| Methanol is the mother of C1 chemicalindustry.In recent years, the scale of domestic methanol plant production is growing.But the problem of excessive energy consumptionof domestic methanol production enterprises as compared with the high cost of production abroad is widespread.Qinghai is located in the Qinghai-Tibet Plateau, where has a high altitude, temperature, low pressure, high temperature characteristics, whose unique characteristics is different from the mainland methanol production.Aiming at the characteristics of a 300,000 tons/year of natural gas methanol plant in Qinghai district.Make simulation and analysis of production status, putting forward the views of the adjustment process parameters.Find a suitablecase for high altitude Qinghai efficient production of methanol solution through the whole production process can be used with water-related systems integration analysis and optimization in order to improve material utilization, and promote energy conservation and reduce production operating costs purpose.Qinghai chemical enterprises, located on the "Three Rivers head" and "Chinese water tower", in improving the ecological carrying capacity of resources and the environment, carrying out the implementation of energy-saving, water-saving and emission reduction work has a more social and economic double meaning.The main work is as following(1)With the use of chemical engineering simulation systemsoftware "ECSS-Chemicals Star" (short for "chemical Star"),natural gas to methanol conversion process, synthesis, distillation and CO2 recovery section were simulated.The results obtained with the plant data collected in the field can be well fit.The model is accurate and reliable.It can be used for process optimization of operating energy and water systems integration and other follow-up work.(2)Through the simulation analysis the effects of high altitude,low pressure methanol distillation process possible for the entire four-column distillation system.Futher more, the atmospheric distillation column are optimized separately:Making use of the feature of crude methanol component at high altitude has low boiling point,in the premise of qualified products refined methanol and waste water discharge standards,the improved operating temperature and pressure of each column were decreased.The amount of fresh water and the cooling and heating loads are declained.Ensure the refined methanol of atmospheric distillation column can meet the purity standards, feed location must be selected in the lower part of the atmospheric tower,at 20 to 25 theoretical plates, selecting the operating reflux ratio of 3.0 to 3.5,the side cutting positions should be elected in the lower part of the 20 to 25 theoretical plates.(3) Through finding the energy "pinch" of natural gas methanol plant which located at high altitudes, putting forward the rational use of energy optimization by pinch analysis.By the analysis, the optimized heat exchanger network can save heating utilities 8622.7kW, energy-saving effect of 18.6%, saving cooling utilities 9891.1kW, energy savings effect of 14.6%.(4) Through the application of water pinch technology to the methanol production enterprises in the water system integration and optimization, which located on the Three Rivers Region, with the higher the total salt content in the raw water:Waste water using back directly network can reduce the amount of raw water 11.57t/h,desalted water 8.12t/h, reducing the amount of sewage discharge 14.7t/h compared to the former water-use network. Regeneration and reuse water network can reduce the amount of raw water 17.79t/h, reducing the amount of sewage discharge 19.95t/h compared to the former water-use network. |
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