Industrial continuous class-based cracking system and process for mixed waste plastics

Abstract

The invention relates to an industrial continuous class-based cracking system and process for mixed waste plastics. The device comprises an extrusion dryer, first and second lifting screw conveyors, acatalytic mixing barrel, a semi-plasticizing feeder, first, second and third cracking reaction furnaces, first, second and third discharged slag screws, a separator, a slag storage tank, first, second and third basket filters, first, second and third settling towers, first, second and third air cooling heat exchangers, first, second and third water cooling heat exchangers, first, second and thirdgas-liquid separation tanks, a first oil tank, a second oil tank, a third oil tank, a non-condensable combustible gas purifier, a tail gas treatment module, a combustion chamber and a combustor. According to the characteristics of different plastic types and different cracking temperatures, the mixed plastic classified cracking method is provided, and the economic additional value of the crackingproduct is increased by independently recycling the cracked oil product; energy consumption in the cracking process is reduced through reuse combustion of non-condensable combustible gas and reuse ofhigh-temperature waste heat, and environmental pollution is avoided through multiple purification steps of waste gas.

Description

technical field [0001] The invention belongs to the technical field of resource utilization of solid waste, in particular to an industrial continuous classification-by-category cracking system and process of mixed waste plastics. Background technique [0002] At present, there are several methods of processing waste plastics in my country: the first is recycled plastics made of plastic granules, which require higher-quality plastics such as beverage bottles; the second is direct incineration or landfilling, which The treatment method is simple but causes serious pollution to the environment; the third is to recycle to generate fuel oil, which does not require high plastic quality and can create better social and economic benefits. Especially the waste plastics in domestic garbage and stale garbage can no longer be sorted and reused, and can only be finally disposed of by cracking and incineration. [0003] Pyrolysis can convert waste plastics into oil rich in aromatics, ...

AI Technical Summary

Problems solved by technology

However, due to the complex composition of waste plastics in domestic garbage and old garbage, which contains a large amount of leachate, mud, bricks and other components, the difficulty of continuous cracking is exacerbated; at the same time, the cracking temperature is relatively high during the cracking process, and the cracking produced all It is a flammable and explosive gas, which makes it difficult to guarantee the safety of the cracking process and makes it difficult to apply cracking industrially. In addition, the current cracking technology does not distinguish between the types of raw materials, and it uses a single cracking temperature for cracking, resulting in cracking products. The composition is complex, and it is impossible to extract valuable key materials from the pyrolysis products, resulting in low value of the pyrolysis oil, which makes the pyrolysis manufacturers have no economic benefits at all, and makes the continuous classification and pyrolysis of mixed plastics such as domestic garbage and stale garbage impossible. accomplish

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