Solvent types hydrocarbon

Lube oil extraction plants often use phenol as solvent. Phenol is used because of its solvent power with a wide range of feed stocks and its ease of recovery. Phenol preferentially dissolves aromatic-type hydrocarbons from the feed stock and improves its oxidation stability and to some extent its color. Phenol extraction can be used over the entire viscosity range of lube distillates and deasphalted oils. The phenol solvent extraction separation is primarily by molecular type or composition. In order to accomplish a separation by solvent extraction, it is necessary that two liquid phases be present. In phenol solvent extraction of lubricating oils these two phases are an oil-rich phase and a phenol-rich phase. Tne oil-rich phase or raffinate solution consists of the "treated" oil from which undesirable naphthenic and aromatic components have been removed plus some dissolved phenol. The phenol-rich phase or extract solution consists mainly of the bulk of the phenol plus the undesirable components removed from the oil feed. The oil materials remaining... 

Metallo-organic compounds possess high reactivity to water, oxygen and nearly all organic solvents, except hydrocarbons and ethers. Chemical properties of the suggested surface complexes of the type M )f in presence of various solvents are unknown. However,... 

Solvent type should be compatible with the processing pressure, selectivity desired, and potential contaminants (organic sulfur, NH3, HCN, hydrocarbons) expected in the feed gas. 

Contrary to what has been observed for radical systems, lithium based anionic copolymerizations usually exhibit pronounced sensitivity to solvent type. Thus, the polarity and solvating power of the solvent will influence the copolymer reactivity ratios while mixtures of e.g. ethers and hydrocarbons will lead to effects intermediate with regard to what is observed for the pure solvents. 

Solubility in water. Since water is a polar compound, it is a poor solvent for hydrocarbons of all types. Salts are usually extremely polar, and are generally water-soluble. Other compounds fall between these two extremes these include alcohols, esters, aldehydes, ketones, adds, ethers, amides, nitriles and amines. Acids and amines are generally more soluble than neutral compounds. 

Halocarbons, a class of polar solvents, are hydrocarbons with an attached halogen. There are commonly three types of halocarbon solvents those based on chlorine, fluorine, and a combination of the two. They are all powerful degreasing materials and can be particularly effective in removing polar contaminants from glass. The chlorofluorocarbons are currently under review because they cause environmental damage to the ozone layer.1... 

The effect of solvent type on the curing rate of epoxy reactions has been well defined. Hydroxyl compounds, such as alcohols, act as catalysts and accelerate curing. However, these solvents are not serious competitors with amines for reacting with the epoxy ring. Water, functioning as a hydroxyl compound, also accelerates the reaction, even more than alcohols. Aprotic solvents, such as aromatic hydrocarbons or mineral spirits, have no effect on the amine-epoxy resin and behave as inert diluents. Carbonyl solvents, such as acetone and methyl ethyl ketone, retard the reaction. 

As the natural gas industry developed and expanded, so did the demand for liquids recovered from natural gas. One way of recovering additional liquids is through the use of a heavy absorption oil that has good solubility characteristics for the propane and heavier hydrocarbon components in the gas stream. As in the case of dehydration, the solvent must be regenerated. Figure 20.1311 shows the absorption-stripping section of an absorption-type hydrocarbon liquids recovery facility. The absorbent is circulated to the top of the absorber and flows downward, absorbing liquefiable components from the... 

A major project added to the information about isopropyl alcohol (IPA) from earlier trials, 97,98 and showed it can be as effective an extraction solvent as hexane.99 However, because of high retrofitting costs, IPA is not likely to be implemented while hexane-type hydrocarbons are allowed. 

PPL catalyzed the polymerization of methyl esters of 5-hydroxypentanoic and 6-hydroxyhexanoic acids.149 In the polymerization of the latter in hexane at 69 °C for more than 50 days, the polymer with DP up to 100 was formed. Relationships between solvent type and polymerization behaviors were systematically investigated hydrophobic solvents such as hydrocarbons and diisopropyl ether were suitable for the enzymatic production of high molecular weight polymer. Pseudomonas sp. lipase catalyzed the polymerization of ethyl esters of 3- and 4-hydroxybu-tyric acids, 5- and 6-hydroxyhexanoic acids, 5-hy-droxydodecanoic acid, and 15-hydroxypentadecanoic acid.157 Oxyacid vinyl esters were demonstrated as new monomers for polyester production under mild reaction conditions, yielding the corresponding polyesters with A/n of several thousands.276... 

