Cryogenic separation process for preparing propylene through propane dehydrogenation in Olflex process

Abstract

A cryogenic separation process for preparing propylene through propane dehydrogenation of an Olflex process is mainly suitable for an Olflex propane dehydrogenation (PDH) project of UOP, cryogenic separation is carried out on a dehydrogenation reaction product gas-phase product, potential cooling capacity of liquid raw material propane gasification, circulating hydrogen and other energy are recycled, and the whole cryogenic separation process does not need external refrigeration, and is more energy-saving and environment-friendly. High-purity hydrogen is adopted as circulating hydrogen, so that cryogenic separation of reaction gas with a low hydrogen-hydrocarbon ratio can be realized, reduction of carbon deposition in a reaction zone of a propane dehydrogenation device is facilitated, and long-period operation of the device is realized.

Description

technical field [0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a cryogenic separation process for producing propylene from propane dehydrogenation in an Olflex process. Background technique [0002] Polypropylene (PP) is a semi-crystalline thermoplastic with high impact resistance, strong mechanical properties, and resistance to various organic solvents and acid and alkali corrosion. It can be used as engineering plastics, mainly for the manufacture of plastic products, such as Household appliances and television equipment, packaging films, plastic containers that can be sterilized, etc., can also be used for synthetic fibers (polypropylene). The raw material propylene is one of the basic raw materials of petrochemicals, and can be used to produce a variety of important organic chemical raw materials. Benefiting from the development of China's economy, the consumption of propylene has grown rapidly, and it has beco...

AI Technical Summary

Problems solved by technology

Many process equipments, poor cooling effect and unsatisfactory separation effect

[0004] Chinese patent CN105439793A discloses a cold box low-temperature separation method for PDH projects. This method has certain technical advantages, but the disadvantage lies in the use of recycled hydrogen It is not high-purity hydrogen. When the cold box fluctuates or the operating load is high, the purity of hydrogen often becomes a key factor limiting the operation of the device. The anti-fluctuation ability is low and the process operation has a great influence

[0005] Chinese patent CN104296499A discloses a dual-turbine supercharger expander propane dehydrogenation cold box separation system and its technology. This patent involves cryogenic separation requiring external The cold source refrigeration, energy consumption is relatively high, not energy-saving

Moreover, this cold box has very low resistance to process fluctuations, and the purity of circulating hydrogen cannot be effectively guaranteed. When the process fluctuates, the operation of the cold box is difficult and difficult to control.

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