
Vesna Najdanovic-VisakLancaster University | LU · Department of Engineering
Vesna Najdanovic-Visak
PhD in Chemical Engineering
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85
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Introduction
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January 2013 - present
November 2005 - December 2012
November 2004 - December 2012
Publications
Publications (85)
The valorization of coffee waste has gained traction due to its potential to generate valuable products, lessen its impact on the environment, and promote sustainability. This review examines the diverse range of coffee waste, including pulp, husk, mucilage, and parchment from the upstream processing of green beans, as well as silverskin (coffee ch...
Supercapacitors hold promise for energy storage due to their exceptional power density and fast charge/discharge cycles. However, their performance hinges on the electrode material. Zeolitic imidazolate frameworks (ZIFs) are attractive options due to their tailorable structure and high surface area. But traditional ZIF synthesis relies on toxic sol...
Despite offering low-carbon and reliable energy, the utilization of nuclear energy is declining globally due to high upfront capital costs and longer returns on investments. Nuclear cogeneration of valuable chemicals from waste biomass-derived feedstocks could have beneficial impacts while harnessing the underutilized resource of ionizing energy. H...
Aqueous biphasic systems (ABS) based on ethyl lactate are novel green solvent systems that are biorenewable and biodegradable with the potential to replace currently used hazardous organic solvents. Models to correlate and predict binodal curves of these systems are crucial for the design of separation processes but are currently nonexistent. Here,...
The olive oil industry generates enormous amounts of olive stones each year, which have the potential to be used as a biofuel but have high oil content, which negatively impacts the combustion process. In addition, olive stones contain high-value antioxidants, and their exploitation can provide additional revenues for the biofuel industry.
In this...
One of the economical approaches to harvest mature microalgal biomass is through the attached growth system, in which the microalgal cells form attachment onto support material to facilitate its separation from the cultivation
medium. Hence, the spent coffee grounds (SCG) was employed as the support material, proffering alimentation, and platform f...
The performances of autotrophic and heterotrophic metabolisms in Chlorella vulgaris were assessed from various photoperiod regimes for the sustainable microalgal biodiesel production. Accordingly, the cellular biomass growth and lipid content in relation to the organic nutrient removals from municipal wastewater medium were evaluated from the vario...
Background & Aims
Elevated circulating uric acid concentrations have been linked to various cardio-metabolic diseases. Bolus consumption of a nucleotide-rich dietary protein source increases postprandial serum uric acid concentrations. We assessed the impact of twice-daily nucleotide-rich mixed-meal consumption for one week on postabsorptive serum...
The solubility ternary system was used to develop a hollow fiber-supported liquid membrane process for the extraction of gold (I) cyanide from electronics industry wastewater. Five kinds of diluents (p-xylene, cyclohexene, 1-dodecanol, n-heptane, and n-dodecane) were applied to the solubility of ternary systems (Aliquat336 + water + diluents) at 30...
Non-intermittent, low-carbon energy from nuclear or biofuels is integral to many strategies to achieve Carbon Budget Reduction targets. However, nuclear plants have high, upfront costs and biodiesel manufacture produces waste glycerol with few secondary uses. Combining these technologies, to precipitate valuable feedstocks from waste glycerol using...
Glycerol carbonate (GC) was synthesized by transesterification of glycerol with dimethyl carbonate (DMC) using calcium oxide (CaO) derived from eggshell as a catalyst. The best results of 96% glycerol conversion and 94% GC yield were achieved under the following reaction conditions: 0.08 mole ratio of CaO to glycerol, 1:2.5 mole ratio of glycerol t...
The pore-scale behaviour of liquid flow over wire mesh stainless-steel packing of variable contact angle is relevant for mass and heat exchanges in multiphase chemical systems. This behaviour was investigated by imaging experiments and 3D volume-of-fluid modelling. The surface of the wire mesh ring was modified by alumina coating to reach both hydr...