The clear-colorless nature of silicone repellents allows preservation of the original appearance of the concrete. Their lack of film formation leaves the masonry pores open, thereby allowing transport of moisture outward to the atmosphere. They are highly durable to environmental conditions and will retain their repellent properties for several years. There are two types of water-repellent silicones (1) one is the resin-solvent type that is characterized as a partially hydrolyzed, partially alcoholized silicone resin dissolved in a hydrocarbon solvent. Generally, such products approach the 5% nonvolatile level. (2) The second is a water-soluble alkaline silicone repellent that is recommended for use on limestone and other nonsiliceous stone and masonry. 

Solvent type plays a very important role in the reactivity ratios of anionic copolymerization pairs. Hydrocarbon solvents, such as C4-C10 alkanes and cycloalkanes, are commonly used. n-Hexane and cyclohexane are employed in many commercial processes. Except for some SBRs with very specific microstructures made at very low temperatures (T < —20°C), the so-called cold rubbers, most anionic polymerization processes occur at relatively high temperatures (T > 30-100°C), isothermally or semiadiabatically. Number average molecular weights for the blocks vary widely but may be most commonly maintained between 30,000 and 100,000 Da. Once all monomer has been consumed via propagation reactions, a short stopper reactant, typically alcohol or water, is added to the mix to kill the living character of the anion and... 

Solubility sol hydrocarbon and ethereal solvents, but should be used at low teir ierature in the latter solvent type half-lives in diethyl ether and THF have been reported reacts violently with H2O and other protic solvents. 

The possibilities inherent in the anionic copolymerization of butadiene and styrene by means of organolithium initiators, as might have been expected, have led to many new developments. The first of these would naturally be the synthesis of a butadiene-styrene copolymer to match (or improve upon) emulsion-prepared SBR, in view of the superior molecular weight control possible in anionic polymerization. The copolymerization behavior of butadiene (or isoprene) and styrene is shown in Table 2.15 (Ohlinger and Bandermann, 1980 Morton and Huang, 1979 Ells, 1963 Hill et al., 1983 Spirin et al., 1962). As indicated earlier, unlike the free radical type of polymerization, these anionic systems show a marked sensitivity of the reactivity ratios to solvent type (a similar effect is noted for different alkali metal counterions). Thus, in nonpolar solvents, butadiene (or isoprene) is preferentially polymerized initially, to the virtual exclusion of the styrene, while the reverse is true in polar solvents. This has been ascribed (Morton, 1983) to the profound effect of solvation on the structure of the carbon-lithium bond, which becomes much more ionic in such media, as discussed previously. The resulting polymer formed by copolymerization in hydrocarbon media is described as a tapered block copolymer it consists of a block of polybutadiene with little incorporated styrene comonomer followed by a segment with both butadiene and styrene and then a block of polystyrene. The structure is schematically represented below ... 

Propylene oxide is soluble in water and miscible with most organic solvents. It is found to be an excellent law-boiling solvent far cellulose acetate, nitrocellulose, adhesive compositions and vinyl chloride-acetate resins. It is also a solvent for hydrocarbons, gums and shellac. Same of its uses are as a solvent and stabilizer in DDT aerosol-type insecticides, and as a fumigant and food preservative. Since it is an acid acceptor, it is also used as a stabilizer for vinyl chloride resins and other chlorinated systems. 

Between 360°C (680°F) and 400°C (750°F), the solvent power of various solvent types has been found to decrease in the following order amines, phenols, cyclic hydrocarbons, aliphatic hydrocarbons, but the substitution of hydrogen for functions such as imine (=NH) or amino (-NHj) may increase the solvent power. With aliphatic amines at lower temperatures, the reverse is true. Insertion of a carbonyl group in the para position causes a sharp increase in effectiveness. 

Water miscibility can rank from complete, for the more polar, hydrogen bonding solvent types (glycols, glycolethers, lower alcohols) via intermediate (higher alcohols, ketones and esters) to hardly miscible as in the case of most apolar hydrocarbon, chlorinated hydrocarbon and ether solvent types (Table 2.13). 

For the long-oil, airdrying types white spirit is the commonly used solvent type. The shorter oil types are dissolved in aromatic hydrocarbons like xylene. In stoving paint formulations, in combination with MF or UF resin, the aromatic solvents are combined with alcohols. A good thinner formulation is for instance xylene/ isobutanol 3/1 v/v. 

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