Citral Moves Front and Center at BASF

The phrase "fine chemicals" conjures up small quantities of product made in batches in liter vessels and flasks. BASF, however, has just opened a petrochemical-sized answer to its need for additional fine chemicals capacity: its new citral plant, where the heaviest reactor weighs 300 metric tons and the tallest distillation column rises 45 meters above the ground.

Inauguration festivities at the company's massive Ludwigshafen complex were led recently by BASF Chairman Jürgen Hambrecht and joined by the governor of the German state of Rhineland-Palatine and the mayor of the city of Ludwigshafen. They celebrated the company's nearly $370 million investment in the site.

The largest portion of that investment was earmarked for the citral plant. At 40,000 metric tons per year of capacity, the plant replaces an older unit of one-quarter the size, which will be scrapped.

Starting from the isobutene and methanol produced by BASF's commodity chemical operations, citral and its family of derivatives carry out the firm's "Verbund" philosophy of complete integration. And with the additional supply, citral becomes an even more important building block for BASF. The firm already uses citral to make vitamin A and a variety of carotenoids. In the future, citral will be the firm's starting point for vitamin E and for the aroma chemicals geraniol and linalool.

Although the new plant has four times the capacity of the old one, it still uses the same number of employees: 30. Indicative of the central role citral will play in the company's fine chemicals operations, however, more than 500 Ludwigshafen-based jobs depend on citral's derivatives.

The products find their way into animal and human nutrition and in the health and cosmetics sectors, all fast-growing markets, according to Peter Oakley, the BASF board director responsible for agricultural products and nutrition.

"Customers are interested in living healthier, longer, and without wrinkles," Oakley said at the plant opening. Consequently, "we expect fine chemicals markets to grow by about 6% on average through 2010. By comparison, experts are forecasting the world economy to grow annually by 3.1% in the same period."

BASF'S REENGINEERED citral process is a multistep, continuous technique. Special catalysts developed by the company are employed in two reactors to cope with the specific synthesis conditions, explained Andreas Henne, group vice president for fine chemicals production and technology. It produces the two citral isomers--geranial and neral--in roughly 1:1 proportions. Both isomers are used in downstream processes.

Reaction conditions, with pressures of 300 bar in the first step and temperatures of more than 300 °C in another, "constitute high technical entry barriers," Henne argued. In fact, he said, BASF has only one competitor for synthetic citral worldwide: Japan's Kuraray, with significantly less capacity. Prior to BASF's development of the original synthesis in 1969, and still to a limited extent, citral--which has a strong lemony odor--was derived from essential oils, including lemongrass and various citrus oils.

Other fine chemicals projects are part of the investment package, pointed out Martin Laudenbach, head of the fine chemicals division. For example, in the works are a doubling of capacity, to 20,000 metric tons per year, for vitamin E and increases in production of carotenoids and other human and animal nutrition additives.

"The new citral plant not only offers a guarantee that we can reliably supply our customers with the products they require, but also marks an important step toward ensuring our competitiveness," Laudenbach said, because the simplified process reduces production costs. With the production integration, he said, BASF will be better placed to withstand the increasing pressure on fine chemicals margins worldwide, as new suppliers--particularly in Asia--make their presence felt.

The investment also signals BASF's commitment to its new logo (C&EN, Dec. 15, 2003, page 7), Oakley said. In a somewhat barbed comment alluding to the recent ins and outs of chemical companies from various businesses, he noted: "We are assuring customers that we want to be the chemical company with a broad technology portfolio and staying power that nobody else has. It is our commitment to still exist as a chemical supplier five years from now."