Absorption process method and apparatus

Claim 3

A method in accordance with claim 1 additionally comprising: establishing a fifth signal representative of a nominal desired flow rate of said feed material to said absorption zone; establishing a sixth signal representative of the actual flow rate of said feed material to said absorption zone; and responsive to said second condition of said mode control signal: generating in response to said first signal, said second signal, said fifth signal, and said sixth signal, a seventh signal representative of the optimum flow rate of said absorption medium to said absorption zone; generating, in response to said first signal, said second signal and said seventh signal, an eighth signal representative of the optimum flow rate of said feed material to said absorption zone; controlling the flow of said absorption medium into said absorption zone in response to said seventh signal; and controlling the flow of said feed material into said absorption zone in response to said eighth signal.

Claim 4

A method in accordance with claim 2 wherein said first signal is representative of the desired ratio of said absorption medium entering said absorption zone to said product constituent entering said absorption zone; wherein said second signal is representative of the concentration of said product constituent in the feed entering said absorption zone; wherein said first signal and said second signal are mutliplied to produce a ratio signal representative of the desired ratio of absorption medium entering said absorption zone to feed material entering said absorption zone; wherein generating said fourth signal comprises dividing said third signal by said ratio signal; and wherein generating said eighth signal comprises dividing said seventh signal by said ratio signal.

Claim 5

A method in accordance with claim 3 wherein establishing said first signal comprises: measuring the concentration of said product constituent leaving said absorption zone in an overhead stream; establishing an average concentration signal representative of the average of a plurality of such product constituent concentration measurements; comparing said average concentration signal with a concentration set point signal representative of an acceptable concentration of said product constituent leaving said absorption zone in said overhead stream; and generating said first signal in response to the comparison of said average concentration signal and said concentration set point signal.

Claim 6

A method in accordance with claim 3 wherein establishing said second signal comprises establishing signals representative of the individual concentrations of all significant nonproduct constituents in a main feed material stream and subtractively establishing a signal representative of the concentration of said product constituent by subtracting all such nonproduct constituent concentration signals from a set point signal representative of 100% product constituent concentration.

Claim 7

A method in accordance with claim 5 additionally comprising correcting the subtractively established product constituent concentration signal in response to the flow of a recycle feed stream carrying a portion of said product constituent to said absorption zone.

Claim 8

A method in accordance with claim 1 wherein said first signal is representative of the desired ratio of said absorption medium entering said absorption zone to said product constituent entering said absorption zone; wherein said second signal is representative of the concentration of said product constituent in the feed entering said absorption zone; wherein said first signal and said second signal are multiplied to produce a ratio signal representative of the desired ratio of absorption medium entering said absorption zone to feed material entering said absorption zone; and wherein generating said fourth signal comprises dividing said third signal by said ratio signal.

Claim 9

A method in accordance with claim 1 additionally comprising: establishing a fifth signal representative of a nominal desired flow rate of said feed material to said absorption zone; establishing a sixth signal representative of the actual flow rate of said feed material to said absorption zone; and responsive to said second condition of said mode control signal: generating, in response to said second signal, said fifth signal, and said sixth signal, a seventh signal representative of the optimum flow rate of said absorption medium to said absorption zone; generating, in response to said first signal, said second signal and said seventh signal, an eighth signal representative of the optimum flow rate of said feed material to said absorption zone; controlling the flow of said absorption medium into said absorption zone in response to said seventh signal; and controlling the flow of said feed material into said absorption zone in response to said eighth signal.

Claim 10

A method in accordance with claim 8 wherein establishing said first signal comprises measuring the concentration of said product constituent leaving said absorption zone in an overhead stream; establishing an average concentration signal representative of the average of a plurality of such product constituent concentration measurements; comparing said average concentration signal with a concentration set point signal representative of an acceptable concentration of said product constituent leaving said absorption zone in said overhead stream; and generating said first signal in response to the comparison of said average concentration signal and said concentration set point signal.

