1, PVC suspension polymerization process of Tunsu Company
Various brands of PVC are produced from vinyl chloride monomer by suspension polymerization: ordinary grade, high K value, low K value, dull type and * * * polymer type. Add water, additives and VCM into the stirred reactor, and control the temperature according to the product grade (using cooling water or frozen water) during the polymerization process. At the end of the reaction, the product is discharged into a discharge tank, where most of the unreacted VCM is evaporated. Wash the reactor and spray the scale inhibitor to prepare for the next batch of production. The PVC slurry containing VCM was continuously sent to the stripper, and VCM was effectively recovered from the PVC slurry. Unreacted VCM is liquefied in VCM recovery equipment and returned to polymerization. The PVC slurry was dehydrated again and dried with a dryer.
This method uses VCM dispersed in water for batch polymerization. The standard reactor size is 60, 80, 100 or 130m3. The material consumption and energy consumption per ton of PVC are VCM 1.003t, electricity 160kWh, steam 0.7t, additives (production pipeline grade) 12 USD respectively. Transferred 12 sets of devices, the total production capacity exceeds100000 t/a, and its VCM removal technology has been adopted by many PVC production enterprises.
2. Removal technology of vinyl chloride monomer in Tunsu Company
Even after the initial flash evaporation, the PVC slurry discharged from the reactor still contains a lot of VCM (higher than 30000× 10-6). The residual VCM content in PVC products can be reduced to less than 1× 10-6, and in some cases, it can be reduced to less than 0. 1× 10-6 by effectively removing the residual VCM and recycling it. VCM removal technology adopts automatic stripping closed system, with the help of advanced design and special tower, which occupies less land and has low investment. The scale of the tower can be 2.5 ~ 30t/h, and the steam consumption is 130kg/t PVC.
Suspension polymerization process of PVC in Inovyl company
The maximum reactor capacity is 140m3, and the conversion rate is as high as 94%. The residual vinyl chloride monomer in the resin can be less than 1× 10-6 by stripping tower. The water polluted by VCM is stripped by steam until the VCM is less than 1× 10-6 and then discharged. The patented scale inhibitor EVICAS 90 is used to prevent resin deposition in the reactor. Closed reaction flow and efficient scale inhibitor can make the reactor operate up to 700 batches. The total environmental emission of PVC factory is less than 20g VCM/t PVC.
According to the cost of the Gulf Coast in the United States, the investment of 6.5438+500,000 t/a suspension PVC plant is 45 million dollars. The material and energy consumption per ton of PVC production are VCM 1.004t, steam 0.9t, cooling water 480,000 kcal, electricity 150kWh, softened water 2.2t, and additive cost (production pipeline grade) 1 1 USD.
The existing stripping system can be reformed by setting EVC slurry stripper. For the 150000 t/aPVC device, the cost of this facility is $2.5 million. The EVC technology has been applied to 6 sets of PVC plants, with the total production capacity exceeding 165438+ 10,000 t/a, and the scale inhibitor EVICAS 90 has been applied to 80% of the global PVC production capacity.
4. Vinnolit process for producing PVC by 4.VinTec Company.
Dispersant, additive, vinyl chloride monomer and water are added into the reactor, and the reaction slurry is sent to the sieve plate type Vino Park Jung Su degassing tower through a heat exchanger. The VCM is stripped by steam, and the concentration of VCM in the slurry leaving the degassing tower is less than 1× 10-6. Unreacted VCM is recovered and liquefied, and then returned to polymerization. The suspension is dehydrated in a centrifuge, and the wet PVC block is sent to Vinnolit rotary drying system. Polymerization does not require cooling water. Adopt internal cooling high efficiency reactor, the size can reach 150m3. Closed and clean reactor technology makes it unnecessary to open the reactor. At the same time, high-pressure water washing is not needed. The whole process is controlled by DCS. Adopt efficient scale inhibitor.
The material consumption and energy consumption per ton of PVC are VCM 1.00 1t, steam 0.8t, electricity 170kWh, and additive cost (pipeline grade) 14 USD respectively. The production efficiency is as high as 600 t/m3 a, and Vinnolit technology has been used to produce 580,000 t/a PVC. The production capacity of Weinote process in the world is about 1 10,000 t/a, and Weinote rotary dryer has been adopted by many PVC manufacturers.
5, waste PVC recycling technology
The recycling process of waste PVC with economic feasibility and environmental benefits is helpful to promote the reuse of PVC. Solvi Company has developed a PVC recycling technology called ethylene ring. The 10000 t/a device was built in Ferrara, Italy, which verified the technical and economic feasibility of recycling cable materials. This process converts the waste cable sheath into plate, and the recovered plate can be sold at half the price of the original mixture. The investment of 1 10,000 t/a factory is 1 10,000 euros. In this process, the cable is pressed to a length of 10cm and the sheath is dissolved in the methyl ethyl ketone mixture. The process was completed in 65438 00 ~ 65438 05 minutes at 85℃. Then filter to remove copper, polyethylene and rubber. The remaining slurry is precipitated by steam a and B.
I'm glad to answer the landlord's question. Please forgive me if there is any mistake.