Diisopropanolamine Research Articles

Development of New Excess Sludge Reduction System with Combination of Alkaline Solubilization and High Speed Mixing

To develop a compact and low cost excess sludge reduction system, alkaline treatments were carried out using sludge from a petroleum refinery. Alkaline treatment with a concentration of 0.025-0.05 mol/L solubilized about 30% of the sludge after 1 h. Alkaline wastes from petroleum refinery such as sodium sulfide, sodium hydrosulfide, and diisopropanol amine could be used to solubilize about 10-30% of the sludge. Combination of alkaline solubilization (0.05 mol/L NaOH) and high speed mixing achieved about 50% solubilization rate after 1 h at 25°C. Application of this system in a petroleum refinery (600 m3 aeration vessel and 450 m3 sedimentation vessel, 3 m3 solubilization vessel) resulted in average solubilization rate of 44% and reduction rate of sludge of 47% during 64 days operation. Return of alkaline solubilized broth into the aeration vessel did not affect the treatment. In 40 L bench scale experiments, solubilization rate of 59% and sludge reduction rate of 94% were obtained when the amount of sludge solubilization was increased up to 2-3 times of excess sludge produced under the standard activated sludge treatment without the solubilization process.

10.2478/s11814-009-0185-8

Modeling of solubility of acid gases in aqueous alkanolamine solutions is essential for design of an absorber for natural gas sweetening. In this work an apparatus similar to the device of Hayduk and Chen (1970), which was improved by Pahlavanzadeh and Motahhari (1997), for the measurement of gas solubility data by the synthetic method was used. The solubility of hydrogen sulfide in aqueous diisopropanolamine (DIPA) solution in mass concentration range of 30–40% for 101,325 Pa pressure and for temperature ranging from 313–343 K was reported. The obtained experimental solubility data of H2S in aqueous solutions of DIPA was used to predict the different interaction parameters of modified UNIQUAC-NRF model for calculating the activity coefficients. For nonideality of species in liquid phase, the UNIQUAC-NRF equation with ion-pair approach was applied. For long range interaction, the Pitzer-Debye-Huckel term was used.

Equilibrium solubility of CO 2 in aqueous solutions of 1-amino-2-propanol as function of concentration, temperature, and pressure

Using a dynamic method with recirculation of the vapour phase, experimental values for the gas solubility of carbon dioxide in aqueous solutions of 1-amino-2-propanol (MIPA) were measured at T = (313.15 and 393.15) K, over the pressure range of (0.2 to 2436.4) kPa. The concentrations of the studied aqueous MIPA solutions were (0.20, 0.30, 0.40, and 0.50) mass fraction. The results of gas solubility are given as the partial pressure of CO 2, p CO 2 , against its mole ratio, α CO 2 (mol CO 2 · mol −1 MIPA), and its mole fraction, x CO 2 . It is observed that the solubility of CO 2 increases as the concentration of MIPA in solution increases, at a given temperature throughout the pressure range considered; also the solubility values increase, under constant temperature, as the pressure increases in the studied concentration range of MIPA. The physicochemical model of Kent and Eisenberg was used to correlate simultaneously all the experimental results of the solubility of CO 2 in the studied aqueous solutions of MIPA. The model correlates satisfactorily the experimental results. The deviation for pressure was 96.9 kPa using 62 experimental solubility points. The solubility results of carbon dioxide presented in this work are compared with those reported in the literature for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and N-methyldiethanolamine (MDEA) and it is possible to conclude that the aqueous solutions of MIPA are an excellent alternative to use in gas purification processes, since the magnitude of the solubility results of MIPA solutions was found to be similar to that in aqueous solutions of MDEA, better than DEA and DIPA.

Thermodynamics of aqueous solutions of methyldiethanolamine and diisopropanolamine

The vapour–liquid equilibrium (VLE) of the systems of water + methyldiethanolamine (MDEA) and water + diisopropanolamine (DIPA) was measured at several temperatures with a static total pressure apparatus. The solid–liquid equilibrium (SLE) of the same systems was measured at low amine concentrations by means of two experimental methods: a visual method and a Differential Scanning Calorimeter (DSC). The activity coefficients of water + MDEA were modelled with the NRTL equations. The model parameters were regressed from VLE, SLE and excess enthalpy data from this work and from the literature. The model developed in this work was compared with models found in the literature. The NRTL equations were also used to model the activity coefficients of the system of water + DIPA. The model parameters were fitted from the VLE and SLE data measured in this work.

