Patent Application
20050025660
This invention is in the field of industrial water systems. Specifically, this invention is in the field of the use of fluorescent tracers in the water of an industrial water system where significant amounts of a corrosive material are present.
Industrial water systems exist so that necessary chemical, mechanical and biological processes can be conducted to reach the desired outcome. Industrial water systems include the following: cooling water systems, including open recirculating, closed and once-through cooling water systems; boilers and boiler water systems; petroleum wells, downhole formations, geothermal wells and other oil field applications; mineral process waters including mineral washing, flotation and benefaction; paper mill digesters, washers, bleach plants and white water systems; black liquor evaporators in the pulp industry; gas scrubbers and air washers; continuous casting processes in the metallurgical industry; air conditioning and refrigeration systems; industrial and petroleum process water; indirect contact cooling and heating water, such as pasteurization water; water reclamation and purification systems; membrane filtration water systems; food processing streams (meat, vegetable, sugar beets, sugar cane, grain, poultry, fruit and soybean); and waste treatment systems as well as in clarifiers, liquid-solid applications, municipal sewage treatment and industrial or municipal water systems.
While water is obviously the major component of an industrial water system there are typically other materials present in an industrial water system. These can include anything from innocuous materials all the way to highly corrosive materials. A corrosive material can be anything that attacks building materials or metals or anything that burns, irritates or destructively attacks organic tissues. Corrosive materials can be in the category of unwanted impurities or they can be present in the water in order to perform a needed function.
As is the case with many industrial water systems, many cooling water systems use treatment products to control undesirable phenomena such as scaling, corrosion, fouling and microbiological growth. These treatment products include chemical materials such as polymers, phosphates, phosphonates, azoles, zinc, molybdate, biocides, and other materials and are known to people of ordinary skill in the art of cooling water systems.
Treatment products are typically prepared by taking these chemical materials and formulating them into aqueous liquid phase products or solid products for distribution to and delivery into an industrial water system. Delivery into an industrial water system, can be accomplished by pump feed or edductor feed system for a liquid product, by solid product feeder for a solid product or even by manual addition of the treatment product for either liquid or solid product. A cooling water system, for example, can be set up to feed treatment product based on either a bleed/feed mechanism where the action of blowdown triggers a chemical feed pump or valve that feeds treatment product; or, in the alternative, the cooling water system feeds treatment product based on timers using a “feeding schedule” or flow meters on the make-up water line trigger the pumping of treatment product based on a certain amount of make-up water being pumped. A limitation of these control methods is that none of these systems measure the treatment product concentration directly online, so if there is a mechanical problem, for example, if a pump fails, a drum empties, or high, low or unknown blowdown occurs, system volume changes or makeup water quality changes; the correct treatment product concentration is not maintained. Because this problem is common, cooling tower systems are typically either overfed with treatment product to ensure the level of treatment product in the system does not drop too low as a result of high variability in product dosage or the treatment product is unknowingly underfed. Both overfeeding and underfeeding of treatment product are undesirable due to cost and performance drawbacks.
One aspect of known control schemes is addition of an inert fluorescent chemical tracer in a known proportion to the active component of the treatment product and feeding this mixture of treatment product and tracer to the cooling water system. Then a fluorometer is used to monitor the fluorescent signal of the inert fluorescent chemical. This technology is commercially available as TRASAR®, which is a registered trademark of Ondeo Nalco Company, Ondeo Nalco Center, 1601 W. Diehl Road, Naperville Ill. 60563, (630) 305-1000.
The fluorescent signal of the inert fluorescent chemical is used to determine how much inert fluorescent tracer is present, and by knowing the amount of inert fluorescent tracer that is present it is possible to determine the amount of treatment product that is present in the cooling tower. If the amount of treatment product that is present is not what is desired then the feed rate of treatment product can be adjusted to provide the desired amount of treatment product.
A known difficulty with the use of inert fluorescent tracers in industrial water systems is the susceptibility of some of them to degradation of their fluorescent signal upon contact, for a sufficient length of time, with corrosive materials. It would be desirable to have inert fluorescent tracers that are capable of maintaining their fluorescent signal in the presence of common corrosive materials.
The first aspect of the instant claimed invention is a method of using an inert fluorescent tracer in an industrial water system wherein the water of said industrial water system contains a certain amount of a corrosive material, comprising the steps of:
The second aspect of the instant claimed invention is a method of tracing a corrosive material, comprising the steps of:
The third aspect of the instant claimed invention is a composition of matter comprising
The fourth aspect of the instant claimed invention is a composition of matter comprising
The fifth aspect of the instant claimed invention is a composition of matter comprising
Throughout this patent application the following terms have the indicated definitions:
“CAS #” refers to the Chemical Abstracts Services Registry Number.
Nalco refers to Ondeo Nalco Company, Ondeo Nalco Center, 1601 W. Diehl Road, Naperville Ill. 60563, telephone number (630) 305-1000.
