Effect of Acid Washing on the Hydrotreatment of Solvent Refined Coal Liquids

Abstract

The major objective of this study was to investigate the effect of a decrease in nitrogen concentration on the catalytic hydrotreatment of Solvent Refined Coal (SRC) liquids. Two coal liquids were used: SRC Process Solvent and SRC II Heavy Distillate. Nitrogen compounds were extracted using dilute acidic solutions~ The effects of temperature, acid concentration and acid solution/oil volume ratio on the removal of nitrogen from the liquids were investigated. The raw SRC liquids, as well as liquids subjected to acid extraction, were hydrotreated in a trickle bed reactor at temperatures of 3 99 C and 413 C at 10. 34 MP a. Two catalysts were used: HDN-30 (American Cyanimid Co.) and Shell 324. The products were analyzed for nitrogen, sulfur, hydrogen, and carbon. Selected samples, as well as the feedstocks, were subjected to ASTM distillation. Representative samples were also analyzed for basic nitrogen. The results of the above analysis were used to compare the hydrotreatment runs made with acid washed feed with that of the raw feed. The effect on catalyst deactivation was then assessed.