PVC Resin Injection Grade
Plastic Chemical: PVC Resin Injection Grade for PVC transparent sheet.The impact modifier and the organotin stabilizer in the PVC are mixed, plasticized and calendered to form a transparent sheet. It can be made into a thin-walled transparent container by thermoforming or used for vacuum blister packaging. It is an excellent packaging material and decorative material - such as moon cake packaging box.
PVC Resin Injection Grade
Ethylene method VS calcium carbide method: PVC process competition
Polyvinyl chloride (PVC) is a vinyl polymer that is one of the world's five most common resins. Due to its good processing performance, low manufacturing cost, corrosion resistance, insulation and other good characteristics, PVC is widely used in various fields such as industry, construction, electrical, decoration, packaging and daily life. The production scale of PVC in China is also growing.
At present, PVC production processes mainly include calcium carbide method and ethylene method. With the changes in international oil prices, the country's environmental protection requirements and market demand changes, the advantages and disadvantages of these two PVC production processes have gradually emerged.
The raw material for the production of PVC by ethylene is petroleum. The oil is cracked to produce ethylene, and ethylene is chlorinated or oxychlorinated to synthesize dichloroethane, which is then cleaved to form vinyl chloride, which is polymerized to form polyvinyl chloride. The advantage of the ethylene method is that chlorine can be fully utilized, and the "three wastes" can be processed without being discharged. The production process is simple and easy to control and mass production. The product has strong adaptability, but the process is long and the investment is large.
The raw material for the production of PVC by calcium carbide is coal. Coal and limestone are made into calcium carbide at high temperature, and calcium carbide forms acetylene in water. Under the action of mercury chloride catalyst, acetylene and hydrogen chloride are synthesized into vinyl chloride, and then polymerized to form polyvinyl chloride. The production process can be divided into acetylene preparation and purification, vinyl chloride synthesis, product refining and vinyl chloride polymerization. The process and equipment are relatively simple, the investment is low, the yield is high, but the energy consumption is large, especially the catalyst mercury salt is highly toxic, which causes great pollution to the environment.
Before 2003, domestic PVC production was still in the stable development stage of ethylene and calcium carbide, and the ethylene method was slightly superior. Since then, due to the high crude oil price, the profit space of calcium carbide method PVC has become larger and larger, making the domestic PVC production capacity expand rapidly. However, with the adjustment of the national industrial structure and the impact of environmental protection policies, the living space of calcium carbide method PVC will be more and more serious threats, and ethylene PVC will usher in new development opportunities.
PVC Resin Injection Grade/PVC Pipe and Fittings
Cost game: ethylene method highlights
Ethylene PVC Because the raw materials are derived from petroleum, the profit of the products is closely related to the oil price. The raw materials and electricity used in the calcium carbide method are all from the domestic market, and generally will not be affected by the international market, only relying on the domestic market. Due to the increase in international crude oil prices in previous years, the calcium carbide process PVC has a significant advantage in production costs, which has led to explosive growth in production capacity. From 2006 to 2008, the price of crude oil was high, the price of ethylene reached more than 1,400 US dollars / ton, while the price of calcium carbide continued to hover around 2,500 yuan / ton. At that time, the production cost of calcium carbide method was lower than the ethylene method by more than 2,000 yuan / ton.
The main factors of ethylene cost are ethylene consumption, chlorine consumption, power consumption, processing aids, management labor costs, etc. Each production of 1 ton of PVC consumes 0.5 tons of ethylene and consumes 0.65 tons of chlorine gas, which accounts for about 60% of the cost. %about. In the past two years, due to the fall in crude oil prices, the prices of raw materials such as ethylene once fell below $1,000/ton, while the price of calcium carbide has risen to over 4,200 yuan/ton due to the impact of national energy conservation and emission reduction policies. The calcium carbide method relies on calcium carbide. The cost advantage of survival has been lost, and the prospect of the calcium carbide process in the future is not optimistic.
PVC Resin Injection Grade/ PVC profiles
Comparison of environmental protection: the calcium carbide method is bearish
The calcium carbide method is characterized by high power consumption and high pollution, which is high energy consumption and high pollution. In addition to the large amount of raw coal required for the production of calcium carbide, it also consumes a large amount of electrical energy. Each kilowatt of PVC produced by the calcium carbide method has a combined power consumption of 8,500 kWh, while the electricity consumption of one ton of PVC produced by the ethylene method is about 3,600 kWh. . A 6300 kV calcium carbide furnace exhaust dust of 15 tons / day, while producing one ton of PVC to produce 1.2 tons of calcium carbide slag, 20 cubic meters of wastewater, 20 kg of dust. As the country attaches more importance to environmental protection, energy and environmental protection policies will further curb the development of calcium carbide process PVC. From the perspective of the future development environment, calcium carbide PVC enterprises without resource advantages will be difficult to survive in the market.
The calcium carbide process PVC production enterprise is still a large consumer of mercury. According to some data, the use of mercury in the calcium carbide process in China accounts for about 60% of the total mercury use in the country. At present, the calcium carbide process PVC industry is facing pressures on mercury production, rising prices and international environmental protection. On the one hand, domestic mercury resources have been basically exhausted, and the domestic mercury market will face greater pressure and prices will continue to rise. On the other hand, the international community has asked countries to comprehensively carry out mercury reduction work, and limiting mercury emissions has become a global trend. If calcium carbide method PVC can not replace the current high mercury catalyst with mercury-free catalyst or low-mercury catalyst, enterprises will not survive.
The ethylene method PVC is the world's recognized energy-saving and environmentally-friendly advanced production route, which is widely adopted in international developed countries. The chlorination conversion rate and selectivity of ethylene can reach about 99%. The raw materials used in production and the wastewater produced can be sent to incineration and treatment, which meets environmental protection requirements.
PVC Resin Injection Grade/ PVC window profile
Quality comparison: ethylene method dominates
It is generally believed that the ethylene method PVC is superior to the calcium carbide method PVC in quality. The PVC produced by Qilu Petrochemical Ethylene Method won the title of “China Famous Brand” in 2007 with the first score of the same industry. The calcium carbide method of polyvinyl chloride still has some shortcomings in product quality, which is difficult to solve and is at a disadvantage in the overall quality of the product. Despite decades of continuous improvement, the calcium carbide process PVC production technology has been greatly developed, and the polymerization kettle has also been developed to a large scale. The implementation of these technologies further improves the product quality, but the calcium carbide method still has disadvantages in the overall quality of the product. . For example, in terms of hygienic performance, the product performance index is not as good as that of ethylene. In the fields where medical and drinking water pipes have strict requirements on impurities and high added value of products, it is difficult for PVC to enter the market.
In addition, the water content of the calcium carbide monomer in the calcium carbide method is 4 to 5 times higher than that of the ethylene method, which is difficult to produce high quality PVC products. At the same time, because the amount of acetylene in the vinyl chloride monomer is higher than that in the ethylene method, when the acetylene content is too high, under the synergistic action of acetaldehyde and iron, the thermal stability of PVC is lowered and the product quality is affected.