ACHEMA 2003
World forum for chemical process engineering showcases new equipment, processes, services, and research and development

MICHAEL FREEMANTLE, C&EN LONDON

Since the previous ACHEMA in 2000, the world has witnessed the terrible events of Sept. 11, 2001, other horrifying acts of terrorism, the conflict in Iraq, a global downturn in the economy, and, most recently, worldwide outbreaks of severe acute respiratory syndrome (SARS). Yet these and other adverse factors did not prevent manufacturers and users of chemical plants, equipment, components, and apparatus from flocking in droves to Germany's weeklong triennial chemical technology exhibition in Frankfurt last month.

	STETTIN/DECHEMA PHOTO

ACHEMA is a German acronym for chemical engineering exhibition and congress. The series is organized by DECHEMA, the Frankfurt-based German Society for Chemical Engineering & Biotechnology.

ACHEMA 2003, the 27th in the series, focused on chemical engineering, environmental protection, and biotechnology. It comprised 12 wide-ranging exhibition groups, a congress consisting of symposia on 12 diverse topics, and other events such as a recruitment forum.

The 3,819 exhibitors from 48 countries this year represented a 7.9% drop from the number of exhibitors in 2000. "ACHEMA 2003 takes place in a considerably chillier economic climate," said DECHEMA Chief Executive Gerhard Kreysa at a press briefing. "Nevertheless, it is the second biggest ACHEMA in its 83-year history."

At the same briefing, ACHEMA committee Chairman Arthur Ruf highlighted some of the latest trends in process engineering, pointing out that there have been key developments in knowledge management, "ecoefficiency" and green chemistry, process-control optimization, sensors, and proteome analysis.

There has also been significant progress in the development of new membrane materials and microreactor technology. "Product innovations in the sector of new membrane materials and process-optimized membrane modules for microfiltration, ultrafiltration, and nanofiltration satisfy rising demands placed on process water quality and are in step with the increasing need worldwide for water treatment technology," Ruf noted. "Water treatment remains a growth market with tremendous potential.

"With its miniaturized components, microreaction engineering is conquering previously undeveloped territory in the handling of reactions that could not be controlled in terms of process engineering on an industrial scale or that proceed with unsatisfactory selectivity," he added.

STETTIN/DECHEMA PHOTOS

THE LARGEST exhibition group at ACHEMA, in numerical terms, consisted of manufacturers of pumps, compressors, valves, and fittings. Among the 855 exhibitors in this group was Watson-Marlow Bredel. The company--which is based in Falmouth, England, and is part of the Spirax-Sarco Engineering Group--manufactures pumps that have no valves, seals, or glands.

On the first day of ACHEMA, the company launched its new 520R pumphead for its 500 range of industrial peristaltic pumps for chemical and industrial processing applications. The two main components of a peristaltic pumphead are a track that holds the tubing through which the fluid flows and a rotor that drives the fluid through the tubing.

"The 520R pumphead is made of polyphenylene sulfide, a truly amazing material that is resistant to corrosion and impact," noted Senior Product Manager Rob Mead. "Its physical properties even outperform aluminum alloy." He added that the easy-release rotor clutch and tube clamps on the pumphead enable operators to make tube changes in a matter of seconds when required.

In the same exhibition group, Swagelok put its new modular platform component (MPC) system on display for the first time. The company, headquartered in Solon, Ohio, develops and manufactures fluid system component technologies for the pharmaceutical, oil and gas, power, petrochemical, and semiconductor industries.

The MPC system and configuration software are designed for use within process analyzer and sample-handling systems. The system consists of three layers: substrate and manifold layers that provide the flow path for the fluid and a surface-mount layer that provides shut-off, flow control, and filtering capabilities for the fluid.

"The components--which include surface mounts, various types of valves, and filters--enable system designers to reduce the size, weight, and flow-path volume of their process analysis and sampling systems," according to William Dickie, Swagelok field engineer for Europe.

The configuration software allows the user to place, define, and connect surface-mount components on a computerized layout grid. It identifies all of the additional flow connectors necessary to build the fluid system.

Another exhibition focused on research and innovation. Degussa was one of the 231 exhibitors. The company displayed a wide range of innovative specialty chemicals, including a material called Glenium Ace for use in the precast concrete industry.

