Carbon black [C.A.S. NO. 1333-86-4] is virtually pure elemental carbon in the form of colloidal particles that are produced by incomplete combustion or thermal decomposition of gaseous or liquid hydrocarbons under controlled conditions. Its physical appearance is that of a black, finely divided pellet or powder. Its use in tires, rubber and plastic products, printing inks and coatings is related to properties of specific surface area, particle size and structure, conductivity and color. Carbon black is also in the top 50 industrial chemicals manufactured worldwide, based on annual tonnage.
Current worldwide production is about 18.8 billion pounds per year [8.5 million metric tons]. Approximately 90% of carbon black is used in rubber applications, 9% as a pigment, and the remaining 1% as an essential ingredient in hundreds of diverse applications.
Modern carbon black products are direct descendants of early "lamp blacks" first produced by the Chinese over 3,500 years ago. These early lamp blacks were not very pure and differed greatly in their chemical composition from current carbon blacks. Since the mid-1970s, most carbon black has been produced by the oil furnace process, which is most often referred to as furnace black.
Two carbon black manufacturing processes (furnace black and thermal black) produce nearly all of the world's carbon blacks, with the furnace black process being the most common. The furnace black process uses heavy aromatic oils as feedstock. The production furnace uses a closed reactor to atomize the feedstock oil under carefully controlled conditions (primarily temperature and pressure). The primary feedstock is introduced into a hot gas stream (achieved by burning a secondary feedstock, e.g., natural gas or oil) where it vaporizes and then pyrolyzes in the vapor phase to form microscopic carbon particles. In most furnace reactors, the reaction rate is controlled by steam or water sprays. The carbon black produced is conveyed through the reactor, cooled, and collected in bag filters in a continuous process. Residual gas, or tail gas, from a furnace reactor includes a variety of gases such as carbon monoxide and hydrogen. Most furnace black plants use a portion of this residual gas to produce heat, steam, or electric power.
The thermal black process uses natural gas, consisting primarily of methane or heavy aromatic oils, as feedstock material. The process uses a pair of furnaces that alternate approximately every five minutes between preheating and carbon black production. The natural gas is injected into the hot refractory lined furnace, and, in the absence of air, the heat from the refractory material decomposes the natural gas into carbon black and hydrogen. The aerosol material stream is quenched with water sprays and filtered in a bag house. The exiting carbon black may be further processed to remove impurities, pelletized, screened, and then packaged for shipment. The hydrogen off-gas is burned in air to preheat the second furnace.
Physical & Chemical Properties
Carbon black is not soot or black carbon, which are the two most common, generic terms applied to various unwanted carbonaceous by-products resulting from the incomplete combustion of carbon-containing materials, such as oil, fuel oils or gasoline, coal, paper, rubber, plastics and waste material. Soot and black carbon also contain large quantities of dichloromethane- and toluene extractable materials, and can exhibit an ash content of 50% or more.
Carbon black is chemically and physically distinct from soot and black carbon, with most types containing greater than 97% elemental carbon arranged as aciniform (grape-like cluster) particulate. On the contrary, typically less than 60% of the total particle mass of soot or black carbon is composed of carbon, depending on the source and characteristics of the particles (shape, size, and heterogeneity). In the case of commercial carbon blacks, organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) can only be extracted under very rigorous laboratory analytical procedures (soxhlet extraction using organic solvents and high temperatures). These extracts, though they may be similar to those derived from soot, are unique, however, because carbon black extracts exist only in extremely small quantities. Water and body fluids are ineffective in removing PAHs from the surface of carbon black and, therefore, they are not considered to be biologically available.
Two other commercial carbonaceous products often confused with carbon black are activated carbon and bone black. Each is produced by processes different from commercial carbon black and possesses unique physical and chemical properties.
Traditionally, carbon black has been used as a reinforcing agent in tires. Today, because of its unique properties, the uses of carbon black have expanded to include pigmentation, ultraviolet (UV) stabilization and conductive agents in a variety of everyday and specialty high performance products, including:
- Tires and Industrial Rubber Products: Carbon black is added to rubber as both a filler and as a strengthening or reinforcing agent. For various types of tires, it is used in inner liners, carcasses, sidewalls and treads utilizing different types based on specific performance requirements. Carbon black is also used in many molded and extruded industrial rubber products, such as belts, hoses, gaskets, diaphragms, vibration isolation devices, bushings, air springs, chassis bumpers, and multiple types of pads, boots, wiper blades, fascia, conveyor wheels, and grommets.
