The commercial use of polyoxyethylene derivaties was in the field of textile auxiliaries. The wetting and detergent properties are important in many processing stages of cotton, such as prescouring desizing, bleaching, kier boiling and the application of resing finishes. The products are widely used for the alkaline or neutral scouring of wools as well as in acid carbonizing. They are useful in the processing of synthetic especially in the formulation of finishes because of their antistatic, emulsifying and lubricating properties.
The major consumption of these non ionic is in domestic and commercial detergent, the domestic product are essentially all formulated products, in commercial application, a considerable volume of non ionic is purchased for direct use but may also be compounded by the user.
Liquid dishwashers, with about 15% water, are day usually formulated product whose main detergent is an anionic such as alkylbenzene sulfonate. polyoxyethelene alkylphenol sulfate, or both. A form booster and stabilizer, usually lauric diethanolamine or dimethyldodecy lamine oxide is usually included, many of the formulations will also include about 5% of a water soluble nonionic.
Heavy-duty products often contain about 15% nonionic, the solid carrier is a mixture polyphoshates and silicates with a small amount of carboxymethyl cellulose as a soil-suspending agent.
Solvent-type cleaners containing 25% or more of refined kerosene are usually formulated with about 10% of the 9 mole adduct or with a combination of the 6 and 9 mole adducts.
These products are popular for floors, woodworks, and general cleaning.
Other household products in which these nonionic used include window cleaners, waterless hand cleaners, metal dip cleaners, bubble bath and hard-water bar soaps.
The water soluble alkylphenol dervatives are used to advantages in the acid pickling opration, where rust and scale are removed in the finishing of steel. They are included in rolling-oil formulations, in cutting and broaching oils of the soluble type, and in water-base hydraulic fluidcumsed in operating heavy equipment such as presses.
A large amount of the non ionic is consumed in the manufacture of emulsifiable concentrates of insecticides and herbicides. Both the oil-soluble and water soluble type are used and most often in conjunction with a sulfonate, sulfate or more recently, with the phosphate esters derived from a polyoxyethelene nonionic.
Latex and Waxes
The higher adducts containing 20 to 100 moles of ethlene oxide are used in the emulsion polymerization of vinyl acetate and acrylates. The water soluble members of short-chain length act as dispersants and stabilizers in synthetics rubber as well as other polymeric latics. Emulsion-type floor polishes are prepared from both natural and synthetics waxes with the higher adducts.
Other industries consuming substantial amounts of these adducts include petroleum, for drilling and crude-oil-emulsion breaking, paper, for pitch control in pulp, felt cleaning and rewetting of paper towels, cosmetics, emulsifier, leather, fat-liquoring, as dust control agents in the coal, mineral, and ceramic industries, and wetting and foaming adjuncts in fire fighting. The chemical industry itself is a large consumer of these materials as an intermediate in the production of the sulfates, the phosphates, and the disinfectant iodophors.
Polyethylene Glycol (PEG) Esters are non-toxic and non-irriting nonionic emulsifiers. They are prepared by the esterification of fatty acids with polyethylene glycols. The low molecular weight ranging PEG Esters are oil-soluble to work in nonaqueous systems. The high molecular esters are water-soluble can be used in aqueous systems. Polyethylene Glycol Esters are used as emulsifiers and in formulating emulsifier blends, thickener, resin plasticizer, emollient, pacifier, spreading agent, wetting and dispersing agent, and viscosity control agents. They also have application in the metalworking, pulp, paper, textile and as defoamers for latex paints.
Polyethylene glycol is a condensation polymers of ethylene oxide and water with the general formula H(OCH2CH2)nOH, where n is the average number of repeating oxyethylene groups typically from 4 to about 180. The low molecular weight members from n=2 to n=4 are diethylene glycol, triethylene glycol and tetraethylene glycol respectively, which are produced as pure compounds.
The low molecular weight compounds up to 700 are colorless, odorless viscous liquids with a freezing point from -10 C (diethylene glycol), while polymerized compounds with higher molecular weight than 1,000 are wax like solids with melting point up to 67 C for n 180. The abbreviation (PEG) is termed in combination with a numeric suffix which indicates the average molecular weights.
One common feature of PEG appears to be the water-soluble. It is soluble also in many organic solvents including aromatic hydrocarbons (not aliphatic). They are used to make emulsifying agents and detergents, and as plasticizers, humectants, and water-soluble textile lubricants. Polyethylene glycol is non-toxic, odorless, neutral, lubricating, nonvolatile and nonirritating and is used in a variety of pharmaceuticals and in medications as a solvent, dispensing agent, ointment and suppository bases, vehicle, and tablet excipient. Lipophilic compounds are ethoxylated ethylene oxide (the monomer of polyglycols) so that the target compounds have hydrophilic (soluble in water).