Synthesis, characterisation and utilisation of hyperbranched poly (ester‐amide) for the removal of some anionic dyestuffs from their aqueous solutions

PurposeThe purpose of this paper is to show how to remove some dyestuffs, as pollutants, from their aqueous solutions.Design/methodology/approachTo achieve the goal, a water soluble hyperbranched poly (ester‐amide) (HBP) was synthesised using the melt polycondensation method by the reaction of maleic anhydride (MA) and diisopropanol amine (DIPA) at 140°C at a molar ratio of 1:1.3 MA: DIPA, respectively. This HBP was incorporated in the preparation of an effective microcrystalline cellulose (MCC)/dimethyloldihydroxyethylene urea (DMDHEU)/HBP adduct by crosslinking HBP with DMDHEU in presence of MCC. Furthermore, the prepared adduct was characterised by investigation its infra red and then utilised in the removal of three anionic dyestuffs from aqueous solutions, namely Irgalan Blau 3GL (an acid dye), SIRIUS Blau S‐BRR (a direct dye) and Levafix Brill Orange P‐GR (a hydrolysed reactive dye).FindingsThe results obtained revealed that the optimum conditions for preparing MCC/DMDHEU/HBP adduct are [HBP], 90 g/l; [DMDHEU], 200 g/l; LR, 1/3.3; [NC4LH], 20 g/l; a time of 30 min and a temperature of 160°C. Moreover, the results also showed that the extent of removal of such dyestuffs from their aqueous solutions by the prepared adduct follows the order: reactive dye>acid dye>direct dye, it is more pronounced at lower than at higher pH values and the removal of each dye by that adduct follows a first‐order reaction.Research limitations/implicationsOther substrates such as chitosan can be used to prepare more effective adducts.Practical implicationsHyperbranched polymers can be used effectively to prepare ion exchangers capable of removing the pollutants of dyestuffs from their aqueous solutions.Originality/valueThe aforementioned prepared HBP is a novel hyperbranched polymer and could be applied in the removal of many other pollutants.

Solubility of carbon dioxide in aqueous solutions of diisopropanolamine and methyldiethanolamine

The solubility of carbon dioxide in aqueous solutions of alkanolamines was measured by means of two experimental methods. The solubility of carbon dioxide was measured at 298 K with a static total pressure apparatus in solutions of water + diisopropanolamine (DIPA) having mass fraction of DIPA equal to 10.1%, 11.0% and 33.9%. The density of the water + DIPA solution was measured continuously during the experiments to investigate the changes in density introduced by the absorption of carbon dioxide. A correlation for the density of CO 2-loaded aqueous solutions of DIPA is presented. The solubility of CO 2 in aqueous solutions of methyldiethanolamine (MDEA) and of DIPA was measured at atmospheric pressure with a bubbling equipment at various temperatures between 298 and 353 K. The mass fraction of MDEA in the solutions was 10%, 20% and 49% and the mass fraction of DIPA was 10%, 20%, 25% and 35%.

Absorption of carbon dioxide into diisopropanolamine solutions of polar organic solvents

The chemical absorption rate of carbon dioxide with diisopropanolamine (DIPA) was measured in such non-aqueous solvents as methanol, ethanol, n-propanol, n-butanol, ethylene glycol, propylene glycol, and propylene carbonate, and aqueous solvent at 298 K and 101.3 kPa using a semi-batch stirred tank with a planar of gas–liquid interface. The pseudo-first-order reaction rate constant obtained from the measured rate of absorption was used to obtain the elementary reaction rate constants in complicated reactions represented by zwitterion mechanism and the order of overall reaction of CO 2 with amine. The enhancement factor of carbon dioxide at a low concentration of DIPA was obtained using the reaction rate constants obtained under the condition of a pseudo-first-order, fast reaction regime. Correlation between the elementary reaction rate constant and the solubility parameter of the solvent is presented.

