The invention discloses a
system and a method for industrially separating and purifying CO2 in
mixed gas by a
hydrate method. The
system consists of a feed gas pretreatment
system, a
hydrate separation
tower, a micro-bubble jet-loop
reaction system, a column bottom
hydrate decomposition system, a CO2 product
collection system, a hydrate formation and
decomposition heat comprehensive utilization system and a
tail gas
energy recovery system. The method integrates hydrate bubbling reaction technology, spraying reaction technology and micro-bubble jet reaction technology, adopts CO2
reflux displacement
fractionation technology to improve the concentration of the CO2 in a hydrate phase, has simple
separation technology and device and high separation rate and efficiency, comprehensively utilizes the formation heat and
decomposition heat of the hydrate during
refrigeration cycle, simultaneously recovers compression work of
tail gas and cold energy for feed gas pretreatment, and has low
energy consumption and cost during separation. The system and the method can be applied to industrial and continuous separation and purification of the CO2 in the
mixed gas such as
flue gas (CO2 / N2), IGCC synthetic gas (CO2 / H2),
biomass synthetic gas (CO2 / H2),
natural gas (CO2 / CH4), coalbed gas and the like.