Polish Journal of Chemical Technology (v.12, #2)
Oxidation of hexafluoropropylene to hexafluoropropylene oxide using oxygen
by Monika Łągiewczyk; Zbigniew Czech; (pp. 1-3).
A method for pressure oxidation of hexafluoropropylene (HFP) to hexafluoropropylene oxide (HFPO), using oxygen, is presented. Oxidation was achieved in a batch-fed reactor at temperature range between 130 to 170°C. The influence of temperature and kind of solvents, such as 1,2,2-trichloro-1,1,2-trifluoroethane (CFC-113) and carbon tetrachloride on the yield of HFPO and the course of oxidation was investigated in preliminary studies. The maximum HFPO yield of approximately 83% was noticed.
Keywords: hexafluoropropylene; hexafluoropropylene oxide; epoxidation
Wastefree purification method for potassium brine used in industrial electrochemical processes
by Bożenna Pisarska; Mariusz Nowak; (pp. 4-8).
A new concept is presented for purifying potassium brine (KCl solution) obtained from technical-grade potassium chloride. This concept is based on the hydroxide/carbonate method of removing ions of alkaline earth metals and on separating SO42- ions by means of zirconyl anion exchanger. The purification process provides the following products: purified potassium brine suitable for the manufacture of KClO3 or for further purification and subsequent manufacture of KOH, Cl2 and H2 using membrane cell technology, magnesium and potassium containing agricultural lime (chalk) suitable for neutralizing soil acidity and enriching soil with magnesium and potassium, and technical-grade potassium sulphate containing 99.0 to 99.8% K2SO4.
Keywords: potassium brine; purification processes; wastefree processes
The effect of medium composition on the production of sophorolipids and the tensiometric properties by Starmerella bombicola MTCC 1910
by Nagarajan Vedaraman; Narayana Murthy Venkatesh; (pp. 9-13).
Starmerella bombicola a teleomorph of Candida bombicola is capable of producing extracellular secondary metabolites known as sophorolipids. In the present work the performance of Starmerella in producing sophorolipids, with standard medium ingredients glucose, sunflower oil, yeast extract and urea was studied. The quantities of different medium ingredients were optimized to maximize the production of sophorolipids. Variation in tensiometric properties like surface tension and interfacial tension during the incubation period were also reported. The optimized mixed substrate composition was found to be 200 g/l, containing equal amounts of glucose and sunflower oil, 4 g/l of yeast extract and 0.6 g/l of urea. With the optimized substrate composition 38.6 g/l of sophorolipids was obtained. The minimum surface tension produced by the culture free cell broth was 36.2 mN/m. Increasing the temperature from 25°C to 35°C has shown adverse effects on sophorolipids production.
Keywords: Biosurfactant; Lipidic substrates; Optimization; SophorolipidsStarmerella bombicolaTensiometric properties
Starch graft copolymers as superabsorbents obtained via reactive extrusion processing
by Magdalena Zdanowicz; Beata Schmidt; Tadeusz Spychaj; (pp. 14-17).
Starch graft copolymers have been obtained via grafting of acrylic monomers i.e. acrylamide (AAm) and acrylic acid (AA) during the reactive extrusion processes. 2,2'-azobis (2-methylpropionamidine) dihydrochloride (AAPH) was used as a radical initiator and N'N-methylenebisacrylamide (MBA), mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (trade name PETIA) and alkoxylated pentaerithritol acrylate (trade name Ebecryl 40) were applied as acrylic crosslinkers. The obtained materials were characterized by FTIR and their water sorption properties investigated using swelling (vol. %) and sorption (wt. %) tests. Sorption of water into these graft copolymer samples reached values of ca. 6-13 g of water per g of dry materials. It was also found that water sorption values were dependent on ratio of AAm and AA as well as on a type of the applied crosslinking agent.
Keywords: superabsorbents; acrylamide; acrylic acid; starch modification; acrylic crosslinkers; reactive extrusion; starch graft copolymers
Parametric studies and simulation of PSA process for oxygen production from air
by Ankit K. Beeyani; Kailash Singh; Raj K. Vyas; Shashi Kumar; Surendra Kumar; (pp. 18-28).
A numerical simulation and parametric studies for the separation of air using 5A zeolite for the production of oxygen are presented for a basic two bed pressure swing adsorption (PSA) process. The simulation is based on an in-house program ‘PSASOL’ developed in MATLABR. The transient process of PSA has been described by a set of partial differential equations, which were solved using a finite difference method. Simulation results have been validated with the experimental data from literature.
