suggested. These areas are: H sub 2 S removal from the retort gas stream (Stretford process); organic removal from process wastewaters (bio-oxidation or other alternatives); and slurry backfilling of spent Modified In Situ (MIS) retorts. The overall results of the assessment and analysis process are summarized in Table 1-1 in terms of total cost for pollution control. The distributions have been divided into three ranges in this table. A center range is given which contains 80% to 90% probability, and the costs outside this range with probabilities are given. The full distributions can be found in Section 5.0. The subjective probability distributions are a quantification of opinion. The probability of encountering costs below the low figure or above the high figure for each process and scenario is judged to be nearly zero. (ERA citation 05:014865)