The first aspect of the instant claimed invention is a method of using an inert fluorescent tracer in an industrial water system wherein the water of said industrial water system contains a certain amount of a corrosive material, comprising the steps of:
Industrial water systems include the following: cooling water systems, including open recirculating, closed and once-through cooling tower water systems; boilers and boiler water systems; petroleum wells, downhole formations, geothermal wells and other oil field applications; mineral process waters including mineral washing, flotation and benefaction; paper mill digesters, washers, bleach plants and white water systems; black liquor evaporators in the pulp industry; gas scrubbers and air washers; continuous casting processes in the metallurgical industry; air conditioning and refrigeration systems; industrial and petroleum process water; indirect contact cooling and heating water, such as pasteurization water; water reclamation and purification systems; membrane filtration water systems; food processing streams (meat, vegetable, sugar beets, sugar cane, grain, poultry, fruit and soybean); and waste treatment systems as well as in clarifiers, liquid-solid applications, municipal sewage treatment and industrial or municipal water systems.
Treatment chemicals for use in industrial water systems include commercially available corrosion inhibitors, biological control agents, scale inhibitors, dispersants, coagulants, flocculants, and pH control agents. These commercially available products are well known to people in the art of industrial water chemistry.
1,3,6,8-pyrene tetrasulfonic acid and the known salts of 1,3,6,8-pyrene tetrasulfonic acid are inert fluorescent tracers that may be used with large amounts of concentrated HCl, concentrated H2SO4, glacial acetic acid, concentrated H3PO4 and dimethylformamide; wherein concentrated HCl is at least about 37 wt. % HCl in water, concentrated H2SO4 is at least about 98 wt. % H2SO4 in water, wherein concentrated H3PO4 is at least about 85 wt. % H3PO4 in water; wherein glacial acetic acid is at least about 100 wt. % acetic acid in water and wherein dimethylformamide is about 100 wt. % dimethylformamide. The preferred known salt of 1,3,6,8-pyrene tetrasulfonic acid for use with corrosive materials is the tetrasodium salt. This material is available from Nalco.
1,5-naphthalenedisulfonic acid and the known salts of 1,5-naphthalenedisulfonic acid disodium salt may be used in water containing large amounts of concentrated HCl and concentrated H3PO4; wherein concentrated HCl is at least about 37 wt. % HCl in water and wherein concentrated H3PO4 is at least about 85 wt. % H3PO4 in water. The preferred known salt of 1,5-naphthalenedisulfonic acid for use with corrosive materials is the disodium salt. This material is available from Nalco.
Isomers of anthracene disulfonic acid and salts thereof, may be used in water containing large amounts of concentrated HCl, concentrated H3PO4 and dimethylformamide; wherein concentrated HCl is at least about 37 wt. % HCl in water, wherein concentrated H3PO4 is at least about 85 wt. % H3PO4 in water and wherein dimethylformamide is about 100 wt. % dimethylformamide.
Known isomers of anthracene disulfonic acid, and certain of their known salt forms include the following:
The preferred isomers of anthracene disulfonic acid are 1,5-anthracene disulfonic acid, magnesium salt, 1,5-anthracene disulfonic acid, sodium salt and 1,8-anthracene disulfonic acid sodium salt and mixtures thereof. The most preferred isomer of anthracene disulfonic acid is about a 2:1 mixture of 1,5-anthracene disulfonic acid, sodium salt and 1,8-anthracene disulfonic acid sodium salt.
Isomers of anthracene disulfonic acid and their known salts can be obtained by following synthetic techniques known in the art of organic chemistry. See GB 1214256, A method of preparing anthraquinone 1,5-disulphonic acid, published Oct. 13, 1976, assigned to Imperial Chemical Industries, Studies on the Sulfonation of Anthracene. Part 1. Sulfonation in neutral or basic solvents, by John O. Morley, Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) (1976), (13), 1554-9, Studies on the Sulfonation of Anthracene. Part 2. Sulfonation in acetic acid and related solvents, by John O. Morley, Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) (1976), (13), 1560-4.
Fluorometers suitable for use in the instant claimed invention are commercially available from Nalco, these include: TRASAR® 8000, TRASARO® 3000, Xe-2 Fluorometer and a TRASAR® 350. Other suitable fluorometers are available from Spex. The preferred fluorometers are a TRASARO® 3000 unit and a TRASARS® Xe-2 Fluorometer.
How to set up and program a fluorometer and use it to measure the fluorescent signal of a fluorescent tracer is known to people of ordinary skill in the art of fluorometry. After the fluorescent signal of the inert fluorescent tracer is detected and measured, it is known how to correlate that information with the concentration of the inert fluorescent tracer and once the concentration of the inert fluorescent tracer is known that information can be used to determine the amount of treatment chemical present in the industrial water system and that information can be used to optimize the operation of the industrial water system.