A novel transdermal patch incorporating meloxicam: In vitro and in vivo characterization

A monolithic drug-in-adhesive (MDIA) type patch containing meloxicam (MX) was designed with an acrylic adhesive, a solubility modulator increasing MX solubility, and enhancers. MDIA patches having one adhesive layer between the backing and the release liner give high productivity and improve patient compliance. The biggest problem to prepare MDIA patch including MX was poor solubility of MX. In this research, solubility modulators to increase solubility of MX and acrylic adhesives and skin permeation enhancers were investigated through solubility tests, in vitro skin permeation tests, and stability tests. Consequently, the composition of sodium methoxide (SM), an acrylic adhesive containing poly(vinyl pyrrolidone) blocks (MAS683), polyoxyethylene cetylether (BC-2), and diisopropanolamine (DIPA) made it possible for MX to be contained in an adhesive layer at a concentration of as much as 15 wt% without MX crystal and with high skin permeation over 400 μG/cm 2. Finally, the patch formulation containing MX (MX-patch) selected through our in vitro study was characterized by in vivo using an animal study to acquire pharmacokinetic (PK) parameters and to confirm the anti-inflammatory efficacy of MX-patch. In the animal study, MX-patch was compared with a commercially available piroxicam patch (PX-patch). The amount of MX delivered from MX-patch to the skin surface was believed to be higher than the amount of MX diffused from the skin tissue to circulatory system because the plasma concentration of MX continuously increased up to 32 h, the end time of PK study, although the patch samples were detached at 24 h. PX-patch produced a C max at 8 h. MX-patch showed better significant efficacy than PX-patch in adjuvant arthritis model.

Measurement and modeling of solubility of H2S in aqueous diisopropanolamine solution

Modeling of solubility of acid gases in aqueous alkanolamine solutions is essential for design of an ab- sorber for natural gas sweetening. In this work an apparatus similar to the device of Hayduk and Chen (1970), which was improved by Pahlavanzadeh and Motahhari (1997), for the measurement of gas solubility data by the synthetic method was used. The solubility of hydrogen sulfide in aqueous diisopropanolamine (DIPA) solution in mass con- centration range of 30-40% for 101,325 Pa pressure and for temperature ranging from 313-343 K was reported. The obtained experimental solubility data of H2S in aqueous solutions of DIPA was used to predict the different interaction parameters of modified UNIQUAC-NRF model for calculating the activity coefficients. For nonideality of species in liquid phase, the UNIQUAC-NRF equation with ion-pair approach was applied. For long range interaction, the Pitzer- Debye-Huckel term was used.

Dissociation constants and thermodynamic properties of alkanolamines

The dissociation constants of protonated 2-amino-2-ethyl-1,3-propanediol (AEPD), 2-amino-2-methyl-1-propanol (AMP), diethylmonoethanolamine (DEMEA), diisopropanolamine (DIPA), dimethylmonoethanolamine (DMMEA), monoethanolamine (MEA), 1-amino-2-propanol (MIPA), and methylmonoethanolamine (MMEA) have been determined by electromotive force measurements from (293 to 353) K. The experimental results and derived values of the standard state thermodynamic properties are reported.

Formula omitted] capture in HFMM contactor with typical amine solutions: A numerical analysis

The absorption behavior of carbon dioxide using a hollow fiber membrane contactor was numerically analyzed. In this analysis, the absorbent solution is flowing in the inner side of the fiber bore and the pure gas in the shell and the module operated in a non-wetted mode. The derived coupled non-linear governing partial differential equations were numerically solved by the orthogonal collocation technique. Three typical alkanolamines of industrial use, the diethanolamine (DEA), the 2-amino-2-methyl-1-propanol (AMP), and the diisopropanolamine (DIPA) were used as absorbents in this work. One important feature of this study was building the mathematical model based on the two-step carbamate formation model instead of the one-step model used by previous investigators. The outlet absorbed dioxide concentration was simulated and studied with respect to the liquid velocity, initial amine concentration and external mass transfer coefficient. The analysis includes the effects of the diameter and length of the fibers on the liquid outlet gas concentration as a function of the liquid velocity in the fiber. Simulation results show that AMP solutions present a much higher absorption capacity compared to the other two amine solutions.

