- Method and device for continuously preparing alkyl nitrite through channelization
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The invention discloses a method and device for continuously preparing alkyl nitrite through channelization. The method comprises the following steps: storing alkyl alcohol and concentrated HCl aqueous solution in a first container and storing sodium nitrite aqueous solution in a second container; continuously conveying the solution in the first container and the second container into a static mixer for mixing by a first metering pump and a second metering pump respectively, enabling mixed solution to continuously enter a tubular reactor for reaction at the temperature of -20 DEG C-5 DEG C for1-250s, enabling feed liquid after reaction to enter a liquid separation tank and performing aftertreatment on the feed liquid in the liquid separation tank, so as to obtain alkyl nitrite. The preparation method disclosed by the invention has the advantages of being good in process safety and easy in control of reaction conditions, achieving continuous production, being high in product yield andachieving large-scale production only through less investment in the industry.
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Paragraph 0023-0026
(2019/07/04)
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- Process for Producing C1-C4 Alkyl Nitrite
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A process of producing C1-C4 alkyl nitrite, comprising the following steps: a) firstly feeding nitrogen oxide and oxygen into Reactor I, contacting with an aluminosilicate catalyst, and reacting to produce an effluent I containing NO2 and unreacted NO; b) feeding the effluent I and C1-C4 alkanol into Reactor II, and reacting to produce an effluent II containing C1-C4 alkyl nitrite; and c) separating the effluent II containing C1-C4 alkyl nitrite to obtain C1-C4 alkyl nitrite; wherein reactor I is a fixed bed reactor, and Reactor II is a rotating high-gravity reactor; said nitrogen oxide in step a) is NO, or a mixed gas containing NO and one or more of N2O3 and NO2, wherein the molar number of NO is greater than that of NO2, if any; and the molar ratio of NO in nitrogen oxide to oxygen is 4-25:1.
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Page/Page column 4
(2011/10/31)
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- Process for Producing Cl-C4 Alkyl Nitrite
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The present invention relates to a process for producing C1-C4 alkyl nitrite, comprising loading a resin catalyst layer and/or a porous filler layer into a reactor, passing nitrogen oxide, oxygen and C1-C4 alkanol as raw materials through the resin catalyst layer and/or porous filler layer in a counter current, parallel current or cross current manner, reacting under the conditions including a reaction temperature of from 0 to 150° C., a reaction pressure of from ?0.09 to 1.5 MPa, a molar ratio of C1-C4 alkanol/nitrogen oxide of 1-100:1, a molar ratio of nitrogen oxide/oxygen of 4-50:1, to obtain an effluent containing C1-C4 alkyl nitrite, wherein said nitrogen oxide is NO, or a mixed gas containing NO and one or more selected from N2O3 and NO2.
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Page/Page column 4
(2011/10/31)
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- NEW METHOD FOR THE MANUFACTURE OF THERAPEUTIC COMPOUNDS AND COMPOSITIONS, COMPOUNDS AND COMPOSITIONS PRODUCED THEREWHITH, AND THEIR USE
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Organic nitrites can be produced from a compound which is a mono/polyhydric alcohol or an aldehyde- or ketone-derivate thereof after de-aeration of the same, using NO gas, and stored in an environment saturated with gaseous NO. Organic nitrites produced according to the invention exhibit less impurities and improved storage stability compared to conventionally produced nitrites. The organic nitrites of the invention can easily be formulated into pharmaceutical compositions and have utility for the treatment of various conditions.
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Page/Page column 26-27
(2008/06/13)
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- Gas phase kinetics of the reaction system of 2NO2 ? N 2O4 and simple alcohols between 293-358 K
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The reversible reactions between nitrogen dioxide and alcohols (CH 3OH, CH3CH2OH, CH3CH 2CH2OH, CH3CHOHCH3) have been studied in the gas phase, using the spectrophotometric method. RONO (R = CH 3, CH3CH2, CH3CH2CH 2, CH3CHCH3) were identified by UV spectra. The equilibrium constants as well as the bimolecular rate constants were determined by computer modeling, using the programme MINICHEM. We calculated the following values for the forward rate constants k3av: (3.0±0.9)×10-18, (8.0±2.4)×10 -18, (5.4±1.6)×10-18, (2.0±0.6) ×10-18 cm3 molec-1 s-1 and the equilibrium constants Kav: 100±30, 40±12, 109±33, 39±12 at 298 K for the reactions with methanol, ethanol, 1-propanol and 2-propanol, respectively. The temperature dependence of the rate constants and the equilibrium constants were studied and it allowed to obtain the activation energy for the forward and for the reverse reaction, as well as thermochemical parameters. The equilibrium constants and the rate constants suggest that symmetrical N2O4 is the reactive species.
