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4 Propylene Derivatives
Numerous propylene derivatives are produced based on the market demands.
Among all the derivatives, a substantial increase in the consumption of polypropylenebased materials over the last two decades has been the key driver for the growing
demand of propylene. As per IHS report, more than 65% of propylene was consumed worldwide in 2015 for the production of polypropylene [1]. Approximately,
7% of the propylene was employed in the production of propylene oxide, which is
a key intermediate for the synthesis of propylene glycol and polyols. The rest of the
propylene was utilized in the manufacture of cumene, and other important C3-based
chemicals. Since this book chapter is intended not to cover polymerization chemistry, apart from polypropylene other valuable C3 chemicals derived from propylene
such as propylene oxide, isopropyl alcohol, acrylonitrile, and acrylic acid have been
covered with the relevant information entailing their recent advances in the commercial as well as emerging processes and associated catalyst developments.
4.1 Propylene Oxide (PO)
Propylene oxide (PO) is one of the fastest-growing consumers of propylene and
around ten million tons of PO production in the world justifies its impact in the
chemical industry. PO is used in the production of various valuable products (Fig. 8)
such as polyols, propylene glycol, propylene glycol ethers, and polyurethane. Polyol
is one of the most important PO derivatives and its consumption is rising nearly 4%
per year and is expected to continue the similar growth in the coming decade. Polyol
is widely used in the production of polyurethane foams, by reactions with isocyanates, like methylene diphenyl diisocyanate (MDI) or toluene di-isocyanate (TDI).
Polyurethanes are versatile material and used in making flexible foams, which are
used in furniture, mattresses, and cushions for automobiles or rigid foams, which
are mainly used for insulation for housing and construction. Other applications of
PO include solvents and miscellaneous chemicals used in oil field drillings, flame
retardants, synthetic lubricants, etc. Consequently, demand for PO is continuously
increasing with a rate of 8% per annum especially in the Asia-Pacific region as the
automobile industry is growing substantially.
4.1.1 Propylene Oxide (PO) Production: Commercial Processes
At present, there are five major industrial processes for the production of PO [63].
These are (a) chlorohydrin (CL) process, (b) tert-butyl hydroperoxide (TBHP) or
PO/TBA (propylene oxide-tert-butyl alcohol) process, (c) ethyl benzyl hydroperoxide (EBHP) or PO/SM (propylene oxide-styrene monomer) process, (d) HPPO
(hydrogen peroxide to propylene oxide) process, and (e) cumene hydroperoxide
C. Samanta and R. K. Das
4 Propylene Derivatives
Numerous propylene derivatives are produced based on the market demands.
Among all the derivatives, a substantial increase in the consumption of polypropylenebased materials over the last two decades has been the key driver for the growing
demand of propylene. As per IHS report, more than 65% of propylene was consumed worldwide in 2015 for the production of polypropylene [1]. Approximately,
7% of the propylene was employed in the production of propylene oxide, which is
a key intermediate for the synthesis of propylene glycol and polyols. The rest of the
propylene was utilized in the manufacture of cumene, and other important C3-based
chemicals. Since this book chapter is intended not to cover polymerization chemistry, apart from polypropylene other valuable C3 chemicals derived from propylene
such as propylene oxide, isopropyl alcohol, acrylonitrile, and acrylic acid have been
covered with the relevant information entailing their recent advances in the commercial as well as emerging processes and associated catalyst developments.
4.1 Propylene Oxide (PO)
Propylene oxide (PO) is one of the fastest-growing consumers of propylene and
around ten million tons of PO production in the world justifies its impact in the
chemical industry. PO is used in the production of various valuable products (Fig. 8)
such as polyols, propylene glycol, propylene glycol ethers, and polyurethane. Polyol
is one of the most important PO derivatives and its consumption is rising nearly 4%
per year and is expected to continue the similar growth in the coming decade. Polyol
is widely used in the production of polyurethane foams, by reactions with isocyanates, like methylene diphenyl diisocyanate (MDI) or toluene di-isocyanate (TDI).
Polyurethanes are versatile material and used in making flexible foams, which are
used in furniture, mattresses, and cushions for automobiles or rigid foams, which
are mainly used for insulation for housing and construction. Other applications of
PO include solvents and miscellaneous chemicals used in oil field drillings, flame
retardants, synthetic lubricants, etc. Consequently, demand for PO is continuously
increasing with a rate of 8% per annum especially in the Asia-Pacific region as the
automobile industry is growing substantially.
4.1.1 Propylene Oxide (PO) Production: Commercial Processes
At present, there are five major industrial processes for the production of PO [63].
These are (a) chlorohydrin (CL) process, (b) tert-butyl hydroperoxide (TBHP) or
PO/TBA (propylene oxide-tert-butyl alcohol) process, (c) ethyl benzyl hydroperoxide (EBHP) or PO/SM (propylene oxide-styrene monomer) process, (d) HPPO
(hydrogen peroxide to propylene oxide) process, and (e) cumene hydroperoxide
C. Samanta and R. K. Das