Effect of diisopropanolamine upon choline uptake and phospholipid synthesis in Chinese hamster ovary cells

Aminoalcohols differ in mammalian toxicity at least in part based upon their ability to alter the metabolism of phospholipids and to cause depletion of the essential nutrient choline in animals. This study examined the incorporation of diisopropanolamine (DIPA) into phospholipids (PLs) and effects of DIPA upon choline uptake and phospholipid synthesis in Chinese hamster ovary (CHO) cells. Results were compared to those of a related secondary alcohol amine, diethanolamine (DEA), whose systemic toxicity is closely associated with its metabolic incorporation into PLs and depletion of choline pools. DIPA caused a dose-related inhibition of 3H-choline uptake by CHO cells that was approximately 3–4 fold less potent, based upon an IC50, than that reported for DEA. DIPA, in contrast to DEA, did not cause changes in the synthesis rates of 33P-phosphatidylethanolamine, 33P-phosphatidylcholine or 33P-sphingomyelin at either non-toxic or moderately toxic concentrations. Only approximately 0.004%, of administered 14C-DIPA was metabolically incorporated into PLs, over 30-fold less than the incorporation of 14C-DEA under similar conditions. Overall, these data and previous pharmacokinetic and toxicity data obtained in vivo suggests that DIPA is distinct from DEA and lacks significant choline and PL metabolism related toxicity in animals.

Preparation, characterization and modification of hyperbranched polyester-amide with core molecules

The synthesis of hyperbranched polyester-amides based on pentaerythritol (PETL) as a core molecule and AB 2 monomer containing one carboxylic group and two hydroxylic groups using core-dilution/slow monomer addition strategy have been studied. The AB 2 monomer was prepared by diisopropanolamine (DIPA) and cis-1,2-clyclohexane-dicarboxylic anhydride (HHPA). Two types of hyperbranched polyester-amide (1G-HP, 2G-HP) were obtained with the molar ratio of AB 2 monomer and pentaerythritol (PETL) was 4 and 8, respectively. The structures of products were characterized by IR, 13C NMR, GPC and viscosity measurement. It was shown that the hyperbranched polymers prepared had high degree of branching (DB) and narrow molecular weight distribution. As for 1G-HP and 2G-HP, the intrinsic viscosity [ η] was 4.32 ml/g and 5.29 ml/g, and the viscometric radius R V was1.28 nm and 1.67 nm, respectively. The results of viscosity measurement indicated that the structures of 1G-HP and 2G-HP were compacted and had a spherical conformation. In addition, the reactions of hydroxyl end-groups with polyethylene glycol monomethyl ether (mPEG550) and glycidyl methacrylate (GMA) were conducted to provide amphiphilic and UV-curable properties of resulting polymers. The properties of the modified hyperbranched polyester-amide were also investigated initially.

Pharmacokinetics and bioavailability of diisopropanolamine (DIPA) in rats following intravenous or dermal application