Based on the simulation results, an optimal set of operational parameter values has been obtained for the PSA bed. The values of the optimal parameters, viz. adsorption pressure, cycle time, feed rate, and product rate have been found to be 2.5 atm, 150 s, 15 cm3/s, and 2.55 cm3/s, respectively. For the optimal conditions, purity of 95.45% and recovery of 77.3% have been achieved. It has also been found that a longer tubular unit with the length to diameter (L/D) ratio of 10.5 is advantageous. The estimated pressure drop across the bed has been found to be negligible. Power consumption and productivity have also been computed.
Keywords: Pressure swing adsorption; mathematical model; simulation; oxygen production; MATLAB; Zeolite 5A
Isolation of 1,2-epoxybutane-3-ol and 2,3-epoxybutane-1-ol from post-reaction mixtures
by Agnieszka Wróblewska; Joanna Wajzberg-Prokowska; Ewelina Ławro; Eugeniusz Milchert; (pp. 29-32).
Attempts were made to isolate 1,2-epoxybutane-3-ol and 2,3-epoxybutane-1-ol from post-reaction mixtures left after the epoxidation of 1-butene-3-ol and 2-butene-1-ol with hydrogen peroxide by thin film distillation. From the raw mixture containing about 8.3 wt% of the epoxide at the first stage the concentration of epoxide is increased to 32 wt%. At the second stage of distillation the epoxide fraction is concentrated to about 76 wt%. After the third stage of thin film distillation the epoxide fraction of 99.6% purity can be obtained. The concentration of this fraction by azeotropic distillation with n-propanol as an azeotropic agent permits obtaining epoxide of 99.6 wt% purity.
Keywords: thin film distillation; isolation of epoxides
Acidic ionic liquids based on phosphonium chloride and metal chlorides-recyclable media and catalysts in the Diels-Alder reaction
by Ewa Janus; (pp. 33-37).
Acidic ionic liquids based on trihexyltetradecylphosphonium chloride-P184.108.40.206 Cl and six different metal chlorides (YCl3, YbCl3, MgCl2, ZnCl2, CuCl2, InCl3) were prepared. The molar fraction of metal chloride (XMClx) used for the formation of acidic ionic liquids with P220.127.116.11 Cl was changed in the range from 0.3 to 0.5. The high catalytic activity in the Diels-Alder reaction of cyclopentadiene and various αβ-unsaturated carbonyl compounds showed ionic liquids at XMClx≤0.4. In general, the highest product yields and endo:exo ratios were achieved in the acidic ionic liquids formed from MgCl2, YCl3 and YbCl3. Thermogravimetric analysis suggested that the prepared ionic liquids were thermally stable up to nearly 400°C. Additionally, they could be reused with only little loss of catalytic activity after the 4th recycle.
Keywords: acidic ionic liquids; Diels-Alder reaction; metal chlorides
Influence of the coating process parameters on the quality of PUR/PVP hydrogel coatings for PVC medical devices
by Anna E. Paradowska; Katarzyna A. Kaźmierska; Tomasz Ciach; (pp. 38-45).
To decrease friction factor and enhance the biocompatibility of medical devices manufactured from poly(vinyl chloride), PVC, the surface modification with wear resistant polyurethane/polyvinylpyrrolidone (PUR/PVP) hydrogel coating can be applied. In the present work substrates were dip-coated with PVP and PUR solutions and thermally cured. The variable process parameters were: solvent system; concentration of polymers (1, 2 or 3% w/v); coating baths temperature (22, 38 and 55°C); drying temperature (32, 50 and 67°C); length of break between process steps (5, 30 and 90 s); and solutions storage time (up to 72 hrs). The quality of coatings was determined by friction coefficients against porcine aorta, weights of the deposited layer and the swelling capacity. The solvent system and polymers concentration were crucial factors. The increased temperature of coating solutions caused increased deposition but decreased durability. The most lubricious samples were dried in 50°C. Coatings from the solutions prepared 24h prior to use had better properties than those from fresh solutions.
Keywords: Hydrogel coatings; dip-coating; poly(vinyl chloride); polyvinylpyrrolidone
Synthesis of inorganic oxide composites with the use of postgalvanic waste solutions of copper(II) sulfate
by Anna Modrzejewska-Sikorska; Filip Ciesielczyk; Teofil Jesionowski; (pp. 46-51).
