阅读说明：本技术 一种联合处理餐厨垃圾和废弃塑料制备富氢燃气的方法 (Method for preparing hydrogen-rich gas by combined treatment of kitchen waste and waste plastic ) 是由 严密 苏红才 冯闳宇 金松洲 杜伟 姜佳豪 周志昊 于 2019-08-27 设计创作，主要内容包括：本发明公开了一种联合处理餐厨垃圾和废弃塑料制备富氢燃气的方法,将收集来的餐厨垃圾和废弃塑料破碎后,输送到超临界水气化反应釜中；反应釜内全是氮气；使用电加热器对反应釜进行加热加压至420℃和23-25MPa；反应连续运行40-60分钟,并使用磁力搅拌器对物料进行搅拌,转速为每分钟100-150转；反应结束后使用冷却水对反应釜进行降至室温；使用抽气机对富氢高品质燃气进行收集,气体干燥后储存。本发明可以实现餐厨垃圾和废旧塑料的高效处理；餐厨垃圾和废弃塑料联合超临界水气化产生的合成气氢气浓度高,品质高；处理过程中极大的降低了对环境的二次污染。(The invention discloses a method for preparing hydrogen-rich gas by jointly treating kitchen waste and waste plastic, which comprises the steps of crushing the collected kitchen waste and waste plastic, and conveying the crushed kitchen waste and waste plastic to a supercritical water gasification reaction kettle; the reaction kettle is filled with nitrogen; heating and pressurizing the reaction kettle to 420 ℃ and 23-25MPa by using an electric heater; the reaction is continuously operated for 40-60 minutes, and a magnetic stirrer is used for stirring the materials, wherein the rotating speed is 100-150 revolutions per minute; cooling the reaction kettle to room temperature by using cooling water after the reaction is finished; and collecting the hydrogen-rich high-quality fuel gas by using an air extractor, and drying and storing the gas. The invention can realize the high-efficiency treatment of the kitchen waste and the waste plastic; the hydrogen concentration of the synthesis gas generated by the combined supercritical water gasification of the kitchen waste and the waste plastic is high, and the quality is high; the secondary pollution to the environment is greatly reduced in the treatment process.)

1. A method for preparing hydrogen-rich gas by jointly treating kitchen waste and waste plastics is characterized by comprising the following steps: the method comprises the following steps:

1) crushing the collected kitchen waste and waste plastics, and mixing according to the mass ratio of 1: 0.25-4;

2) conveying the mixed materials to a supercritical water gasification reaction kettle;

3) the materials are supplemented with water until the water content is 85-90%;

4) discharging air in the reaction kettle by using pure nitrogen, so that the reaction is carried out in the nitrogen atmosphere; discharging nitrogen into the reaction kettle from the air inlet, discharging air from the air outlet, and closing the air inlet and the air outlet simultaneously when the gas collected by the air outlet is detected to be nitrogen completely;

5) heating and pressurizing the reaction kettle to 420 ℃ and 23-25MPa by using an electric heater;

6) the reaction is continuously operated for 40-60 minutes, and a magnetic stirrer is used for stirring the materials, wherein the rotating speed is 100-150 revolutions per minute;

7) cooling the reaction kettle to room temperature by using cooling water after the reaction is finished;

8) and collecting the hydrogen-rich high-quality fuel gas by using an air extractor, and drying and storing the gas.

Technical Field

The invention belongs to the technical field of environmental protection, and particularly belongs to the field of treatment and resource utilization of kitchen waste and waste plastic, and particularly relates to a method for preparing hydrogen-rich high-quality fuel gas by jointly treating kitchen waste and waste plastic based on supercritical water gasification.

Background

The kitchen waste is mainly waste generated in the processing process of resident daily life and food processing enterprises, the kitchen waste is high in water content (70% -90%), high in organic matter content, high in grease and inorganic salt content, rich in nutrient content, extremely easy to acidify, go bad, breed harmful bacteria and microorganisms, and pose a great threat to the nature and the living environment. The annual output of kitchen waste in China is huge, and the kitchen waste accounts for 30-60% of urban domestic waste in China.

China is the first major plastic producing country in the world, the production amount of plastic products reaches 7515.54 ten thousand tons in 2017, a large amount of plastic garbage is produced every year, and a part of plastic which is difficult to recover enters the ocean, so that the survival of marine organisms is threatened greatly. According to the communique of marine environmental conditions in China, the average density of the floating micro-plastics in the water bodies of the Bohai sea, the east sea and the south sea is about 0.29/m³. In addition, due to the rapid development of electronic commerce and takeout industry in recent years in China, the yield of plastic meal boxes and packaging bags is increasing continuously, and great pressure is caused to the environment, so that the treatment of plastic garbage is a difficult problem.

