Method and hydrothermal reaction system for efficient and clean oil production by using mixed plastic waste

Abstract

The invention provides a method for efficiently and cleanly preparing oil through mixed waste plastic garbage and a hydrothermal reaction system. The method comprises the steps that under the conditions that the temperature ranges from 160 DEG C to 300 DEG C and the pressure ranges from 20 bar to 220 bar, an alkaline water solution is used for carrying out pyrohydrolysis treatment on the mixed waste plastic garbage; the mixed waste plastic garbage contains one or more of PE, PP and PS, and PET, and the mixed waste plastic garbage can selectively comprise PVC; a water phase and a solid phase in a material obtained after hydro-thermal treatment are separated, and the solid phase obtained after separation is subjected to oil preparation. The negative influence of the PET and PVC in mixed waste plastic on the quality of the oil is avoided, the oil can be prepared efficiently and cleanly, a product, such as TA powder or particles and PS reprocessed plastic, with high additional value can be produced, organic matter in screened materials can also be utilized for anaerobic fermentation, the economical efficiency of this type of projects is improved, and meanwhile better circular using of resources is achieved.

Description

technical field [0001] The invention relates to a method and a hydrothermal reaction system for efficiently cleaning oil by using mixed plastic garbage, and belongs to the field of garbage recycling and processing. Background technique [0002] Recycling and recycling of garbage is a long-term technical problem that needs to be solved, and it is also a social problem that has attracted much attention. Waste plastics are an important part of waste. Waste plastics are fluffy and occupy a large volume. According to calculations, the loose bulk density of waste plastics in domestic waste is 55-66kg / m2. 3 . When waste plastics are disposed of in landfills, the storage capacity is occupied, and the degradation rate is slow, which seriously affects the stabilization process of the landfill; and when incinerated, serious pollutants such as dioxins are easily produced. In the prior art, there is a method of sorting and enriching waste plastics in garbage to increase the content of ...

AI Technical Summary

Problems solved by technology

[0003] As mentioned above, if the mixed plastics PE, PP, PS, PET and PVC recovered from garbage are directly pyrolyzed to make oil, the quality of the fuel oil produced will be poor, mainly due to the decomposition of the two components of PET and PVC. A large number of acidic substances (hydrogen chloride and organic acids) and particulate matter are easily oxidized and unstable in nature, while the pyrolysis products of PE, PP and PS plastics are ideal, and the quality of the products that are all mixed together to crack and produce oil is very poor

Using existing separation technology, it is very difficult to separate PVC and PET from PE, PP and PS, mainly because impurities such as grease, dust and food residues are often attached to mixed plastics, making common wet density separation and electrostatic separation difficult. The selection efficiency is low, and the classification recovery rate of various plastics is low

If a large amount of water is used to wash, dry and then sort, it will cause high water consumption and energy consumption, and the separated PET and PVC mixed with dirt are difficult to reuse

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