High-Sulfurous Argentinian Asphaltites and Their Thermal Liquefaction Products

Abstract

The results of profound chemical studies of asphaltites from the Rafaelita and Toribia fields (Mendosa and Neuquen provinces, Argentina) and prospects for their processing are presented. The composition and structural features of maltenic, asphaltene-carbenic and carboid components of these natural coal-like substances were investigated. Laboratory experiments on thermal liquefaction of asphaltites were performed, including: 1) destructive distillation (pyrolysis) at temperatures gradually rising up to 600°C; 2) thermal destruction under conditions of programmed temperature increase from 25 up to 350 or 450°C with a rate of 5°C/min and with simultaneous dilution of reaction products by straight-run diesel petroleum distillate; 3) thermal treatment of the studied sample under stationary conditions (at 350°C for one hour in water, tetraline or n-decane); and 4) thermal destruction of asphaltite samples under flow conditions (continuous ablution of reactor with water or decane, temperature rising from 25 up to 500°C, with periodical sampling at different temperature levels). The largest yields of liquid fuels were obtained when the thermal destruction process was performed in hydrocarbon medium at temperatures not lower than 400-450°C, with continuous removal of products from the reaction zone. The yield of desirable hydrocarbon products reached 25 wt.% of asphaltite organic mass, when decane served as reaction medium, and could be increased up to 70 wt.% by substituting this solvent with real petroleum (diesel) distillate.