US3814916A
Expired / Lapsed
US
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Means and method for controlling an alkylation unit to achieve a desired feed isobutane flow rate
Assignee: Texaco Inc
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Filing: 1973-03-19
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Granted: 1974-06-04
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Expires: 1993-03-19
Abstract
Abstract A control system and method controls an alkylation unit in a manner to achieve a desired feed isobutane flow rate. Trial isobutane flow rates and their effects are calculated. The trial isobutane flow rate, along with its corresponding discharge acid flow rate, that obtains a desired effect is then imposed on the feed isobutane and discharge acid, respectively.
Inventors
- 👤 D Sweeney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:08
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/0006; B01J19/0033; C; C07; C07C; C07C2/00; C07C2/54; C07C2/56; C07C2/58; C07C2/62; Y; Y10; Y10S; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
49 words
A system as described in claim 1 in which the Delta Q signal means includes G signal means for providing signals corresponding to quantities GC and GB, and means for providing the Delta Q signal in accordance with the GC, GB signals and the following equation: Delta Q GC-GB.
Claim 2
Dependent Claim
139 words
A system as described in claim 2 in which the G signal means includes means for providing a signal corresponding to a quantity SB, means for providing a signal corresponding to a quantity SC, means for providing a signal corresponding to a calculated fraction volume VCC of isobutane in the hydrocarbon product, means connected to the SB signal means and to the sensing means for providing the GB signal in accordance with the SB signal, a signal from the sensing means corresponding to the volume fraction VCB of isobutane in the hydrocarbon product and the following equation: GB b1SB2+b21n(100VCB+b3) where b1, b2 and b3 are constants, and means connected to the SC signal means and to the VCC signal means for providing the GC signal in accordance with the SC and VCC signals and the following equation: GC b1SC2+b21n(100VCC+b3)
Claim 3
Dependent Claim
114 words
A system as described in claim 1 in which the Delta A signal means includes means for providing a signal corresponding to the existing acid consumption AB, means for providing a signal corresponding to a quantity FSC, means for providing a signal corresponding to a quantity FSB, means for providing a signal corresponding to a quantity FMB, means for providing a signal corresponding to a quantity FMC, and means connected to the AB, FSC, FSB, FMB and FMC signal means for providing a signal corresponding to the change Delta A in acid consumption in accordance with the AB, FSC, FMC, FSB, FMB signals and the following equation: Delta A AB (ESC FMB/FSBFMC - 1).
Claim 4
Dependent Claim
75 words
A system as described in claim 4 in which the AB signal means includes means connected to the sensing means for providing a signal corresponding to the acid consumption AB in accordance with the signals from the sensing means corresponding to the discharge acid flow rate RAB, the hydrocarbon product flow rate RCB and the volume fraction VCK of alkylate in the hydrocarbon product and the following equation: AB aRAB/RCBVCK where a is a constant.
Claim 5
Dependent Claim
114 words
A system as described in claim 5 in which the FSB signal means includes means for providing a signal corresponding to the ratio PB or propylene to olefins, and means connected to the SB and PB signal means for providing the FSB signal in accordance with the SB and PB signals and the following equation: FSB exp(SB2( d1(PB/1+PB) +d2(PB/1-PB)2 +d3(PB/1-PB)3 +d4(PB/1-PB)4)) where d1 through d4 are constants, and the FSC signal means includes means connected to the SC signal means and to the PB signal means for providing the signal corresponding to the quantity FSC in accordance with the SC signal and the PB signal and the following equation: FSC exp(SC2(d1(PB/1-PB) +d2(PB/1-PB)2 +d3(PB/1-PB)3 +d4(PB/1-PB)4))
Claim 6
Dependent Claim
212 words
A system as desscribed in claim 6 in which the SB signal includes means connected to the sensing means for providing a signal corresponding to the hydrocarbon content H on the recycle acid in accordance with signals from the sensing means corresponding to the sensed densities DF, DB and DH corresponding to the densities of the fresh acid, of the recycle acid and of the hydrocarbon product, respectively, and the following equation: H (DF-DB)/(DF-DH)100 and means connected to the H signal means and to the sensing means for providing the signal corresponding to the quantity SB in accordance with the H signal and signals from the sensing means corresponding to the flow rates RO, RR and RCB of the oelfins, the recycle acid and the hydrocarbon product, respectively, and to the volume fraction VI of olefins in the olefin stream and the following equation: SB 100ROVT(RR+RCB)/CVRR(100 -H) where CV is the volume of the contactor, means for providing a signal corresponding to a calculated flow rate RCC for the discharGe acid; and the SC signal means includes means connected to the H signal means, to the sensing means and to the RCC signal means for providing in accordance with the RO, RR, RCC and VT signals and the following equation: SC 100ROVT(RR+RCC)/CVRR(100-H)
Claim 7
Dependent Claim
105 words
A system as described in claim 7 in which the FMB signal means includes means connected to the sensing means for providing the FMB signal in accordance with a signal from the sensing means corresponding to the volume fraction VCB of isobutane in the hydrocarbon product and the following equation: FMB (100VCB)c where c is a constant; and the FMC signal means includes means for providing a signal corresponding to a calculated volume fraction VCC of isobutane in the hydrocarbon product, and means connected to the VCC signal means for providing the FMC in accordance with the VCC signal and the following equation: FMC (100VCC)c.