Claim 11

A method in accordance with claim 8 wherein establishing said second signal comprises establishing signals representative of the individual concentrations of all significant nonproduct constituents in a main feed material stream and subtractively establishing a signal representative of the concentration of said product constituent by subtracting all such nonproduct constituent concentration signals from a set point signal representative of 100% product constituent concentration.

Claim 12

A method in accordance with claim 8 wherein generating said seventh signal comprises: establishing a first partial absorption medium requirement signal in response to the difference between said fifth signal and said sixth signal; establishing a second partial absorption medium requirement signal by multiplying said sixth signal and said second signal; and adding said first partial absorption medium requirement signal, said second partial absorption medium requirement signal, and a constant partial absorption medium requirement signal to generate said seventh signal.

Claim 13

A method in accordance with claim 1 additionally comprising: establishing a fifth signal representative of a nominal desired flow rate of said feed material to said absorption zone; establishing a sixth signal representative of the actual flow rate of said feed material to said absorption zone; establishing a recycle feed flow signal representative of the flow rate of a recycle feed containing said product constituent to said absorption zone; and responsive to said second condition of said mode control signal: generating, in response to said second signal, said fifth signal, said sixth signal and said recycle feed flow signal, a seventh signal representative of the optimum flow rate of said absorption medium to said absorption zone; generating, in response to said first signal, said second signal and said seventh signal, an eighth signal representative of the optimum flow rate of said feed material to said absorption zone; controlling the flow of said absorption medium into said absorption zone in response to said seventh signal; and controlling the flow of said feed material into said absorption zone in response to said eighth signal.

Claim 14

A method in accordance with claim 12 wherein establishing said first signal comprises measuring the concentration of said product constituent leaving said absorption zone in an overhead stream; establishing an average concentration signal representative of the average of a plurality of such product constituent concentration measurements; comparing said average concentration signal with a concentration set point signal representative of an acceptable concentration of said product constituent leaving said absorption zone in said overhead stream; and generating said first signal in response to the comparison of said average concentration signal and said concentration set point signal.

Claim 15

A method in accordance with claim 12 wherein establishing said second signal comprises establishing signals representative of the individual concentrations of all significant nonproduct constituents in a main feed material stream and subtractively establishing a signal representative of the concentration of said product constituent by subtracting all such nonproduct constituent concentration signals from a set point signal representative of 100% product constituent concentration.

Claim 16

A method in accordance with claim 12 wherein generating said seventh signal comprises: establishing a first partial absorption medium requirement signal in response to the difference between said fifth signal and said sixth signal; establishing a second partial absorption medium requirement signal by mutiplying said sixth signal and said second signal; establishing a third partial absorption medium requirement signal in response to said recycle feed flow signal; and adding said first partial absorption medium requirement signal, said second partial absorption medium requirement signal, said third partial absorption medium requirement signal, and a constant partial absorption medium requirement signal to generate said seventh signal.

Claim 19

A method in accordance with claim 16 wherein said first signal is representative of the desired ratio of said absorption medium entering said absorption zone to said product constituent entering said absorption zone; wherein said second signal is representative of the concentration of said product constituent in the feed entering said absorption zone; wherein said first signal and said second signal are multiplied to produce a ratio signal representative of the desired ratio of absorption medium entering said absorption zone to feed material entering said absorption zone; and wherein generating said sixth signal comprises dividing said fifth signal by said ratio signal.

Claim 20

A method in accordance with claim 17 wherein establishing said first signal comprises measuring the concentration of said product constituent leaving said absorption zone in an overhead stream; establishing an average concentration signal representative of the average of a plurality of such product constituent concentration measurements; comparing said average concentration signal with a concentration set point signal representative of an acceptable concentration of said product constituent leaving said absorption zone in said overhead stream; and generating said first signal in response to the comparison of said average concentration signal and said concentration set point signal.

Claim 21

A method in accordance with claim 17 wherein establishing said second signal comprises establishing signals representative of the individual concentrations of all significant nonproduct constituents in a main feed material stream and subtractively establishing a signal representative of the concentration of said product constituent by subtracting all such nonproduct constituent concentration signals from a set point signal representative of 100% product constituent concentration.

