Method for preparing aromatic hydrocarbon and hydrogen-rich fuel gas through catalytic thermal conversion of polyolefin waste plastics

Abstract

The invention discloses a method for preparing aromatic hydrocarbon and hydrogen-rich fuel gas through catalytic thermal conversion of polyolefin waste plastics. The method comprises: feeding pretreated polyolefin waste plastics into a reaction container, and using a metal-loaded zeolite molecular sieve as a catalyst, wherein a mass ratio of the polyolefin waste plastics to the catalyst is 5-30:1;introducing nitrogen into the reaction container; after the initial nitrogen pressure in the reaction container reaches 1-30 bar, maintaining the reaction system closed, heating the reaction container to 320-500 DEG C, stopping the heating, and collecting a gas product and a solid-liquid product in the reaction container after the reaction container is cooled to a normal temperature, wherein thegas product is collected through a gas collecting tank, the solid-liquid product passes through a filter to collect the catalyst and the residue of the reaction raw material, and the obtained liquid product is further treated. According to the invention, the aromatic hydrocarbon compound is directionally prepared through catalytic thermal conversion by using the polyolefin waste plastics as the raw material, and is used as a chemical raw material for production processing, so that the method is an effective waste plastic resource utilization method.

Description

technical field

[0001] The invention relates to the technical field of resource recycling and utilization, in particular to a method for preparing aromatic hydrocarbons and hydrogen-rich gas by catalytic thermal conversion of polyolefin waste plastics. Background technique

[0002] As a daily product with a huge output, plastic brings great processing pressure because it is difficult to degrade. Statistics show that only 9% of plastic waste is recycled, 12% is incinerated, and 79% is landfilled or dumped into land and marine ecosystems. It not only causes the waste of land resources, but also pollutes the soil, water quality and atmospheric environment, and loses the opportunity of resource utilization.

[0003] Ratio of waste plastics in domestic waste - polyethylene: polypropylene: polystyrene: polyvinyl chloride: others = 48:18:16:7:11, proportion of polyolefin plastic (mainly polyethylene and polypropylene) waste Up to 66%, it is an important part of waste plastics. P...

Examples

Embodiment 1

[0025] use as figure 1 As shown in the device, the pretreated polyethylene is fed into the autoclave reactor, and 3wt.% zinc-loaded ZSM-5 is used as the catalyst. The mass ratio of polyethylene raw material to catalyst is 15:1, and nitrogen is purged to remove all After the air in the reactor, close the gas outlet on the reactor, continue to feed nitrogen, make the initial nitrogen pressure to 1bar (that is, no pressurization), close the autoclave reactor, and set the temperature rise rate of the autoclave reactor to 15°C / min, heat the autoclave to 380°C and stop heating. After the autoclave reactor is cooled to normal temperature by air, first open the outlet valve of the autoclave reactor, use the air bag to collect the gas product, then open the reactor outlet valve to collect the liquid product, and the catalyst and solid product are collected by filtering through the filter.

[0026] The 2wt.% zinc-loaded zeolite molecular sieve catalyst is prepared by the following ste...

Embodiment 2

[0046] use as figure 1 The shown device feeds the pretreated polyethylene into the autoclave reactor, adopts 5wt.% zinc-loaded ZSM-5 as a catalyst (the steps of the zinc-loaded zeolite molecular sieve catalyst are the same as in Example 1), and the polyethylene raw material The mass ratio to the catalyst is 10:1. After purging the air in the reactor with nitrogen, close the gas outlet on the reactor, continue to feed nitrogen, and make the initial nitrogen pressure to 10bar, close the autoclave reactor, and the autoclave reactor The heating rate was set at 15°C / min, and the autoclave was heated to 450°C before heating was stopped. After the autoclave reactor is cooled to normal temperature by air, first open the outlet valve of the autoclave reactor to collect the gaseous product, then open the liquid outlet valve of the reactor to collect the liquid product, and the catalyst and solid product are collected by filtering through the filter.

[0047] The mass of liquid and soli...

