Sequential Ruthenium Ion-catalyzed Oxidation Of Char Powder And Petroleum Coke

Shanbei Subbituminous Coal Char (SSBCC) and Yanshan Petrolum Coke (YPC) weresubjected to13steps and10steps sequential oxidation (RICO), respectively. Then, in order toobtain high value-added organic chemicals, the separation of oxidation products was conductedby medium-pressure preparative liquid chromatography (MPLC). The oxidation products andMPLC fractions were analyzed by GC-MS. The structural features of two samples arepresumed by comparing the differences in products among different steps. The results showthat the yield of benzenecarboxylic acids (BCAs) takes a dominant part in the oxidationproducts of SSBCC and YPC, and a certain amount of aromatic carboxylic acids (ACAs) weredetected, which imply that SSBCC and YPC are mainly made up of fused aromatic ring.Meanwhile, alkanoic acids (AAs) and akanedioic acids (ADAs) also exist in the oxidationproducts. With the oxidation step increasing, the yield and carbon number of AAs and ADAsare mostly decreasing, while the yield of BCAs and the number of carboxylic groups in BCAsare growing basically, suggesting the degree of condensation increase s progressively, while thenumber and carbon number of substituent reduce progressively from the external portion toinner portion in the two samples. In addition, there is ether linkage as well as polymethylenelinkages connecting aromatic rings in SSBCC, and there are structures of imidazole, pyridine,indole and thiophene unit existing in YPC. The differences in composition and structure amongSSBCC and YPC are presumed by comparing the differences among the products. The resultsshow that in oxidation products of SSBCC the yield of ACAs and the proportion of BCAs withmore carboxylic groups are higher than that in YPC, suggesting that the degree of condensationof aromatic rings in SSBCC is higher than that in YPC. Besides, the kind and carbon numberof AAs and ADAs are less in oxidation products of YPC than that in oxidation products ofSSBCC, implying the type and carbon number of alkyl side chains and alkyl bridged linkagesare less in YPC than that in SSBCC. Six purity were detected in the MPLC fractions, includingbis(2-ethylhexyl) phthalate,1,2,3-benzenetricarboxylic acid, trimethyl ester,1,2,4-benzenetricarboxylic acid, trimethyl ester,1,2,3,5-benzenetetracarboxylic acid,tetramethyl ester, benzenepentacarboxylic acid, pentamethyl ester and benzenehexacarboxylicacid, hexamethyl ester. Bis(2-ethylhexyl) phthalate is regarded as a biomarker, and the rest arethe prominent component from RICO. So, it is feasible to separate oxidation products ofSSBCC and YPC using MPLC to obtain high value-added organic chemicals.