Waste plastics pretreatment process based on coking by coke oven

Abstract

The invention discloses a waste plastics pretreatment process based on coking by a coke oven, which solves the problems of low equipment life, large environmental influence and influenced coke quality after coal blending in the process of treating waste plastics by using the coking process in the prior art. The technical scheme adopted by the invention is as follows: (1) performing coarse crushing on the waste plastics by a crusher until the grain size is 8-12mm; (2) feeding the waste plastics with the grain size of 8-12mm after coarse crushing in a pyrolysis oven, heating to 225-275 DEG C under the condition of air isolation, pyrolyzing for 30-90min at a constant temperature and dissolving out pyrolysis gas; (3) cooling the fluid residue of the waste plastics after pyrolysis to form solid-state solids, and feeding the solid-state solids in the crusher again for crushing until the grain size is no more than 1mm; and (4) blending the solid-state solids in coking coal according to the proportioning of 1% by weight. The invention has the advantages of simple process, no environment pollution and no influence on coke quality.

Description

technical field [0001] The invention relates to an environmental protection technology, in particular to a waste plastic pretreatment process based on coking in a coke oven. Background technique [0002] Recycled waste plastics have the following characteristics: [0003] 1. This kind of waste plastics has a large amount of recycling, and most of them contain chlorine, and some chlorine content is even as high as 51.10%. [0004] 2. Wide range of sources and many inclusions: this type of plastic comes from scraps, defective products, etc. produced during the production process of the factory, as well as various post-consumer products recycled in the society, etc. Such waste products have often been discarded Pollution, some have been colored and printed with trademarks, and some also contain impurities such as sand, broken metal, wood chips or shredded paper. Small solid impurities are difficult to remove through ordinary sorting or pre-treatment. [0005] 3. Different deg...

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Problems solved by technology

[0011] 1. When processing waste plastics with high chlorine content, if they are directly mixed with coking coal, most of the decomposed chlorine will enter the coke oven gas during the coking process, which will cause serious corrosion to gas pipelines and gas purification equipment, affecting equipment When the temperature is higher than 500°C, the chlorine in waste plastics will generate dioxins, which will have a serious impact on the environment

[0012] 2. Due to the plasticity of waste plastics, commonly used pulverizers cannot crush waste plastics to a finer particle size (≤1mm). When mixed into coking coal, it will cause uneven dispersion of waste plastic particles in coking coal, resulting in coke quality loss problem

[0013] 3. Due to the wide range of sources of waste plastics, it is inevitable to be mixed with various inclusions, especially trademark paper, fine sand, gravel or metal particles attached to the surface of the plastic or dissolved in it. These substances are difficult to pass through conventional waste plastics. The method is difficult to remove, and it will also affect the quality of coke after being mixed with coking coal

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