The process and energy intensifications for the synthesis of glycerol carbonate (GC) from glycerol and dimethyl carbonate (DMC) using an eggshell-derived CaO heterogeneous catalyst were investigated. The transesterification reaction between glycerol and DMC was typically limited by mass transfer because of the immiscible nature of the reactants. By...
Ethyl lactate is a hydrophilic solvent produced from bio-renewable sources (bioethanol and lactic acid produced from corn fermentation) that is considered a “green” solvent due to its extremely low toxicity, biodegradability and negligible eco-toxicity.
This work focuses on the utilization of ethyl lactate to form aqueous two-phase systems (ATPS) i...
COVID-19, caused by a member of the coronavirus family of viruses, has spread to most countries around the world since it was first recorded in humans in China in late 2019. Closing universities and cancelling all face-to-face activities have become a COVID-19 inevitable reality in many parts of the world. Its impact on university programs, particu...
Spent coffee grounds (SCGs) have a potential to be used as a feedstock for higher value-added products, such as biodiesel. However, the environmental implications of the valorisation of SCGs are largely unknown. This study evaluates the life cycle environmental impacts of utilising SCGs for biodiesel production in comparison with the widely used di...
Wired mesh packings have seen increasing applications to multiphase processes in recent years. Despite the high surface area, open structure and thermal and chemical resistance, wired mesh packings have a complex geometry which hinders some chemical applications, including changes of surface properties through application of a uniformly adhesive co...
Circulating uric acid concentrations have been linked to various metabolic diseases. Consumption of large boluses of nucleotides increases serum uric acid concentrations. We investigated the effect of a nucleotide-rich mixed meal on postprandial circulating uric acid, glucose, and insulin responses. Ten healthy adults participated in a randomised,...
In this paper, the irradiation of glycerol and ethylene glycol by either mixed (neutron-γ) or γ-only (γ) fields at the TRIGA reactor of the Jožef Stefan Institute is described. This is highly relevant to future applications of fission reactor systems to produce useful feedstock derivatives from organic waste, beyond the production of heat and power...
To fulfill the conditions required for a nuclear renewable energy concept, one has to explore the combination of processes going from the front end of the nuclear fuel cycle, to...
For the first time, we report on the performance of biphasic system composed of ethyl lactate, water and inorganic salt (K3PO4, K2HPO4 and K2CO3) for the separation of amino acids (L-phenylalanine, L-tryptophan and L-tyrosine) from their aqueous solutions. Cloud points (solubility curve) and tie-lines for three ternary (ethyl la ctate + water + ino...
Ethyl lactate is a hydrophilic green solvent which is bio-renewable and biodegradable with low toxicity towards humans and animals. For the first time, we report that aqueous solutions of ethyl lactate separate into two aqueous phases upon addition of salts. The performance of trisodium citrate, disodium tartrate and disodium succinate as salting-o...
Enormous amounts of brewers' spent grains (BSGs) per year are generated to produce bear worldwide. BSGs can be used as a carbon source, biofuel to generate energy and as a source of biogas. Typically, BSGs contain >60 mass% of water and, therefore, drying kinetics is a paramount for the development of any of these valorisation processes.
In this wo...
Waste eggshell is proposed as a highly active catalyst for glycerol carbonate production from dimethyl carbonate (DMC) and glycerol. The effect of reaction temperature, reaction time and catalyst loading on the reaction performance were investigated in order to find a suitable operating condition. CaO derived from waste eggshell exhibits catalytic...
Resource limits, environmental concerns and unstable petroleum costs have led to an increased effort to develop alternative liquid fuels. Purpose grown feedstocks are expensive and demand additional resources such as land and water. Spent coffee grounds (SCGs) are a good potential low-cost feedstock, however, processing times and costs must be lowe...
The phase equilibrium of the binary system (CO2 + propionic anhydride) was determined experimentally at temperatures of 308, 313, and 323 K and pressures up to 10 MPa. Measurements were carried out in a high-pressure visual cell with variable volume. The experimental data were modeled using the Peng–Robinson equation of state and the Mathias–Klotz–...
