FREE ESSAY ON ADIPIC ACID

ADIPIC ACID

SWOSU ICER98
submitted 2/23/98
Bart Barnett, Bill McKinley, Darren Toczko, Kevin Worley
Adipic acid is one of the most used chemicals in the world today, conversly, it
contributes significantly to the production of nitrous oxides (NOx), a greenhouse gas.
Many methods are available to produce adipic acid, with various results and potential for
pollution. The following paper discusses the impacts that adipic acid has on our society
and the world's environment. At the end of the paper, is a list of some of the sources
used for this topic. Any disagreements between the various sections of this article
probably resulted from this being a group effort. 
Uses
Adipic acid is a very important chemical that is used all over the world to produce
various products that people use every day. Nylon 6.6, foams, paints and tires are just a
few of the products that are formed by the use of adipic acid (AAD). Adipic acid is also
used as a food ingredient in gelatins, desserts and other foods that require
acidulation.
Nylon 6.6 is the largest outlet for adipic acid, accounting for more than 89% of the
total consumption in North America. One of the leading producers, BASF, produces 70
million pounds of nylon per year. Nylon is used for everyday applications such as
electrical connectors, cable tires, fishing line, fabrics, carpeting, and many other
useful products.
Production
The consumption and production for adipic acid is dominated by the United States. Of the
2.3 million metric tons of adipic acid produced worldwide, 42% is produced in the United
State while the United State consumes 62% of total production. Western Europe produces
the majority of the remaining adipic acid with 40%, and 13% in Asia-Pacific, while the
other regions account for the remaining 5%. The process of producing adipic acid can be
done by using different reactions. The main reaction is by the oxidation of cyclohexane
into cyclohexanol and cyclohexanone. Another industry reaction is by the hydrogenation of
benzene into cyclohexane and then oxidation. Adipic acid can be produced from butadiene
by carboalkoxylation, but this process is not commercialized.
The production of adipic acid through the oxidation of cyclohexane is done by reacting
cyclohexane with oxygen for air in the presents of a catalyze of cobalt or manganese at a
temperature of 150C to 160C. This reaction forms a mixture of the
cyclohexanol and cyclohexanone. The products are distilled to remove the unreacted
cyclohexane which is recycled. The cyclohexanol and cyclohexanone are then reacted with
nitric acid and air with a copper and vanadium catalyst. In this reaction, air is the
oxidation reactant that produces the adipic acid. This reaction produces almost all of
the world's adipic acid. There are variations of this reaction's first step producing
cyclohexanone and cyclohexanol from cyclohexane. This includes the using of Boron oxide
hydroxide and oxygen, or by oxygen and a catalysis to form the intermediate cyclohexyl
hydroperoxide with further reaction with catalytic amounts of transition metals. The
second step also can be done by reacting cyclohexanol and cyclohexanone with only air and
catalytic amounts Cobalt, copper, and manganese. This non-nitric acid process has the
advantages of no risk of corrosion and no NOx are produced. The disadvantage is that
succinic acid and glutartic acid is formed with the adipic acid, thus making purification
a problem. Phenol can be substituted for cyclohexane. This involves the hydrogenation on
the phenol into cyclohexanol with elemental hydrogen and a catalysis. From the
cyclohexanol, nitric acid is used to form the adipic acid.
The process of production of adipic acid from benzene is commercially used, but does not
account for a major amount of the total production. This reaction, starting with benzene,
produces cyclohexane as an intermediate step. Then the reaction continues, as in the
cyclohexane path of reaction. The change of the benzene to cyclohexane is done by simply
hydrogenation of the benzene. The benzene can also be change into phenol, and the
reaction process that pathway. The production of adipic acid with carboalkoxylation of
butadiene is new and only in the experimental stage, but may hold promise for a less
expense production. Many alternate processes have been researched; but so far, the
oxidation of cyclohexane with nitric acid is the most efficient. So in turn, it is the
most used.
Summary of reactions 
Environmental Effects
The adipic acid industry has a detrimental impact on the environment by letting out an
enormous amount of greenhouse gas. Estimated current global production of adipic acid is
at 1.8 million metric tons per year. The largest use is to make the common product nylon.
The greenhouse gas is specifically N2O. The N2O is produced during two oxidization steps
in the production of adipic acid. The large amount of adipic acid production per year,
due to the common product that it produces, has led to an enormous amount of this
greenhouse gas to be emitted.
There are several specific facts about why N2O is so bad for the environment. First, N2O
is a radioactively and chemically active trace gas believed to contribute to the recent
increase in the Earth's surface temperature. N2O absorbs reflected infrared radiation.
Also, estimated atmospheric lifetime of N2O is 150 years. Last, the estimated impact of
anthrogenic N2O is a 6% increase in ozone depletion rate. N2O from the production of
adipic acid is harmful to the environment because of its heat absorbing and ozone
depleting qualities.
Producers have recognized N2O production as making a measurable contribution to global
warming and ozone depletion. Manufacturers of adipic acid are attempting to reduce
emmisions by forming inter-industry groups, which share information, and the use of
different technologies. They have come up with three technology options. The first option
is improvement for N2O decomposition in special designed boilers. The second option is
conversion of N2O to recoverable NO. The third option is the catalytic dissociation of
N2O to N2 and O2.
References:
Bill's part. (Production Section)
Y.R Chin, PEP abstract: Adipic acid, September 1996.Copyright 1998 SRI consulting.
http://piglet.sri.com/CIN/NovemberDecember96/Article11.html
Authors: A. Castellan, J.C.J. Bart and S. Cavalllaro
Journal: Catalysis Today, 9 (1991) pg. 237-254
Title of article: Industrial Production and Uses of Adipic Acid.
Darren's part (Environmental Section)
Authors: R.A. Reimer, C.S. Slaten, M. Seapan, M.W. Lower, and P.E.Tomlinson
Journal: Environmental Progress, vol 13, No.2, May 1994.
Title of article: Abatement of N2O Emissions Produced in the adipic acid industry
Bibliography
References:
Bill's part. (Production Section)
Y.R Chin, PEP abstract: Adipic acid, September 1996.Copyright 1998 SRI consulting.
http://piglet.sri.com/CIN/NovemberDecember96/Article11.html
Authors: A. Castellan, J.C.J. Bart and S. Cavalllaro
Journal: Catalysis Today, 9 (1991) pg. 237-254
Title of article: Industrial Production and Uses of Adipic Acid.
Darren's part (Environmental Section)
Authors: R.A. Reimer, C.S. Slaten, M. Seapan, M.W. Lower, and P.E.Tomlinson
Journal: Environmental Progress, vol 13, No.2, May 1994.
Title of article: Abatement of N2O Emissions Produced in the adipic acid industry