Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J10/00—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor
  • B01J10/002—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor carried out in foam, aerosol or bubbles
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
  • C01B11/02—Oxides of chlorine
  • C01B11/022—Chlorine dioxide (ClO2)
  • C01B11/023—Preparation from chlorites or chlorates
  • C01B11/024—Preparation from chlorites or chlorates from chlorites
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/24—Stationary reactors without moving elements inside
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J4/00—Feed or outlet devices; Feed or outlet control devices
  • B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
  • B01J4/002—Nozzle-type elements
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
  • C01B11/02—Oxides of chlorine
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B7/00—Halogens; Halogen acids
  • C01B7/01—Chlorine; Hydrogen chloride
  • C01B7/03—Preparation from chlorides
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/68—Treatment of water, waste water, or sewage by addition of specified substances, e.g. trace elements, for ameliorating potable water
  • C02F1/685—Devices for dosing the additives
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/72—Treatment of water, waste water, or sewage by oxidation
  • C02F1/76—Treatment of water, waste water, or sewage by oxidation with halogens or compounds of halogens
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2204/00—Aspects relating to feed or outlet devices; Regulating devices for feed or outlet devices
  • B01J2204/005—Aspects relating to feed or outlet devices; Regulating devices for feed or outlet devices the outlet side being of particular interest
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00002—Chemical plants
  • B01J2219/00027—Process aspects
  • B01J2219/00033—Continuous processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00049—Controlling or regulating processes
  • B01J2219/00164—Controlling or regulating processes controlling the flow
  • B01J2219/00166—Controlling or regulating processes controlling the flow controlling the residence time inside the reactor vessel
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/008—Control or steering systems not provided for elsewhere in subclass C02F

Definitions

• the present invention relates to a novel chlorine dioxide production apparatus, or reactor, to a novel system for production of quantities of chlorine dioxide from commercial and other grades of starting materials, and to methods of using the reactor in situ.
• a common approach for large-scale water purification that can be safer than the transportation and subsequent on-site use of chlorine gas is the on-site production of chlorine dioxide.
• This strong oxidant is used for oxidation to disinfect water flows in drinking water treatment plants and in wastewater treatment plants.
• chlorine dioxide destroys viruses, bacteria, and other microscopic organisms as it oxidizes compounds having a lower oxidation potential than itself.
• chlorine dioxide is preferably added after the sedimentation tank or basin.
• Chlorine dioxide (CIO 2 ; CASR n 10049-04-4) is a greenish-yellow gas at room temperature that is stable in the dark but unstable in the light. As noted, it is recognized as an extremely powerful biocide, disinfectant agent and oxidizer. As to regulatory allowance of chlorine dioxide in commercial and wastewater and water purification applications, in 1967, the United States Environmental Protection Agency (“EPA") first registered the liquid form of chlorine dioxide for use as a disinfectant and sanitizer. In 1988, EPA registered chlorine dioxide gas as a sterilant.
• EPA United States Environmental Protection Agency
• Chlorine dioxide kills microorganisms by disrupting transport of nutrients across the cell wall. Chlorine dioxide is a gas, is highly soluble in water and smells like chlorine bleach. However, chlorine dioxide is not to be confused with chlorine gas. They are two distinct chemicals that react differently and produce byproducts that also have little in common.
• Chlorine dioxide, CI0 2 offers the following benefits.
• CIO 2 functions via an oxidative rather than chlorinating reaction, the mode of action of chlorine gas. This virtually eliminates the formation of chlorinated organic compounds that are suspected to increase certain cancer risks.
• CIO 2 when generated on site eliminates the need for site storage of chlorine and/or transportation thereof.
• the present invention advances the art by providing a reaction chamber, a system, and methods for the production of chlorine dioxide gas for oxidation and disinfection purposes. As described below, it advances the art by meeting the needs stated immediately above.
• the present invention relates to a novel reaction chamber useful in the high-yield production of chlorine dioxide gas from commercial and technical grade reactants.
