Partial Oxidation Of Methane In The Acetate Mixed Solvent

In this thesis,the current research of catalytic partial oxidation of methane at home and abroad was reviewed.And the literature indicated that the solvent which used in the partial oxidation of methane were mainly trifluoroacetic acid(TFA) solution and H₂SO₄ solution. For the high cost of TFA,the research of partial oxidation of methane in TFA solution was not so many,and the research was not making much progress.The research of partial oxidation of methane in H₂SO₄ and oleum system were a lot,because the lower cost of solvent system,higher conversion of methane and a better prospect for industrialization. However,the problems of this system are the corrosion of equipments,environmental pollution and recycle process of oleum.According to the above problems,this research was based on the feature of the solution used in partial oxidation of methane,exploited a new kind of mixed solvent which contains heteropolyacid(HPA) and acetic acid.The main work included the screening of solvent, oxidant,and the catalysts.Above all,the process conditions were studied.In the end,the catalytic mechanism and the thermodynamic of partial oxidation methane were also investigated.Firstly,the screening of solvent,include the concentration of the acetic acid solution and the type of the HPA was carried out.Secondly,KMnO₄ was found out as the proper oxidant. Thirdly,several kinds of catalysts were also investigate such as I₂ series,metal transitional ion,platonic complex,SO₄^2-/M_xO_y solid super acid catalyst and acetate catalyst.According to the result above,the conditions such as temperature and pressure were studied.The experimental results indicated that the methane conversion of 12.98%and methyl acetate selectivity of 84.39%can be obtained when the concentration of I₂ 0.04 mol·L^-1, phosphotungsticacid 0.072 mol·L^-1,KMnO₄ 0.158 mol·L^-1,reaction temperature 210℃, pressure of methane 4.0MPa.Based upon the literature and the phenomena of the experiments,mechanism studies show that this reaction was suggested as the electrophilic alternative mechanism.In the end, thermodynamic of partial oxidation methane were analyzed.It results that the way methane was transformed into methyl acetate can react spontaneously in this temperature range.