Process flow and industrial chain
PP polypropylene comes from crude oil and belongs to the downstream industry of petrochemical industry. The basic flow is: petroleum—naphtha—propylene—polypropylene (PP packaging box raw materials). In recent years, the domestic coal-to-olefins industry can also produce polypropylene. The basic process flow is: coal—coal gas (mixture of carbon monoxide and hydrogen gas)—methanol—propylene—polypropylene.
Its industrial chain is as follows: Crude oil is processed into oil, naphtha, kerosene and other refined oils and naphtha through refinery equipment. Naphtha is produced by cracking equipment to produce olefins and benzene, and the production ratio of ethylene and propylene is roughly 5:3 (ie, per production. One ton of ethylene produces approximately 0.6 tons of propylene at the same time, which varies from device to device). Ethylene is mainly used for the production of polyethylene and propylene is used for the production of polypropylene.
Crude Oil - Naphtha: From the perspective of naphtha production, all are produced through oil refining, the yield of which is limited by the composition of crude oil. In addition, since crude oil belongs to a mixture, the naphtha yield is limited by the composition of crude oil. It will be adjusted within a certain range according to the changes in demand for products such as refined oil and ethylene. From a worldwide perspective, the output of naphtha is about 17-18%. The average gross margin of naphtha in the world is basically 35-50 U.S. dollars per ton (ie naphtha processing costs).
Olefins-polyolefins: Almost 100% of ethylene and propylene are used in the production of polyethylene and polypropylene, of which one ton of polyethylene consumes 1.01 ton of ethylene, homopolypropylene and propylene are also almost a 1:1 relationship, polypropylene is copolymerized. The proportion of ethylene and propylene consumed is about 2:8.