Electrochemical Oxidation Of Daqing Oil Shale In Alkaline Medium

In order to optimize factors of electrochemical oxidation process and improve utilization efficiency of oil shale, this study focuses on the reaction characteristics of electrochemical oxidation of Daqing oil shale in alkaline medium and investigating electrochemical methods to obtain organic products, such as Water-soluble acid (WSA) and Water-insoluble acid (WIA).Based on the KOH alkaline medium, this study focuses on several oxidation conditions, such as current, potential, reaction time, temperature, alkaline electrolyte concentration of KOH and concentration of oil shale, which have effect on the process of oil shale electrochemical oxidation and regulation of products with the method of cyclic voltammetry, chronotentiometry and chronoamperometry in an H-style diaphragm electrolytic reactor with three electrodes.It finds that the yield of WIA is much more than WSA in the production and the rate-controlling step is that WIA turns into WSA. The best electrolysis factors are charged at Ni anodic, Pt cathode,0.2A (vs.SCE),60?,5h,8wt% of the KOH solution,16.67g/L of oil shale concentration with the method of chronotentiometry and the maximum of total oxidation product is 93.03%(daf oil shale).These factors prove that the yield of total oxidation products, WIA and WSA increase first and then decrease with higher current and alkaline electrolyte concentration. With reaction time going on and temperature increasing, the yield of total oxidation products and WIA increase first and then decrease, but the yield of WSA decreases.With higher concentration of oil shale, the yield of total oxidation products, WIA and WSA all decrease. Compared with the metal of Pt, Ni can reach to a higher yield of WIA and WSA as the anodic. When the method of chronoamperometry is applied, it proves that oxidation current increases with higher alkaline electrolyte concentration, however, the electrode is easier to be inactivated in higher alkaline electrolyte concentration. With higher anodic potential, the oxidation current increases. When the concentration of oil shale gets higher, the initial oxidation current and the ending stable current all decrease. As temperature and effective current corresponding to Arrhenius Equation, the apparent activation energy of electrochemical oxidation of Daqing oil shale in alkaline medium is 23.097kJ/mol. Aimed at obtaining much more organic acid with the method of chronoamperometry, the experiments should be carried out at 1.2V(vs.SCE),60?,5h,4wt% of the KOH solution,16.67g/L of oil shale concentration. And the maximum of total oxidation product reach to 96.63%(daf oil shale).The purity of gas production in cathode can reach to 99% in electrochemical oxidation of oil shale. The structure of WIA, electrolysis oil shale and ash-removed oil shale are analyzed by infrared absorption spectrum instrument.It finds that WIA is a kind of organic macromolecular chemical compound with several groups of aromatic ring, carbonyl and carboxyl.There is nearly no difference on the structure of the electrolyzed oil shale compared with the initial oil shale. With most of ash removed, the heterocyclic ring and branch in oil shale are broken. The connection of macromolecular structure gets weaken and the organic substance is added in inner oil shale.