The bi-functionality in one molecule provides the basic properties of surfactants. Fatty acids rather lipophilic (or hydrophobic) exhibiting low HLB (Hydrophilic-Lipophilic Balance) values; having an affinity for, tending to combine with, or capable of dissolving in lipids (or water-insoluble). While, the ethoxylated fatty acids are hydrophilics exhibiting high HLB values; having an affinity for water; readily absorbing or dissolving in water. The type of fatty acid and the mole number of ethylene oxide provides diverse HLB values for proper applications. There are almost infinite ethoxylated compounds. In combination with the average molecular weights and water-soluble property of PEG, the wide range of chain lengths of fatty acids provide identical physical and chemical properties for the proper application selections directly or indirectly.
Demulsifier is a chemical used to break emulsions that is, to separate the two phases. The type of demulsifier selected depends on the type of emulsion, either oil-in-water or water-in-oil. Demulsifiers are used in the chemical analysis of oil and synthetic mud and to treat produced hydrocarbons.
Demulsification is used to describe the separation of water from crude oil. As crude oil is produced from a reservoir it tends to become mixed with either natural formation water or mixed formation and injection water. This produced mixture of crude oil and water is termed an oil and water emulsion. It is critical to topsides process operations that the crude oil is efficiently and quickly separated from the water to allow dry oil to be exported and clean water to be discharged within consent, thus maximising crude oil value and minimising operating costs.
Typically the emulsions formed are water in oil with the continuous phase being oil and the dispersed phase being water. The severity of the emulsion formed and thus the ease at which it can be broken is dependant on many factors including:
Physical and chemical properties of the crude oil
- Production temperature
- Distance between reservoir and topsides
- Degree of agitation experienced between reservoir and separator, turbulent flow presence of solids (sand, clay, bacteria, scale, asphaltenes, corrosion product, napthenates) and / or natural surfactants which act to stabilise the emulsion
The most common method of breaking emulsions is with the use of demulsifying / desalting chemicals.
Demulsifying / desalting chemicals tend to act on the emulsion by:
- Flocculation of the oil droplets
- Dropping of the water
- Coalescence of the water droplets
- The speed and efficiency at which this occurs can be improved by process equipment design and operating conditions e.g. increasing the temperature, separator design etc.
Demulsifier Selection and Application
- Demulsifiers are generally injected on a continuous basis upstream of the 1st stage production separator but in certain circumstances they can be injected subsea.
- Demulsifier selection is best performed on live crude oil thus the selection process must be performed in the field and is generally performed using the bottle test method. Using this method numerous base chemicals can be tested on fresh emulsions and at the exact operating conditions thus a product can be formulated which is specific to the field and the emulsion. As field conditions change over its lifetime it is essential to optimise demulsifier performance on a regular basis.
Demulsifier: Oil and Gas Solutions
In Oil and Gas Industry, recently, new products have extended the application area for silicones from traditional antifoam and demulsifier applications.
Major oil and gas application areas include:
- Gas/oil separation foam control
- Refinery foam control
- Amine sweetening and dehydration processes
- Oil/water demulsification
- Oil well sealing for repair, abandonment, and zonal isolation
- Oxygen scavenger/deaeration
- Fuel and lubricant additives
- Vanadium Corrosion control
Esterification is the name for a chemical reaction in which two chemicals form an ester as the reaction product, commonly used as fragrance or flavour agents.
Esterification is the general name for a chemical reaction in which two chemicals (typically an alcohol and an acid) form an ester as the reaction product, commonly used as fragrance or flavour agents.
Examples of esterification reactions include: Heating to reflux an acid and an alcohol in the presence of an catalyst forms the ester and water byproduct which can be removed to force the equibilibrium across to the desired products. This method is called Fischer esterification. For example, esterification of acetic acid in excess ethanol in the presence of sulfuric acid results in an ester.
Esters are an important class of organic compounds that often have pleasant odors and are responsible for many distinctive smells in fruits and flavorings. Esters can be readily prepared from a carboxylic acid and an alcohol. Choosing the right combination of alcohol and acid determines the odor.
Acetate esters, except methyl acetate, are marketed primarily as solvents for surface coatings, inks and chemical processing. Methyl acetate is used in the United States as a chemical intermediate to produce acetic anhydride.
The traditional method of acetate production is by esterification of acetic acid with alcohol in the presence of sulfuric acid or sulfonic acid catalyst. However, utilization of sulphonic acid resin catalysts as the replacement for liquid acids is gaining importance.
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Ethylene Oxide Derivatives : | 1 | 2 | 3 |