Chemistry
Carbon black

What is Carbon Black



Tweet
Carbon black
William O'Neal Stringer's image for:
"What is Carbon Black"
Caption: Carbon black
Location: 
Image by: FK1954
© I, the copyright holder of this work, release this work into the public domain http://commons.wikimedia.org/wiki/File:Carbon_black.jpg

An unrefined form of carbon black was first produced by the Chinese about 3,500 years ago. Another source from the ancient past would be forest fires where the incomplete combustion of wood has occurred. Early forms of carbon black were impure and their chemical compositions were quite diverse. They are known as “lamp blacks.” 

Modern day carbon black, as explained in a report by Eric L. Crump for the U.S. Environmental Protection Agency, is produced all over the world. Carbon black is used mostly as a pigment, by Natural Pigments, and as a reinforcement filler in rubber compounds. As filler the use of carbon black in rubber reduces the cost of automotive tires. Products made from rubber are “elastomers,” as explained by the Polymer Science Learning Center, The University of Southern Mississippi, and they respond to the addition of carbon black in a way that improves their properties. 

There are over 50 different grades of carbon black produced by several processes. According to the U.S. Environmental Protection Agency, “There are five processes currently used to make carbon black.” The Furnace black process, Thermal black process, Acetylene black process, Lampblack process and the Bone black process, which is no longer used. Other carbonaceous products similar to carbon black but produced by different processes are activated carbon and bone black. They have different physical and chemical properties. 

The furnace black and thermal black processes produce almost all of the carbon black manufactured in the world. Aromatic oils are used as the main component to produce furnace black. The oil is subjected to temperature and pressure in a closed reactor where the oil is atomized. The atomized oil is then vaporized and pyrolyzes, from Dictionary 30, to form microscopic carbon particles. 

Natural gas is used to produce carbon black in the thermal black process. Natural gas is injected into a brick lined furnace, where in the absence of air, the heat decomposes the gas into carbon black and hydrogen. The thermal black process and the furnace black processes do more refining of the product into the various grades for commercial use. 

There is an organic contaminant in carbon black known as a, “polycyclic aromatic hydrocarbon,” or PAH. According to the United States Geological Survey, “PAHs are an environmental concern because they are toxic to aquatic life and because several are suspected human carcinogens.” This contaminant is found in fossil fuel emissions from the burning of gasoline and diesel fuels. 

External exposure to carbon black in the work place is not toxic. Dust from carbon black is very fine and can cause irritation to the eyes. If dust is inhaled deep into the lungs, it can cause damage if it is in large quantities. It would have the same ramifications as “black lung” developed by miners. Cancer and COPD, explained by Mayo Clinic, from carbon black can cause death. 

Virtually every part in an automobile that is not metal contains carbon black. Paint pigments and all of the plastics in your car contain filler amounts of carbon black. The problem arises when you understand that the parts containing carbon black are produced using non-renewable resources, most notably oil. Nearly any product you use in daily life that is made of plastic contains carbon black. Efforts are under way by researchers to replace carbon black with a polymer made from corn, which is a renewable resource. The future holds promise in reducing or eliminating the use of carbon black in plastic and rubber products. This will affect the environment and the global dependence on oil.

Tweet
More about this author: William O'Neal Stringer

From Around the Web




ARTICLE SOURCES AND CITATIONS
  • InfoBoxCallToAction ActionArrowhttp://www.epa.gov/ttnecas1/regdata/EIAs/carbonblackeia.pdf
  • InfoBoxCallToAction ActionArrowhttp://www.naturalpigments.com/detail.asp?PRODUCT_ID=480-50S
  • InfoBoxCallToAction ActionArrowhttp://www.pslc.ws/mactest/elas.htm
  • InfoBoxCallToAction ActionArrowhttp://www.dictionary30.com/meaning/Pyrolyze
  • InfoBoxCallToAction ActionArrowhttp://toxics.usgs.gov/definitions/pah.html
  • InfoBoxCallToAction ActionArrowhttp://www.mayoclinic.com/health/copd/DS00916