This study was conducted to determine the relative dermal bioavailability (absorption), distribution, metabolism, and excretion (ADME) of diisopropanolamine (DIPA), an alcohol amine used in a number of industrial and personal care products. Groups of 4 female Fischer 344 rats received either a single bolus i.v. dose of 19.0 mg/kg 14C-DIPA in water or a dermal application of 19.5 mg/kg 14C-DIPA in acetone to an area of 1 cm 2 on the back and covered with a bandage. Time-course blood and excreta were collected and radioactivity determined. Urine was analyzed for DIPA and monoisopropanolamine (MIPA). Following i.v. administration, DIPA was rapidly cleared from the plasma and excreted into urine in a biexponential manner ( t 1/2 α , 0.4 h; t 1/2 β , 2.9 h). The levels of radioactivity in plasma dropped below the limit of detection 12 h post-dosing. A total of 97 ± 4% of the dose was actively excreted in urine by kidney, most (∼71%) within 6 h of dosing, virtually all as parent compound; renal clearance exceeded the glomerular filtration rate. Following dermal application, ∼20% of the dose was absorbed in 48 h with the steady-state penetration rate of ∼0.2%/h. Most (14.4%) of the applied radioactivity was excreted in urine at a relatively constant rate due to the presence of large amount of the 14C-DIPA at the application site. Fecal elimination was <0.2% of the dose. The absorbed DIPA did not accumulate in tissues; only ∼0.1% of the administered dose was found in liver and kidney. The absolute systemic dermal bioavailability (dose corrected AUC dermal/AUC i.v.) of 14C-DIPA was 12%. The ADME of DIPA contrasts that of its diethanol analogue, diethanolamine, which displays a broad spectrum of toxicity in rats and mice. Toxicologically significant concentrations of DIPA are unlikely to be achieved in the systemic circulation and/or tissues as a result of repeated dermal application of products containing DIPA due to slow absorption from the skin, rapid unchanged elimination in urine, and majority of the products contain ⩽1% DIPA.

Repeated dose toxicity and developmental toxicity of diisopropanolamine to rats

The repeated dose oral and dermal toxicity of diisopropanolamine (DIPA) was evaluated in rats and compared to the reported toxicity of the related secondary alcohol amine, diethanolamine (DEA). Fischer 344/DuCrl rats were given up to 750 mg /kg/day by dermal application, 5 days/week, for 4 weeks; or up to 1000 mg DIPA/kg/day by drinking water for 13 weeks to evaluate potential toxic effects. Time-mated female CRL:CD(SD) rats were given up to 1000 mg/kg/day by gavage on gestation days (GD) 6–20 for evaluation of maternal and fetal effects. In the dermal toxicity study, no adverse treatment-related in-life effects other than mild irritation at the site of dermal application at ⩾500 mg/kg/day were observed. There were no systemic effects in rats given up to 750 mg/kg/day. In the subchronic oral toxicity study, the most significant effects were an increase in absolute and relative kidney weights, unaccompanied by histopathologic changes, at ⩾500 mg/kg/day DIPA. The latter effect was ameliorated following a 4-week recovery period. In the developmental toxicity study, there were no maternal or developmental effects at any dose level evaluated. The toxicity of DIPA contrasts with that of DEA which has been shown to affect a number of organ systems when repeatedly administered orally or dermally at similar or lower dosages.

Solubility of Carbon Dioxide in Aqueous Mixtures of DIPA + MDEA and DIPA + PZ Solutions

The new data for solubility of carbon dioxide are reported in mixed solvents containing (2.00 to 2.50 kmol/m 3 ) Diisopropanolamine (DIPA), (0.86 to 1.36) kmol/m 3 ) Piperazine (PZ), (0.86 to 1.36) kmol/m 3 ) N-methyldiethanolamine (MDEA) and water, keeping the amine total concentration in the aqueous solution at 3.36 kmol/m 3 for temperatures from (40 to 70) °C and CO 2 partial pressures in the range of (30 to 5000) kPa. Experimental solubility results were represented by the mole ratio of CO 2 per total amine in the liquid mixture. Results show that at a given partial pressure of CO 2 the solubility of CO 2 in the DIPA solutions is lower than solubility in MDEA or PZ solutions and the CO 2 loading increased with decreasing temperature and increasing CO 2 partial pressure.

Absorption of Carbon Dioxide at High Partial Pressures in Aqueous Solutions of Di-isopropanolamine

The process of carbon dioxide (CO2) absorption is analyzed at high partial pressures, in aqueous solutions of di-isopropanolamine (DIPA). The experiments were performed in a stirred tank reactor with a planar and known interfacial area. The variables considered were the DIPA concentration (within a range of 0.0413−1.90 kmol/m3) and the temperature (within an interval of 288−313 K). From the results, we deduce that the absorption process occurs in a moderately fast reaction regime with a second-order kinetic for the amine and a first-order kinetic for the CO2. The reaction rate constant for each process was calculated and correlated as a function of temperature.

