Study On The Complexion Property Between Vanadium Ions Of Different Valance States And Tannin Extract

With natural gas, coal gas, petroleum and chemical industries, H2S pollution problems have become increasingly prominent, desulfurization technology is gradually attention.Tannin extract desulfurization process is the improvement of A.D.A desulfurization process for further optimization of desulfurization process, is an important component of the system, in the country in various fields has been widely used.On the improvement of A.D.A desulfurization process, in order to prevent the precipitation of the generation, need to add potassium sodium tartrate, and tannin extract desulfurization process, extract the join, not to add other complexing agent under the conditions of no precipitation, formation.The extract has certain complexation.Tannin extract is rich in single Ning bark, shell and gall as raw material, after extraction, concentration, drying and other steps of evaporation process, is a kind of complicated natural compounds.By reading the literature and found, to extract and vanadium ion complexation studies is still not perfect, based on this, this article through the infrared spectroscopy analysis qualitative analysis of tannin extract oxide and reducing tannin structure difference and by chemical titration method for quantitative analysis of the oxidized tannin extract, reduction of tannin extract and single Ning in the acidic functional groups content of tannin and experimental conditions; tetravalent vanadium ion and pentavalent vanadium ion complexing effect made detailed research; to extract and two valence vanadium ion complexation were compared.According to the experimental results, both the oxidized tannin extract or reduction of tannin extract, contains a lot of associating the hydroxyl group, this is the extract can be used as an oxygen carrier and has complex root causes; tannin extract oxide containing carboxyl, hydroxyl content of0.4735mmol/g; reduction of carboxyl group content of tannin in3.410mmol/g, the phenolic content of2.177mmol/g; single Ning in the carboxyl content of4.640mmol/g, phenolic hydroxyl group content of1.838mmol/g.Vegetable is the main component of single Ning, Ning and single tetravalent vanadium ions and pentavalent vanadium ions complexation in200-400nm of near ultraviolet region of the spectrum with absorption, and absorption of the difference is not big, single note Ning with two valence vanadium ion complexation alike; single Ning and vanadium ion complexation absorption intensity as the solution system temperature decreased; with the complex time and decreased with the increase of pH.Study of catechol, even of three phenol, gallic acid, single Ning four tannin extract small molecule model compounds with tetravalent vanadium ion and pentavalent vanadium ion complexation, found four model compounds can and tetravalent vanadium ion and pentavalent vanadium ion complexation reaction, and pentavalent vanadium ion complexing ability to tetravalent vanadium ion.When the vanadium ions with model compounds than the concentration reaches to a certain degree, model compounds with pentavalent vanadium ion complexation, and almost no and tetravalent vanadium ion complexation; in the tannin extract model compounds in complex reaction, not only in the presence of single molecule in Pro a hydroxyl on vanadium ion complexation, the simultaneous presence of the two ligand molecules two phenolic hydroxyl group on a vanadium ion complexation; ligand and vanadium ion complex occurs mainly in the pro a phenolic hydroxyl group, when the ligand molecules containing carboxyl groups on the benzene ring, so that the phenolic hydroxyl group rich electronic, so as to facilitate the molecules within the complex, and the carboxyl group of the steric hindrance may inhibit intermolecular complexation reaction.