Supercritical CO₂ Recovery Plant

CO₂ discharged from the hops extractors is vented at high pressure, typically between 700 and 900 psig, depending on the hops variety and extraction process parameters. This CO₂ contains hop oils, hop dust, other hydrocarbon traces, oxygen, and moisture, which are introduced during the supercritical hops extraction process

The primary challenge in CO₂ recovery is the rapid release of a substantial quantity of CO₂, approximately 1,500 to 1,700 lb per batch, within just 20 minutes. To manage this high-pressure discharge, the supercritical CO₂ recovery system first captures more than 80 to 90% of the released CO₂ in two pressure buffer tanks. The first stage operates at 150 to 350 psig, while the second operates at 15 to 65 psig. These buffer tanks subsequently release the collected CO₂ at a controlled outflow for purification.

The purification process begins with the separation of dust, oil mist, liquid droplets, and aerosols through coalescing filtration, with separation performance down to less than 0.1 µm. The CO₂ is then passed through adsorption towers to remove oil in vapor form, other vapor-phase hydrocarbons, and moisture. The gas is dried to a dew point below -76°F, and odor compounds are removed.

Following purification, the CO₂ is fed into condensation equipment, where the CO₂ vapors are condensed into liquid CO₂. The resulting liquid CO₂ is then distilled in a distillation column to remove oxygen. The purified CO₂ is collected in the day liquid CO₂ receiver and pumped back into the hops extraction process for reuse. The process achieves a CO₂ purity exceeding 99.997% v/v, enabling the recovered CO₂ to be recycled within the extraction process.