Acrylic acid scale

Conventional polymer and phosphonate scale inhibitors may not be appropriate for application in high-pressure and high-temperature reservoirs. Only a limited range of commercially available oil field scale inhibitor chemicals are sufficiently thermally stable at temperatures above 150° C. These chemicals are homopolymers of vinyl sulfonate and copolymers of acrylic acid... 

Scale inhibitors may also be used in acidizing. These include alcohol ethoxysulfonic acids (152). Scale inhibitors are also used in water and enhanced oil recovery injection wells and include low molecular weight poly(vinylsulfonate), poly(methylmethacrylate-co-ethylenediamine) (153), bis(phosphonomethylene)aminomethylene carboxylic acid, and poly(acrylic acid-co-3-acrylamido-3-methylbu-tanoic acid). Ethylenediaminetetraacetic acid and similar complex-ing agents have been used to remove scale from formation surfaces near wellbores. 

During the experimental large scale continuous polymerisation of acrylic acid in aqueous solution in presence of an initiator and a moderator, failure of one of the feed pumps led to an unusually high concentration of monomer in solution. This led to runaway polymerisation which burst a glass vent line and the escaping contents ignited and led to an explosion and fire. 

Compared with 3-alkyl-3-(acylamino)acrylic acid derivatives, much less success has been obtained in the asymmetric hydrogenation of 3-aryl-3-(acylamino)acrylic acid derivatives. An Et-FerroTANE-Rh catalyst has provided up to 99% ee for the hydrogenation of a series of (E)-3-aryl-3-(acylamino)acrylates.95 Since (E)-3-aryl-3-(acylamino)-acrylic acid derivatives are difficult to obtain in large scales compared to (Z)-3-aryl-3-(acylamino)acrylic acid... 

Relative humidity changes were measured with a nano-scale HRI-coated LPG in a wide range from 38.9% to 100% RH with a sensitivity of 0.2 nm/%RH, and an accuracy of 2.3% RH59. The material used was a hydro-gel layer composed by, among other chemicals, acrylic acid and vinyl pyridine. Fine adjust of the components proportion made possible to obtain a refractive index of the gel of about 1.55. The overlay thickness was estimated to be in that case 600 nm. 

Chemical intermediates are produced at a scale that is close to that of biomass conversion plants, e.g., between 100 kt a-1 (e.g., for acrylic acid) to 800 kt a-1 (e.g., for ethene diol). This has to be compared with the 20 Mt a-1 scale of a major oil refinery. 

Poly(acrylic acid) and partially hydrolyzed polyacrylamide are used for the prevention of scale in water used for boilers and for flocculating agents in water purification. 

The total concentration of complex formed during the complexation is proportional to X. During template polymerization of acrylic acid, a stable colloidal precipitate resulted in the systems under investigation, and turbidity measurements could be used, assuming that direct reading from the turbidimeter (in logarithmic scale) is proportional to the amount of polymeric product. The assumption was checked by calibration procedure. The light absorption (%) is proportional to the concentration of poly(acrylic acid)-poly(vinyl pyrrolidone) mixture.100% conversion was assumed when no increase in turbidity was detected by the recorder. In the case when copolymers were used as templates, the apparatus was calibrated for each copolymers separately. 

The hydrolysis of nitriles can be carried out with either isolated enzymes or immobilized cells. For example, resting cells of P. chlororaphis can accumulate up to 400 g/L of acrylamide in 8 h, provided acrylonitrile is added gradually to avoid nitrile hydratase inhibition (116). The degree of acrylonitrile conversion to acrylamide is 99% without any formation of acrylic acid. Because of its high efficiency the process has been commercialized and currendy is used by Nitto Chemical Industry Co. on a multithousand ton scale. 

The two extremes on the styrene-butadiene block copolymer composition scale are homopolymers of butadiene or styrene, respectively. To test the usefulness of homopolymers as dispersants, polybutadiene (PB) was carboxylated by adding thioglycolic acid, and polystyrene (PS) having carboxylic groups was prepared by copolymerizing small amounts of acrylic acid (AA) into the styrene chain. Adsorption experiments with these carboxylated homopolymers are listed in Table V. In the first... 

Coons R. Arkema finds glycerol-to-acrylic acid catalysts, demo-scale plant possible. Chem Week. 2009 171 36. 

The checkers prepared this ester on a 0.7-mol scale by a modification of the previously published method.2 The modification was effected as follows. The ethereal extract from the formaldehyde-diethyl malonate reaction, after drying over sodium sulfate for 3 hr, was concentrated in a rotary evaporator and the residue was stored in a refrigerator overnight. The crude ester was obtained as white crystals, mp 47-50°C yield 85.6%. The checkers found that the ester prepared in this manner gave superior yields of the acrylic acid. 

Hydroxypropanoic acid (3HPA) is under development as a future platform chemical and monomer derived from biomass. It is, at the present time, not produced on an industrial scale, either chemically or biotechnologically. 3HPA could be a key compound for the production of biomass-derived C3 intermediates, such as acrylic acid, acrylic amide and malonic acid (see Fig. 8.11). Hydrogenation of 3HPA would provide a competing procedure for the production of 1,3PD (see Section 8.2.4) that could be more economical than the DuPont and Shell processes [65]. 

Consideration of the dipolarity of the two activated complexes can explain the observed trend. If the reactants are pictured as lying in roughly parallel planes, the dipole moments for the exo orientation are seen to be nearly opposite in direction, whereas for the endo orientation they are parallel. Therefore, the net dipole moment for the endo transition state is greater than that for the exo. Thus, the solvation of the endo activated complex will be more pronounced as the polarity of the solvent increases. This leads to a lowering of the activation enthalpy and preferential formation of the endo adduct. The logarithm of the endojexo product ratio in various solvents has been used to define an empirical solvent polarity scale [124] [cf. Section 7.3). Analogous solvent-dependent endolexo product ratios have been obtained in [4 -1- 2]cycloadditions of cyclopentadiene to other acrylic acid derivatives [560]. Theoretical calculations on exoj endo structures for activated complexes of [4 + 2]cycloadditions have shown that the observed endo preference in polar solvents is due to the influence of the medium, and that secondary orbital interactions are not involved [808]. The solvent has the decisive influence on the exo/endo selectivity. 

The polymeric products can be made to vary widely in physical properties through controlled variation in the ratios of monomers employed in their preparation, cross-linking, and control of molecular weight. They share common qualities of high resistance to chemical and environmental attack, excellent clarity, and attractive strength properties (see Acrylic ESTER POLYMERS). In addition to acrylic acid itself, methyl, ethyl, butyl, isobutyl, and 2-ethylhexyl acrylates are manufactured on a large scale and are available in better than 98—99% purity (4). They usually contain 10—200 ppm of kydroquinone monomethyl ether as polymerization inhibitor. 

Little, if any. commercial use is made of these palladium-catalyzed carbonyla tions at present, but the nickel-catalyzed system for the production of acrylic acid and esters, in particular methyl methacrylate, i Still used on a commercial scale, especially in Germany and Eastern Europe. 

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