Means and method for controlling the strength of acid in an alkylation unit

Claim 1

A system for controlling the strength of an acid in an alkylation unit wherein an isoparaffin is reacted with olefin in the presence of the acid to provide an acid-hydrocarbon mixture to a settler where the hydrocarbon is separated from the acid to provide a hydrocarbon product and a portion of the acid is recycled while the remaining acid is discharged from the alkylation unit, wherein fresh acid is added to the recycle acid to affect the strength of the acid and wherein the reaction of the olefin with the isoparaffin in the presence of the acid results in a first compound being formed from the olefin and isoparaffin in the acid phase and immediately leaving the acid phase after formation, a second compound being formed in the acid phase from the first compound and which may return to the first compound, and a third compound in the acid phase formed from the first compound and which cannot return to the first compound, comprising means for controlling the strength of the acid in accordance with a control signal, means for sensing the water content of the olefin and the isoparaffin and providing a signal corresponding thereto, means for determining the composition of the olefin and providing a cOrresponding composition signal, means for sensing the flow rate of the olefin and providing a signal corresponding thereto, means for sensing the flow rates of the fresh acid and the discharged acid and providing signals corresponding thereto, said control signal means includes a first circuit connected to the olefin and isoparaffin flow rate sensor and to the composition signal means provides a signal corresponding to the quantity Alpha o of acid consuming constituents contacting the acid; a second circuit connected to the analyzer and to the olefin and isoparaffin flow rate sensing means provides a signal corresponding to the quantity Alpha m of water in the olefin and isoparaffin contacting the acid; means connected to the fresh acid flow rate sensing means for providing a signal corresponding to the quantity gamma m of water in the fresh acid entering the alkylation unit; means for providing direct current voltages corresponding to the reaction rates R1, R2, R3 and R4 between the olefin, the isoparaffin, the acid, the first, second and third compounds, to the initial volume Vo of acid in the alkylation unit, to the molecular weights WA, WB and WC of the first, second and third compounds, respectively, to the molecular weight WM of water, to the densities Rho A, Rho B and Rho C of the first, second and third compounds, respectively, to the densities Rho s, and Rho M of the acid and of water, respectively, and to a unit value 1; first analog computing means for providing signals corresponding to the quantities A, B and C of the first, second and third compounds, respectively, and to the quantity M of water in accordance with the Alpha o, Alpha m and gamma m signals and the discharged acid flow rate and the following equations:

Claim 2

A system for controlling the strength of an acid in an alkylation unit wherein an isoparaffin is reacted with olefin in the presence of the acid to provide an acid-hydrocarbon mixture to a settler where the hydrocarbon is separated from the acid to provide a hydrocarbon product and a portion of the acid is recycled while the remaining acid is discharged from the alkylation unit, wherein fresh acid is added to the recycle acid to affect the strength of the acid and wherein the reaction of the olefin with the isoparaffin in the presence of the acid results in a first compound being formed from the olefin and isoparaffin in the acid phase and immediately leaving the acid phase after formation, a second compound being formed in the acid phase from the first compound and which may return to the first compound, and a third compound in the acid phase formed from the first compound and which cannot return to the first compound, comprising means for controlling the strength of the acid in accordance with a control signal, means for sensing the water content of the olefin and the isoparaffin and providing a signal corresponding thereto, means for determining the composition of the olefin and providing a cOrresponding composition signal, means for sensing the flow rate of the olefin and providing a signal corresponding thereto, means for sensing the flow rates of the fresh acid and the discharged acid and providing signals corresponding thereto, said control signal means includes a first circuit connected to the olefin and isoparaffin flow rate sensor and to the composition signal means provides a signal corresponding to the quantity Alpha o of acid consuming constituents contacting the acid; a second circuit connected to the analyzer and to the olefin and isoparaffin flow rate sensing means provides a signal corresponding to the quantity Alpha m of water in the olefin and isoparaffin contacting the acid; means connected to the fresh acid flow rate sensing means for providing a signal corresponding to the quantity gamma m of water in the fresh acid entering the alkylation unit; means for providing direct current voltages corresponding to the reaction rates R1, R2, R3 and R4 between the olefin, the isoparaffin, the acid, the first, second and third compounds, to the initial volume Vo of acid in the alkylation unit, to the molecular weights WA, WB and WC of the first, second and third compounds, respectively, to the molecular weight WM of water, to the densities Rho A, Rho B and Rho C of the first, second and third compounds, respectively, to the densities Rho s, and Rho M of the acid and of water, respectively, and to a unit value 1; first analog computing means for providing signals corresponding to the quantities A, B and C of the first, second and third compounds, respectively, and to the quantity M of water in accordance with the Alpha o, Alpha m and gamma m signals and the discharged acid flow rate and the following equations:

