Maleic Anhydride Video Lecture | Chemical Technology - Chemical Engineering

maleic anhydride is an organic compound
with the formula C 2 h 2 co 2 O it is
the acid anhydride of maleic acid it is
a colorless or white solid with an acrid
odor it is produced industrially on a
large scale for applications in coatings
and polymers production maleic anhydride
was traditionally produced by the
oxidation of benzene or other aromatic
compounds as of 2006 only a few smaller
plants continue to use benzene instead
most maleic anhydride is produced by
vapor phase oxidation of n-butane the
overall process converts the methyl
groups to carboxylate and dehydrogenase
the backbone the selectivity of the
process reflects the robustness of
maleic anhydride with its conjugated
double bond system in both cases benzene
and butane are fed into a stream of hot
air and the mixture is passed through a
catalyst bed at high temperature the
ratio of air to hydrocarbon is
controlled to prevent the mixture from
igniting vanadium pentoxide and
molybdenum trioxide are the catalysts
used for the benzene route whereas
vanadium phosphate is used for the
butane route c4h10 plus 3.5 o2a c 2 h 2
c 2 o 3 plus 4 hours duo a hour equals
minus 12 36 kilojoules per mole the main
competing process entails full
combustion of the butane a conversion
that is twice as exothermic as the
partial oxidation industrial production
of maleic anhydride is achieved by
integration of following unit processes
catalyst packed bed reactor adsorption
tower maleic acid reactor distillation
column the reactant stream of n butane
and air mixture enters the packed bed
reactor at a temperature of 120 to 150
degrees Celsius and a pressure of 2 to 3
atmospheres the product stream is then
sent to a packed bed adsorption column
where the condensable maleic anhydride
reacts with the water stream to give
maleic acid and then non condensable
ascent for fuel gases treatment the
condensable stream from adsorption tower
is sent to homily
Cassatt reactor where maleic acid is
again converted back to the anhydride
this product stream from reactor is sent
to distillation column to obtain pure
maleic anhydride as product reactions
the chemistry of maleic anhydride is
very rich reflecting its ready
availability and by functional
reactivity it hydrolyzes producing
maleic acid
Sayaka euro C H equals car euro COOH
with alcohols the half ester is
generated for example cyano kaguro see H
equals car euro co o ch3 maleic
anhydride is a classic substrate for
diels-alder reactions it was used for
work in 1928 on the reaction between
maleic anhydride and 1/3 butadiene that
Otto Poole Herman D else and Kurt alder
were awarded the Nobel Prize in 1950 it
is through this reaction that maleic
anhydride converted to many pesticides
and pharmaceuticals in 1979 a patent was
granted to lever brothers for the
Michael reaction of maleic anhydride
with active methylene or methane
compounds such as Mullen 8 or a snowsuit
a test is in the presence of sodium
acetate catalysts
these intermediates were subsequently
used for the generation of the krebs
cycle intermediates a kinetic and ISO
citric acids maleic anhydride dim arises
in a photochemical reaction to form
Cigala betaine tetra carboxylic
dianhydride this compound is used in the
production of polyamides and as an
alignment film for liquid crystal
displays it is also a ligand for low
valent metal complexes examples being PT
pph3 2 ma and PHA company 4 ma uses
around 50% of world maleic anhydride
outputs is used in the manufacture of
unsaturated polyester resins chopped
glass fibers are added to UPR to produce
fiberglass reinforced plastics which are
used in a wide range of applications
such as pleasure boats bathroom fixtures
automobiles tanks and pipes
however the UPR market reflects general
economic condition
as it is tied to the construction
automobile and marine industries the
production of one full butane DL is also
having an impact on the maleic anhydride
market video is one of the world a euro
unregistered trademark s fastest-growing
chemicals used in the production of
thermoplastic polyurethanes elastane
spandex fibers polybutylene
terephthalate resins and many other
products however BDL was made from a
crude maleic anhydride which is not
traded and only used for this
application another market for maleic
anhydride is lubricating oil additives
which are used in gasoline and diesel
engine crankcase soils as dispersants
and corrosion inhibitors changes in
lubricant specifications and more
efficient engines have had a negative
effect on the demand for lubricating oil
additives giving flat growth prospects
for maleic anhydride in this application
there are a number of smaller
applications for maleic anhydride the
food industry uses maleic anhydride in
artificial sweeteners and flavor
enhancements personal care products
consuming maleic anhydride include hair
sprays adhesives and floor polishes
maleic anhydride is also used in water
treatment chemicals detergents
insecticides and fungicides
pharmaceuticals and copolymers major
producers source Kirk and off mer
solid-state chemicals limited started
production of solid maleic anhydride
pastilles in the USA in 2014 world
maleic anhydride capacity by region data
in kilotons per annum source Kirk and
off mer packing and transport liquid
maleic anhydride is available in road
tankers and/or tank containers which are
made of stainless steel which are
insulated and provided with hating
systems to maintain the temperature of
65 to 75 degrees Celsius tank cars must
be approved for the transport of a
molten maleic anhydride liquid molten
maleic anhydride is a dangerous material
in accordance with our ID ADR solid
maleic anhydride pastilles are
transported by transit
trucks packaging is generally in 25
kilograms polyethylene bags storage
requirements for storage buildings local
exhaust systems to take vapors away from
the places of emission and general
ventilation in rooms protection against
static charges impervious floor which
makes it possible to collect the spilled
material and which prevents its entry to
the sewage system storage rooms should
be cool and dry storage conditions keep
ignition sources away do not smoke
product dust may form explosive air dust
mixtures keep humidity away from storage
rooms keep containers tightly closed
store them in cool dry and
well-ventilated places tank / containers
must be properly marked hand-operated /
portable firefighting equipment should
be available in storage rooms neutral
gas blanketing is required inside
storage tanks effects on human health
and the environment
this compound also poses relatively low
risk environmental hazards an important
feature for those applications exposure
to maleic anhydride may cause
respiratory tract irritation skin
irritation and respiratory irritation
maleic anhydride is a skin and
respiratory sensitizer maleic anhydride
is a low hazard profile chemical maleic
anhydride rapidly hydrolyzes - for
maleic acid in the presence of water and
hence environmental exposures to maleic
anhydride are not expected to occur
maleic anhydride maleic acid a
biodegraded under aerobic conditions in
sewage sludge and in both soil and water
food starch for use in night markets
sold from a supplier in Tay Ninh City
Taiwan were found to contain maleic
anhydride in December 2013 the supplier
was investigated regarding the 300
tonnes of tainted starch an earlier
inspection in November had found 32
tonnes references
external links international Chemical
Safety card oh 7 9 9 ni oh Sh pocket
guide to chemical hazards number oh
three seven six National Institute for
Occupational Safety and Health chronic
toxicity summary maleic anhydride at
Occupational Safety and Health
Administration