Coal-to-olefin process tail gas internal recycling system and working method thereof

Abstract

The invention discloses an internal recycling system for tail gas in a coal-to-olefin process and a working method thereof, and belongs to the technical field of coal chemical industry. A coal ash outlet of a coal-to-olefin unit is connected with an inlet of a coal ash collection unit, an outlet of the coal ash collection unit is connected with an inlet of a coal ash pretreatment unit, and an outlet of the coal ash pretreatment unit is connected with a solid inlet of a tail gas treatment unit; a steam outlet of the coal-to-olefin unit is connected with an inlet of a discharged steam recovery unit, and an outlet of the discharged steam recovery unit is connected with a steam inlet of the tail gas treatment unit; a tail gas outlet of the coal-to-olefin unit is connected with an inlet of thetail gas collection unit; an outlet of the tail gas collection unit is connected with a tail gas inlet of the tail gas treatment unit; an outlet of the tail gas treatment unit is connected with an inlet of a product collection unit. The system is low in tail gas emission, equipment investment is reduced, energy in the process is effectively utilized, products with economic value are produced, andthe system has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry, and in particular relates to an internal circulation utilization system of tail gas in the coal-to-olefins process and a working method thereof. Background technique [0002] With the rapid development of the coal-to-olefins industry, CO in the production of coal-to-olefins 2 Emissions are also increasing. In the coal-to-olefins process, the unit product CO 2 Emissions are 10 tons of CO 2 / ton of olefins. Carbon emissions from coal-to-olefins production process accounted for 53.38%, carbon emissions from fuel combustion in thermoelectric boilers accounted for 36.25%, and carbon emissions from net purchased electricity consumption accounted for 10.36%. It can be seen that direct carbon emissions are the main CO 2 Emission source, CO 2 There is a lot of room for emission reduction utilization. Therefore, the research on carbon capture and utilization in coal-to-olefins proces...

AI Technical Summary

Problems solved by technology

[0003] At present, in large-scale coal-to-synthetic ammonia and coal-to-methanol projects, a large amount of CO in tail gas 2 Due to the low concentration, it is directly vented, which not only causes a large amount of greenhouse gas emissions, but also causes CO 2 waste of resources

In order to recover the CO emitted from the exhaust gas 2 , can be recovered by PSA or MEA, MDEA, etc., and can even be directly compressed and returned to the raw gas, but this requires additional capture equipment and consumes a lot of energy

Images