Claim 22

A method in accordance with claim 19 additionally comprising correcting the subtractively-established product constituent concentration signal in response to the flow of a recycle feed stream carrying a portion of said product constituent to said absorption zone.

Claim 25

A method in accordance with claim 21 wherein establishing said first signal comprises measuring the concentration of said product constituent leaving said absorption zone in an overhead stream; establishing an average concentration signal representative of the average of a plurality of such product constituent concentration measurements; comparing said average concentration signal with a concentration set point signal representative of an acceptable concentration of said product constituent leaving said absorption zone in said overhead stream; and generating said first signal in response to the comparison of said average concentration signal and said concentration set point signal.

Claim 26

A method in accordance with claim 21 wherein establishing said second signal comprises establishing signals representative of the individual concentrations of all significant nonproduct constituents in a main feed material stream and subtractively establishing a signal representative of the concentration of said product constituent by subtracting all such nonproduct constituent concentration signals from a set point signal representative of 100% product constituent concentration.

Claim 27

A method in accordance with claim 21 wherein generating said fifth signal comprises: establishing a first partial absorption medium requirement signal in response to the difference between said fifth signal and said sixth signal; establishing a second partial absorption medium requirement signal by multiplying said sixth signal and said second signal; and adding said first partial absorption medium requirement signal, said second partial absorption medium requirement signal, and a constant partial absorption medium requirement signal to generate said seventh signal.

Claim 28

A method in accordance with claim 21 additionally comprising establishing a recycle feed flow signal representative of the flow rate of a recycle feed containing said product constituent to said absorption zone and wherein said fifth signal is generated in response to said second signal, said third signal, said fourth signal and said recycle feed flow signal.

Claim 29

A method in accordance with claim 25 wherein establishing said first signal comprises measuring the concentration of said product constituent leaving said absorption zone in an overhead stream; establishing an average concentration signal representative of the average of a plurality of such product constituent concentration measurements; comparing said average concentration signal with a concentration set point signal representative of an acceptable concentration of said product constituent leaving said absorption zone in said overhead stream; and generating said first signal in response to the comparison of said average concentration signal and said concentration set point signal.

Claim 30

A method in accordance with claim 25 wherein establishing said second signal comprises establishing signals representative of the individual concentrations of all significant nonproduct constituents in a main feed material stream and subtractively establishing a signal representative of the concentration of said product constituent by subtracting all such nonproduct constituent concentration signals from a set point signal representative of 100% product constituent concentration.

Claim 33

A method in accordance with claim 28 wherein said first signal is representative of the desired ratio of said absorption medium entering said absorption zone to said product constituent entering said absorption zone; wherein said second signal is representative of the concentration of said product constituent in the feed entering said absorption zone; wherein said first signal and said second signal are multiplied to produce a ratio signal representative of the desired ratio of absorption medium entering said absorption zone to feed material entering said absorption zone; wherein generating said fourth signal comprises dividing said third signal by said ratio signal; and wherein generating said eighth signal comprises dividing said seventh signal by said ratio signal.

Claim 36

A method in accordance with claim 30 wherein generating said seventh signal comprises: establshing a first partial absorption medium requirement signal in response to the difference between said fifth signal and said sixth signal; establishing a second partial absorption medium requirement signal by multiplying said sixth signal and said second signal; and adding said first partial absorption medium requirement signal, said second partial absorption medium requirement signal, and a constant partial absorption medium requirement signal to generate said seventh signal.