"The material is a new-generation polycarboxylic ether-based polymer," explained Andrea Fenchl, an expert in oil-field polymers at Degussa Construction Chemicals, Trostberg, Germany. "The electrostatic and steric properties of the polymer molecules enable the individual molecules in the cement slurry to be powerfully dispersed.

"When concrete is poured into a mold, it is conventionally heavily vibrated to expel air and achieve a high level of compaction," Fenchl told C&EN. "The process is very noisy and can damage hearing. After compaction, the precast concrete is usually heated to 70–90 °C to accelerate hardening."

However, the use of Glenium Ace--in conjunction with a new energy-saving concrete technology known as the zero-energy system--avoids the use of mechanical and thermal energy and results in high-strength and durable precast concrete, Fenchl said. "It reduces environmental impact by significantly lowering energy use and improves the working conditions for users by lowering noise levels."

Argonaut Technologies exhibited its new Advantage Series 3400 multireactor system for chemical process development and scale-up. The company, which was founded in 1994 and has headquarters in Foster City, Calif., provides consumables, instruments, and services that help accelerate the development of new medicines.

The 3400 process chemistry workstation, designed to automate chemical process development, was on display in an exhibition of laboratory and analytical techniques. "The workstation has four independent modular reactors that allow chemists to set up their own individual reactions away from the workstation," explained European sales manager Ian Jennings. "The workstation automatically captures and documents process chemistry workflow. Data are recorded in a format that teams and individuals can easily adopt.

"We call it walk-up chemistry," he continued. "Chemists can walk up, slide the prepared reactor in place, and use the workstation to design, analyze, and apply processes." Each reactor has individual temperature control and can be started and stopped independently, allowing chemists to carry out several reactions on the workstation simultaneously.

	Kreysa WACHENDORFER/ DECHEMA PHOTO

At the same exhibition, Ashe Morris, a small, specialist engineering company based in Radlett, England, displayed its novel constant-flux reactor, which is based on a new heat-transfer technology. "Conventional heat-transfer techniques have traditionally used the heat-transfer fluid temperature to control process temperature," explained the company's managing director, Richard Barker. "With our technology, the process temperature is controlled by using constant-temperature cooling fluids and varying the heat-transfer area."

The technology can be applied to a wide range of heat exchangers and reactors and is fully scalable from laboratory to industrial scale. It is attracting commercial interest in the pharmaceutical, chemical, polymer, biotechnology, and food industries, according to Barker.

The constant-flux reactor was invented by Robert Ashe. "I started developing the idea in 1990 when I was working as a chemical engineer in the pharmaceutical industry," he told C&EN. "In my spare time, I investigated ways of measuring heat in large systems. I concluded that a fundamental reappraisal of classical temperature control methods was required. The 'constant-flux temperature control' concept developed from the idea of variable-area heat-transfer surfaces made up from small incremental elements."

Ashe's early calculations suggested that incredible improvements in calorimetry were possible at any scale if heat-transfer area was used as the control parameter. Improved temperature control and the possibility of handling temperature-sensitive materials were additional, unexpected benefits.

"After about 10 years work, I was convinced that constant-flux control had compelling benefits for a wide range of applications," Ashe said. "I joined forces with another engineer, David Morris, and formed Ashe Morris Ltd. in 2000. Our prototype was completed in the spring this year."

The company is currently offering for sale a small number of reaction calorimeters. "We are also looking for development partners and licensees within different industrial niches," Ashe said.

An ACHEMA exhibition on engineering focused on the development, planning, and execution of complete production units for all chemical engineering sectors. The exhibition covered catalysts, reactors, computer-aided engineering, and plants for water and sewage treatment, exhaust gas purification, waste disposal, and recycling.

STETTIN/DECHEMA PHOTO

THE 332 EXHIBITORS in this group included the San Diego-based company Reaction Design, which launched a new in-depth process value improvement service last month. "Traditional approaches to process improvement have focused on fitting a model based on a few chemical reactions to experimental results," Reaction Design's chief engineer Herman De Meyer noted. "The problem with this approach is that it fails to consider hundreds of other reactions involved in the process--for example, trace ingredients that may have a significant impact on the effectiveness of a catalyst.

