Kinetics of CO₂ hydrate formation in coffee aqueous solution: Application in coffee concentration

Abstract

In this study, concentration of the coffee aqueous solution was performed using CO₂ hydrate formation. The experiments were aimed to investigate the effects of the solution of coffee and pure water on the amount and rate of CO₂ consumption, water to hydrate conversion, storage capacity, induction time, and initial apparent rate. These experiments were carried out at a pressure of 3.0 MPa, a mean temperature of 275.15 K, and weight percentages of 1.5, 5, 10, 15 w/w%. The results show that increasing the concentration of coffee solution leads to decrease of the induction time, and also demonstrates its inhibitor effect on water in all concentrations of coffee. Investigating the amount of gas consumption over the initial 30 minutes of the experiments reveal that the mole number for CO₂ consumption reached its ultimate value during this period, while it stood 17% less for all coffee concentrations as compared to pure water. This clearly indicates the inhibiting effect of the coffee solution in comparison to pure water.

Graphical Abstract

Keywords:

• Clathrate hydrate
• gas hydrate
• CO₂
• coffee
• concentration