Carbon dioxide with amines

In principle, the combination of membranes for bulk removal of the carbon dioxide with amine units as polishing systems offers a low-cost alternative to all-amine plants for many streams. However, this approach has not been generally used because the savings in capital cost are largely offset by the increased complexity of the plant, which now contains two separation processes. The one exception has been in carbon dioxide flood enhanced oil-recovery projects [49,54], in which carbon dioxide is injected into an oil formation to lower the viscosity of the oil. Water, oil and gas are removed from the formation the carbon dioxide is separated from the gas produced and reinjected. In these projects,... 

Even though water has a low solubility in carbon dioxide, it has been shown that it can also be effectively removed with supercritical carbon dioxide in formation of nylon 66 (a polyamide) [34]. In this polyamide formation, because of the reactivity of carbon dioxide with amines, instead of using hexamethylene diamine, reaction was carried out with a nylon salt. Carbon dioxide was shown to lower the melting point of the nylon salt and permit polymerization to proceed at lower temperatures. At temperatures around 270 and over a reaction time of about 3 hr at 3000 psi polyamides of high molecular weight (Mn = 25,000) have been produced. 

The experimental results of this work were analysed using the theory of mass transfer with chemical reaction. The data presented in this work have been obtained at conditions where the mathematical treatment of the problem was simplified assuming a pseudo-first-order assumption for kinetics. In this case, the concentration of the amine across the cross section of the liqitid boundary layer was assumed to be uniform. Thus, transforming the second-order reaction expression of carbon dioxide with amine into an approximated first-order expression. Hence, For piperazine ... 

Sharma, M. M., 1965, Kinetics of Reaction of Carbonyl Sulfide and Carbon Dioxide with Amines and Catalysis by Brmisted Bases of the Hydrolysis of COS, Trans. Faraday Soc., VoL61,p.681. 

Water, in small amount, reacts with the diisocyanate to generate carbon dioxide, and amine and is used most frequendy as the foaming agent. Polyurethanes have been treated in detail in the Hterature (66—68). 

Zinc carbamate complexes are well known, and the structural types and stabilities can be compared with thiocarbamates and dithiocarbamates which are discussed in Sections 6.8.11.1.3 and 6.8.7.1.4482 Carbamates of zinc can be formed from the reaction of carbon dioxide with alkylzinc alkyl amides and further reaction with alkylzinc can give a distorted cubane structure.483 The tetrameric diethylcarbamate species initially formed can also be used to produce monomeric or dimeric carbamate structures in reaction with amines tetramethylethylenediamine forms a monomer [(Me2NCH2)2Zn(02CN(C2H5)2)2] with an octahedral zinc center and pyridine forms a dimer[CsH5NZn2Me(02CN(C2H5)2)3] with tetrahedral zinc centers.484... 

Iridium(III) hydride forms complexes with DIOP, BDPP (2,4-bis(diphenyl-phosphino)pentane), NORPHOS, and BINAP ligands to produce amines in 11 -80% ee.679 Similar modest results are obtained in the reduction of N-arylketimines with an iridium(HI) complex with (2S,3 S) -C HIRA PHOS as the chiral ligand.680 The indium complexes with chiral phosphinodihydrooxazoles catalyze the enantioselective hydrogenation of imines in supercritical carbon dioxide with up to 80% ee, but generally lower ee values are observed in... 

The [8 + 2] cycloaddition reactions between substituted cyclohcpta h]furan-2-ones and enamines have been described by Kuroda and coworkers312. The cycloaddition reactions proceeded with concomitant elimination of carbon dioxide and amine. Thus, the reaction between 527 and enamine 528 afforded [8 + 2] cycloadduct 529 with good yield (equation 153)312c. 

The major problem is moisture that is absorbed into the polyurethane system or into the curative and auxiliary materials. Free water will liberate carbon dioxide when the chain extension is carried out. It is important to keep the reactants dry, as any moisture that may have come in contact with the prepolymer will react to give an amine and carbon dioxide. This amine reacts with more isocyanates to form a disubstituted diamine. The reaction is outlined in Figure 2.9. 