Although it was originally developed for a business school environment to promote the benefits of small-group teaching in a large group setting, the method of the Team-based Learning (TBL) has recently been increasingly used within medical education. On the other hand, the reports on its implementation in engineering and science education are much...
This paper presents data on mutual solubility of the binary (soybean oil + ionic liquid) and ternary (soybean oil + methanol + ionic liquid) systems, where ionic liquid stands for 1-butyl-3-methylimidazolium thiocyanate [C4MIM][SCN] or 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4MIM][NTf2] or 1-butyl-3-methylimidazolium dicyana...
The production of cyclic styrene carbonate from CO2 cycloaddition to styrene oxide, using tetrabutylammonium bromide (TBABr) as catalyst, was investigated. Two different reaction systems, a CO2-rich and an epoxide-rich were studied. Reactions were performed in a visual high pressure cell, at different temperatures (313.2, 333.2, and 353.2 K) and pr...
In this work, the performance of inorganic salt sodium chloride and ionic liquid (molten salt) ECOENG212 as salting-out media for the separation of nicotine from its aqueous solutions was examined. In this respect, liquid–liquid equilibria of the ternary solutions nicotine + water + NaCl and nicotine + water + ECOENG212 were determined at ambient p...
This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very su...
The solubility of carbon dioxide in ionic liquids was measured in a new apparatus. The ionic liquids chosen have ammonium-based cations and show melting temperature decreases under CO2 pressure that range from low (25 K) to extremely high (120 K). The main purpose of this study was to check whether the solubility of the gas in each liquid could exp...
Solubility of choline chloride and choline acetate in short-chain linear alcohols (ethanol, 1-propanol and 1-butanol) at various temperatures.
Liquid–liquid equilibria (LLE) of the solutions of imidazolium ionic liquids having bistriflamide [NTf2]− and triflate [OTf]− anions with non-polar (benzene, toluene and p-xylene) and polar aromatic compounds (nicotine and aniline) were investigated. The respective temperature-composition phase diagrams were obtained at 0.1 MPa and in a temperature...
Vapour–liquid equilibria of ionic liquid – carbon dioxide systems, as well as thermo-physical properties of the system components are very important to design and optimize various separation and reaction processes. In this work the solubility of carbon dioxide (CO2) in trihexyl(tetradecyl)phosphonium bromide([THTDP][Br]) was measured using a high-p...
In this work, the solubility of carbon dioxide (CO2) in seven different ionic liquids (ILs) was measured using a high-pressure sapphire cell, in the pressure range of 8–22 MPa and at two temperatures, 313.2 K and 323.2 K. In order to discuss the influence of the cation, ILs based on bis(trifluoromethylsulfonyl)imide, [NTf2] were chosen. They were c...
Mutual miscibility in mixtures containing ethyl lactate and various hydrocarbons (alkanes, alkenes, cyclohexane, alkyl cyclohexanes and terpenes) were explored in a range of temperatures from (273.2 to 320.9) K and at atmospheric pressure. Thus, the respective temperature–composition phase diagrams were constructed. The influence of temperature, al...
(Solid + liquid) and (liquid + liquid) phase equilibria of binary mixtures containing various ionic liquid and erythromycin were studied. The solubility of erythromycin in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, or 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, or trihexiltertadecilphosphonium chloride, or but...
Liquid–liquid equilibria were measured for solutions containing: (1) nicotine, and one of the solvents PEG 200 or ethyl-lactate, and the ionic liquid 1-ethyl-3-methylimidazolium ethyl sulphate (ECOENG 212®); (2) a (nicotine+water) mixture of close to critical composition and one of the co-solvents PEG 200, or glycerol, or ethyl-lactate; and (3) a (...
Densities and molar excess volumes of the solutions of pyridine or nicotine in liquid polyethylene glycol, PEG200 and PEG400, have been determined at several temperatures. The experimental molar excess volumes are negative, thus indicating strong attractive interactions between the components, as could be expected considering their highly polar nat...