Claim 8
Dependent Claim
76 words
A system as described in claim 8 in which the VCC signal means includes means connected to the RCC signal means, to the Delta M signal means and to the sensing means for providing the VCC signal in accordance with the Delta M, RCC, RCB, VCB signals and a signal from the sensing means corresponding to the sensed volume fraction VM of isobutane in the isobutane stream and the following equation: VCC ( Delta M)(VM) +RCBVCB/RCC.
Claim 9
Dependent Claim
77 words
A system as described in claim 1 in which the Delta M signal means includes means connected to the trial isobutane flow rate signal means and to the sensing means for providing a signal corresponding to Delta M for each trial isobutane flow rate in accordance with the trial isobutane flow rate signal and a signal from the sensing means corresponding to the sensend flow rate RMB of the isobutane and the following equation: Delta M RMj-RMB.
Claim 10
Dependent Claim
150 words
The system as described in claim 1 in which the trial isobutane flow rate signal means is connected to the sensing means and includes means for providing a signal corresponding to a maximum flow rate change Delta RMax for the isobutane stream, means for providing a signal corresponding to a whole integer J, means for providing a signal corresponding to j which increases in unit steps until J is reached, means connected to the J signal means, to the j signal means, to the Delta RMax signal means and to the sensing means for providing the trial isobutane flow rate RMj signals, in accordance with the RMB, J, j and Delta RMax signals and the following equation: RMj RMB+((2j/J) - 1 )( Delta RMax), and means connected to the j signal means for providing a pulse indicative of the end of current operation when j is substantially equal to J.
Claim 11
Dependent Claim
148 words
A system as described in claim 11 in which the selecting means includes means for storing the RMj signal, the RAC signal and the EC signal, means connected to the storing means for comparing a stored EC signal with the EC signal from the profit change signal means and for clearing the storing means when the EC signal from the profit change signal means is greater than the stored EC signal and storing the RMj signal, EC signal and the RAC signal and for not clearing the storing means when the EC signal from the profit change signal means is not greater than the stored EC signal so that the storing means contains the RMj and RACj signals for a maximum increase in profit, and means for providing the stored RMj and RACj signals as the control signals to the control means in response to an end pulse.
Claim 12
Independent Claim
359 words
A method for controlling an alkylation unit to achieve a desired operating condition, said alkylation unit includes a contactor wherein olefin and isobutane streams, entering the contactor, are contacted in the presence of acid and said contactor provides an acid-hydrocarbon mixture to a settler which separates the acid to provide a hydrocarbon product, including alkylate, and acid, a portion of the separated acid is discharged while the remainder of the separated acid along with fresh acid entering the alkylation unit is recycled to the contactor which comprises controlling the isobutane flow rate and one acid flow rate of the fresh acid and discharge acid flow rates relative to the other acid flow rate in accordance with control signals; sensing certain operating parameters of the alkylation unit; providing signals corresponding to the sensed parameters; providing a signal corresponding to trial isobutane flow rates RMj; providing a signal corresponding to trial one acid flow rates RACj associated with the trial isobutane flow rates; determining an anticipated change in profits associated with the implementation of each trial isobutane flow rate and its corresponding one acid flow rate and providing a corresponding signal, said profit change determining step includes providing signals corresponding to economic values DM, DA and DQ associated with the isobutane, the acid and the octane rating of the alkylate, respectively, providing a signal corresponding to a change Delta Q in octane rating, providing a signal corresponding to a change Delta A in acid consumption, providing a signal corresponding to a change Delta M in the isobutane, and providing the profit change EC signal in accordance with the signals from the Delta Q, Delta A, Delta M, DQ, DA and DM signals and signals from the sensing means corresponding to the flow rate RCB of the hydrocarbon product and the volume fraction VCK of alkylate in the hydrocarbon product and the following equation: EC ( Delta Q)(DQ)-( Delta A)(DA)-Delta MDM/RCBVCK; and selecting the trial isobutane flow rate and its corresponding one acid flow rate that provides for the greatest increase in profits in accordance with the profit signal and providing the selected signals as the control signals to the control means.
Claim 13
Dependent Claim
46 words
A method as described in claim 13 in which the step of providing the Delta Q signal includes providing signals corresponding to quantities GC and GB, and providing the Delta Q signal in accordance with the GC, GB signals and the following equation: Delta Q GC-GB.