Claim 37

Apparatus comprising: an absorption column; a feed stream input conduit means in communication with said absorption column; an absorption medium input conduit means in communication with said absorption column; a bottom output conduit means in communication with the bottom of said absorption column; an overhead conduit means in communication with the top of said absorption column; first valve means for controlling the flow rate of material through said feed stream input conduit means; second valve means for controlling the flow rate of material through said absorption medium input conduit means; first analyzer means for generating one or more first analyzer signals representative of the composition of material within said feed stream input conduit means; second analyzer means for generating one or more second analyzer signals representative of the composition of material within said overhead output conduit means; first flow transducing means for measuring the flow rate of material through said feed stream input conduit means and establishing a first flow rate signal representative thereof; second flow transducing means for measuring the flow rate of material through said absorption medium input conduit means and establishing a second flow rate signal representative thereof; first set point generating means for accepting said one or more first analyzer signals and said first flow rate signal and establishing therefrom an optimum absorption medium flow set point signal; mode selection means for selecting, as a selected absorption medium flow set point signal, either said optimum absorption medium flow set point signal or a preselected maximum absorption medium flow set point signal; means for operating said second valve means in response to a comparison of said selected absorption medium flow set point and said second flow rate signal; second set point generating means for accepting said one or more of said first analyzer signals, said one or more of said second analyzer signals, and said selected absorption medium flow set point signal, and establishing therefrom an optimum feed stream flow set point signal; and means for operating said first valve means in response to a comparison of said optimum feed stream flow set point signal and said first flow rate signal.

Claim 38

Apparatus comprising: an absorption column; a feed stream input conduit means in communication with said absorption column; an absorption medium input conduit means in communication with said absorption column; a bottom output conduit means in communication with the bottom of said absorption column; an overhead conduit means in communication with the top of said absorption column; first valve means for controlling the flow rate of material through said feed stream input conduit means; second valve means for controlling the flow rate of material through said absorption medium input conduit means; first analyzer means for generating one or more first analyzer signals representative of the composition of material within said feed stream input conduit means; second analyzer means for generating one or more second analyzer signals representative of the composition of material within said overhead output conduit means; first flow transducing means for measuring the flow rate of material through said feed stream input conduit means and establishing a first flow rate signal representative thereof; second flow transducing means for measuring the flow rate of material through said absorption medium input conduit means and establishing a second flow rate signal representative thereof; first set point generating means for accepting said one or more first analyzer signals and said first flow rate signal and establishing therefrom an optimum absorption medium flow set point signal; mode selection means for selecting, as a selected absorption medium flow set point signal, either said optimum absorption medium flow set point signal or a preselected maximum absorption medium flow set point signal; means for operating said second valve means in response to a comparison of said selected absorption medium flow set point and said second flow rate signal; second set point generating means for accepting said one or more of said first analyzer signals, said one or more of said second analyzer signals, and said selected absorption medium flow set point signal, and establishing therefrom an optimum feed stream flow set point signal; and means for operating said first valve means in response to a comparison of said optimum feed stream flow set point signal and said first flow rate signal.

Claim 39

Apparatus in accordance with claim 32 wherein said first set point generating means comprises; first proportional-integral-derivative means for accepting said first flow rate signal and generating a first partial absorption medium requirement signal in response to said first flow rate signal and a set point signal representative of a nominal desired flow rate of material through said feed stream input conduit means; means for generating a second partial absorption medium requirement signal in response to said first flow rate signal and said one or more first analyzer signals; and means for adding said first partial absorption medium requirement signal and said second partial absorption medium requirement signal.

Claim 40

Apparatus in accordance with claim 33 additionally comprising: means for adding a constant partial absorption medium requirement signal to the sum of said first partial absorption medium requirement signal and said second partial absorption medium requirement signal.

Claim 41

Apparatus in accordance with claim 32 wherein said first set point generating means establishes said optimum absorption medium flow set point signal in response to said one or more first analyzer signals, said first flow rate signal, and said one or more second analyzer signals.

Claim 42

Apparatus in accordance with claim 35 wherein said second set point generating means comprises: means for generating, from said one or more first analyzer signals and said one or more second analyzer signals, a ratio signal representative of a desired ratio of material flow rate through said absorption medium input conduit to material flow rate through said feed stream input conduit means; and means for dividing said selected absorption medium flow set point signal by said ratio signal to produce said optimum feed stream flow set point signal.