- Wojcik-Pastuszka,Gola,Ratajczak
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p. 1301 - 1313
(2007/10/03)
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- Dispersed fluorescence spectroscopy of primary and secondary alkoxy radicals
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Dispersed fluorescence (DF) spectra of 1-propoxy, 1-butoxy, 2-propoxy, and 2-butoxy radicals have been observed under supersonic jet cooling conditions by pumping different vibronic bands of the B-X laser induced fluorescence excitation spectrum. The DF spectra were recorded for both conformers of 1-propoxy, three conformers of the possible five of 1-butoxy, the one possible conformer of 2-propoxy, and two conformers of the possible three of 2-butoxy. Analysis of the spectra yields the energy separations of the vibrationless levels of the ground X and low-lying A electronic state as well as their vibrational frequencies. In all cases, the vibrational structure of the DF spectra is dominated by a CO stretch progression yielding the vco stretching frequency for the X state and in most cases for the A state. In addition to the experimental work, quantum chemical calculations were carried out to aid the assignment of the vibrational levels of the X state and for some conformers the A state as well. Geometry optimizations of the different conformers of the isomers were performed and their energy differences in the ground states were determined. The results of the calculation of the energy separations of the close-lying X and A states of the different conformations are provided for comparison with the experimental observations.
- Jin, Jin,Sioutis, Ilias,Tarczay, Gyoergy,Gopalakrishnan, Sandhya,Bezant, Andrew,Miller, Terry A.
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p. 11780 - 11797
(2008/01/27)
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- Atmospheric fate of alkoxy radicals: Branching ratio of evolution pathways for 1-propoxy, 2-propoxy, 2-butoxy and 3-pentoxy radicals
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As the last step of VOC oxidation in the atmosphere, the evolution of alkoxy radicals determines the nature and the concentration of the secondary compounds formed. Branching ratios between decomposition and reaction with O2 of 1-propoxy, 2-propoxy, 2-butoxy, and 3-pentoxy radicals were measured at room temperature and 1 atm in a simulation chamber using FTIR spectroscopy as an analytical device. The ratio varied depending on the leaving alkyl group and the class of alkoxy. No additional decomposition due to excited radicals was observed. The results could be used directly for tropospheric simulation purposes. Formaldehyde might be a photolytic source of HOx through the production of H and HCO radicals and acetaldehyde is the key precursor of the toxic NOx reservoir, peroxy-acetyl nitrate. In the lower troposphere, 1-propoxy and 2-propoxy radicals react mainly with O2 while decomposition is an important reaction pathway for 2-butoxy and 3-pentoxy. Consequently, C1 and C2 aldehyde production from the two longer chain alkoxys will occur very close to the area of initial VOC oxidation, while for the alkoxys exhibiting a minor decomposition pathway, the formaldehyde or acetaldehyde production will take place after oxidation of all the intermediate secondary compounds, far from the emission area of the primary compound.
- Meunier,Doussin,Chevallier,Durand-Jolibois,Picquet-Varrault,Carlier
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p. 4834 - 4839
(2007/10/03)
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- Rate constants for the reactions of C2H5O, i-C3H7O, and n-C3H7O with NO and O2 as a function of temperature
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The rate constants of the reactions of ethoxy, i-propoxy and n-propoxy radicals with O2 and NO was investigated as function temperature. The radicals were generated by laser photolysis from the appropriate alkyl nitrite and characterized by laser-induced fluorescence. For the reactions with O2, the ethoxy radical reacted somewhat slower than recently recommended. The values obtained for i- and n-propoxy had been combined with the measurements from a recent study at lower temperatures, allowing a more reliable determination of the Arrhenius parameters.
- Fittschen,Frenzel,Imrik,Devolder
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p. 860 - 866
(2007/10/03)
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- LIF spectra of n-propoxy and i-propoxy radicals and kinetics of their reactions with O2 and NO2
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Fluorescence excitation spectra of CH3CF2CH2O (n-propoxy) and (CH3)2CHO (i-propoxy) radicals were obtained using a combined laser photolysis/laser-induced fluorescence (LIF) technique and the kinetics of reactions of these radicals with (1) O2 as a function of temperature and with (2) NO2 as a function of pressure have been determined. Propoxy radicals were produced by excimer laser photolysis of the appropriate propyl nitrites at γ=351 nm. The spectra of the (A?←X?) transitions show progressions of the CO-stretching vibration in the electronically excited states with spacings of the bands of (560±10)cm-1 for i-propoxy and (580±10)cm-1 for n-propoxy. Fluorescence spectra taken after excitation in the (4,0) band at λ=340.1 nm (i-propoxy) and in the (1,0) band at λ=342.4 nm (n-propoxy) show progressions of the CO-stretching vibration in the electronic ground state of (900±60) cm-1 for i-propoxy and (1000±50) cm-1 for n-propoxy. The Arrhenius expressions for the ractions of n-propoxy and i-propoxy with O2 have been determined to be k1 (n) = (1.4±0.6)×10-14 exp (-(0.9±0.5) kJ mol-1/RT) cm3 s-1 and kt (i) = (1.0±0.3)×10-14 exp (-(1.8±0.4) kJ mol-1/RT) cm3 s-1 in the range 218-313 K. The rate coefficients for the reactions of NO2 with n-propoxy and i-propoxy at T=296 K were found to be independent of total pressure with k2(n)=(3.6±0.4)×10-14 cm3 s-1 (6.7-53 mbar) and k2(i)=(3.3±0.3)×10-11 cm3 s-1 (6.7-106 mbar). WILEY-VCH Verlag GmbH, 1998.
