The occurrence of oxygen in lignite derivatives and residue from catalytic ethanolysis of Shengli lignite under an inert atmosphere

Abstract

Lignite is rich in aromatic structures and oxygen atoms, which have the potential to produce organic oxygen-containing compounds. Investigating the cleavage of the >CH–O– bond and oxygen transfer behavior in the catalytic ethanolysis of lignite is indispensable. Herein, A difunctional catalyst composed of HZSM-5 and Ni nanoparticles was fabricated for splitting the >CH–O– bond in the absence of H2. It is found that the >CH–O– bond in Benzyloxy benzene (BOB) could be completely broken with ethanol in the absence of H2. Ethanol can be activated and release H+ over Ni/HZSM-5, which transfers and attacks the >CH–O– bond for obtaining toluene and phenols. The soluble portions from ethanolysis of Shengli lignite were analyzed with fourier transform infrared spectrometer and gas chromatograph/mass spectrometer for tracking the migration of oxygen atoms. It is apparent that esters with higher relative content (32.6 %) were detected in soluble portion 1 (SP1), while alcohols (35.3 %) dominate catalytically soluble portion 1 (CSP1). Moreover, a large number of alkyl-substituted phenols were identified in both SP1 and CSP1. Additionally, related analysis of SL and residual coal manifested that >CH–O– and >C=O bonds were the main forms of existence in residue from catalytic ethanolysis of SL. In a word, exploring the occurrence of oxygen in catalytic ethanolysis of lignite has the potential to produce lignite-derived organic oxygenated chemicals.