Claim 43

Apparatus in accordance with claim 32 additionally comprising: a recycle feed stream conduit means in communication with said absorption column; and third flow transducing means for measuring the flow rate of material through said recycle feed stream conduit and establishing a third flow rate signal representative thereof; and wherein said first set point generating means establishes said optimum absorption medium flow rate signal in response to said one or more first analyzer signals, said first flow rate signal, and said third flow rate signal.

Claim 44

Apparatus in accordance with claim 37 wherein said first set point generating means comprises: first proportional-integral-derivative means for accepting said first flow rate signal and generating a first partial absorption medium requirement signal in response to said first flow rate signal and a set point signal representative of a nominal desired flow rate of material through said feed stream input conduit means; means for generating a second partial absorption medium requirement signal in response to said first flow rate signal and said one or more first analyzer signals; means for generating a third partial absorption medium requirement signal in response to said third flow rate signal; and means for adding said first partial absorption medium requirement signal, said second partial absorption medium requirement signal, and said third partial absorption medium requirement signal.

Claim 45

Apparatus in accordance with claim 38 additionally comprising means for adding a constant partial absorption medium requirement signal to the sum of said first partial absorption medium requirement signal, said second partial absorption medium requirement signal, and said third partial absorption medium requirement signal.

Claim 46

Apparatus in accordance with claim 37 wherein said first set point generating means establishes said optimum absorption medium flow rate signal in response to said one or more first analyzer signals, said first flow rate signal, said third flow rate signal, and said one or more second analyzer signals.

Claim 47

Apparatus in accordance with claim 40 wherein said second set point generating means comprises: means for generating, from said one or more first analyzer signals, said one or more second analyzer signals and said third flow rate signal, a ratio signal representative of a desired ratio of material flow rate through said absorption medium input conduit to material flow rate through said feed stream input conduit means; and means for dividing said selected absorption medium flow set point signal by said ratio signal to produce said optimum feed stream flow set point signal.

Claim 48

Apparatus comprising: an absorption column; a feed stream input conduit means in communication with said absorption column; an absorption medium input conduit means in communication with said absorption column; a bottom output conduit means in communication with the bottom of said absorption column; an overhead output conduit means in communication with the top of said absorption column; first valve means for controlling the flow rate of material through said feed stream input conduit means; second valve means for controlling the flow rate of material through said absorption medium input conduit means; first analyzer means for generating one or more first analyzer signals representative of the composition of material within said feed stream input conduit means; second analyzer means for generating one or more second analyzer signals representative of the composition of material within said overhead output conduit means; first flow transducing means for measuring the flow rate of material through said feed stream input conduit means and establishing a first flow rate signal representative thereof; second flow transducing means for measuring the flow rate of material through said absorption medium input conduit means and establishing a second flow rate signal representative thereof; first set point generating means for accepting said one or more first analyzer signals, and said first flow rate signal, and establishing therefrom an optimum absorption medium flow set point signal; means for operating said second valve means in response to a comparison of said optimum absorption medium flow set point signal and said second flow rate signal; second set point generating means for accepting said one or more of said first analyzer signals, said one or more of said second analyzer signals, and said optimum absorption medium flow set point signal, and establishing therefrom an optimum feed stream flow set point signal; and means for operating said first valve means in response to a comparison of said optimum feed stream flow set point signal and said first flow rate signal.

