14 June 2004 00:01 [Source: ICB Americas]
With hydrogenated vegetable oils under scrutiny, major catalyst producers are developing possible so-lutions to address the trans fatty acid (TFA) issues in the food processing industry. Among them is using precious metals as catalysts in the hydrogena-tion process. Other options include: modifying reaction conditions when using conventional nickel-based cata-lysts, using an interesterification process in place of hydrogenation, and using electrochemicals hydrogenation, a technique still under development.
Engelhard Corp. is currently developing new hydrogenation technologies that would enable the production of partially hydrogenated vegetable oils with the desired low levels of TFAs (less than 10 percentage weight) and without the subsequent elevation of solid fat levels in the oil mixture. The company says it is working to produce an affordable technology with high activity and trans-selectivity that could be used as a drop-in substitute in existing hydrogenation reactors.
“Extensive research is ongoing in Engelhard to investigate second generation platinum-based catalytic technologies that not only can suppress the formation of trans-isomers but also saturated fats during the hydrogenation of edible oils,” says Gerard Mangnus, product manager for process technologies. “Early results indicate that compared to other edible oils technologies, the performance of the second generation platinum-based technologies lead to a suppression of the saturates formed, while keeping TFA production low,” he adds.
Johnson Matthey PLC is also involved in research and development for new low trans fat hydrogenation technology. The company is also looking at drop-in solutions that could be used in existing hydrogenation plants and which would probably involve precious metal catalysts such as platinum.
“All of the edible oil companies are very keen in reducing trans fats and have shown great interest in the development of new low trans technologies,” says Kieran Furlong, product manager at Johnson Matthey Catalysts. “We have a major project that has been ongoing for over a year that is pursuing this goal. In the meantime, we are assisting our customers with technical service in maximizing the potential of their current equipment and catalyst to lower trans fat. Significant gains have already been made with trans fat contents in certain hydrogenated fats already cut in half,” he adds.
In using platinum catalysts, there are some hurdles to overcome before they can be widely used in the edible oil industry. Cost is an obvious obstacle, particularly when compared to conventional nickel-based catalysts.
However, both companies say price is a not big issue when accounting for the catalyst’s life cycle costs. While a nickel catalyst is typically used only once in an oil hydrogenation reaction, a precious metal catalyst may be used at much lower dosages—at least 10 times lower—and could be reused extensively.
“While precious metal-based tech-nologies are more expensive than nickel-based ones, the precious metal content of the spent catalysts can be recycled, thereby lowering the overall cost associated with these catalysts,” says Engelhard’s Mr. Mangnus. “Only about 10 percent of the financial value of the nickel can be recovered by selling the spent catalyst after its use, whereas up to 95 percent of the precious metal content can be physically recovered and reused during the manufacture of fresh catalyst.”
Processing issues, such as recycling as well as the poison resistance and selectivity of the catalysts, need to be addressed as well and require further research, says Johnson Matthey’s Mr. Furlong. “We have made advances in the poison resistance of these catalysts and how to maintain their activity and selectivity as they age. Edible oil customers are becoming more familiar with the concept of using a precious metal catalyst and the fact that financial management will be as much a part of the process as operations management,” he adds.
Among the various new methods to reduce trans fats, the use of precious metal technologies are a good option, says Mr. Mangnus. While the use of a commercially available interesterification process can obtain lower trans fat levels, some say its relatively high cost and/or the limited availability of the desired liquid oils produced hinders its acceptability in the market.
Reduced TFA levels can also be achieved when using conventional nickel-based catalytic technologies by changing the hydrogenation reaction conditions. However, most edible oils producers have current equipment limitations in terms of maximum operating pressures. “Such extreme reaction condition modifications are not likely to be an affordable or practical solution to meet the demand for lower TFA products,” adds Mr. Mangnus.
Soybean Oil Hydrogenation to IV70 at Pressures <5>5>
Source: Engelhard Corp.
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