The feasibility of in situ extraction and transesterification of spent coffee ground oil into fatty acid methyl esters with supercritical methanol has been investigated in the temperature range 473-603 K, and in the pressure range 10.0-30.0 MPa. At 30.0 MPa and 603 K, a fatty acid methyl esters (FAME) yield of 84.9% was obtained. Carbon dioxide was...
The alternative solvents poly(ethyleneglycol)s (PEGs) with various molar masses and room temperature ionic liquids (RTILs) AMMOENG100 and 1-butyl-3-methylimidazolium dicyanamide (bmimDCA) were studied for the purpose of extraction of linoleic acid from soybean oil. Liquid-liquid phase equilibrium was measured for binary (PEG + soybean oil), (RTIL +...
Experimental and modeling studies of the liquid−liquid equilibria at ambient pressure of three model systems—squalene + ethyl lactate, olive oil + ethyl lactate, and squalene + olive oil + ethyl lactate—were performed with the view to explore the potential application of an agrochemical solvent, namely, ethyl lactate, to recover squalene from pretr...
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
This work paper presents vapour–liquid equilibrium (VLE) data for binary (CO2+nicotine) and ternary (CO2+nicotine+solanesol) mixtures, at 313.2K and 6, 8 and 15MPa. The (CO2+nicotine) system exhibits three phases (L1L2V) in equilibrium at 8.37MPa. It is estimated that this system most likely follows the type-III phase behaviour. In the ternary syst...
The hydrogenation of two liquid terpenes, alpha-pinene and limonene, was carried out in the presence of high-pressure carbon dioxide, using carbon-supported Pt catalysts. Phase equilibrium data on terpene + CO(2) + hydrogen were used to interpret the kinetics of hydrogenation in liquid + vapor systems close to the critical lines of the mixtures.
This paper presents vapor−liquid equilibrium (VLE) data for systems containing high-pressure CO2, an ionic liquid, and products of an enzymatic reaction between succinic anhydride and (R,S)-2-octanol in the presence of a lipase. VLE experiments were used to calculate partition coefficients of reaction products between the ionic liquid-rich phase an...
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The fascinating, complex behavior of ionic liquids is analyzed using a molecular perspective that emphasizes the doubly dual nature of ionic liquids underlying the existence of cations and anions forming high- and low-charge-density regions. Our work bridges the liquid, gas, and solid phases spanning 5 years of research on themes as diverse as the...
The salting-out effect produced by the addition of potassium phosphate, K3PO4to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazoliumethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl) is investigated. The effects areanalyzed using both the...
Several regimes of the (T, x1, x2) surface of the liquid–liquid phase diagram at or close to a nominal pressure of 0.1 MPa of the ternary systems 1-hydroxyethyl-3-methylimidazolium based ionic liquids (1), [C2OHmim][X] ([X] = [PF6]− or [BF4]− or [CF3SO3]− or [(CF3SO2)2N]−), +dichloromethane or 1,2-dichloroethane (2), +2-propanol (3) were investigat...
Phase diagrams (liquid-liquid equilibrium) obtained by Solubility measurements at 298 K have shown very interesting and rare behaviour for the ternary systems 1-(2-hydroxyethyl)3-methylimidozolium based ionic liquids ([EtOHmim][X], [X] [PF6](-) or [BF4](-) or [CF3SO3](-) or [(CF3SO2)(2)N](-)) + dichloromethane + 2-propanol. Strong co-solvent effect...
The liquid-liquid equilibrium of the (C4mim)(NTf2)-1-butanol system presents upper critical solution temperature (UCST) behaviour. We report the influence of added water as well as the effect of hydrostatic pressure on the cloud points. Similarly to previously studied systems that involved RTILs in our laboratories, water is shown to be a very good...