Claim 49

Apparatus comprising: an absorption column; a feed stream input conduit means in communication with said absorption column; an absorption medium input conduit means in communication with said absorption column; a bottom output conduit means in communication with the bottom of said absorption column; an overhead output conduit means in communication with the top of said absorption column; first valve means for controlling the flow rate of material through said feed stream input conduit means; second valve means for controlling the flow rate of material through said absorption medium input conduit means; first analyzer means for generating one or more first analyzer signals representative of the composition of material within said feed stream input conduit means; second analyzer means for generating one or more second analyzer signals representative of the composition of material within said overhead output conduit means; first flow transducing means for measuring the flow rate of material through said feed stream input conduit means and establishing a first flow rate signal representative thereof; second flow transducing means for measuring the flow rate of material through said absorption medium input conduit means and establishing a second flow rate signal representative thereof; first set point generating means for accepting said one or more first analyzer signals, and said first flow rate signal, and establishing therefrom an optimum absorption medium flow set point signal; means for operating said second valve means in response to a comparison of said optimum absorption medium flow set point signal and said second flow rate signal; second set point generating means for accepting said one or more of said first analyzer signals, said one or more of said second analyzer signals, and said optimum absorption medium flow set point signal, and establishing therefrom an optimum feed stream flow set point signal; and means for operating said first valve means in response to a comparison of said optimum feed stream flow set point signal and said first flow rate signal.

Claim 50

Apparatus in accordance with claim 42 wherein said first set point generating means establishes said optimum absorption medium flow set point signal in response to said one or more first analyzer signals, said first flow rate signal, and said one or more second analyzer signals.

Claim 51

Apparatus comprising: an absorption column; a stripping column; an overhead accumulator associated with said stripping column; an absorber feed stream input conduit means in communication with said absorption column; an absorption medium conduit means for carrying material from the bottom of said stripping column to said absorption column; an absorber bottom output conduit means for carrying material from the bottom of said absorption column to said stripping column; an absorber overhead output conduit in communication with the top of said absorption column; a stripper overhead conduit means for carrying material from the top of said stripping column to said overhead accumulator; an accumulator output conduit means in communication with said overhead accumulator for withdrawing liquid therefrom; first valve means for controlling the flow rate of material through said absorber feed stream input conduit means; second valve means for controlling the flow rate of material from said absorption medium conduit means into said absorption column; third valve means for controlling the flow rate of material through said accumulator output conduit means; first analyzer means for generating one or more first analyzer signals representative of the composition of material within said absorber feed stream input conduit means; second analyzer means for generating one or more second analyzer signals representative of the composition of material within said absorber overhead output conduit means; first flow transducing means for measuring the flow rate of material through said absorber feed stream input conduit means and establishing a first flow rate signal representative thereof; second flow transducing means for measuring the flow rate of material from said absorption medium conduit means into said absorption column and establishing a second flow rate signal representative thereof; third flow transducing means for measuring the flow rate of material through said accumulator output conduit means and establishing a third flow rate signal representative thereof; liquid level transducing means for measuring the level of liquid within said overhead accumulator and delivering a liquid level signal representative thereof; first set point generating means for accepting said one or more first analyzer signals and said first flow rate signal and establishing therefrom an optimum absorption medium flow set point signal; mode selection means for selecting, as a selected absorption medium flow set point signal, either said optimum absorption medium flow set point signal or a preselected medium absorption medium flow set point signal; means for operating said second valve means in response to a comparison of said selected absorption medium flow set point signal and said second flow rate signal; second set point generating means for accepting said one or more of said first analyzer signals, said one or more of said second analyzer signals, and said selected absorption medium flow set point signal, and establishing therefrom an optimum feed stream flow set point signal; means for operating said first valve means in response to a comparison of said optimum feed stream flow set point signal and said first flow rate signal; function generating means for generating, in response to said liquid level signal, a correction factor signal; proportional-integral-derivative means for generating a first output signal in response to said liquid level signal and a liquid level set point signal representative of a desired liquid level within said overhead accumulator; means for altering at least one response characteristic of said proportional-integral-derivative means in response to said correction factor signal; and means for controlling the operation of said third valve means in response to said first output signal.

