Turning the Global "Black Pollution" Issue into "Black Gold"

China is the world's largest consumer and importer of rubber, and also the largest tire producer globally. According to the data from the National Bureau of Statistics, China's production of rubber tire outer casings was 818 million and 899 million in 2020 and 2021, respectively. The amount of waste tires generated is nearly 20 million tons, with the harmless disposal rate of waste tires being less than 60%.

The Global Challenge of "Black Pollution"

Waste tires, a major category of waste rubber, cannot naturally degrade for decades or even a hundred years due to advancements in material properties, leading to a severe environmental issue known as "black pollution." The increasing production of waste tires, coupled with frequent safety incidents and pollution problems, has created a pollution challenge even more difficult to address than plastic pollution (white pollution), resulting in significant resource wastage.

Utilizing waste tires is a crucial issue under the backdrop of the dual-carbon strategy for achieving comprehensive resource utilization. It is also a vital measure for promoting the transformation of the national economic growth model and sustainable development under the strategy of a large-scale circulation. Currently, mainstream waste tire resource utilization methods worldwide include crushing and grinding, auxiliary fuel, and pyrolysis. In China, leading companies like Vary Technology have made significant breakthroughs in comprehensive waste tire utilization using pyrolysis technology.

"Black Gold" from Chemical Recycling

In Hubei Hedeli Recycling Technology Co., Ltd., there are large piles of waste tires collected from various places. After a series of preprocessing and steel wire separation, these waste tires are transformed into rubber particles and fed into a continuous pyrolysis furnace. In this furnace, they undergo chemical transformation into pyrolysis oil, carbon black, and non-condensable combustible gas. The entire pyrolysis process takes place in a closed, oxygen-free environment, meeting environmental, energy-saving, and carbon reduction requirements.

After preprocessing, waste tires are transformed into rubber particles. Under anaerobic conditions, when the temperature reaches 400-600 degrees Celsius, the main chains of the rubber particles, with unsaturated bonds, undergo thermal chemical reactions, breaking into small molecules or monomers. The output includes pyrolysis gas, pyrolysis carbon, and steel wire. The non-condensable gas enters the combustion chamber for heating, and the high-temperature flue gas, after absorbing most of the heat energy in the pyrolysis main furnace, enters the rear flue gas system for standard emission treatment. The condensable gas forms pyrolysis oil.

After pyrolysis treatment, waste tires can effectively recover carbon black, oil rich in aromatic hydrocarbons, and high-calorific-value fuel gas, achieving maximum energy recovery and full resource utilization. The tire oil produced mainly consists of alkanes, alkenes, benzene, toluene, xylene, styrene, and polycyclic aromatic hydrocarbons, with the advantages of low viscosity and high light fraction oil content. It can be widely used in industrial fuel oils for steel plants, boiler heating, heavy oil generators, cement plants, etc. It can also be refined into diesel for use in trucks, diesel generators, marine steam turbines, heavy machinery fuel oil, or as raw material oil in refineries. The pyrolysis carbon obtained from waste tire pyrolysis is a black powder solid with higher economic value than carbon black in petroleum. It can enhance the strength, durability, and coloring performance of rubber products and serve as a reinforcing and filling agent for tire manufacturing, cables, rubber rollers, conveyor belts, and other rubber and plastic products, such as breathable plastic tracks. It can also be made into spherical carbon black or carbon black coal balls for heating and combustion, with a calorific value equivalent to coal. It can also be further processed into powder or processed into masterbatch for sale to the plastic industry. In addition to these applications, carbon black has many other uses, such as road paving, making it highly valuable. The waste tire steel wire, extracted after preprocessing, can be sold directly or recycled for steelmaking or further processed into steel wire cut shots for use in shipyards, rust removal equipment, etc., doubling the profit compared to selling steel wire directly.

This is Vary Technology's first industrial continuous production project for pyrolyzing 60,000 tons of waste tires in Hubei. "Automated feeding, fully enclosed production, and pyrolysis in this way almost achieve the goal of 'maximizing the utilization of waste tires,'" said the project leader during the operation. Based on the processing of 60,000 tons of waste tires per year, the project can yield approximately 24,000 tons of pyrolysis oil, 22,000 tons of carbon black, 7,200 tons of steel wire, and a small amount of combustible gas, all of which can be sold directly. Currently, the market prices for pyrolysis oil, pyrolysis carbon, and steel wire are approximately 4,000 yuan, 900 yuan, and 2,000 yuan, respectively (prices may fluctuate with market conditions), resulting in an annual sales revenue of around 130.2 million yuan.

Affected by the international situation, raw material prices and oil prices have risen significantly. In the current context of favorable policies for dual carbon and a circular economy, there is vast market space for the pyrolysis utilization of waste tires. With the national designation of "comprehensive utilization of waste tires as a strategic emerging industry" and the 70% tax rebate for the production of regenerated oil and pyrolysis carbon from waste tires and waste rubber products, the power of pyrolysis has transformed "black pollution" into "black gold."

With a promising outlook, opportunities have arrived. Vary Technology will comprehensively utilize waste tires, connect the front-end preprocessing and the back-end deep processing equipment processes, solve the operational stability and economy of waste tire comprehensive utilization projects, and contribute technological strength to solving the "black pollution" of waste tires and building a "beautiful China"!

Note:

• The National Development and Reform Commission released the "Guidance Catalog for Key Products and Services of Strategic Emerging Industries" in 2016, including waste tire normal temperature crushing, waste tire decomposition oil and carbon black units in the catalog. Link: http://www.gov.cn/xinwen/2017-02/04/content_5165379.htm

• The Ministry of Finance and the State Administration of Taxation issued the "Announcement on Improving the Value-Added Tax Policy for Comprehensive Resource Utilization," and the "Catalog of Value-Added Tax Preferential Policies for Resource Comprehensive Utilization Products and Services (2022 Edition)" officially took effect in March 2022, making significant adjustments to the value-added tax preferential policies for resource comprehensive utilization. Link: http://www.chinatax.gov.cn/chinatax/n359/c5171843/content.html