Scientists and engineers at CEBC are developing three technologies that, together, will significantly improve an important industrial process.
Have you ever noticed the laundry list of chemical ingredients in shampoos and other personal care products? Many of these ingredients were made by a chemical process called hydroformylation. The reaction involves the addition of a chemical structure (called a formyl group) to the carbon-carbon double bonds in oils (called unsaturated hydrocarbons).
This reaction is important because the resulting chemicals (called aldehydes) can easily be converted into many other products, such as detergents, fragrances, etc.
The chemical industry currently uses less selective cobalt catalysts for this process instead of more expensive, but better performing rhodium catalysts. This is because effective and economical catalyst recycling techniques are lacking for this process.
CEBC researchers are working to solve this problem by demonstrating a new catalyst separation process. It allows the product to be continuously removed from the reaction zone while leaving the metal catalyst behind. The process leaves the catalyst intact, active and ready for more work.
Because the catalyst is retained in the reactor, more active and selective rhodium catalysts can now be used. Rhodium catalysts have long been known to be superior catalysts for hydroformylation. But their high cost has made cobalt the catalyst of choice for industrial practice.
Cobalt catalysts are less selective than rhodium catalysts. They require higher operating temperatures and pressures. And, they are less active. But in order for rhodium to replace cobalt commercially, catalyst containment efficiency in the reactor must be extraordinarily high. An economic evaluation revealed that rhodium recycling efficiency must be greater than 99.8% effective for commercial viability. CEBC researchers are applying quantitative analytical techniques to verify that the level of rhodium retained in their process meets the needed performance requirements.
But that’s not all.
They are also adding carbon dioxide to the reaction mixture. This patented technology increases the efficiency and speed of removing the product from the reaction chamber. It also results in a higher selectivity to the most valued products.
To measure catalyst selectivity, the research team is using hydroformylation of 1-octene to the linear aldehyde as a model system. If the catalyst is not selective, several byproducts (isomeric aldehydes, internal olefins, and hydrogenated product) may also be produced in the reaction.
The combination of three promising technologies – a new catalyst retainment method, an economically viable rhodium catalyst, and the addition of carbon dioxide – are proving to add up to a commercially and environmentally attractive hydroformylation process.