Upgrading Coal-Derived Liquids for Toxicity Mitigation. I. Evaluation of Non-Hydrotreatment Processes as Alternates or Supplements to Hydrotreatment

摘要

Seven non-hydrotreatment processes related to petroleum refining practices have been evaluated at the laboratory scale as alternates to hydrotreatment in the toxicity mitigation of several coal-derived liquids. These treatments were distillation, acid treatment, alkaline treatment, pentane deasphalting, pentane-furfural partitioning, clay percolation, and oxidation. The treated products were subjected to Ames microbial mutagenicity testing or 10-animal mouse dermal tumorigenicity screening. The effects of treatment on dermal tumorigen PAH (especially BaP) in some of the treated products also were determined. The results confirm that distillation is a generally desirable first step in upgrading coal-derived liquids. Only the VGO fraction (or distillates containing VGO-boiling range material) shows significant positive results in mutagenicity and mouse skin tumorigenicity assays. Acid treatment, pentane deasphalting, and pentane-furfural partition were found to be promising for removing mutagenicity, but less effective in removing tumorigenicity from an H-Coal VGO. Alkaline treatment did not reduce mutagenicity but might remove tumor promoting agents. The effectiveness of both sulfuric acid and sodium hydroxide processes as pretreatments to improve toxicity mitigation by catalytic hydrotreatment (over Pd/C or sulfided Shell 324 M nickel/molybdenum catalyst) was also investigated by laboratory hydrogenation of H-Coal VGO. Sulfuric acid pretreatment improved the reduction of BaP, especially in the case of Pd/C. However, sodium hydroxide pretreatment did not substantially improve BaP reduction. 21 refs., 8 tabs. (ERA citation 11:006891)