Supercritical water is a homogeneous, highly diffusive, highly transmissive nonpolar solvent. Supercritical water has good transmission and dissolution characteristics as a medium for chemical reaction, and the physical properties of supercritical water can be easily controlled by adjusting pressure and temperature. At T>374℃，P>Under the supercritical state of 22.1MPa, the supercritical water can mix plastics and kitchenThe organic matters in the garbage are quickly dissolved and gasified to generate H₂，CO，CO₂，C_XH_Y。

In addition, the common plastics are low-density polyethylene, high-density polyethylene, polypropylene and the like, compared with the kitchen waste, the common plastics have the advantages of smaller C/H ratio, higher hydrogen element content and no oxygen element, the main hydrogen production reaction in supercritical water gasification is water-gas conversion reaction and steam reforming reaction, and the plastics can reduce the concentration of carbon dioxide in the supercritical water gasification of the kitchen waste to improve the hydrogen concentration and improve the heat value and the quality of synthetic gas.

Therefore, the method for preparing the hydrogen-rich high-quality fuel gas by jointly treating the kitchen waste and the waste plastic based on supercritical water gasification is promising for treating the kitchen waste and the waste plastic and realizing energy conversion.

Disclosure of Invention

The technical problem to be solved is as follows: according to the problems, the invention provides a method for preparing hydrogen-rich gas by jointly treating kitchen waste and waste plastics based on supercritical water gasification, the joint treatment of the kitchen waste and the waste plastics is realized through a supercritical water gasification technology, meanwhile, the addition of the waste plastics can improve the concentration of hydrogen in a gas-phase product, reduce the concentration of carbon dioxide, improve the calorific value and the quality of synthesis gas, finally obtain the hydrogen-rich high-quality gas, and achieve the purpose of resource utilization of the kitchen waste and the waste plastics.

The technical problem solved by the invention is realized by the following technical scheme:

a method for preparing hydrogen-rich gas by jointly treating kitchen waste and waste plastics is characterized by comprising the following steps: the method comprises the following steps:

1) crushing the collected kitchen waste and waste plastics, and mixing according to the mass ratio of 1: 0.25-4;

2) conveying the mixed materials to a supercritical water gasification reaction kettle;

3) the materials are supplemented with water until the water content is 85-90%;

4) discharging air in the reaction kettle by using pure nitrogen, so that the reaction is carried out in the nitrogen atmosphere; discharging nitrogen into the reaction kettle from the air inlet, discharging air from the air outlet, and closing the air inlet and the air outlet simultaneously when the gas collected by the air outlet is detected to be nitrogen completely;

5) heating and pressurizing the reaction kettle to 420 ℃ and 23-25MPa by using an electric heater;

6) the reaction is continuously operated for 40-60 minutes, and a magnetic stirrer is used for stirring the materials, wherein the rotating speed is 100-150 revolutions per minute;

7) cooling the reaction kettle to room temperature by using cooling water after the reaction is finished;

8) and collecting the hydrogen-rich high-quality fuel gas by using an air extractor, and drying and storing the gas.

The invention has the following technical effects:

(1) can realize the high-efficiency treatment of the kitchen waste and the waste plastic.

(2) The hydrogen concentration of the synthesis gas generated by the kitchen waste and the waste plastic combined supercritical water gasification is high, and the quality is high.

(3) The secondary pollution to the environment is greatly reduced in the treatment process.

Drawings

The following detailed description is made with reference to the accompanying drawings and embodiments of the present invention

FIG. 1 is a diagram of an apparatus for producing a hydrogen-rich high-quality fuel gas according to the present invention.

Labeled as: the device comprises a cooling pipe 1, a pressure safety valve 2, a pressure gauge 3, a magnetic stirrer 4, an electric heating furnace 5 and a heat insulation layer 6.

Detailed Description

See the drawings. FIG. 1 is a supercritical water gasification combined treatment kitchen garbage and waste plastic preparation hydrogen-rich high-quality gas device, and in electric heating furnace 5 was arranged in to cooling tube 1, electric heating furnace 5 outside was equipped with heat preservation 6, and cooling tube 1 embeds has magnetic stirrers 4, and magnetic stirrers 4 is rotatory by motor drive, be equipped with pressure relief valve 2 and manometer 3 on the cooling tube 1.