"We begin by reviewing the chemistry of the process in order to gain an in-depth understanding of the limiting mechanisms involved," De Meyer explained. "We then start an iterative process to create a broad range of technical options by defining ways of eliminating constraining conditions. Rigorous dynamic modeling of reactors and other relevant unit operations follows as a quantification step. Subsequent ranking of the improvement opportunities is based on their return on investment. Our innovative approach integrates unit operation models and thermodynamics with fluid dynamics and microscale chemistry."

The approach has been proven in the analysis of the reactor and recycle loop of an ethylene oxide plant. It identified opportunities to generate incremental operating margins of $8.7 million by improving control of the combustion inhibitor, up to $4.4 million by improving carbon dioxide removal, and up to $3.5 million through homogenizing flow.

Honeywell Industry Solutions, part of Honeywell's Automation & Control Solutions group, launched and demonstrated its new Process Knowledge Solution (PKS) for Asset Effectiveness platform at the ACHEMA exhibition on instrumentation, control, and automation techniques.

The platform incorporates Honeywell's Experion PKS industrial automation system, which controls, monitors, and manages complex control processes in many types of industrial settings, including refineries; pharmaceutical plants; power and chemical plants; and pulp, paper, and printing mills. The PKS system facilitates the flow of information across entire organizations.

The PKS for Asset Effectiveness platform is an integrated suite of data collection tools, services, and analysis software that generates prioritized, actionable tasks. It aims to increase the overall operational effectiveness of maintenance personnel by improving their ability to target and more closely manage assets that have the greatest impact on business success.

"It gets the right information to the right people so that they can take the right actions at the right time," remarked David R. Kaufman, director of integrated field solutions at Honeywell. "The system gives operators freedom of choice to combine different products and protocols and leads to a reduction in maintenance costs."

According to Honeywell, businesses can expect to achieve a financial impact ranging from $500,000 to more than $4 million during the first year of full-scale implementation of the PKS for Asset Effectiveness platform--owing to reduced maintenance costs, improved energy efficiency, and other factors.

	Hinz BAYER AG PHOTO

Bayer Industry Services (BIS), the service company that recently emerged from the new holding structure of the Bayer Group, presented the Bayer Chemical Park concept, including a novel start-up initiative, at the ACHEMA exhibition.

BIS operates Bayer Chemical Parks in Leverkusen, Dormagen, Krefeld-Uerdingen, and Brunsbüttel, Germany. The parks employ around 48,000 people, including employees of national and international partner companies located in them.

"We own and operate the largest German chemical park network and offer our services both within and without the four BIS sites," explained BIS Managing Director Jürgen Hinz at a press conference.

Four Bayer operational subgroups--Bayer Polymers, Bayer CropScience, Bayer HealthCare, and Bayer Chemicals--and more than 25 national and international partner companies are already located in the chemical parks network and use the BIS service package, which includes licenses, supplies of raw materials and intermediates, disposal facilities, analytical services, and safety and security facilities. "We provide them with everything they need, ensuring that they can concentrate fully on their core business," Hinz said.

BIS is also helping fledgling chemical companies locate themselves in the chemical park network with its Bayer Chemistry Start Up Initiative. "Our initiative provides, at our sites, the ideal environment for anyone with good ideas for new chemical products looking to set up a successful business," Hinz noted.

The initiative provides support in the testing of financial models; in forging contacts with industrialists, financial institutions, and investors; and in solving problems that may arise in complicated licensing procedures. In addition, the initiative offers laboratory and environmental protection facilities, workshops, training, and other services and facilities.

DECHEMA Chief Executive Kreysa observed that ACHEMA is a unique event that demonstrates to a broad public just how indispensable chemistry and its products have become to our technological civilization.

He pointed out that ACHEMA 2003 launched the second cycle of ACHEMA worldwide. The 6th ACHEMASIA will be held in Beijing in 2004, and the 2nd ACHEMAMERICA will be in Mexico City in 2005.

"ACHEMA worldwide is the only event in the world in chemical engineering, environmental protection, and biotechnology that acts as a gateway to globalization for all participants and integrates them into a worldwide human network," Kreysa concluded.