Claim 4

A method for controlling the strength of an acid in an alkylation processing unit wherein an isoparaffin is reacted with olefin in the presence of the acid to provide an acid-hydrocarbon mixture to a settler where the hydrocarbon is separated from the acid to provide a hydrocarbon product and a portion of the acid is recycled while the remaining acid is discharged from the alkylation unit, wherein fresh acid is added to the recycle acid to affect the strength of the acid and wherein the reaction of olefin with isoparaffin in the presence of acid results in the first compound being formed from the olefin and isoparaffin in the acid phase and which leaves the acid phase upon formation, a second compound in the acid phase being formed from the first compound and which may return to the first compound, and a third compounD in the acid phase formed from the first compound and which cannot return to the first compound, which comprises determining the composition of the olefin; sensing the flow rates of the olefin and isoparaffin, the fresh acid and the discharge acid; providing a signal corresponding to the quantity Alpha o of acid consuming constituents contacting the acid in accordance with the sensed olefin and isoparaffin flow rate and with the determination of the olefin composition; providing a signal corresponding to the quantity Alpha m of water in the olefin and isoparaffin contacting the acid, providing a signal corresponding to the quantity gamma m of water in the fresh acid entering the alkylation unit; providing direct current voltages corresponding to the reaction rates R1, R2, R3 and R4 between the olefin, the isoparaffin, the acid, the first, second and third compounds, to the initial volume Vo of acid in the alkylation unit, to the molecular weights WA, WB and WC of the first, second and third compounds, respectively, to the molecular weight WM of water, to the densities Rho A, Rho B and Rho C of the first, second and third compounds, respectively, the densities Rho s and Rho M of acid and water, respectively, and to a unit value 1; providing signals corresponding to the quantities A, B and C of the first, second and third compounds, respectively, formed during the reaction and to the quantity M of water in accordance with the Alpha O, Alpha m and gamma m signals and the discharged acid flow rate and the following equations:

Claim 5

A method for controlling the strength of an acid in an alkylation processing unit wherein an isoparaffin is reacted with olefin in the presence of the acid to provide an acid-hydrocarbon mixture to a settler where the hydrocarbon is separated from the acid to provide a hydrocarbon product and a portion of the acid is recycled while the remaining acid is discharged from the alkylation unit, wherein fresh acid is added to the recycle acid to affect the strength of the acid and wherein the reaction of olefin with isoparaffin in the presence of acid results in the first compound being formed from the olefin and isoparaffin in the acid phase and which leaves the acid phase upon formation, a second compound in the acid phase being formed from the first compound and which may return to the first compound, and a third compounD in the acid phase formed from the first compound and which cannot return to the first compound, which comprises determining the composition of the olefin; sensing the flow rates of the olefin and isoparaffin, the fresh acid and the discharge acid; providing a signal corresponding to the quantity Alpha o of acid consuming constituents contacting the acid in accordance with the sensed olefin and isoparaffin flow rate and with the determination of the olefin composition; providing a signal corresponding to the quantity Alpha m of water in the olefin and isoparaffin contacting the acid, providing a signal corresponding to the quantity gamma m of water in the fresh acid entering the alkylation unit; providing direct current voltages corresponding to the reaction rates R1, R2, R3 and R4 between the olefin, the isoparaffin, the acid, the first, second and third compounds, to the initial volume Vo of acid in the alkylation unit, to the molecular weights WA, WB and WC of the first, second and third compounds, respectively, to the molecular weight WM of water, to the densities Rho A, Rho B and Rho C of the first, second and third compounds, respectively, the densities Rho s and Rho M of acid and water, respectively, and to a unit value 1; providing signals corresponding to the quantities A, B and C of the first, second and third compounds, respectively, formed during the reaction and to the quantity M of water in accordance with the Alpha O, Alpha m and gamma m signals and the discharged acid flow rate and the following equations: