Aqueous industrial fluids

VARIOUS AQUEOUS INDUSTRIAL FLUIDS REQUIRING IN-CAN/ IN-TANK PROTECTION BY PRESERVATIVES... 

V. F. Lvovich, C. C. Liu, M. F. Smiechowski, Optimization and fabrication of planarilnter-digitated impedance sensors for highly resistive non-aqueous industrial fluids. Sensors and Actuators, 2007,119,2, pp. 490-496. 

Quite new ideas for the reactor design of aqueous multiphase fluid/fluid reactions have been reported by researchers from Oxeno. In packed tubular reactors and under unconventional reaction conditions they observed very high space-time yields which increased the rate compared with conventional operation by a factor of 10 due to a combination of mass transfer area and kinetics [29]. Thus the old question of aqueous-biphase hydroformylation "Where does the reaction takes place " - i.e., at the interphase or the bulk of the liquid phase [23,56h] - is again questionable, at least under the conditions (packed tubular reactors, other hydrodynamic conditions, in mini plants, and in the unusual,and costly presence of ethylene glycol) and not in harsh industrial operation. The considerable reduction of the laminar boundary layer in highly loaded packed tubular reactors increases the mass transfer coefficients, thus Oxeno claim the successful hydroformylation of 1-octene [25a,26,29c,49a,49e,58d,58f], The search for a new reactor design may also include operation in microreactors [59]. 

Mixed aqueous electrolyte solutions such as body fluids, rivers, lakes, oceans and, at times, laboratory and industrial fluids present important problems which are not found 1n single electrolyte solutions. New perceptions and results are being obtained in complex media and some examples will be covered in this paper. 

Typical application areas are industrial gear oils and greases, compressor lubricants, metalworking fluids, aqueous quenching fluids, fire-resistant hydraulic fluids, textile lubricants and heat transfer liquids. Section 2.7.5 gives a detailed account of these applications. 

Separation using UF and MF membranes is most selective, however, if soluble reagents are added. Such techniques may supplement two-phase distribution methods (e.g., liquid-liquid extraction, sorption, and precipitation), which are frequently used to extract species from dissolved matrices, industrial fluids, or natural waters. Although many such methods have been developed and successfully used, their application is sometimes troublesome. Some problems are caused by heterogeneous reactions and transfer between phases. Other problems can arise from the composition of the solution finally obtained, which is analyzed using the final determination method. In such cases, additional procedures may be required, e.g., back-extraction or desorption, which make the analytical procedure more complex and can cause additional contamination. Membrane separation can yield a homogeneous aqueous phase suitable for subsequent analysis using a number of methods. 

Industrial aqueous process fluids, e.g. cooling waters, pulp and papermill process waters and suspensions, secondary oil recovery systems, spinning fluids, metal working fluids. 

Textile auxiliaries, such as spinning lubricants, sizes, finishes, yam humidifying agents and print thickeners often provide an excellent nutrient medium for mould fungi and putrefactive bacteria they can be regarded as aqueous functional fluids which need in-tank or in-can protection with suitable microbicides. Examples of microbicides to be used in the textile industry are ... 

As a preservative for industrial fluids, formaldehyde (formalin and paraformaldehyde) is preferably used in cosmetic products and in polymer dispersions (natural and synthetic latex) often in combination with other microbicides. Formaldehyde is listed in the EC list of preservatives allowed for the in-can protection of cosmetics (maximum authorized concentration 0.2%, except for products for oral hygiene 0.1%, prohibited in aerosol dispensers). Percentage of use in US cosmetic formulations 0.11% paraformaldehyde. Oil, fat and wax emulsions, starch and dextrine glues, adhesive dispersions, pigment and filler slurries, thickening solutions and other aqueous formulations containing no proteins can be preserved by the addition of formaldehyde, too in order to... 

One can characterize DBNPA as a potent but not persistant microbicide the application of which does not cause waste water problems. Formulations containing 40%, 20% or 5% a.i., are available. They may be used to inhibit biofouling in recirculating water (cooling towers) and once-through industrial water systems, in pulp, paper and paperboard mills, in enhanced oil recovery systems, in aqueous metalworking fluids. As a preservative DBNPA is efficient only for the short term protection of aqueous products. 

Supercritical Extraction. The use of a supercritical fluid such as carbon dioxide as extractant is growing in industrial importance, particularly in the food-related industries. The advantages of supercritical fluids (qv) as extractants include favorable solubiHty and transport properties, and the abiHty to complete an extraction rapidly at moderate temperature. Whereas most of the supercritical extraction processes are soHd—Hquid extractions, some Hquid—Hquid extractions are of commercial interest also. For example, the removal of ethanol from dilute aqueous solutions using Hquid carbon dioxide... 