Claim 14
Dependent Claim
106 words
A method as described in claim 14 in which the step of providing the G signal includes providing a signal corresponding to a quantity SB, providing a signal corresponding to a quantity SC, providing a signal corresponding to a calculated fraction volume VCC of isobutane in the hydrocarbon product, providing the GB signal in accordance with the SB signal, a signal corrresponding to the sensed volume fraction VCB of isobutane in the hydrocarbon product and the following equation: GB b1SB2+b21n(100VCB+b3) where b1, b2 and b3 are constants, and providing the GC signal in accordance with the SC and VCC signals and the following equation: GC b1SC2+b21n(100VCC+b3).
Claim 15
Dependent Claim
89 words
A method as described in claim 13 in whicH the step of providing the signal includes providing a signal corresponding to the existing acid consumption AB, providing a signal corresponding to a quantity FSC, providing a signal corresponding to a quantity FSB, providing a signal corresponding to a quantity FMB, providing a signal corresponding to a quantity FMC, and providing a signal corresponding to the change Delta A in acid consumption in accordance with the AB, FSC, FMC, FSB, FMC signals and the following equation: Delta A AB(FSCFMB/FSBFMC -1).
Claim 16
Dependent Claim
70 words
A method as described in claim 16 in which the step of providing the AB signal includes providing a signal corresponding to the acid consumption AB in accordance with the signals corresponding to the sensed discharge acid flow rate RAB, the sensed hydrocarbon product flow rate RCB and the sensed volume fraction VCK of alkylate in the hydrocarbon product and the following equation: AB aRAB/RCBVCK where a is a constant.
Claim 17
Dependent Claim
98 words
A method as described in claim 17 in which the step of providing the FSB signal means includes providing a signal corresponding to the ratio PB of propylene to olefins, and providing the FSB signal in accordance with the SB and PB signals and the following equation: FSB exp SB2(d1(PB/1-PB) +d2(PB/1-PB)2 +d3(PB/1-PB)3 +d4(PB/1-PB)4) where d1 through d4 are constants, and the steps of providing the FSC signal includes providing the signal corresponding to the quantity FSC in accordance with the SC signal and the PB signal and the following equation: FSC exp SC2) d1(PB/1-PB) +d2(PB/1-PB)2 +d3(PB/1-PB)3 + d4(PB/1-PB)4).
Claim 18
Dependent Claim
182 words
A method as described in claim 18 in which the step of providing the SB signal includes providing a signal corresponding to the hydrocarbon content H on the recycle acid in accordance with signals from the sensing means corresponding to the sensed densities DF, DB, and DH corresponding to the densities of the fresh acid, of the recycle acid and of the hydrocarbon product, respectively, and the following equation: H (DF-DB)/(DF-DH)100, and providing the signal corresponding to the quantity SB in accordance with the H signal and signals corresponding to the sensed flow rates RO, RR, and RCB of the olefins, the recycle acid and the hydrocarbon product, respectively, and to the sensed volume fraction VT of the olefins in the olefin stream and the following equation: SB 100ROVT(RR+RCB)/CVRR(100- H) where CV is the volume of the contactor, providing a signal corresponding to a calculated flow rate RCC for the discharge acid; and the step of providing the SC signal includes providing the SC signal in accordance with the RO, RR, RCC and VT signals and the following equation: SC 100ROVT(RR+RCC)/CVRR(100- H).
Claim 19
Dependent Claim
91 words
A method as described in claim 19 in which the step of providing the FMB signal includes providing the FMB sigNal in accordance with a signal corresponding to the sensed volume fraction VCB of isobutane in the hydrocarbon product and the following equation: FMB (100VCB)c where c is a constant; and the step of providing the FMC signal includes providing a signal corresponding to a calculated volume fraction VCC of isobutane in the hydrocarbon product, and providing the FMC in accordance with the VCC signal and the following equation: FMC (100VCC)c.
Claim 20
Dependent Claim
55 words
A method as described in claim 20 in which the step of providing the signal includes providing the VCC signal in accordance with the Delta M, RCC, RCB, VCB signals and a signal corresponding to the sensed volume fraction VM of isobutane in the isobutane stream and the following equation: VCC ( Delta M)(VM) +RCBVCB/RCC.
Claim 21
Dependent Claim
60 words
A method as described in claim 15 in which the step of providing the Delta M signal includes providing a signal corresponding to Delta M for each trial isobutane flow rate in accordance with the trial isobutane flow rate signal and a signal corresponding to the sensed flow rate RMB of the isobutane and the following equation: Delta M RMj-RMB.
Claim 22
Dependent Claim
109 words
The method as described in claim 13 in which the step of providing the isobutane flow rate signal RMj includes providing a signal corresponding to a maximum flow rate change Delta RMax for the isobutane stream, providing a signal corresponding to a whole integer J, providing a signal corresponding to j which increases in unit steps until J is reached, providing the trial isobutane flow rate RMj signal, in accordance with the RMB, J, j and Delta RMax signals and the following equation: RMj RMB + (2j/J -1) ( Delta RMax), and providing a pulse indicative of the end of current operation when j is substantially equal to J.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |