Propylene Oxide Production Process: From Feedstock to Versatile Intermediate
The propylene oxide production process has evolved significantly over the decades, with several commercial routes available to manufacturers worldwide. The choice of production process is a strategic decision that influences a producer's economic competitiveness, environmental profile, and product quality. The three primary commercial processes for propylene oxide production are the Styrene Monomer (SM) co-production process, the Chlorohydrin process, and the more recent Hydrogen Peroxide Propylene Oxide (HPPO) process .
The Styrene Monomer (SM) process, also known as the PO/SM co-production process, currently dominates the global propylene oxide market in terms of both value and volume . This process involves the indirect epoxidation of propylene using ethylbenzene hydroperoxide as the organic peroxide. Ethylbenzene is first oxidized to produce ethylbenzene hydroperoxide, which is then reacted with propylene to form propylene oxide. The process co-produces styrene monomer in a 1:1 ratio with propylene oxide, which enhances overall plant economics and reduces market risk . Major producers using this route include LyondellBasell, Shell, and Nihon Oxirane .
The Chlorohydrin process is an older technology that involves the reaction of propylene with chlorine and water, followed by the dehydrochlorination of the resulting propylene chlorohydrin to yield propylene oxide. While historically important, this process has significant environmental drawbacks, including the production of large quantities of calcium chloride waste. The HPPO process has emerged as the cleanest and most sustainable alternative, using hydrogen peroxide as the oxidant with water as the only by-product . The growing emphasis on sustainability and environmental performance is driving the adoption of HPPO technology, with several new facilities coming online or under development, particularly in Asia . For a comprehensive view of propylene oxide production processes, consult the main Propylene Oxide Market report.
