Overview of Advances in EB/Styrene and Phenolics Technologies

Badger Licensing LLC, a joint venture between The Shaw Group and ExxonMobil, offers licensing for premier processes for production in the Styrenics and Phenolics petrochemical chains. Through legacy companies, Badger's history includes more than 40 years of petrochemical process development experience supported by strong business relationships among its catalyst suppliers, operating partners and licensees. Badger maintains its home staff in Cambridge, Mass., and also in its Weymouth, Mass., research center. Engineering support for transfer technology, along with expanded engineering services, are provided through Shaw's Energy & Chemicals Group.

Core technologies available from Badger include ethylbenzene (with ExxonMobil catalysts), styrene via EB dehydrogenation in partnership with TOTAL, cumene (with ExxonMobil catalysts) and Bisphenol A.

Badger has been a leader in ethylbenzene/styrene monomer (EB/SM) technologies for more than 45 years. Excluding the aluminum-chloride-catalyzed EB technologies licensed prior to 1978, 49 EB plants have been licensed by Badger using ExxonMobil zeolites, including 31 plants using the EBMaxSM process since 1995. The styrene process, in partnership with TOTAL, the world's third-largest producer of SM, has been licensed 51 times. There are more than a dozen projects under way worldwide using Badger EB/SM technologies.

The current EBMaxSM process uses a custom-tailored zeolite to alkylate benzene with ethylene in the liquid phase. Because the benzene is strongly adsorbed onto the catalyst-active site, olefin oligomerization is avoided, which results in negligible catalyst aging by coke formation, a problem with most other catalysts. Byproduct make of di-alkyl olefins is also reduced, which minimizes trans-alkylation requirements and improves product purity. The process also can operate at a low aromatic-to-olefin ratio, which saves capital investment as well as utility consumption.

The styrene monomer technology focuses on a low steam-to-hydrocarbon ratio in the high-temperature EB dehydrogenation reactor section. All EB dehydrogenation processes operate at high temperatures, usually in excess of 600°C and with direct injection of even higher steam temperatures, as well as heat exchangers operating at similarly severe conditions. Given the ease at which aromatics can form coke at such conditions, the mechanical and process design of these plants requires considerable know-how. This includes design issues related to thermal expansion of the reactor internals, steam and hydrocarbon mixing, materials of construction and tubesheet design of heat exchangers.

The Badger SM units are known for their robust mechanical design, including the reactors, fired heaters and heat exchangers. Considerable design experience also has evolved around the EB/SM splitter column, some of the largest vessels used in the petrochemical industry. The Badger process has low raw material and utility utilization, and these numbers have improved markedly during the years because of improvements in available catalysts and better, but still operable, utility integration. Cumene is produced commercially by alkylation of benzene with propylene. Until the Badger cumene technology was available in the mid 1990s, all cumene in the world was produced over solid phosphoric acid or homogeneous aluminum chloride. These older processes suffered from poor yields, low purity, corrosion and other operational difficulties. The application of advanced zeolite technology developed by Mobil resulted in a much-improved process. The ExxonMobil zeolites had high alkylation activity and surprisingly low activity for propylene oligomerization (similar to the EB process), cumene isomerization and cracking reactions. These unique features of the ExxonMobil catalysts resulted in extremely stable performance with lifetimes that eventually were as high as seven years if the feedstocks were sufficiently clean. The resulting process also had very high selectivity and high propylene conversion, as well as low formations of impurities such as ethylbenzene, n-propylbenzene and butylbenzenes. The process could operate at extremely low benzene-to-propylene ratios, which enabled efficient plants, as well as an ability to revamp older technologies, usually with a large simultaneous capacity expansion. Badger has licensed the technology 20 times in a period of about 12 years.

Commercial demand for cumene is almost entirely limited to phenol production, while about half of phenol production (and a quarter of the byproduct acetone production) is used for production of Bisphenol A. This product has experienced high growth rates in recent years because of polycarbonate expansion, as well as GDP-fueled growth of epoxy resins, particularly in Eastern Asia. Shell developed BPA technology in the 1990s that eventually was acquired by Badger from a Shell spin-off, Hexion Specialty Chemicals (Resolution Performance Products at the time). Shell/Hexion has been a major merchant market producer of BPA for sale to polycarbonate producers, with major production in Houston and Rotterdam. The quality of this BPA is respected worldwide for its outstanding purity and color, which are important issues in high-end polycarbonate applications such as optical disks (DVDs).

The BPA technology, which is licensed by Badger, is operating or licensed in five plants in the world, with Badger about to complete another license agreement. Since 2001, this technology has gained more than 50 percent of the licensed market share. The BPA produced from these plants has supplied every major polycarbonate producer in the world and is widely accepted. Typical purity is 99.95 percent, which is particularly high for a product purified by crystallization. Catalysts for the condensation reaction between acetone and phenol use modern ion exchange resin with advanced promoters. BPA technology involves considerable know-how related to complicated chemistry, the handling of ion exchange resins, highly advanced crystallization technology, heat sensitivity of molten product and prill manufacture from molten BPA.

Accordingly, Shaw's olefin technologies and Badger's olefin/aromatic derivatives work very closely; we combine to contribute key projects, effective feeds and products, and optimum financial results.