Sustainability challenges in the carbon black industry

Sustainability challenges in the carbon black industry

Every year, more than “1.7 billion” tires reach the end of their virtual lives and end up in landfills that pollute the environment. Hence, recycling these tires to recover carbon black from them and other chemicals becomes crucial; To ensure a healthy and sustainable environment for the carbon black industry, it is also considered an important step towards achieving a circular economy.

Not long ago, there were very limited efforts to recycle spent tires in order to recover carbon black, and in the past few years there has been an increasing global push for sustainability in all types of industrial processes and various economic activities. Among the manufacturers of carbon black, Orion Engineered Carbon and Birla Carbon are considered leaders in the field of carbon black worldwide, and therefore a large part of the responsibility for introducing and adopting environmentally friendly practices in this industry falls on their shoulders, in addition to working on recovering and recycling carbon black.

What is carbon black?

Carbon black is a substance consisting mainly of pure carbon element in the form of colloidal particles produced by incomplete combustion or thermal decomposition of gaseous or liquid hydrocarbons at temperatures from 1320 to 1540 degrees Celsius under specific conditions. The product is in the form of a black carbon powder with a grain diameter ranging from 10 to 500 nm.

Carbon black is an extremely versatile product that serves many major industries, including automotive, rubber, rubber, paints, coatings, adhesives and sealants, and its use has recently increased in battery production. Manufacturers globally have been very vigilant in seizing the market opportunity and expanding production capacity.

Currently, the manufacture of carbon black is considered an extremely environmentally harmful process, as 1 ton of carbon black is produced using 1.2 - 1.5 tons of fossil fuels in the form of residual heavy oils derived from petroleum refining and coal tar distillation processes, in addition to the consumption of huge amounts of water, and therefore the production process significantly releases tons of carbon dioxide along with other gases and harmful chemical compounds, and to reduce the release of some other pollutants that are legally regulated, including carbon dioxide Sulfur oxide and carbon monoxide. Companies burn these gases, which produces usable energy as a byproduct.

The carbon black market is expected to show modest growth between 2022 to 2027. The carbon black rubber market is expected to grow by 2-3%, while the specialty carbon black products market is expected to grow at an annual growth rate of 4-5% for the above years, according to Orion estimates.

Carbon black in the rubber and rubber industries

Carbon black rubber is of great benefit in the tire industry. The total global production of carbon black has reached about 13.5 million metric tons, including rubber and various carbon black products. The need to integrate recycled or recovered carbon black into various value chains is therefore more important than ever. Hence, it is time to integrate recovered carbon black into various value chains not only to meet the growing demand for carbon black but also to reduce environmental degradation.

Carbon black is considered an integral part of the tire manufacturing process, as it is used as a rubber strengthening agent. To provide greater durability, reduce resistance caused by friction, and prevent slipping. More than 2.5 billion tires are produced annually, and each tire contains approximately 3 kg of carbon black, with a total of 7.5 million tons of carbon black. Therefore, one source of readily available black carbon is worn out tires.

However, due to the use of some metals in tire manufacturing, tire recycling processes to recover carbon black pose a major challenge; Therefore, the alternative was to use waste tires in power generation processes, as this represented a suitable economic option, but efforts did not stop towards finding a suitable way to remove metals from waste tires and extract high-purity carbon black, and then use the recovered carbon black (rCB) in the manufacture of new tires or other industrial applications.

The importance of the role of large companies in leading the industry to sustainability

Among the top 4 carbon black producers, Birla is the largest producer of carbon black rubber, accounting for the bulk of the global demand for carbon black in this product. At the same time, Orion is the largest producer of carbon black in the world to meet the demand for different types of carbon black.

Orion has been very active in its efforts to ensure sustainability in its business operations; With the aim of achieving a circular economy, the company's strategy includes three sections: carbon empowerment, carbon recycling, and renewable carbon. Given the great growth expectations for the lithium-ion battery industry, the focus is now shifting to more conductive carbon products, which will necessarily mean increased demand, especially with the increasing trend in adopting electric cars.

Carbon recycling involves using end-of-life tires in the process of pyrolysis (exposure to high heat in the absence of oxygen) to produce oil, then using it to produce both specialist carbon black and rubber. Orion was a world leader in its search for a bio-alternative raw material to produce carbon black instead of conventional oils that contain a high percentage of sulfur.

In 2021, Orion partnered with the Swedish Research Institute (RISE) to produce recovered carbon black on a commercial scale. According to the Economic Cooperation Organization, the use of renewable recyclable carbon in tires will account for 10% of the market by 2030.

On the other hand, Birla Carbon Company, which has a total carbon black capacity of more than 2 million tons annually, is also among the responsible manufacturers that work for sustainability in its production processes. The company entered into a partnership with Circtec to produce a product from a sustainable carbon material by recycling end-of-life tires, ensuring a reduced carbon footprint for the rubber, plastics and paint industries.

Main challenge for carbon black recovery

The main challenge in recovering carbon black from tires lies in the large presence of mineral ash, which is produced during pyrolysis processes, and is a result of the use of some minerals that are added during tire manufacturing to strengthen them. However, in 2021, a group of researchers in Munich, Germany developed a process to remove metals from recovered carbon black. According to the researchers, the recovered carbon black processed from this developed technology will be free of any metal residue and can be used in tire manufacturing without using virgin carbon black.

Previously only about 10% of recovered carbon black could be used in tire manufacturing; However, after the new technology we mentioned above, the recovered carbon black that has been processed can completely replace the primary material, according to the researchers. Another advantage that the technology has is the extraction of high-quality metals from tires, which can be reused in industrial applications as well.

Recovered carbon black could be the ideal solution to replace carbon black that is produced for the first time. As processing technologies advance, various industries will be able to rely on 100% recovered carbon black in many applications. The production of recovered carbon black will reduce water use in this industry by 90% and will result in 90% fewer emissions compared to virgin carbon black. The researchers estimate that treated recovered carbon black is 20 times more valuable than untreated recovered carbon black.

Another important benefit of expanding carbon recovery from end-of-life tires is ridding the environment of millions of tons of rubber waste that can remain in the environment for centuries without decomposing, or being burned, thus generating Greenhouse Gases (GHGs). Reintegrating end-of-life tires back into the industry means a sustainable application, a circular and environmentally friendly economy.

In conclusion, the continuous development of recovered carbon black purification technologies and its increasing use in various industries, along with the growing need for the classification of recovered carbon black, has paved the way for its integration into the manufacturing of tires, paints, coatings, automobiles, and a number of other industries. Through research conducted, it was found that currently a ratio of 10-20% of the carbon black mixture with recovered carbon black can be used in most rubber applications, which means that there is sufficient space to increase this percentage in light of progress in finding ways to purify recovered carbon black.