- Mund,Fockenberg,Zellner
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p. 709 - 715
(2007/10/03)
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- Reaction of alcohol with NO2 on a Cleaned Glass Surface
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Formation of alkyl nitrite from alcohol and NO2 was very fast on a Pyrex glass surface cleaned with chromic acid mixture.The reaction was practically zero order with respect to NO2.The rate constant was (1.7 +/- 0.08)*10E-18 cm3*molecule-1*s-1 for methyl nitrile formation and the apparent activation energy was -53.5 kJ*mol-1.
- Maeda, Yasuaki,Fujio, Yoshifumi,Munemori, Makoto
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p. 2127 - 2130
(2007/10/02)
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- Disproportionation to Combination Ratios of Alkoxy Radicals with Nitric Oxide
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The disproportionation to combination ratios were measured at 175 deg C for the reactions RO + 15NO -> RO15NO (2a) and RO + 15NO -> RCHO + H15NO (2b), with the following alkoxy radicals: C2H5O, n-C3H7O, n-C4H9O, and i-C4H9O.The alkoxy radical was generated by the termal decomposition of the corresponding alkyl nitrite in the presence of 15NO.The rate of the corresponding isotopically enriched alkyl nitrite was measured by mass spectrometry while the aldehyde rate was determined by gas chromatography.The results obtained for k2b/k2 were 0.22 +/= 0.02, 0.26 +/= 0.03, 0.29 +/= 005, and 033 +/= 0.03, respectively, for C2H5O, n-C3H7O, n-C4H9O, and i-C4H9O.With these values of k2b/k2 we were able to determine the primary quantum yield of the photolysis of the corresponding alkyl nitrites at 366 nm to be, respectively, 0.32 +/= 0.04, 0.44 +/= 0.06, 0.19 +/= 0.04, and 0.19 +/= 0.02.
- Morabito, Paul,Heicklen, Julian
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p. 2914 - 2916
(2007/10/02)
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- Formation of Organic Nitro-compounds in Flowing H2O2+NO2+N2+Organic Vapour Systems. Part 2.-H2O2+NO2+N2+Alkane System
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The principal products from the surface-initiated reactions in flowing mixtures of H2O2, NO2,N2 and RH, where RH=ethane, propane, n-butane and n-pentane, have been identified as the nitroalkane, alkyl nitrite and alkyl nitrate.The product yields have been measured; in the case of propane the variation of the yields with total gas pressure has also been studied.Values have been obtained for the relative rates of primary and secondary H-atom abstraction from each alkane by OH and for the rate-constant ratios k3/k4 and k5/k6 at 298 K:.The trends in the product yields with the variation of pressure and change of R indicate that RO radicals are produced via reactions (4)-(6) rather than by a single-step reaction of R with NO2.
- Baulch, Donald L.,Campbell, Ian M.,Chappel, Jonathan M.
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p. 609 - 616
(2007/10/02)
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- A kinetic study of the influence of alcohols on the nitrosation of morpholine in acid media. Equilibrium constants for the formation of alkyl nitrites
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The effect of the aliphatic alcohols methanol, ethanol, propanol, isopropanol, 2-butanol, isobutanol, and tert-butanol on the rate of nitrosation of morpholine at pH 3 and 25 deg C has been studied.The inhibition observed is attributed to the formation of alkyl nitrites, which are poor nitrosating agents in acid media.The equilibrium constants for the formation of alkyl nitrites from nitrous acid and alcohols have been calculated both spectrophotometrically and from kinetic data for the inhibitory effect, and there is agreement between the two sets of results.The molar absorptivities at 265 nm of the alkyl nitrites have also been determined.When the concentration of alkyl nitrite is very low, a slight catalytic effect considered to be an effect of the medium has been observed.
