Basic knowledge of PVC II

Last time we talked about the classification of polyvinyl chloride. Today, ZHONGSHAN LINYANG PLASTIC CO.LTD will come again to talk about the production process and cost analysis of polyvinyl chloride. 1. Production process PVC production mainly has two preparation processes, one is calcium carbide method, the main raw materials are calcium carbide, coal and raw salt; the other is ethylene method, the main raw material is petroleum. The production of PVC in the international market is mainly based on the ethylene method, while in China, due to the resource endowment of rich coal, poor oil and little gas, the calcium carbide method is the main method. As of December 2007, the calcium carbide method accounted for about more than 70% of the total capacity. It is worth noting that in the preparation of PVC by the calcium carbide method, hydrogen chloride is used to produce PVC after electrolysis of the original salt, and the remaining sodium part is used to produce caustic soda. Therefore, there is actually a symbiotic relationship between chlorine and alkali, and the balance of chlor-alkali is also a must in the development process of the entire industry. important factors not considered. 2. Cost analysis From the perspective of production cost, the cost of the two processes is quite different in different economic development cycles. Under normal circumstances, in the stage of rapid development of the international macro economy, due to the high oil price, the production cost of the ethylene method is relatively high, and the cost advantage of the calcium carbide method is obvious; but once the international economy enters a recession, the oil price will operate at a low level. , the prices of coal, electricity and oil transportation are supported, and the cost advantage disappears. Since 2003, the international oil price has risen sharply, which has increased the cost of PVC by the ethylene method, while the production of the calcium carbide method has been less affected by this, which has led to a new upsurge in the construction of domestic calcium carbide method PVC production units, which has greatly expanded the production capacity of calcium carbide method PVC. , posing a great challenge to the production of ethylene-based PVC, and many ethylene-based enterprises are on the verge of loss. However, with the continuous reduction of crude oil prices after May 2008, the cost advantage of the ethylene method is obvious, and the calcium carbide method manufacturers are operating at a low profit, or even unsustainable. The cost composition of the calcium carbide method is mainly composed of calcium carbide fees, hydrogen chloride fees and water and electricity fees. The national standard stipulates: the production of 1 ton of PVC consumes 1.45 to 1.5 tons of calcium carbide, (usually calculated at 1.45, but generally the actual production process consumption will be higher than this ratio, only a few can meet the standard), and the consumption of hydrogen chloride gas is 0.75 to 0.85 tons (generally Calculated at 0.76), the power consumption per ton is about 450 ~ 500kw?h, and other project expenses, such as packaging fees, initiators, dispersants, water fees, management personnel fees, etc. are different due to different manufacturers and production scales. all the same. Generally speaking, the distribution ratio of the cost composition of the calcium carbide method is about: calcium carbide accounts for 65-70%, hydrogen chloride accounts for 15%, electricity accounts for 6%, and other manufacturing costs account for 6%. A notable feature of the calcium carbide method is its high power consumption, which not only consumes electricity when producing PVC, but also consumes a lot of electricity when preparing calcium carbide from coke. and 0.9 tons of limestone. The main factors of the cost of ethylene method are ethylene consumption, chlorine consumption, power consumption, processing aids, management labor costs, etc. The ethylene method consumes 0.5 tons of ethylene and 0.65 tons of chlorine gas for every ton of PVC produced by the ethylene method, and the two account for about 60% of the cost. In the cost of raw materials, the cost of ethylene accounts for the main part, and the price of ethylene has a great influence on the cost of PVC. Although the energy consumption of the ethylene method is lower than that of the calcium carbide method, its equipment investment is very huge, so the equipment depreciation accounts for a large proportion of the cost. The equipment investment is fixed, so the change in the price of ethylene and vinyl chloride is the main factor for the price change of polyvinyl chloride resin. Founded in 2003, Zhongshan ZHONGSHAN LINYANG PLASTIC CO.LTD Decoration Materials Co., Ltd. is a modern enterprise specializing in the production, sales and service of PVC blister film for cabinets. The company covers an area of u200bu200b20,000 square meters and has an existing asset of 200 million yuan. It is the largest PVC sales company in the Central Plains region. At the same time, small batch delivery and 24-hour fastest delivery service are provided.