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ASYMMETRIC CATALYSIS

Evolutionary Method Creates Enantioselective Enzymes

A strategy developed in Germany for generating enantioselective enzymes is based on Darwin's evolutionary principle. The method, which relies on a technique known as directed evolution, was pioneered by Manfred T. Reetz, a chemistry professor at the Max Planck Institute for Coal Research, Mülheim an der Ruhr.

	BIOCATALYTIC Max Planck team--(from left) Ph.D. student Birgit Brunner, technician Marcus Hermes, Ph.D. student Toni Schneider, and Reetz--investigates the directed evolution of an enzyme for the Baeyer-Villiger oxidation. COURTESY OF MANFRED REETZ

"Chemists have two options for the catalytic stereoselective synthesis of chiral organic compounds," he said in a plenary lecture at ACHEMA 2003 in Frankfurt last month. "They can either employ biocatalysts or chiral synthetic catalysts such as transition-metal catalysts."

The starting point of Reetz's biocatalytic method is a wild-type enzyme that catalyzes a reaction of interest but not enantioselectively. An example is the lipase from the bacterium Pseudomonas aeruginosa that catalyzes the hydrolysis of esters.

The gene that encodes the enzyme is first subjected to random mutagenesis to create a library of mutant genes in a test tube. The library is then inserted into a suitable microorganism and expressed as a library of mutant enzymes, which are screened for enantioselectivity. The inferior mutants are discarded. The mutant gene of the enzyme exhibiting optimal enantioselectivity is then subjected to further cycles of mutagenesis, expression, and screening.

"In each round of mutation, about 2,000–5,000 mutant enzymes are created, which means that efficient high-throughput screening for enantioselectivity is necessary," Reetz said. "Our group has developed several high-throughput ee [enantiomeric excess] assays," including nuclear magnetic resonance spectroscopy-based and mass spectrometry-based systems that allow 1,000 to 10,000 ee values to be determined per day.

Reetz and colleagues have shown that directed evolution can dramatically enhance the enantioselectivity of a lipase in the hydrolytic kinetic resolution of a chiral ester. "We improved the selectivity factor from 1.1 to more than 51," Reetz said.

In his plenary lecture, Reetz described preliminary unpublished research, carried out in collaboration with University of New Brunswick, Saint John, chemistry professor Margaret M. Kayser, on the directed evolution of an enantioselective cyclohexanone monoxygenase for the Baeyer-Villiger oxidation of 4-hydroxycyclohexanone to form two lactone enantiomers.

Using an Escherichia coli expression system, the team created a library of 4,000 mutants from which a dozen improved enzyme variants were identified. The two best ones showed an (R)-selectivity of 77:23 and an (S)-selectivity of 88:12.

"This is the first time that directed evolution has been used to evolve enantioselectivity in an oxidation process," Reetz said. "It is also the first time that directed evolution of an enantioselective process has been performed using whole cells. The approach has great potential because transition-metal catalysis is problematic in such systems."

Reetz also outlined a new concept in combinatorial enantioselective transition-metal catalysis that his group has developed [Angew. Chem. Int. Ed., 42, 790 (2003)]. The strategy is based on the use of mixtures of at least two different chiral monodentate ligands (L^a and L^b) that coordinate with a metal (M) to form an active catalyst (ML_x). With two such ligands, three different catalysts exist in equilibrium with one another: one heterocombination, ML^aL^b, and two homocombinations, ML^aL^a and ML^bL^b.

Reetz's group employed the technique for rhodium-catalyzed hydrogenations of olefins using BINOL-based modular monophosphonites, monophosphites, and monophosphoramidites as ligands (where BINOL is 2,2´-dihydroxy-1,1´-binaphthyl).

"There is enormous industrial interest in the use of monodentate BINOL-derived phosphites, phosphonites, and phosphoramidites" because of their low cost, Reetz explained. Using mixtures of ligands "allows ready access to high catalytic diversity, so that catalysis of a given substrate is rapidly optimized." Reetz's group has prepared some 70 different monophosphite and phosphonite ligands that can be used to form the catalysts.

As an example, he pointed out that the traditional use of a BINOL-derived methylphosphonite ligand for the rhodium-catalyzed hydrogenation of an N-acylenamine affords an ee of 78.2%, whereas the tert-butyl analog of the ligand affords only 3.0% ee. A 1:1 mixture of the two ligands, however, results in 97% ee.

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