Supercritical carbon dioxide can be used to extract caffeine from coffee and tea. Coffee beans are soaked in water then put in a sealed vessel with carbon dioxide which is pressurized to approximately 70 atm (70 times atmospheric pressure). Once the caffeine has dissolved in the supercritical carbon dioxide, the solution flows to another chamber in which the pressure is reduced and the carbon dioxide vaporizes. This is an alternative to more traditional processes in which solvents like CHCl are used to extract caffeine from coffee. Evaluate the use of supercritical fluid as a decaffeinating agent in terms of green chemistry. Suggest at least one benefit, at least one drawback and at least one way in which you could ensure that the process was as green as possible. [3 marks]