Uptake of sulfolane and diisopropanolamine (DIPA) by cattails ( Typha latifolia)

Sulfolane (tetrahydrothiophene 1,1-dioxide, C 4H 8O 2S) and diisopropanolamine (DIPA) are highly water-soluble organic compounds used in the Sulfinol™ process to remove hydrogen sulfide from natural gas and have been found in samples of wetland vegetation collected near a sour gas processing facility in Alberta, Canada. Concentrations within individual plants and between plants at different locations within the wetland varied greatly but were generally higher than expected, based on exposure concentrations and plant uptake predictions using octanol/water partition coefficients. To better understand the uptake of these highly water-soluble compounds by wetland plants and to substantiate the field findings, the uptake of sulfolane and DIPA by cattails ( Typha latifolia) was investigated in a greenhouse microcosm study. Cattails were grown hydroponically in aqueous solutions containing sulfolane and DIPA for a period of 50 days. Non-planted and non-planted poisoned hydroponic systems were run simultaneously as controls. Sulfolane and DIPA concentrations in the hydroponic solution and plant tissues were monitored throughout the study. Uptake and translocation of sulfolane and DIPA by cattails were found to be a function of exposure concentration and water transpired. However, the neutral sulfolane was translocated into the foliar portion of the cattails to a significantly greater extent than the protonated DIPA. Sulfolane concentrations were consistently greatest in the leaf tips with concentrations as high as 33,000 mg/kg dry weight for the 200 mg/L exposure. DIPA leaf concentrations were more uniform but much lower than sulfolane. The highest DIPA concentration observed was 1014 mg/kg dry weight for the 100 mg/L exposure. The average leaf to root tissue concentration ratio for sulfolane was 53 (152 for leaf tips), while for DIPA the ratio was 0.6. Normalizing the leaf concentration in each system to the amount of water transpired during exposure and dividing it by the average exposure concentration yielded approximate transpiration stream concentration factors (TSCF) that ranged from 0.1 (entire leaf) to 0.9 (leaf tip) for sulfolane and < 0.01 to 0.02 for DIPA. Overall, the laboratory uptake trends matched those observed in the limited field sampling and suggest that the uptake of non-ionizable, highly water-soluble organics such as sulfolane may not be well predicted using existing relationships between TSCF and log K ow. In addition, the relatively high concentrations observed in the foliar tissue suggest that wetland plants could play an important role in the natural attenuation of sulfolane, provided the sulfolane is not released by the plants during winter dormancy.

Determination of alkanolamines in cattails (Typha latifolia) utilizing electrospray ionization with selected reaction monitoring and ion-exchange chromatography.

Selected reaction monitoring (SRM) with electrospray ionization was used as a specific detection technique for the analysis of alkanolamines in plant tissue extracts. Ion-exchange chromatography was used as the method of separation. Quantification was based on monitoring the loss of either H2O or 2(H2O) from the protonated molecule [M+H]+. The method provided increased selectivity for all analytes and better detection limits for three of the six analytes investigated compared with an earlier method using selected ion monitoring with liquid chromatography. Instrumental detection limits ranged from 6-300 pg injected for monoethanolamine (MEA), monoisopropanolamine (MIPA), diethanolamine (DEA), methyldiethanolamine (MDEA), diisopropanolamine (DIPA), and triethanolamine (TEA). Method robustness and selectivity were demonstrated by the determination of DIPA and a known transformation product MIPA in over 35 plant extract samples derived from a laboratory study of plant uptake mechanisms.

Development of DSM's hybrane® hyperbranched polyesteramides

AbstractThe development of DSM's Hybrane® hyperbranched poly(ester amides) is described. The monomer (1) for the hyperbranched polyester is obtained from the reaction of a cyclic anhydride with diisopropanol amine, yielding a tertiairy amide with one COOH and two OH groups. Polycondensation takes place via an oxazolinium intermediate in bulk at relatively mild conditions in the absence of catalyst. The reaction has been scaled up to ton scale. By varying and combining anhydrides, and modification with several types of end groups, a large variety of structures with concomitant properties and industrial applications has been realized. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3110–3115, 2004