Cinnamic Acid Has Bright Market Prospect

By Wen Yongxiang


Extensive application sector

Cinnamic acid is an important organic synthesis intermediate
extensively used in fine chemicals such as perfumes, foods,
cosmetics, pharmaceuticals, pesticides, plastics and
photosensitive resins.
    Cosmetics and foods: Cinnamic acid has a blocking effect on
ultraviolet ray and is therefore an indispensable ingredient in
sunscreen creams. It is mainly used to synthesize
L-phenylalanine that is a main raw material in the synthesis of
new health-care sweet agent aspartame. The combination of
cinnamic acid with pasteurizing assistants has strong
antibacterial and anti-mildew effect and is often used in the
corrosion prevention and freshness preservation of grains,
vegetables and fruits and the color adjustment of grape wines.
    Pharmaceuticals: Cinnamic acid can be used to synthesize
drugs for coronary heart diseases and also produce local
anesthetics, fungicides and hemostatics.
    Pesticides: Cinnamic acid is a plant production promoter and
a lasting-effect fungicide used in high yield, corrosion
prevention and freshness preservation of fruits and vegetables.
    Others: Cinnamic acid can be used as corrosion inhibitor for
galvanized plates, heat stabilizer for PVC (polyvinyl chloride)
and antibacterial, anti-mildew and odor-removing agent. It can
also be used as raw material for the synthesis of negative
photosensitive resins.

Strong competitive edge of the styrene process

Methods for the cinnamic acid production mainly include the
benzaldehyde process and the styrene process.
    Benzaldehyde process: Benzaldehyde and acetic anhydride are
used as raw materials, anhydrous potassium carbonate (or
anhydrous potassium acetate) is used as solvent to conduct
reaction at 150℃ - 180℃ and produce cinnamic acid. As the
process has great energy consumption, low product yield, massive
generation of byproducts and difficult treatment of waste water,
it has gradually been eliminated.
    Styrene process: Styrene and carbon tetrachloride are used
as raw materials to have addition reaction. The intermediate
product is taken to a hydrolysis reactor. The reaction medium
is adjusted to a certain acidity to produce cinnamic acid.
Hydrogen chloride is produced as byproduct. As the cost is 30%
- 40% lower than the benzaldehyde process and there are also
advantages such as abundant and low-priced raw materials, mild
reaction conditions, low energy consumption and convenient
treatment of wastes, the process has strong competitive edge.
    Sino-EU BioMedChem Lda. has recently developed an
environment-benign process for the cinnamic acid synthesis
using a high-effect catalyst. Chlorinated aromatics, acrylic
acid and derivatives are used as raw materials and pure water
is used as solvent. The outstanding advantage of the process is
the small consumption of catalyst. The catalyst can maintain
very high catalytic activity after repeated uses. The production
cost is also 40% - 50% lower than the styrene process and 70%
lower than the benzaldehyde process. Different cinnamic acid
varieties can be produced in the same reactor according to market
needs. It has the features of short process flow, mild reaction
conditions, easy raw material availability, high conversion
rate and stable product quality. The process is not yet
commercialized.

Great deficit in the domestic market

The total capacity of cinnamic acid in China is around 1.5
thousand t/a. Major producers include Wuhan Yuancheng
Technology Developing Co., Ltd., Zhejiang Juhua Co., Ltd. Lanxi
Agrochemical Factory and Tianjin Yitian Industry & Trade Co.,
Ltd. Cinnamic acid units in China have small capacity, outdated
process technology and low operating rate.
   Cinnamic acid has extensive applications, but the
consumption in the domestic market is very small today. With the
development of the aspartame production and the expansion of its
consumption sectors, the consumption of L-phenylalanine will
become brisk and the cinnamic acid production will be promoted.
   The demand of L-phenylalanine in the world is around 15
thousand tons a year, needing 23 thousand tons of cinnamic acid.
The demand of L-phenylalanine in China is around 2 thousand tons
a year, needing around 3 thousand tons of cinnamic acid. The
output of cinnamic acid in China is only less than 1 thousand
tons today and the deficit has to be bridged by imports. It is
expected that the demand of L-phenylalanine in China will reach
3 thousand tons a year during the Eleventh Five-year Program
period (2006-2010) and the annual consumption of cinnamic acid
will be 5 thousand tons.
   Carbon tetrachloride is the main raw material for the
cinnamic acid production using the styrene process. With the
prohibition in the use of carbon tetrachloride in solvents, CFC
(chlorofluorocarbon)-11 and CFC-22, the price of carbon
tetrachloride will go down and the production cost of cinnamic
acid can be reduced.