Aqueous solutions of propylene glycol display excellent antifree2e properties and are therefore valuable as low temperature heat-transfer fluids. For apphcations involving indirect food contact, heat-transfer fluids formulated with the USP grade product are preferred, since there could be inadvertent contact with a food product. These fluids are commonly used in the brewing and dairy industries as well as in refrigerated display cases in retail grocery stores. 

Heat Exchangers Using Non-Newtonian Fluids. Most fluids used in the chemical, pharmaceutical, food, and biomedical industries can be classified as non-Newtonian, ie, the viscosity varies with shear rate at a given temperature. In contrast, Newtonian fluids such as water, air, and glycerin have constant viscosities at a given temperature. Examples of non-Newtonian fluids include molten polymer, aqueous polymer solutions, slurries, coal—water mixture, tomato ketchup, soup, mayonnaise, purees, suspension of small particles, blood, etc. Because non-Newtonian fluids ate nonlinear in nature, these ate seldom amenable to analysis by classical mathematical techniques. 

Antimicrobials. In slightly alkaline aqueous solutions, nitro alcohols are useful for the control of microorganisms, eg, in cutting fluids, cooling towers, oil-field flooding, drilling muds, etc (8—15) (see INDUSTRIAL ANTIMICROBIAL AGENTS Petroleum). However, only... 

Extraction from Aqueous Solutions Critical Fluid Technologies, Inc. has developed a continuous countercurrent extraction process based on a 0.5-oy 10-m column to extract residual organic solvents such as trichloroethylene, methylene chloride, benzene, and chloroform from industrial wastewater streams. Typical solvents include supercritical CO9 and near-critical propane. The economics of these processes are largely driven by the hydrophihcity of the product, which has a large influence on the distribution coefficient. For example, at 16°C, the partition coefficient between liquid CO9 and water is 0.4 for methanol, 1.8 for /i-butanol, and 31 for /i-heptanol. 

Acrylamide polymers are used as multipurpose additives in the oil-producing industry. Introduction of polymers into drilling fluids-drilling muds improves the rheological properties of the fluids in question, positively affects the size of suspended particles, and adds to filterability of well preparation to operation. Another important function is soil structure formation, which imparts additional strength to the well walls. A positive effect is also observed in secondary oil production, where acrylamide polymers additives improve the mobility of aqueous brines injections, which contribute to... 

Phenolic biocides are still used extensively throughout the Figure 4 PCMC metalworking industry to preserve aqueous based metalworking fluids. One of the most commonly used phenolic biocides is p-chloro-m-cresol, (see PCMC, Figure 4). 

Mixtures of aqueous sodium hypochlorite (presumably the 15% available chlorine commercial product) and ethylene glycol were observed to erupt violently after an induction period of 4 to 8 minutes. Caution is advised in view of the use of glycol as a cooling fluid in industrial reactors. 

Thermally enhanced extraction is another experimental approach for DNAPL source removal. Commonly know as steam injection, this technique for the recovery of fluids from porous media is not new in that it has been used for enhanced oil recovery in the petroleum industry for decades, but its use in aquifer restoration goes back to the early 1980s. Steam injection heats the solid-phase porous media and causes displacement of the pore water below the water table. As a result of pore water displacement, DNAPL and aqueous-phase chlorinated solvent compounds are dissolved and volatilized. The heat front developed during steam injection is controlled by temperature gradients and heat capacity of the porous media. Pressure gradients and permeability play a less important role. 

Franck, E. U. "Equilibrium in Aqueous Electrolyte Systems at High Temperatures and Pressures" in "Phase Equilibria and Fluid Properties in the Chemical Industry" Storvick, F. S. Sandler, S. I., Eds., ACS Symposium Series 60, American Chemical Society,... 

With the widening use of the liquid-liquid extraction for the separation of complex mixtures into their components, it has been necessary to develop fluids with highly selective characteristics. The metallurgical, nuclear, biotechnolgy and food industries are now major users of the technique, and many of the recent developments have originated in those fields. Some of the characteristics and properties of two classes of fluids of increasing importance-supercritical fluids and aqueous two-phase systems are described in this section. 

Although the general principles of separation processes are applicable widely across the process industries, more specialised techniques are now being developed. Reference is made in Chapter 13 to the use of supercritical fluids, such as carbon dioxide, for the extraction of components from naturally produced materials in the food industry, and to the applications of aqueous two-phase systems of low interfacial tensions for the separation of the products from bioreactors, many of which will be degraded by the action of harsh organic solvents. In many cases, biochemical separations may involve separation processes of up to ten stages, possibly with each utilising a different technique. Very often, differences in both physical and chemical properties are utilised. Frequently... 

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