- Casado, Julio,Lorenzo, Francisco Manuel,Mosquera, Manuel,Prieto, Maria Flor Rodriguez
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p. 136 - 138
(2007/10/02)
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- Hydrolysis, Nitrosyl Exchange, and Synthesis of Alkyl Nitrites
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Alkyl nitrites undergo relatively slow hydrolysis in phosphate-buffered aqueous media under neutral conditions with small but significant dependence of reactivity on structure.However, rapid nitrosyl exchange with alcohols is observed, and equilibrium constants for this transformation exhibit remarkable correlation with equilibrium constants for nitrosyl exchange of alcohols with nitrosyl chloride and with nitrous acid. tert-Butyl nitrite has the greatest driving force for nitrosyl transfer among the 12 alkyl nitrites examined, and this capability is used for the synthesis of alkyl nitrites derived from steroidal alcohols and of alkyl thionitrites.
- Doyle, Michael P.,Terpstra, Jan W.,Pickering, Ruth A.,LePoire, Diane M.
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p. 3379 - 3382
(2007/10/02)
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- Kinetics and Mechanism of the Nitrosation of Alcohols, Carbohydrates, and a Thiol
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Rate constants have been determined by stopped-flow spectrometry for the nitrosation in water of the following alcohols and carbohydrates: methanol, ethanol, propan-l-ol, propan-2-ol, ethane-1,2-diol, propane-1,2,3-triol, mannitol, sucrose, and glucose, in some cases at 25o and others at 0o.In all cases the reactions were reversible, forming equilibrium concentrations of the corresponding alkyl nitrites.With a large excess of the alcohol present over the total nitrous acid concentration, the observed first order rate constants increased linearly with the alcohol concentration, and from the slope and the intercept the rate constants of the forward and reverse reactions were obtained.Both reactions were acid catalysed and also catalysed by chloride and bromide ion.The forward reaction is interpreted as one involving O-nitrosation by H2NO2+ (or NO+), NOCl or NOBr.For methanol, rate constants for attack by nitrosyl chloride and by nitrosyl bromide were 2.1 x 105 mol-1s-1, respectively.There was little difference between the rate constants for chloride ion and bromide ion attack for the reverse reaction, suggesting that the reactions for attack on the protonated alkyl nitrite are very rapid, possibly approaching the diffusion-controlled limit.There was a decrease in the overall equilibrium constant for the non-halide ion-catalysed pathway, along the series MeOH, EtOH, PriOH, and ButOH; the value for the latter was so small as to make the quantitative determination of the rate constants impossible by this method.This decrease was due almost entirely to a decreasing value for the forward rate constant along the series, which implies that a steric effect is operational.All the carbohydrates studied had very similar equilibrium constants of ca. 1.5.In contrast the nitrosation of N-acetylpenicillamine gave the thionitrite quantitatively at low acidities.Again the reaction was acid- and halide (and thiocyanate) ion-catalysed and the reactivity sequence NOCl > NOBr > NOSCN was established.For both the alcohols and the thiol, the forward rate constants are well below the diffusion controlled values and are several powers of ten less than the corresponding values for the reactions of aniline.The results are discussed in terms of the nucleophilicities of the oxygen and sulphur sites for the forward reaction and in terms of the protonation equilibria of the nitrites and thionitrite for the reverse reaction.
- Aldred, S. Elaine,Williams. D. Lyn H.,Garley, Michael
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p. 777 - 782
(2007/10/02)
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- Gas-phase Reaction of Hydroxyl Radicals with Alkyl Nitrite Vapors in H2O2+NO2+CO Mixtures
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The yields of CO2 from the chain reaction in H2O2+NO2+CO+alkyl nitrite mixtures, in wich OH is the chain carrier and alkyl nitrites induce a chain termination step, have been used to deduce rate constants (ks) for OH attack on alkyl nitrites (RONO) in the vapour phase at ambient temperatures.Values of ks/E9 dm3 mol-1 s-1 as a function of R were determined as follows: 0.71 +/-0.12 (CH3), 1.15+/-0.23 (C2H5), 1.56+/-0.32 (n-C3H7), 3.41+/-1.48 (n-C4H9), 3.89+/-0.58 (sec-C4H9), 3.47+/-0.52 (i-C4H9), 0.91+/-0.15 (t-C4H9), all based on ks=(1.63+/-0.16)E9 dm3 mol-1 s-1 for OH +n-butane.The small increase in ks from R=CH3 to t-4H9 is considered to support a recent postulate that both H-abstraction and NO-abstraction pathways are operative, at least for R=CH3.Under typical, sunlit urban atmosphere conditions it is deduced that OH attack on alkyl nitrites is a minor removal process compared to their photodissociative destruction.
- Audley, Gary J.,Baulch, Donald L.,Campbell, Ian M.,Waters, Des J.,Watling, Gillian
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p. 611 - 618
(2007/10/02)
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