Evaluation of an Ethanol Distillation/Dehydration Process Utilizing Ammonium Nitrate as an Extractive Agent. Final Progress Report

摘要

The purpose of this grant was to evaluate a process where a fertilizer is used as an extractive agent for the distillation/dehydration of ethanol. Preliminary studies indicated such a process would have certain advantages over the traditional benzene process for producing gasohol quality ethanol. This work had two main objectives. First, commercial fertilizers were screened to identify those which would break the ethanol-water azeotrope. Then, process economics for this process were compared with the benzene process. During this study, seven fertilizers were screened. Only ammonium nitrate had sufficient effect to break the azeotrope. Once a suitable fertilizer was identified, enough additional data was obtained to make process design calculations. The process evaluation which followed showed that at a 20MM production rate distillation costs ranged from 31 cents/gal to 38 cents/gal (depending on the reflux ratio). This compares well with the 36 cent/gal cost that was calculated for the benzene process. The principle difference between the above numbers is the energy consumption. A price/volume relationship was also established for this process. The principle disadvantage of this process is the high consumption of fertilizer. It was hoped that the fertilizer usage could be limited to that needed to grow the crops. Actual usage is estimated to be 6 to 10 times this requirement. Thus, if this process is used, a market for this fertilizer must be available. This study is based on lab scale experimental results. While these results are adequate for this economic evaluation, the process should be through a pilot plant evaluation before definitive process design work is undertaken. 16 references, 10 figures, 25 tables. (ERA citation 09:004517)