The second aspect of the instant claimed invention is a method of tracing a corrosive material, comprising the steps of:
The inert tracers that can be used with the specific corrosive materials listed in the first aspect of the instant claimed invention are the same as those that can be used in the second aspect of the instant claimed invention. The fluorometers that can be used in the second aspect of the instant claimed invention are the same as those fluorometers that can be used in the first aspect of the instant claimed invention. How to set up and program a fluorometer and use it to measure the fluorescent signal of a fluorescent tracer is known to people of ordinary skill in the art of fluorometry. After the fluorescent signal of the tracer is detected and measure, it is known how to correlate that information with the concentration of the inert fluorescent tracer and once the concentration of the inert fluorescent tracer is known that information can be used to determine the amount of corrosive material present in the industrial water system and that information can be used to optimize the operation of the industrial water system.
The third aspect of the instant claimed invention is a composition of matter comprising
The amount of 1,3,6,8-pyrene tetrasulfonic acid or a known salt of 1,3,6,8-pyrene tetrasulfonic acid present in the corrosive material is from about 0.01 ppm to about 10,000 ppm, preferably from about 0.05 ppm to about 10 ppm and most preferably from about 0.1 ppm to about 1.0 ppm. The preferred compound is 1,3,6,8-pyrene tetrasulfonic acid, tetrasodium salt.
The fourth aspect of the instant claimed invention is a composition of matter comprising
The amount of 1,5-naphthalenedisulfonic acid or a known salt of 1,5-naphthalenedisulfonic acid present in the corrosive material is from about 0.01 ppm to about 10,000 ppm, preferably from about 0.05 ppm to about 10 ppm and most preferably from about 0.1 ppm to about 1.0 ppm. The preferred compound is 1,5-naphthalenedisulfonic acid, disodium salt.
The fifth aspect of the instant claimed invention is a composition of matter comprising
The amount of isomer of anthracene disulfonic acid and salts thereof present in the corrosive material is from about 0.01 ppm to about 10,000 ppm, preferably from about 0.05 ppm to about 10 ppm and most preferably from about 0.1 ppm to about 1.0 ppm. The preferred isomers of anthracene disulfonic acid are 1,5-anthracene disulfonic acid, magnesium salt, 1,5-anthracene disulfonic acid, sodium salt and 1,8-anthracene disulfonic acid sodium salt and mixtures thereof. The most preferred isomer of anthracene disulfonic acid is about a 2:1 mixture of 1,5-anthracene disulfonic acid, sodium salt and 1,8-anthracene disulfonic acid sodium salt.
The ability to trace a corrosive material is useful for the operation of many different industrial water systems.
The following examples are presented to be illustrative of the present invention and to teach one of ordinary skill how to make and use the invention. These examples are not intended to limit the invention or its protection in any way.
Sample Preparation:
Fluorescent tracer solutions (see Table 1) were prepared by adding a specified weighed amount of a stock solution of fluorescent tracer into a corrosion-resistant 250 mL polypropylene bottle. Corrosive liquid solution was added to the propylene bottle containing tracer solution to provide a total volume of 100 mL. The fluorescent tracer and corrosive liquid were mixed. The samples were stored at ambient temperature for a total of 59 days. Test samples were taken at defined intervals from each traced corrosive liquid solution (initial, 4 days and 59 days) and fluorescence level was measured.
*Tracer concentration expressed as acid equivalent form
Fluorometer Selection and Set-Up for Detection of Fluorescent Signal A SPEX fluorometer (Model FluoroMax-2) was used to measure the fluorescent signal and determine dosages of fluorescent tracers being tested in corrosive liquids. The fluorescent signal of each tracer was measured at the excitation and emission wavelengths listed in Table 2. A rectangular quartz cuvette (10 mm×3 mm, inner dimensions) was used to hold the sample. Each combination of fluorescent tracer and corrosive liquid was normalized to 100% in the “initial sample” (Table 3) which was measured within one hour after the tracer and corrosive liquid were mixed. In a few cases (Samples # 6, 16-19, and 21), the fluorescent tracer was not chemically stable with the corrosive liquid being tested and the fluorescent signal quickly decreased to virtually zero. In those cases, the “Initial Sample” was listed as having 0-1% fluorescence and that combination of tracer and corrosive fluid was judged as not acceptable. The fluorescence of the tracer and corrosive liquid solutions were tested again at 4 days and 59 elapsed time. The relative fluorescence of the samples measured at 4 days and 59 days are listed in Table 3. The fluorescence of tracers which change by less than or equal to +/−10% (% relative fluorescence range=90 to 110%, as compared to initial sample) on Day 59 are given an acceptable rating and are defined as being inert over long time periods in the corrosive liquid environment being tested. % relative fluorescence readings on Days 4 and 59 which are greater than 100% indicate an increase in % relative fluorescence, as compared to initial sample. % relative fluorescence readings on Days 4 and 59 which are less than 100% indicate an decrease in % relative fluorescence, as compared to initial sample.
*Acceptable value range is 90-110, which is +/− 10% of the initial reference point (100%)
**Not acceptable due to very high background fluorescence
{circumflex over ( )}Comparative Example, not an Example of the invention
The present method has been described in an illustrative manner. Many modifications and variations are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
