Research On Refined Extraction Process Of Cyclopentane In Daqing Oilfield

Daqing Oilfield is the largest onshore oil field in China, every year, in which the naturalgas production has reached3.3billion cubic meters, along with the gas producing1.04million tons Light hydrocarbons. Daqing Oilfield chemical engineering ltd can process tonsof light hydrocarbon accordingly producing50thousand tons of pentane,3000ofCyclopentane. On the basis, the topic focuses on the refining process of cyclopentane.As an important chemical material, cyclopentane has no potential harmful influence onozone and global warming. Thus cyclopentane can be used to replace chlorofluorocarbon(CFCS) and be widely used the production of Freon-free refrigerator freezers industry, coldpipeline etc. In Daqing Oilfield Chemical Co., Ltd., however, the cyclopentane productcontains3.33%of2,2-dimethylbutane and its purity achieves only96%, lower than theindustry standard98.5%. This purity problem impacts the business economic benefits in along-term. In order to solve the purity problem and improve the quality and gradescyclopentane, the Chemical Co., Ltd and Institute of Chemical Technology carry out thetopic research cooperatively.Cyclopentane/2,2-two system not only a system, but also azeotropic system. In thecommon methods of separation are extractive distillation, distillation and extraction.Traditionally, extractive used single solvent as agent, but recently, scholars began to themixed solvent as agent. American Lee developed the of mixed solvent in extractivedistillation and some scholars also have some relative researches. But so far, neither theinternational nor domestic researchers have studies or detailed reports on the extraction agentabout cyclopentance/2,2-two methyl butane system, and also lack the datas of relativesystematic and feasible liquid-gas equilibrium. In order to confirm the suitable extractingagents, first of all, we can refer to the screening methods of tetrahydrofuran/ethanol azeotrope,methanol/acetone azeotropic system, and use the exiting thermodynamic models to predict itsrelative volatility and find the high selectivity of extracting agent. Finally, we integrateseveral factors, including the solvent selectivity, solubility, boiling point, corrosion resistance,compatibility, the energy consumption, price and raw material sources of separation process. We study the composition of the raw materials of pentane from the device in TheChemical Industry Co.,Ltd and conduct a comprehensive analysis of the hydrocarboncomponents with close-boiling to cyclopentane/2,2-two methyl butane. Then, we selected12kinds of commonly used solvents to test and verify the possibility of forming the closeboiling between other components and the current components. By means of preliminaryscreening of extraction solvent, experiments and computer simulation experiment, we finallydetermined the two formamide (DMF) with the most outstanding performance as theextraction solvent. According to the preliminary experiments, we carried out the refinedresearch and development on cyclopentane to design the process of extraction distillation.Ultimately, after determination of the extraction distillation route and preliminary design for3000tons/year device, in Daqing Oilfield Chemical Co.,Ltd., the product purity has reached99.2%, higher than the industry standard98.5%, achieving the effect project.