The study was undertaken to obtain an oxide composite (inorganic colourful pigment) in the method based on the use of postgalvanic waste solution of copper(II) sulfate. The conditions of the process of precipitation of synthetic CuOSiO2 were optimised by checking the effect of the concentration and the volume ratio of the reagents and the temperature on the physico-chemical parameters of the final product. The oxide composite obtained in the optimum conditions was characterised by high refinement of particles and large specific surface area BET of 326 m2/g.
Keywords: oxide composite CuO·SiO2waste solution of copper(II) sulfate; precipitation; particle size distribution; surface area; colorimetric characteristics
Physico-chemical and dispersive characterisation of magnesium oxides precipitated from the Mg(NO3)2 and MgSO4 solutions
by Agnieszka Pilarska; Dominik Paukszta; Filip Ciesielczyk; Teofil Jesionowski; (pp. 52-56).
An attempt was made to synthesise magnesium oxide of a high degree of dispersion permitting its use as adsorbent or catalyst. The synthesis method proposed was precipitation with the use of magnesium nitrate or magnesium sulfate. The influence of temperature, the mode and the rate of dosing, the concentration and the ratio of the reagents on the properties of the final product was analysed. Magnesium oxides were obtained by thermal decomposition of magnesium hydroxides and subjected to thorough analysis. The results permitted selection of the reaction systems ensuring synthesis of the final products of the desired properties.
Keywords: Magnesium oxide; Magnesium hydroxide; Precipitation; Particle size distribution and surface morphology; Adsorptive properties
Epoxidation of crotyl alcohol in the presence of titanium silicalite Ti-MWW catalyst — the new and friendly method of 2,3-epoxybutane-1-ol synthesis
by Agnieszka Wróblewska; Anna Fajdek; Eugeniusz Milchert; (pp. 57-61).
Epoxidation of crotyl alcohol (CA) with 30 wt% hydrogen peroxide over Ti-MWW catalyst has been studied with methanol as a solvent and at autogenic pressure. The influence of temperature in the range of 20-120°C, the molar ratio of CA/H2O2 1:1-5:1, methanol concentration 5-90 wt%, Ti-MWW catalyst concentration 0.0-5.0 wt% and the reaction time 5-300 min have been studied. The main product of CA epoxidation is 2,3-epoxybutane-1-ol (2,3EB1O), a compound with many applications.
Keywords: Ti-MWW; crotyl alcohol epoxidation; 2,3-epoxybutane-1-ol
Application of pyrolysis residue from waste materials in black coal flotation
by Peter Fečko; Alena Kašpárková; Eva Pertile; Vlastimil Kříž; Barbara Tora; Andrzej Jarosiński; Iva Janáková; (pp. 62-66).
The paper deals with the verification of the floatability of pyrolytic oils, which were obtained through the pyrolysis of waste, namely mixed plastics, tyres and waste rubber in combination with black coal from Lazy Mine, and classical collector Montanol 551 in black coal flotation. Black coal from ČSA OKD, a.s. coal preparation plant was used for flotation tests. The results imply that it is possible to produce collectors from waste materials which may be applied in the flotation of black coal. Next, the paper focused on the identification of a suitable combination of pyrolytic oils and Montanol 551 in order to reach ash content in the concentrate below 10%.
Keywords: flotation; black coal; pyrolysis; plastic waste; tyre and rubber
Assessment of the loss of mass, organic substance and combustible elements in the waste biodegradation process
by Agnieszka Generowicz; Małgorzata Olek; (pp. 67-69).
The paper presents the results of an analysis of the changes of the mass and amounts of organic substances and combustible elements in a biodegradation process. The prepared sample of organic waste constituted the material used for the tests. The composting process was being carried out for 9 weeks in field conditions. The samples for analyses were collected every 7 days. The content of a biodegradable fraction was determined according to the procedure described in the standard of PN - EN 15169: 2007 "Characterization of waste-Determination of loss on ignition in waste, sludge and sediments". Reduction of the mass of the organic waste during the composting process amounted to 35%. A significant content of organic fraction (about 60-70% after 9 weeks) remains in the composted waste; and the content of combustible elements is reduced (by about 30%.)
Keywords: biodegradable fraction; loss on ignition; composting