• the invention also includes systems useful for the addition of chlorine dioxide to flows in need of such compound in which more than one point of addition is provided, and monitoring of more than one point along the flow provides for replenishment of chlorine dioxide at points after the initial point of addition.
• one object of the present invention is to advance the art of chlorine dioxide generation with a new design of a reaction chamber in which commercial and technical grades of common reactants are driven to safely react to completion or near completion to generate high yields of chlorine dioxide gas.
• a related aspect is to have the ability to generate a large or small quantity of chlorine dioxide using a single reaction chamber without the need to change anything other than the reactor volume or quantity (flow rate) of the precursor chemicals.
• Another aspect of the present invention is to practice a method of chlorine dioxide production to generate high yields of chlorine dioxide gas.
• Another aspect of the present invention is to provide a means to produce chlorine dioxide in a place close to its use for disinfection of a stream of water or other liquid, to reduce the risks of toxics release and harm to workers, the environment, and nearby persons.
• FIG. 1 presents a generalized depiction (not to scale) of an embodiment of the chlorine dioxide system of the present invention.
• FIG. 2 shows an embodiment of a chlorine dioxide dosing system that includes two chlorine dioxide reactors.
• One embodiment of the present invention relates to a chlorine dioxide generating system, having as a key component a reaction chamber, wherein the system is engineered to optimize the production of chlorine dioxide gas from reactions among various combinations of reactants.
• reactants, pre-cursor chemicals, pre-cursor materials, and starting materials are defined to mean the same thing, namely, the chemicals that are passed into the reaction chamber for reaction to form the one or more products, or end-products, of the reaction.
• pipe has its normal meaning, and "flow channel” is taken to mean a pipe as well as any open channel through which a fluid passes.
• Typical embodiments of the chlorine dioxide system of the present invention utilize an acid solution and chlorite solution to produce chlorine dioxide.
• this system utilizes a raw water pump to supply the water (carrier media) to an in-situ chemical reactor (also referred to as a reaction chamber or generator).
• the carrier water pump runs once the system is powered up and wastewater is flowing through the main wastewater conduit (pipe, channel, etc) of the waste stream that is being treated.
• input data may be obtained from a CI0 2 monitor and the flow switch signal a system controller to drive the chemical feed pumps.
• the chemical feed pumps draw their individual chemical solutions up from their storage tanks and deliver them to the chemical reactor.
• this reactor is located so as to be effected by the flow of the water supplied by the raw water pump. This is done as a safety feature to assure that the chlorine dioxide goes into immediate solution preventing any potentially explosive conditions from occurring.
• a flow switch may optionally be provided in the raw carrier water line for halting the chemical feed, hence stopping CI0 2 generation, should a loss of carrier water occur.
• each of the chemical feed lines is equipped with a flow switch connected in series with the other flows' flow switches, so that if one flow is interrupted, all flows cease.
• the system includes a reactor that delivers
• a target water-containing source so as to achieve a target CI0 2 concentration to the target source.
• a target water-containing source include, but are not limited to, potable and non-potable water sources, sewer sludge, swimming pools, fountains, or other reservoirs containing a water component.
• the system will dose target sources via a conduit carrying a running stream.
• the delivery of CI0 2 to the target source is adjusted based on the known flow rate of the flow stream, the known volume of the reactor and the flow rates of delivery of reactants to the reactors so as to allow a contact time among the reactants of 0.5-30 minutes in the reactor.
• a target concentration is achieved based on the following:
• F flow rate of delivery of sodium chlorite to the at least one reactor (volume/time),
• C 2 CIO 2 output (amount/time).
• output is adjusted by varying F-i so long as the reactor volume and flow rate are such to enable contact time of the reactants of between 0.5-30 minutes.
• the target contact time is between about 1 minute and about 20 minutes. In a more specific embodiment, the target contact time is 1.5 minutes to 20 minutes.