Lower critical solution temperatures (LCST)-type of phase diagrams, including the presence of closed loops, have been encountered for the first time in binary and quasi-binary liquid solutions of ionic liquids. Furthermore, the results constitute the first experimental support for the existence of a theoretically postulated, but never encountered,...
The current study focuses on 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4], and 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6]. The objective is to study the influence of pressure as well as that of the anion on several properties of this type of ionic liquid. The speed of sound and densities in pure ionic liquids (ILs) a...
The ionic liquid [C4mim][PF6] and supercritical carbon dioxide produce multiphase systems when mixed with ethanol and water. Mixtures of these four solvents can be made to go, by small changes in composition, through a succession of phase changes, involving one, two and three-phase situations. Increasing carbon dioxide pressure induces first the ap...
An overview of experimental and theoretical studies recently performed in the Oeiras/Lisbon laboratories is provided. Typical showcase examples of UCST demixing of ionic liquid solutions are presented and discussed. Co-solvency, pressure, and isotope effects were investigated. In order to rationalize the observed effects, a phenomenological gE-mode...
A study of the behavior of the response functions of the [C4mim] [BF4] + water ionic binary solution near its liquid-liquid critical point at atmospheric pressure is presented. Phase equililibrium temperatures, which allow to obtain the critical coordinates of this system, are determined. Measurements of the isobaric heat capacity per unit volume i...
A study of the behavior of the response functions of the [C(4)mim][BF4] + water ionic binary solution near its liquid-liquid critical point at atmospheric pressure is presented. Phase equililibrium temperatures, which allow to obtain the critical coordinates of this system, are determined. Measurements of the isobaric heat capacity per unit volume...
The ionic liquid [C(4)mim][PF6] and supercritical carbon dioxide produce multiphase systems when mixed with ethanol and water. Mixtures of these four solvents can be made to go, by small changes in composition, through a succession of phase changes, involving one, two and three-phase situations. Increasing carbon dioxide pressure induces first the...
Since determining experimentally a wide variety of thermophysical properties - even for a very small portion of the already known room temperature ionic liquids ( and their mixtures and solutions) - is an impossible goal, it is imperative that reliable predictive methods be developed. In turn, these methods might offer us clues to understanding the...
Liquid-liquid phase splitting in ternary mixtures that contain a room-temperature ionic liquid and an alcohol aqueous solutionsnamely, [bmim][PF 6 ] + ethanol + water and [bmim][NTf 2 ] + 2-methylpropanol + waters is studied. Experimental cloud-point temperatures were obtained up to pressures of 400 bar, using a He-Ne laser light-scattering techniq...
The best of both worlds: Phase changes in ionic liquid + water systems, induced by addition of ethanol and supercritical carbon dioxide, allow reaction cycles to proceed as depicted, combining the high rates of one-phase conditions with easy separation of products; characteristic of biphasic catalysis. The (usually slow) epoxidation of isophorone b...
In the search for understanding of several types of abnormal thermodynamic behaviour in the vicinity of critical lines of binary liquid mixtures, we have revisited an apparently forgotten relationship between the pressure dependence of the critical temperature and the second derivatives with respect to the composition of the volumetric and enthalpi...
In the search for understanding of several types of abnormal thermodynamic behaviour in the vicinity of critical lines of binary liquid mixtures, we have revisited an apparently forgotten relationship between the pressure dependence of the critical temperature and the second derivatives with respect to the composition of the volumetric and enthalpi...
A surprising mixed solvent effect, both in its magnitude and direction, has been found in the phase diagram of the ternary mixture of ([C4mim][PF6]+(water+ethanol)). For a molar ratio of 1∶1 of water to ethanol, the co-solvent effect in the near-critical demixing temperature can be as large as 80 K.
Aqueous solutions of a copolymer derivative of a polyacrylamide showed very interesting behavior, that in which the system evolves from one kind of double criticality (pressure-hypercritical point) to another (temperature-hypercritical point) as polymer molecular weight decreases. While in the neighboring region of the former point one expects a ch...