US3594580A
Expired / Lapsed
US
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Chlorine dioxide process ii
Assignee: Chemech Engineering Ltd
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Filing: 1969-04-16
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Granted: 1971-07-20
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Expires: 1989-04-16
Abstract
Abstract A continuous recyclic process and apparatus for the production of chlorine dioxide from an aqueous chloration solution of gaseous hydrochloride. The hydrogen chloride is formed in situ by combustion of hydrogen gas and chlorine gas. The chlorine dioxide is used for bleaching pulp.
Inventors
- 👤 Gothe Oscar Westerlund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:10
CPC Classifications
C; C01; C01B; C01B11/00; C01B11/02; C01B11/022; C01B11/023; C01B11/025
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
107 words
In a process for converting an aqueous solution of chlorate into chlorine dioxide by reaction thereof with hydrogen chloride gas produced in situ by combustion of hydrogen gas with chlorine gas at a temperature in excess of 600* C., the improvement which comprises cooling the so-produced hydrogen chloride gas to a temperature of 150* C. or less by diluting said hydrogen chloride gas with sufficient chlorine gas, thereby to provide a final gaseous reaction product comprising less than 10 percent chlorine dioxide diluted with 90 percent or more chlorine gas, or diluted with 90 percent or more of a mixture of chlorine, carbon dioxide and water vapor.
Claim 2
Dependent Claim
26 words
The process of claim 2 wherein the chlorine gas diluent is introduced into a closed loop system as excess chlorine gas for reaction with hydrogen chloride.
Claim 3
Dependent Claim
26 words
The process of claim 3 wherein the gaseous effluent from the chlorine dioxide reaction is subjected to a separation step to provide the chlorine gas diluent.
Claim 4
Dependent Claim
195 words
A continuous process for the production of chlorine dioxide which comprises: a. effecting electrolysis of an aqueous solution of a metal chloride whereby to form i. an aqueous solution of a metal chlorate and ii. gaseous hydrogen; b. reacting gaseous hydrogen with gaseous chlorine whereby to form iii. gaseous hydrogen chloride c. reacting the aqueous solution of metal chlorate (a) (i) with the gaseous hydrogen chloride from step (b) (iii) whereby to form iv. an aqueous solution of metal chloride v. an aqueous solution of chloric acid, d. reacting in situ the aqueous solution of chloric acid (c)(v) with the gaseous hydrogen chloride from step (b) (iii) whereby to form vi. chlorine dioxide vii. gaseous chlorine, and viii. water, and c. mixing a preselected amount of gaseous chlorine with the gaseous hydrogen reactant for step (d) whereby to provide a final product from step (d) consisting of up to 10 percent chlorine dioxide and 90 percent or more chlorine, or a mixture of chlorine, carbon dioxide and water vapor. 6 The process of claim 5 including the step of separating the gaseous effluents from steps (c) and (d) to provide gaseous chlorine for step (c).
Claim 5
Dependent Claim
41 words
The process of claim 6 wherein the gaseous hydrogen reacted in step (b) is derived from the reaction in step (a) including the step of separating the gaseous effluents from steps (c) and (d) to provide gaseous chlorine for step (e).
Claim 6
Dependent Claim
19 words
The process of claim 7 including the step of removing excess carbon dioxide gas from the closed loop system.
Claim 7
Dependent Claim
63 words
The process of claim 5 including the steps of subjecting the aqueous solution of metal chloride to a stripping action to remove entrained and/or occluded gases therefrom, then subjecting a portion of the stripped gases to the reaction in step (b) while recycling the remaining portion to the stripping zone, and recycling the stripped metal chloride solution to be reacted in step (a).
Claim 8
Dependent Claim
41 words
The process of claim 9 wherein the gaseous hydrogen reacted in step (b) is derived from the reaction in step (a) including the step of separating the gaseous effluents from steps (c) and (d) to provide gaseous chlorine for step (e).
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) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |