An amine gas processing controller system, comprising: one or more tangible, non-transitory, machine-readable media collectively storing one or more sets of instructions; and one or more processing devices configured to execute the one or more sets of instructions to: transfer a rich amine stream from a contactor to a regenerator using an isobaric pressure exchanger, IPX,; and transfer a lean amine stream from the regenerator to the contactor using the IPX; wherein the IPX transfers pressure from the rich amine stream to the lean amine stream; receive a desired flow bias input comprising a difference between a desired flow rate of the lean amine stream to the contactor and a desired flow rate of the rich amine stream to the regenerator; receive a measured high-pressure lean amine flow rate signal; receive a measured low-pressure lean amine flow rate signal; determine a ratio of the measured high-pressure lean amine flow rate signal to the measured low-pressure lean amine flow rate signal; compare the ratio with the desired flow bias input to obtain a second comparison; and adjust the flow rate of the lean amine stream from the regenerator to the IPX based at least in part on the second comparison. one or more tangible, non-transitory, machine-readable media collectively storing one or more sets of instructions; and one or more processing devices configured to execute the one or more sets of instructions to: transfer a rich amine stream from a contactor to a regenerator using an isobaric pressure exchanger, IPX,; and transfer a lean amine stream from the regenerator to the contactor using the IPX; wherein the IPX transfers pressure from the rich amine stream to the lean amine stream; receive a desired flow bias input comprising a difference between a desired flow rate of the lean amine stream to the contactor and a desired flow rate of the rich amine stream to the regenerator; receive a measured high-pressure lean amine flow rate signal; receive a measured low-pressure lean amine flow rate signal; determine a ratio of the measured high-pressure lean amine flow rate signal to the measured low-pressure lean amine flow rate signal; compare the ratio with the desired flow bias input to obtain a second comparison; and adjust the flow rate of the lean amine stream from the regenerator to the IPX based at least in part on the second comparison. transfer a rich amine stream from a contactor to a regenerator using an isobaric pressure exchanger, IPX,; and transfer a lean amine stream from the regenerator to the contactor using the IPX; wherein the IPX transfers pressure from the rich amine stream to the lean amine stream; receive a desired flow bias input comprising a difference between a desired flow rate of the lean amine stream to the contactor and a desired flow rate of the rich amine stream to the regenerator; receive a measured high-pressure lean amine flow rate signal; receive a measured low-pressure lean amine flow rate signal; determine a ratio of the measured high-pressure lean amine flow rate signal to the measured low-pressure lean amine flow rate signal; compare the ratio with the desired flow bias input to obtain a second comparison; and adjust the flow rate of the lean amine stream from the regenerator to the IPX based at least in part on the second comparison.