• the reactor volume also affects the maximum output of the chlorine dioxide generating system. That is, once the flow rate is such as to meet the lowest desired contact time (or "reaction time"), the reactor volume must be increased to increase output. Accordingly, those skilled in the art will be able to modify the reactor volumes so as to meet the needed contact times and target output in order to meet target water-containing source chlorine dioxide concentrations (see e.g., Example 1 , infra).
• FIG. 1 provides a general operational diagram of a portion of a treatment (not to scale) system that shows the reactor of the present invention configured to dose a flow stream of a water-containing target source.
• FIG. 1 provides a general operational diagram of a portion of a treatment (not to scale) system 90 that shows a reactor embodiment 100 configured to dose a flowstream 142 of a water-containing target source.
• the reactor 100 has a volume 110 into which an acidifying agent source 103 delivers via a first conduit 106 an acidifying agent 106'.
• a chlorite source 105 also delivers a chlorite agent 108' to the volume 110 via conduit 108. Acidifying agent 106' and chlorite agent 108' react with each other in the volume 110 to produce CI0 2 130.
• the reactor 100 is fluidly connected to a flow conduit 140.
• CIO 2 When CIO 2 is produced, it delivers the CIO 2 to the flowstream 142 in the flow conduit 140.
• one exemplary reaction involves using sodium chlorite and sulfuric acid as the proton donor as shown below:
• the concentration of chlorine dioxide inside the reactor is determined by the concentration of the precursor chemicals. Utilizing a 15 % (pph) concentration of sodium chlorite for example, the maximum yield of chlorine dioxide is around 13% (pph). Under normal conditions, sodium chlorite is able to convert at a 85 percent (85%) conversion rate. Chlorine dioxide is highly soluble in water (up to 8%), and any CI0 2 gas coming out of solution rapidly dissolves in the treatment stream upon leaving the chamber. Since chlorine dioxide gas is explosive in concentrations exceeding 10% in air, this feature provides a level of safety unique to this invention.
• an effective amount is meant a quantity in relation to other additions that has been found, or is determinable without undue experimentation, to be a sufficient amount to achieve a stated purpose, reaction, or goal.
• concentrations of sulfuric acid of between 30-60 percent (pph) can be reacted with Sodium chlorite solutions of between 7.5 to 25 percent (pph).
• a volume of sulfuric acid at 40-60 percent (pph) is combined in a reaction chamber with a volume of aqueous sodium chlorite at 7.5-25 percent (pph) and allowed to react for a predetermined period of time.
• a volume of 45-55 percent (pph) sulfuric acid is reacted with a volume of 12-17 percent (pph) sodium chlorite.
• the 50 percent (pph) sulfuric acid solution and a 15 percent (pph) sodium chlorite solution is provided to the reaction chamber.
• the volumes may be in ratios from 0.1- 10.0:10-0.1. In more specific embodiments, the ratio of volumes is 1-10:10-1 , 1-5:5- 1 , 1-2:2-1 , 1-1.5:1.5-1 or 1 :1.
• the present invention relates to the use of ' dilute sulfuric acid ' in the generation of chlorine dioxide, resulting in higher conversion rates than would be expected for this chemistry when used with prior-art methods. Further, generation according to the present invention produces CI0 2 with little or no conversion of generated chlorine dioxide to chlorate even with prolonged residence time in the reactor as occurs when hydrochloric acid two chemical generation methods are employed.
• the general operating parameters of a typical reaction and reactor are as follows.
• pressure when the reactor is "in situ” (within a pipe that is carrying water into which the reactor releases the reaction products), the input flow rate of the reactants, the reaction chamber volume, and the outflow from the reactor (typically a nozzle that prevents dilution of the reactants while not allowing excessive pressure to build up inside the reaction vessel) are configured so that the delivered reactants and reaction product flows toward the target water-containing source.
• reaction products i.e., chlorine dioxide gas, minerals in solution or expelled as a diluted slurry, chlorine dioxide dissolved within the aqueous phase that largely is comprised of the combined water component of the chemical reactant solutions
• reaction products i.e., chlorine dioxide gas, minerals in solution or expelled as a diluted slurry, chlorine dioxide dissolved within the aqueous phase that largely is comprised of the combined water component of the chemical reactant solutions
• an option is to monitor flow rate cessation by each chemical reactant solution pump, and shut down the entire system shut down if one fails.
