Pilot Plant Experts

Decaffeination is the process of removing caffeine from materials such as coffee beans, tea leaves, kola nuts and cocoa beans.  Over the years, dozens of decaffeination methods have been developed and tested, and some have been commercialized with varying degrees of success.  Most of these methods fall into one of the following three categories: 

• Water based processes such as the Roselius (Kaffee HAG) process and the Swiss Water Process.
• Direct and indirect methods using extraction solvents such as methylene chloride or ethyl acetate.
• Direct and indirect methods using supercritical carbon dioxide.

The project customer is an East Coast company that markets a line of high-end premium coffee products.  Coffee contains more than 1,000 compounds that contribute to the taste and aroma of the final drink.  In order to remove the caffeine from green coffee beans, without affecting the concentrations of the other compounds, the customer had developed a novel technology that uses supercritical carbon dioxide to selectively disengage caffeine, and only the caffeine, from the extracting green bean liquor without perturbing any of the other taste and aroma compounds.  

Taste tests proved that our customer’s decaffeinated coffee was clearly superior to all other competing products. 

We designed and built a demo plant that produced several hundred pounds of decaffeinated green coffee beans per day.  The system was designed to operate at 6,000 psig – we had to address and overcome a variety of problems, including the fact that supercritical carbon dioxide can play havoc with conventional pump and valve elastomers.   

Engagement:  C, B, D, O.  Status – completed.