Piperylene: Creating Applications & Differentiated Products
Year:2018 ISSUE:7
COLUMN:ORGANICS
Click:314    DateTime:Apr.09,2018


By Zhao Hongfu, Wu Yongqiang, Xinjiang Tianli PC Holdings Co., Ltd.,
Yao Yuanhong, Fan Yuanyuan, Xinjiang Huanqiu Contracting & Engineering Co., Ltd.

C5 fractions are by-products of ethylene production via petroleum cracking. The mass of C5 fractions produced is generally 10% - 20% that of ethylene output. About 15% - 20% of the C5 fractions is piperylene (PIPS), an important organic chemical intermediate.

Rich in resources but underutilized

   The main use of piperylene is to make C5 aliphatic petroleum resins. The liquid oligomers of piperylene can be used to make epoxy resin and heat-cured acrylic powder coatings, phenolic resins, adhesives, epoxy resins, inks, caulking materials, water-based paints, road marking paint raw materials, greases and synthetic oils, while terpolymers of piperylene, styrene and acrylonitrile, together with SBR, can be useful in making porous synthetic leather.
   In China, the content of piperylene separated from the C5 fractions is generally more than 65%, and about 80% of the piperylene is polymerized to produce piperylene petroleum resin, modified petroleum resin and hydrogenated petroleum resin; 10% for the production of methyl tetrahydrophthalic anhydride and methyl hexahydrophthalic anhydride epoxy curing agent; about 10% for the production of paints, inks, spices and other fine chemical products.
   Although China's piperylene supply is abundant, it is underutilized. A lack of scaled production and product serialization restricts its development. Meanwhile, separation and purification technologies still lag way behind the world’s best, limiting the products’ applications. In addition, most domestic products are low-grade, so medium- and high-grade products must be imported. Therefore, it is necessary to adjust the product mix, innovate and improve the technology, and develop the applications of piperylene.

Domestic supply volume will top the world

   Before 2010, the products of piperylene were mainly from ExxonMobil, Goodyear, Shell and ZEON. Boosted by the strong demand for ethylene in the Chinese market, many new ethylene crackers have been put into operation in China and the Middle East. As by-products of ethylene, the output of C5 fractions and piperylene separated from the fractions has increased rapidly.
   According to statistics, China’s production of piperylene will probably exceed 600 kt by 2020. Producers like Xinjiang Tianli Petrochemical Holdings Co., Ltd., Jinhai Chenguang, Shanghai Jinsen, and Luhua each have capacity exceeding 10 kt. There are more than 20 piperylene manufacturers in China, but only a few of them have technology for separation and purification.

Lack of product differentiation is to be solved

   In China at present, piperylene is used mainly to produce petroleum resins. In 2017, China’s C5 petroleum resin demand was 200 kt, and production capacity exceeded 500 kt. The C5 petroleum resin currently circulating in the market has only two main uses: hot melt road marking coatings and hot melt adhesives and pressure sensitive adhesives. The lack of product differentiation is very serious for the sector, which has little capability for product innovation and market development.
   Improving the economic efficiency and competitiveness by product differentiation is a critical issue that each company faces. Technological innovation is of course essential, but the added value can also be increased by identifying more functions of the product. Production of modified petroleum resins and hydrogenated petroleum resins would be a suitable choice.
   In addition, by continuously improving C5 separation technology, the purity of piperylene can be improved (above 95%), and as a raw material of synthetic rubber, its value can thus be greatly enhanced. The application of piperylene in making other fine chemicals can be promoted. For instance, it can be applied to the production of expensive spice leaf alcohol as leaf alcohol and its derivatives are among the most popular fragrance-based luxury spices in the world. Polymer grade piperylene can be applied to produce β-damascone, which is a very important component of aroma for high-grade cosmetics and food spices.