Means and method for controlling an absorber system

Claim 3

A system as described in claim 1 in which the monitoring means includes chromatograph signal means sampling the effluent gases, the feed gases and the feed solvents and providing signals corresponding to mole fractions of the components in the effluent gases, to mole fractions of the components in the feed solvents and to moles of the components in the feeD gas to each absorber per mole of feed gas to that absorber; and sensors sensing the flow rates of the feed solvents, the feed gases and the effluent gases and providing signal corresponding thereto.

Claim 4

A system as described in claim 2 in which the control signal means includes X and Z signal means receiving signals from the flow rate sensors and from the chromatograph signal means for providing Xij signals, with each Xij signal corresponding to the moles of a different component in the feed solvent to a different absorber per mole of component-free solvent to the absorber, and Zij signals, where each Zij signal corresponds to moles of a different component in the effluent gas from a different absorber per mole of feed gas to the absorber in accordance with the received signals; means receiving signals provided by the gas chromatograph means for providing signals corresponding to a molar conversion factor Fj for each absorber in accordance with the received signals; multiplier means connected to the Fj signal means and to the flow rate sensors for providing signals, each signal Lj corresponds to the moles of component-free solvent to a different absorber per unit time in accordance with the feed solvent flow rate signals and the Fj signals; means for providing control pulses; L and G signal means connected to the control pulse means, to the multiplier means and to the flow rate sensors for providing L and G signals in accordance with the signals from the multiplier means and the flow rate signal and as controlled by the control pulse so that each L signal at different time intervals corresponds to the determined number of moles of component-free solvent per unit time entering a different absorber, to a number of moles, more than the determined number, of the component-free solvent per unit time for that absorber and to a number of moles, less than the determined number, of the component-free solvent per unit time for that absorber, and each G signal at different time intervals corresponds to a sensed flow rate of feed gas to a different absorber, to a calculated feed gas flow rate for that absorber which is greater than sensed flow rate and to a calculated feed gas flow rate for that absorber which is less than the sensed flow rate; profit signal means connected to the X and Z signal means, to the multiplier means, to the flow rate sensors and to L and G signal means for calculating the profit of the absorber system for the different values of the L and G signals in accordance with the signals from the L and G signal means, the X and Z signal means, the flow rate sensors and the multiplier means and providing a profit signal corresponding to the calculated profits, and storage means connected to Fj signal means, to the profit signal means, to the L and G signal means and to the control pulse means for storing the profit signal when the profit signal corresponds to a profit greater than a previous profit and for storing the values of L and G signals associated with the stored profit signal so that after the L and G signals have changed through the different combinations of values for the L and G signals so that the stored profit signal in the storage means corresponds to a maximum profit for the various values of L and G signals and the storage means provides control signals in accordance with the L and G signal values associated with the stored profit signal, and the Fj signals.

Claim 5

A system as described in claim 3 in which the L and G signal means includes L1'' signal means connected to the multiplier means for providing a signal corresponding to the number L1'' of moles of component-free solvent per unit entering an absorber which is greater than the determined number L1 of moles in accordance with one of the signals from the multiplier means and the following equatioN: L1'' L1 + Delta L where Delta L is a predetermined change in the number of moles of component-free solvent per unit time entering the absorber, L1'''' signal means connected to the multiplier means for providing a signal corresponding to the number L1'''' of moles of component-free solvent per unit time entering the absorber which is less than the determined number L1 in accordance with the one signal from the multiplier means and the following equation L1'''' L1 -Delta L, L2'' signal means connected to the multiplier means and to the L1'' signal means for providing at least one signal corresponding to a number L2'' of moles of component-free solvent per unit time entering another absorber which is greater than the determined number L2 of moles entering that absorber in accordance with the signals from the multiplier means, the L1'' signal and the following equation

