In-Depth Experimental Study on Thermochemical Conversion of Furan in Molten Alkali Carbonates

Abstract

Furan is a typical heterocyclic compound in pyrolytic tar and has a strong tendency of coke deposition in thermochemical conversion, leading to catalyst deactivation for tar upgrading. The present study proposed a promising method for furan cracking and reforming using molten alkali carbonates (Li2CO3–Na2CO3–K2CO3). The results showed that a little gas was generated in the conversion process and CO dominated the gas species. In comparison to the experiment under salt-free conditions, the decarbonylation of furan in molten salt conversion was strengthened and oxygen could be removed as H2O into the liquid products. Under the catalysis of alkali metal cations, the conversion of furan to aromatic compounds was promoted at each temperature. Moreover, excess CO2 enhanced the reverse water–gas reaction, resulting in the consumption of H2 and the increase of CO in gaseous products. In addition, coke produced in molten salts was of higher reactivity and could hardly affect the stability of the molten salt system. On the basis of the good thermal conversion behavior as well as anticoking performance of molten carbonates, these findings offer a new way for the proper reforming and upgrading of furan through molten salt thermal treatment.