Selective production and characterization of aromatic carboxylic acids from Xianfeng lignite-derived residue by mild oxidation in aqueous H2O2 solution

Oxidation of Zhundong subbituminous coal in aqueous Fe2+/ glacial acetic acid solution with H2O2

“…Low-rank coals (LRCs) are plentiful fossil resources, but they have low calorific value, high water content, high ash yield, poor thermal stability, and easy spontaneous combustion, which make LRCs difficult in the current industrial use, such as combustion, pyrolysis and gasification (Doskočil et al 2014;Liu et al 2019b;Liu et al 2016;Liu et al 2013a;Liu et al 2013b;Liu et al 2013c;Liu et al 2018;Liu et al 2015;Mae et al 2001;Miura et al 1996;Wang et al 2013;Wang et al 2012;Wang et al 2014;Yu et al 2014). Therefore, it is necessary to exploit a new conversion method for utilizing LRCs efficiently based on its structural characteristics (Liu et al 2019b;Liu et al 2018).…”

“…Hence, the oxidation of LRCs have attracted much attention from researchers. Classified by the kinds of oxidants, the method of oxidative depolymerization of LRCs includes RuCl 3 -NaIO 4 oxidation (Huang et al 2008;Liu et al 2014;Lv et al 2016;Murata et al 2001;Stock and Wang 3 1986), O 2 oxidation (Wang et al 2013;Wang et al 2012), NaClO oxidation (Liu et al 2013a;Lv et al 2018;Wang et al 2014;Yao et al 2010) and H 2 O 2 oxidation (Doskočil et al 2014;Liu et al 2019b;Liu et al 2018;Liu et al 2015;Mae et al 2001;Miura et al 1996;Tahmasebi et al 2015;Wang et al 2018). The high cost of RuCl 3 -NaIO 4 makes it difficult for industrial applications.…”

“…Miura et al (Miura et al 1996) found that the oxidation of LRCs using H 2 O 2 under mild conditions could produce small molecule fatty acids in high yield and in high selectivity in 1996. After that, H 2 O 2 oxidation of coal was used to produce carboxylic acids, including aliphatic carboxylic acids and benzenepolycarboxylic acids, and reveal molecular structure of coal (Doskočil et al 2014;Liu et al 2018;Liu et al 2015;Wang et al 2015b;Wang et al 2018). However, to our knowledge, few reports were issued on improving the reactivity of H 2 O 2 and coal.…”

“…Oxidation of coal with H 2 O 2 was a free radical reaction, which hydroxyl radicals (•OH), derived from the decomposition of H 2 O 2 , reacted with coal to achieve oxidative depolymerization of coal (Liu et al 2018;Pan et al 2013). Fe 2+ is prone to catalyze H 2 O 2 decomposition to form •OH, as shown in Eq.…”

Conversion of Organic Matter in Coal by Photocatalytic Oxidation with H2O2 over SFC/TiO2 in Isolated Oxygen System

“…In understanding the composition and structure of organic matters (OMs) in coals and in using coals effectively, the mild oxidation and the separable and nondestructive analysis method of coals at the molecular level coals have increasingly been the focus of scientific study over the past decades [1][2][3][4][5][6][7][8][9][10][11][12][13]. Meanwhile, the oxidation products of coals are usually viewed as an important source of high value-added products [14][15][16][17][18][19].…”