- Plastics: Carbon blacks are now widely used for conductive packaging, films, fibers, moldings, pipes and semi-conductive cable compounds in products such as refuse sacks, industrial bags, photographic containers, agriculture mulch film, stretch wrap, and thermoplastic molding applications for automotive, electrical/electronics, household appliances and blow-molded containers.
- Electrostatic Discharge (ESD) Compounds: Carbon blacks are carefully designed to transform electrical characteristics from insulating to conductive in products such as electronics packaging, safety applications, and automotive parts.
- High Performance Coatings: Carbon blacks provide pigmentation, conductivity, and UV protection for a number of coating applications including automotive (primer basecoats and clearcoats), marine, aerospace, decorative, wood, and industrial coatings.
- Toners and Printing Inks: Carbon blacks enhance formulations and deliver broad flexibility in meeting specific color requirements.
In India carbon black is produced by 5 companies with combined total capacity of 10.28 lakh tons. Phillips Carbon Black Ltd. Is the largest company with capacity of 4.72 lakh tons. The other companies making carbon black are: SKI Carbon Black (India) Private Limited, Himadri Specialty Chemicals Limited, Continental Carbon India Limited and Ralson Carbon.
In 2016-17 the production of carbon black was 7.95 lakh tons, imports at 1.0 lakh tons and exports at 1.30 lakh tons. Total demand during the year was 7.63 lakh tons and is expected to reach 7.98 lakh tons in 2017-18. Of the total demand 79% of the demand is for Tyre industry while Non-tyre applications constitute 21%.
Major Factors Driving the Carbon Black Market
India’s carbon black market is expected to grow at around 14% CAGR until 2020. Superior reinforcing properties make carbon black a suitable material for use in diverse applications ranging from tyres, plastics, electronic equipment to inks, dyes and coatings. The expansion of tyre and rubber industries in the southern region of India is boosting the demand for carbon black in the country.
The shift in manufacturing base of automobiles and tyre industries is expected to be a major driver for the carbon black market over the coming years. Additionally, the use of carbon black has increased in specialty segments such as inks, conductive plastics and high-performance coatings, which has led to diversification in product range offered by key industry players.
In the past, Indian carbon black industry faced stiff competition from cheaper imports coming from China, which adversely affected the sales and profit margins of domestic players. However, various duties and taxes imposed by the Indian government on these imports have provided a respite to domestic industry players in the country.
Carbon black market in India is set to show promising growth in the next five years on account of various favorable developments in the country. Major players such as Phillips Carbon Black Limited have started incorporating backward integration to counter the fluctuation in prices of feedstock and volatility in crude oil prices. Moreover, low cost production in the APAC region has helped Indian players to consolidate their position in the carbon black market
Demand for carbon black in paints and coatings, and inks is expected to show an increase over the next five years. Demand for non-rubber applications that mainly use specialty blacks will display significant increase. Plastic and printing inks are likely to account for significant share of specialty black demand.
Another emerging application area for specialty carbon black is metallurgy. Moreover, as special black’s commands higher price than the widely used furnace blacks, they offer higher margins to suppliers. Furthermore, the demand for special blacks is not influenced by the cyclicality in the rubber and motor vehicle industries.
Indian Automobile Industry’s domestic market recorded an increase in passenger vehicle sales by 7%, commercial vehicle by 11% and muted growth of 1 - 3% in two and three wheeler segments in FY16. Low cost of ownership, improving demand from infrastructural activity and better monsoon should drive the FY18 growth across the segments. Auto exports grew by 1.9% on account of lower sales in two wheeler segment. Tyre Industry recorded lower production amid exports falling by 13-15% and increased imports by 12-14% in FY16. FY17 growth across segments is expected to improve with improving rural demand and increased infrastructural activity.
In terms of value Indian carbon black market stood at $ 879.26 million in 2016, and is projected to grow at a CAGR of 8.78%, in value terms, to reach $ 2,003.14 million by the end of 2026, on the back of expanding manufacturing facilities of tire manufacturing companies coupled with implementation of antidumping duty on carbon black imports by Government of India.
