Did you know that coffee is the second most valuable traded commodity? Second only to petroleum. Not only do coffee and petroleum share the top spots, they also use common separation technologies, specifically absorption.
Industrial chemical absorption is defined as a process in which one or more soluble components (solutes) are removed from the gas phase by contact with a liquid phase (solvent) into which the components of interest dissolve.
So how does it actually work?
- A gas stream is introduced at or near the bottom of a packed column. Something in this gas stream needs to be removed or separated from the other elements.
So how do we separate what we don’t want from what we do want?
- As the gas rises through the column a solvent is introduced at or near the top of the column. For this example let’s call the solvent water. The water then begins to trickle down the packed column, coming into contact with the rising gas.
- The water droplets effectively absorb certain elements in the gas stream and gravity takes the mixture down to a holding tank. What is collected in the holding tank can either be an impurity you are trying to remove from a gas stream OR a valuable resource that you want to reclaim.
- The elements in the gas that are not absorbed by the solvent continue to rise to the top of the column and are removed (typically these gases are inert)
How does this relate to coffee?
When you make coffee you introduce a solvent (water) into a packed column (coffee grounds in the filter). The solvent (water) trickles through the packing (coffee grounds) and gravity takes the solution to a holding tank (your coffee pot). You then ingest the legal stimulant and it powers you through the day.
So the next time you make coffee think about the unit operation of industrial chemical absorption and how its helping get you through your long work week.
For additional information about other unit operations in the chemical and petrochemical industries visit: https://pilotplantdesign.com/unit-operations