Claim 6

A system as described in claim 4 in which the L and G signal means includes G'' signal means connected to the flow rate sensors for providing a signal corresponding to a flow rate G1'' of feed gas entering an absorber which is greater than the sensed flow rate G1 of the feed gas entering that absorber in accordance with one of the flow rate signals from the flow rate sensors and the following equation G1'' G1 + Delta G where Delta G is a predetermined change in the feed gas flow rate entering that absorber, G1'''' signal means connected to the flow rate sensors for providing a signal corresponding to a flow rate G1'''' of feed gas entering the absorber which is less than the sensed flow rate G1 of the feed gas entering the absorber in accordance with the one flow rate signal from the flow rate sensors and the following equation G1'''' G1 - Delta G G'' signal means connected to the flow rate sensors and to the G1'' signal means for providing at least one signal corresponding to a Flow rate G2'' of feed gas entering another absorber which is greater than the sensed flow rate G1 entering that absorber in accordance with the feed gases flow rate signals, the G1'' signal and the following equation

Claim 7

A system as described in claim 5 in which the profit signal means includes mij computing means connected to the chromatograph signal means, to the flow rate sensors, to the control pulse means, to the Fj signal means, and to the X and Z signal means for providing signals, each signal corresponds to an equilibrium slope factor mij for a different component in a different absorber, computing means connected to the mij computing means, to the economic value signal means, to the L and G signal means, to the X and Y signal means and to the chromatograph signal means for providing a plurality of signals, each signal corresponding to an individual profit pij associated with a different component in a different absorber, each individual profit signal varying in accordance with the changes in the L and G signals from the L and G signal means; means for summing the individual profit signals from the individual profit signal means for providing the profit signal to the storage means.

Claim 8

A control system as described in claim 6 in which each individual profit signal means provides its individual profit signal in accordance with the following equation

Claim 9

A system as described in claim 7 in which the mij signal means provides each mij signal in accordance with the following equation

Claim 10

A system as described in claim 8 in which the X and Z signal means provide each X signal in accordance with the following equation

Claim 11

A system as described in claim 9 in which the X and Z signal means provide each Zij signal in accordance with the following equation

Claim 12

A system as described in claim 10 in which the control pulse means includes a control pulse network which provides the first through sixth pulses in a manner so that the fourth, fifth and sixth control pulses occur at different times, and the first, second and third pulses occur at different times with respect to each other but during the time interval for each fourth, fifth and sixth control pulse.

Claim 13

A system as described in claim 11 in which the control pulse means includes means for periodically providing a reset pulse to the chromatograph means and to the control pulse network so as to periodically recycle the optimizing operation.

Claim 14

A system as described in claim 12 in which the control pulse means includes means for providing an ''''enter'''' pulse just prior to the occurrence of a reset pulse; and the storage means includes third switching means receiving L and G signals from the L and G signal means, the profit signal from the profit signal means and a direct current voltage corresponding to a substantial zero profit condition and controlled by the L and G signals from the L and G signal means for passing a profit signal from the profit signal means when the L and G values are within the predetermined limits while blocking the direct current voltage and for blocking the profit signal from the profit signal means when an L or G value is not within the predetermined limits while passing the direct current voltage, a plurality of analog-to-digital converters for the L and G signals, the passed signal from the seventh switching means converts the received signals to corresponding digital signals, first register means connected to the plurality of analog-to-digital converters and controlled by a ''''store'''' pulse to store the digital signals provided by the plurality of converters and providing digital signals corresponding to the stored digital signals; comparator means receiving the passed signal from the seventh switching meanS and an analog signal corresponding to the stored profit signal for providing the ''''store'''' pulse when the passed signal from the seventh switching means is greater than the analog signal corresponding to the stored profit so as to control the register means to enter the digital signals corresponding to the greater profit and to the values of L and G associated with the greater profit in the first register means.

Claim 15

A system as described in claim 13 in which the storage means also includes a second plurality of analog-to-digital converters receiving the Fj signals, second register means connected to the last-mentioned analog-to-digital converters, to the first register means and to the ''''enter'''' pulse means in the control pulse means for storing the digital signals from the last-mentioned analog-to-digital converters and the L and G digital signals from the first register means in response to an ''''enter'''' pulse from the ''''enter'''' pulse means, a second plurality of digital-to-analog converters connected to the second register means for providing analog signals corresponding to the digital signals provided by the second register means, divider means connected to the last-mentioned digital-to-analog converters for dividing the analog signals corresponding to the Fj factors with the signals corresponding to the stored values for L associated with the maximum profit to provide control signals to the control means while the digital-to-analog converters provide signals corresponding to the stored values of G associated with the maximum profit as control signals to the control means so that the control signals may change once during each cycle of operation.