• Another control mechanism is to have a control feedback loop that adjusts the pumping rate of one or more pumps based on a parameter of the system being out of a desired range.
• the reactants may at times yield a build-up of calcium or other metals within the reactor. This may be caused where the water to be treated contains high levels of calcium and/or other metals, such as iron. These metals may precipitate out and build up as scale within the reactor.
• an additional input/output port, or feed line is introduced into the reactor. This allows for a water and/or chemical flushing of the reactor. Such flushing may be done with an acid such as that used in the reaction process. The frequency of the flushing is dependent upon the levels of precipitants in solution.
• the present invention is described in certain examples below as being used to disinfect the effluent in wastewater treatment plants, it is recognized that the present invention has numerous other applications and is quite versatile.
• the reactions, apparatuses, methods and systems of the present invention may be used to disinfect or otherwise treat not only the effluent of wastewater treatment plants, but also the following:
• ballast water of ocean-going ships to kill the larval and adult stages of exotic species that may have been pumped into the bilge at a foreign port, prior to discharging such ballast water at another port (to prevent environmental problems such as the zebra mussel in the United States);
• SARS severe acute respiratory syndrome
• Odor control to oxidize sulfur compounds, such as hydrogen sulfide, without forming colloidal sulfurs.
• FIG. 2 shows a chlorine dioxide generator system 200 used to treat a
• the system 200 includes a first reactor 206 and a second reactor 208 that are in fluid communication with a pool pipe 240, which pertains to the flow stream of the pool targeted by system 200.
• the system 200 also includes a first tank 210 containing a 15 percent, pph, aqueous sodium chlorite solution and a second tank 212 containing a 45-55 percent, pph, aqueous concentration (preferably 50 percent, pph), of sulphuric acid.
• the reactants in tanks 210 and 212 fluidly communicate with pumps 216, 218 and 214, 220 respectively, via tubes 236, 238 and 234, 232, respectively.
• Pumps 214 and 216 pump sodium chlorite and acid into reactor 206 via tubes 224 and 222, respectively.
• Pumps 218 and 220 pump sodium chlorite and acid into second reactor 208 via tubes 226 and 228, respectively.
• Table 1 sets forth a calculation demonstrating a maximum chlorine dioxide output using system 200 pertaining to a target reaction time of 3 minutes.
• the concentration of CI02 can be calculated based on the flow rate of the treatment stream or carrier water
• 239 ppm (mg/L) can be added to the treatment stream with a three minute contact time in the generator given a process stream flow rate of 60 gpm.
• the dose can be effectively doubled by doubling the chemical pump outputs. This would still allow 1.5 minutes contact time in the generator, which is sufficient for conversion of the chlorite to chlorine dioxide.
• the dose rate can be lowered substantially by decreasing the pump output. Since the reaction is not sensitive to extended holding times (up to 15 minutes with no appreciable degradation of chlorine dioxide)

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• Dispersion Chemistry (AREA)
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• Environmental & Geological Engineering (AREA)
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• 2010
  • 2010-12-07 CA CA2783194A patent/CA2783194C/en active Active
  • 2010-12-07 EP EP10836506.5A patent/EP2509914A4/en not_active Withdrawn
  • 2010-12-07 JP JP2012543193A patent/JP5764572B2/ja active Active
  • 2010-12-07 WO PCT/US2010/059208 patent/WO2011071862A2/en active Application Filing
  • 2010-12-07 US US13/514,545 patent/US9492804B2/en active Active
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  • 2010-12-07 MX MX2012006529A patent/MX338643B/es active IP Right Grant
  • 2010-12-07 KR KR1020127015815A patent/KR20120105477A/ko not_active Application Discontinuation
  • 2010-12-07 BR BR112012013874A patent/BR112012013874A2/pt not_active IP Right Cessation
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