Epoxidation of styrene with tBuOOH catalysed by Au/Si02 in the presence of zinc and tetrabutylammonium bromides and carbon dioxide led directly to styrene carbonate at 1 MPa pressure and 353 K, conversion was 90% and selectivity 35%.47 Gold on functionalised polymer also catalyses the reaction of carbon dioxide with various epoxides to give lactones, and with amines to give carbonates.48... 

H. Hikita, S. Asai, H. Ishikawa, and M. Honda The Kinetics of Reactions of Carbon Dioxide with Monoethanol-amine, Diethanolamine, and Triethanol-amine by a Rapid Mixing Method, Chem. Eng. J. (Printed in the Netherlands), 13 7 (1977). 

TRIISOBUTYLALUMINUM (100-99-2) Extremely flammable liquid (flash point <39°F/<4°C). Pyrophoric ignites spontaneously on contact with air. Reacts with water. A strong reducing agent. Violent reaction with oxidizers. Reacts with acids, carbon dioxide, alcohols, amines, ammonia, halogens, halogenated hydrocarbons. Attacks silicone and urethane rubbers. Store under inert gas blanket. Reacts with most common fire extinguishers ... 

In one of the most interesting reports to appear during the year, Tazuke and Ozawa have provided the first example of the abiological photofixation of COa in the formation of 9,10-dihydrophenanthrene-9-carboxylic acid from irradiation of phenanthrene and carbon dioxide with an amine in dimethyl sulphoxide or dimethylformamide. Naphthalene and some other polycyclic aromatic systems also seem to react similarly. 

Terminal alkyne complexes with ruthenium react with carbon dioxide and amines to yield urethanes, as shown in reaction 8. ... 

Another method for formylation of amines is withp-nitrophenyl formate, which usually gives products in high yield. However, removing the last traces of the p-nitrophenol is difficult. Treating carbon dioxide and amines with EDC gives symmetrical ureas (eq 4). DCC with CO2 at ambient pressure works equally well. 

It is the control of the reactivity of this carbamate anion which has allowed us to generate in quantitative yields either urethanes or isocyanates directly. By understanding those factors which promote the nucleophilicity of the carbamate oxygen, we have discovered how to generate urethanes directly from either primaiy or secondary amines (Activated Carbon Dioxide Chemistry-I (ACDC-I) (12, 13, 15-18). A key aspect of this chemistry was our discovery that carbamate anions can serve as excellent nucleophiles, when a suitable tertiary amine base is utilized to generate the carbamate anion in the reaction of carbon dioxide with a primary or secondary amine (equation 4). By proper choice of the tertiary amine co-base, which in general does not react with CO2 under the mild conditions employed. 

As noted above, the reaction of amines, carbon dioxide and electrophiles has been reported in the literature, but the products generally are derived from attack on the nitrogen center, liberating CO2 and producing the substituted amine or amide. Both the ACDC-I and -II chemistries rely on the production of the carbamate anion from the reaction of carbon dioxide with the substrate amine. Very few reports have appeared which have addressed the issue of utilizing the carbamate anion as an oxygen- nucleophile in direct substitution reactions (9-14). 

Nozaki s zirconium(iv) BOXDIPY initiator was inactive for the copolymerisation of PO/carbon dioxide with the addition of 1 equivalent of [PPN]Cl (2.0 MPa carbon dioxide, 60 °C) forming the cyclic carbonate in 100% yield. ° Tbe complex was able to produce a polycarbonate with CHO, although the proportion of ether linkages was high. Titanium(iv) and germanium(iv) complexes were also screened, with more success than the zirconium(iv) analogue. In 2014 Ko prepared a series of zirconium(iv) amine-bis(benzo-triazole) phenolate complexes for the ROP of rac-LA and the production of... 

The vast majority of current power plants use coal or natural gas as the fuel source and air as the source of oxygen. In these plants, the stack gas is at essentially atmospheric pressure and contains a large concentration of nitrogen (76 mol%). A small amount of excess air is used, which gives a stack composition of 4.8 mol% O2. The carbon dioxide concentration is only 13.2 mol%. The principal proven method for carbon dioxide removal from a low-concentration, low-pressme gas uses amine absorption, which involves chemical reaction of carbon dioxide with an amine, such as monoethanolamine (MEA). 

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