Embodiment 3

[0052] use as figure 1 The shown device feeds the pretreated polyethylene into the autoclave reactor, and adopts 1wt.% zinc-loaded ZSM-5 as a catalyst (the steps of the zinc-loaded zeolite molecular sieve catalyst are the same as in Example 1), and the polyethylene raw material The mass ratio to the catalyst is 20:1. After purging the air in the reactor with nitrogen, close the gas outlet on the reactor, continue to feed nitrogen, and make the initial nitrogen pressure to 15bar, close the autoclave reactor, and the autoclave reactor The heating rate was set at 15°C / min, and the autoclave was heated to 340°C and then stopped heating. After the autoclave reactor is cooled to normal temperature by air, first open the outlet valve of the autoclave reactor to collect the gaseous product, then open the liquid outlet valve of the reactor to collect the liquid product, and the catalyst and solid product are collected by filtering through the filter.

[0053] The mass of liquid and so...

technical field

[0001] The invention relates to the technical field of resource recycling and utilization, in particular to a method for preparing aromatic hydrocarbons and hydrogen-rich gas by catalytic thermal conversion of polyolefin waste plastics. Background technique

[0002] As a daily product with a huge output, plastic brings great processing pressure because it is difficult to degrade. Statistics show that only 9% of plastic waste is recycled, 12% is incinerated, and 79% is landfilled or dumped into land and marine ecosystems. It not only causes the waste of land resources, but also pollutes the soil, water quality and atmospheric environment, and loses the opportunity of resource utilization.

[0003] Ratio of waste plastics in domestic waste - polyethylene: polypropylene: polystyrene: polyvinyl chloride: others = 48:18:16:7:11, proportion of polyolefin plastic (mainly polyethylene and polypropylene) waste Up to 66%, it is an important part of waste plastics. P...

Examples

Embodiment 1

[0025] use as figure 1 As shown in the device, the pretreated polyethylene is fed into the autoclave reactor, and 3wt.% zinc-loaded ZSM-5 is used as the catalyst. The mass ratio of polyethylene raw material to catalyst is 15:1, and nitrogen is purged to remove all After the air in the reactor, close the gas outlet on the reactor, continue to feed nitrogen, make the initial nitrogen pressure to 1bar (that is, no pressurization), close the autoclave reactor, and set the temperature rise rate of the autoclave reactor to 15°C / min, heat the autoclave to 380°C and stop heating. After the autoclave reactor is cooled to normal temperature by air, first open the outlet valve of the autoclave reactor, use the air bag to collect the gas product, then open the reactor outlet valve to collect the liquid product, and the catalyst and solid product are collected by filtering through the filter.

[0026] The 2wt.% zinc-loaded zeolite molecular sieve catalyst is prepared by the following ste...

Embodiment 2

[0046] use as figure 1 The shown device feeds the pretreated polyethylene into the autoclave reactor, adopts 5wt.% zinc-loaded ZSM-5 as a catalyst (the steps of the zinc-loaded zeolite molecular sieve catalyst are the same as in Example 1), and the polyethylene raw material The mass ratio to the catalyst is 10:1. After purging the air in the reactor with nitrogen, close the gas outlet on the reactor, continue to feed nitrogen, and make the initial nitrogen pressure to 10bar, close the autoclave reactor, and the autoclave reactor The heating rate was set at 15°C / min, and the autoclave was heated to 450°C before heating was stopped. After the autoclave reactor is cooled to normal temperature by air, first open the outlet valve of the autoclave reactor to collect the gaseous product, then open the liquid outlet valve of the reactor to collect the liquid product, and the catalyst and solid product are collected by filtering through the filter.

[0047] The mass of liquid and soli...

Embodiment 3

[0052] use as figure 1 The shown device feeds the pretreated polyethylene into the autoclave reactor, and adopts 1wt.% zinc-loaded ZSM-5 as a catalyst (the steps of the zinc-loaded zeolite molecular sieve catalyst are the same as in Example 1), and the polyethylene raw material The mass ratio to the catalyst is 20:1. After purging the air in the reactor with nitrogen, close the gas outlet on the reactor, continue to feed nitrogen, and make the initial nitrogen pressure to 15bar, close the autoclave reactor, and the autoclave reactor The heating rate was set at 15°C / min, and the autoclave was heated to 340°C and then stopped heating. After the autoclave reactor is cooled to normal temperature by air, first open the outlet valve of the autoclave reactor to collect the gaseous product, then open the liquid outlet valve of the reactor to collect the liquid product, and the catalyst and solid product are collected by filtering through the filter.

[0053] The mass of liquid and so...

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