Claim 52

Apparatus comprising: an absorption column; a stripping column; an overhead accumulator associated with said stripping column; an absorber feed stream input conduit means in communication with said absorption column; an absorption medium conduit means for carrying material from the bottom of said stripping column to said absorption column; an absorber bottom output conduit means for carrying material from the bottom of said absorption column to said stripping column; an absorber overhead output conduit in communication with the top of said absorption column; a stripper overhead conduit means for carrying material from the top of said stripping column to said overhead accumulator; an accumulator output conduit means in communication with said overhead accumulator for withdrawing liquid therefrom; first valve means for controlling the flow rate of material through said absorber feed stream input conduit means; second valve means for controlling the flow rate of material from said absorption medium conduit means into said absorption column; third valve means for controlling the flow rate of material through said accumulator output conduit means; first analyzer means for generating one or more first analyzer signals representative of the composition of material within said absorber feed stream input conduit means; second analyzer means for generating one or more second analyzer signals representative of the composition of material within said absorber overhead output conduit means; first flow transducing means for measuring the flow rate of material through said absorber feed stream input conduit means and establishing a first flow rate signal representative thereof; second flow transducing means for measuring the flow rate of material from said absorption medium conduit means into said absorption column and establishing a second flow rate signal representative thereof; third flow transducing means for measuring the flow rate of material through said accumulator output conduit means and establishing a third flow rate signal representative thereof; liquid level transducing means for measuring the level of liquid within said overhead accumulator and delivering a liquid level signal representative thereof; first set point generating means for accepting said one or more first analyzer signals and said first flow rate signal and establishing therefrom an optimum absorption medium flow set point signal; mode selection means for selecting, as a selected absorption medium flow set point signal, either said optimum absorption medium flow set point signal or a preselected medium absorption medium flow set point signal; means for operating said second valve means in response to a comparison of said selected absorption medium flow set point signal and said second flow rate signal; second set point generating means for accepting said one or more of said first analyzer signals, said one or more of said second analyzer signals, and said selected absorption medium flow set point signal, and establishing therefrom an optimum feed stream flow set point signal; means for operating said first valve means in response to a comparison of said optimum feed stream flow set point signal and said first flow rate signal; function generating means for generating, in response to said liquid level signal, a correction factor signal; proportional-integral-derivative means for generating a first output signal in response to said liquid level signal and a liquid level set point signal representative of a desired liquid level within said overhead accumulator; means for altering at least one response characteristic of said proportional-integral-derivative means in response to said correction factor signal; and means for controlling the operation of said third valve means in response to said first output signal.

Claim 53

Apparatus in accordance with claim 44 additionally comprising means for generating a second output signal representative of the predicted flow of material through said input conduit, wherein said means for controlling the operation of said valve means in response to said first output signal comprises: means for adding said first output signal and said second output signal to produce an output set point signal; and means for controlling the operation of said valve in response to said output set point signal.

Claim 54

Apparatus in accordance with claim 45 wherein said first set point generating means establishes said optimum absorption medium flow set point signal in response to said one or more first analyzer signals, said first flow rate signal, and said one or more second analyzer signals.

Claim 55

A method in accordance with claim 29 wherein the relationship between said liquid level signal and said correction factor signal is nonlinear; wherein utilizing said correction factor to alter said at least one tuning parameter of said proportional-integral-derivative integral-derivative means comprises multiplying said at least one tuning parameter by said correction factor; and wherein said correction factor signal is zero when said liquid level is representative of the desired liquid level within said liquid accumulator.

Claim 56

Apparatus in accordance with claim 31 wherein the relationship between said liquid level signal and said correction factor signal is nonlinear; wherein utilizing said correction factor to alter said at least one tuning parameter of said proportional-integral-derivative means comprises multiplying said at least one tuning parameter by said correction factor; and wherein said correction factor signal is zero when said liquid level is representative of the desired liquid level within said liquid accumulator.

Claim 57

Apparatus in accordance with claim 46 additionally comprising means for generating a second output signal representative of the predicted flow of material through said stripper overhead conduit means, wherein said means for controlling the operation of said third valve means in response to said first output signal comprises: means for adding said first output signal and said second output signal to produce an output set point signal; and means for controlling the operation of said third valve means in response to said output set point signal; and wherein said function generating means comprises means for producing a correction factor signal bearing a nonlinear relationship to said liquid level signal.