Process flow of pyrolysis of waste rubber tires

The process flow of waste rubber tire pyrolysis mainly includes: pretreatment stage, pyrolysis reaction stage, oil and gas recovery stage, solid separation stage, tail gas treatment stage and other stages. For details, please consult Zhengzhou Dingli New Energy Equipment Co., Ltd.!

1. Pretreatment stage: For intermittent production lines, tires can be put in directly; if it is a continuous production line, the waste tires must be torn into small pieces first for subsequent feeding. At the same time, it is also necessary to use a wire separator to separate the steel wire from the waste tires, and use a wire drawing machine to pull out the thick steel wire, and the steel wire is packaged and sold. The waste tire blocks after removing the steel wire need to be magnetically screened using a roller screening machine and a magnetic separator to recover impurities such as iron nails and waste steel wire stored in the blocks. The screened blocks need to meet certain specifications, such as about 20mm, in order to carry out subsequent pyrolysis reactions.

2. Pyrolysis reaction stage:

Feeding and heating: The pretreated tire blocks are sent into the pyrolysis reactor and heated under the protection of oxygen-free or inert gases (such as water vapor, nitrogen, etc.). During the heating process, the heating rate and cracking temperature need to be controlled to ensure that the rubber and organic matter can be fully decomposed. Usually, the cracking temperature is maintained at around 330°C to 350°C or 400°C.

Cracking reaction: In the cracking reactor, the rubber and organic matter in the tire block will undergo cracking reaction at high temperature to produce products such as gas, fuel oil and carbon black. During the cracking reaction, it is necessary to maintain a slightly negative pressure in the cracking furnace to promote the cracking reaction.

3. Oil and gas recovery stage

The oil and gas produced by the cracking reaction need to be cooled by the condensation system to convert the gaseous oil into liquid. The condensation process is usually completed with water circulation cooling. The condensed oil and gas need to be further separated into liquid fuel oil and non-condensable gas (such as C1~C4 hydrocarbon gas). The liquid fuel oil is transported to the oil tank for storage through a pipeline, while the non-condensable gas can be used as a heating reaction medium for the cracking furnace or for other treatment.

4. Solid separation stage

The solid matter remaining after cracking is mainly carbon black and incompletely cracked rubber fragments, as well as metal impurities such as steel wire that were not completely separated before. These solid materials need to be separated by an air-lock continuous discharger or other equipment to separate the carbon black and metal impurities. The separated carbon black can be further crushed by a mill to achieve a certain fineness requirement (such as 400~1500 mesh or less). The crushed carbon black powder can be directly packaged and stored, or subjected to other deep processing. 

5. Tail gas treatment stage

The non-condensable combustible gas (such as methane, etc.) generated during the cracking process can be used as a self-supplied heat source for the cracking furnace to save energy. The remaining exhaust gas needs to be purified by desulfurization and dust removal to ensure that the emission is harmless and meets environmental protection requirements. During the entire pyrolysis process, the composition and concentration of the exhaust gas need to be monitored in real time to ensure that the emission meets national or local environmental protection standards.

Each stage requires strict control of process parameters and operating conditions to ensure the efficiency, safety and environmental protection of the pyrolysis process. If you have any equipment needs, please feel free to contact Zhengzhou Dingli New Energy Equipment Co., Ltd. The manufacturer will arrange professional engineers and sales managers to give you a detailed reply!