Recent Trends impacting demand of Carbon Black in India
Following trends are impacting the demand for carbon black in India:
Radialization in Truck/Bus segment has steeply increased by 10% in last 2 years reaching 36% in March 17 & is expected to be at 42% in March 2018. This would lead to sales of super hard grades steeply increasing to 37% which four years ago was 25%. Effect - Production capacity of Hard Blacks is going down.
With boom in auto sectors demand for Moulded Rubber Goods (MRG) has been continuously increasing. This has led to sales % of N550/Clean N550 grade CB rising. Effect- Production capacity of soft black is reducing.
Trend towards optimization of rolling resistance, light weight and fuel efficiency – all have to be represented in the tyre. This has led to development of newer grades of Black.
Speciality Carbon Blacks
Specialty carbon black has better growth potential compared to commodity carbon blacks. Generally carbon black used in plastics is produced by a process called furnace. Over 90% of commodity and specialty carbon blacks used in plastics are produced via the furnace process. There are several markets of plastics that use carbon black including agriculture film, antistatic flooring, appliance, automobile, cables/wire, consumer products, film, geomembrane, household products, pipes, roto moulded water tank. Commodity carbon black grows almost at the same rate as that of commodity plastics like polyolefins and PVC. The growth could be lesser than that of these commodity polymers because newer grades can be used at lower dosage additions to achieve similar tint strength. Specialty carbon black grades are expected to grow faster. Tyres and rubber products represent the major end-use applications, accounting for about 90% of global carbon black market.
Demand for speciality blacks in India is estimated at 49,000-tons in 2016, which is less than 5% of the global demand of speciality blacks at 9,15,000-tons. Global Speciality Blacks constitute around 10-12% of the total global carbon black market by volume.
Global Carbon Black Market is forecasted to grow at a CAGR of 8.42% during 2016 - 2021. The strong growth in carbon black industry is driven by the surging demand from tire and rubber industries. Emerging shift from commodity black to more specialized grade carbon black is projected to have a positive impact on the overall market growth.
Hurdles in the Market
The major hurdle for carbon black manufacturers is the emission of CO2 gas. Under the Kyoto Protocol, most countries have agreed to reduce and minimise their greenhouse emissions. In addition to CO2, other gases include nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride have been prime targets. The European Community has commitments to achieve reductions in its emissions levels by 2012 at 92 percent of base year 1990. This is a considerable challenge to manufacturers who need to explore alternative solutions to CO2 usage.
Globally there have been concerns over carbon black and its possible harmful effects to humans though evidence collected has been inconclusive. It has been labeled as possible human carcinogen (Group 2B) by International Agency for Research on Cancer (IARC).
Material handling and transport of products such as carbon black presents significant risk of soiling. As these products are available in various forms it’s possible to transport them in closed systems. Due to their flow properties, the most preferred mode of shipping is flexible intermediate bulk containers rather than rigid containers or silos.
Due to these hurdles mentioned above the virgin carbon black industry is likely to come under increased pressure from governments and environmental groups, as this product is a significant greenhouse gas emitter. Globally efforts are already on to try to use other substitute products in place of carbon black. Silica and other silanes are expected to offer a serious challenge to carbon black in the future and are fast emerging as major substitutes to carbon black due to better performance and environmental friendly nature. These products reduce rolling resistance in tyres at the same time improve fuel efficiency, hence they are increasingly finding usage in tyres market. Some of the OEM green tyres already use silica to the tune of 65% by weight.
A researcher in Iran has found using nanosilicate as a reinforcement in tire rubber can reduce tire weight, but the process has implications for carbon black usage. “The application of layered nanosilicate results in the reduction of carbon black quantity used in rubber blends thus reduces the density of blend so that it is possible to synthesize products with less weight,” said Azam Jalali Arani, a faculty member of the Polymer Engineering Department of Amirkabir University of Technology. “Tires lightening decreases fuel consumption of vehicles as well as the environmental pollution and consequently saves the energy consumption. Other specifications and final properties of the blend would also be improved and tire lifetime would be increased”, she added.
Researchers claim to reduce tire weight through nanosilicates instead of carbon black
Jalali Arani first formulated the nanosilicate incorporated rubber blend. Then she analyzed and determined the optimized conditions for preparation of this blend. After that, blending and producing the nanocomposite sample and also analyzing and testing the properties of sample vulcanization were done by rheometric test. Sample vulcanization and cure according to the results obtained from rheometric test and produced nanocomposite properties study were a part of research outcomes.**_