Methyl Ethyl Ketone Concentration Research Articles

A mixed agro-waste based biofilter for the removal of methyl ethyl ketone: Kinetics and modeling

Biofiltration has grown worldwide, as an inexpensive and consistent air pollution control technology for the elimination of numerous organic compounds. In this work, the biofiltration of methyl ethyl ketone (MEK) has been studied. The agro-wastes namely pressmud and cornstack are mixed and used as packing materials for the removal of MEK. The performance of the biofilter has been explored over 200 days. Experiments are carried out in four periods. In every period, the biofiltration of pollutants is performed for various inlet concentrations (IC) of MEK (0.2–1.2 g m−3) and gas flow rates (GFR) (0.03 m3 h−1 to 0.12 m3 h−1). The biofilter performances are investigated by their removal rates, elimination capacity, temperature, pressure drop, carbon dioxide production, and variation of bed height at the time of operations. For the IC of 0.2 ± 10% g m−3 and GFR of 0.03 m3 h−1, the removal efficiency (RE) of MEK is 97% using the mixture of cornstack (80%) and pressmud (20%). The MEK removal efficiency decreases, when the cornstack ratio increases. The maximum RE is obtained at the IC of 1.2 g m−3 and GFR of 0.12 m3 h−1 for all the tested conditions. The pressure drop (PD) is also measured for all the operating conditions. It is found that the PD rises with an increase in height. The temperature is monitored throughout the biofiltration process. It is observed that an increase in RE leads to a rise in temperature in the biofilter. SEM images confirm the growth of microbes on the packing material. The kinetics of removal of MEK is investigated by using Ottengraf–van den Oever model.

Dual-Band Microwave Circuits for Selective Binary Gas Sensing System

A noninvasive contactless binary gas sensing system is enabled using coupled passive flexible tag integrated with porous adsorbent beads tower. The platform is based on two flexible passive tags coupled with a dual-reader resonator operating at 4.86 GHz, while the distance between passive reader and tags can be extended to 10 mm. The sensor demonstrates the capability of detecting and monitoring more than one gas simultaneously and independently from each other. Various concentrations of methyl ethyl ketone (MEK) and humidity have been detected distinctively by using a hyper cross-linked polymer as volatile organic compounds (VOCs) and silica gel as humidity adsorbent beads. Selective accumulation of the gas molecules in the beads’ pores is monitored with less than 5% error and by separate coupled tags and their associated resonant frequencies. The proposed structure offers a low-cost conformal solution and has the potential for real-time contactless multiple gas sensing in environmental applications. The structure demonstrates the sensitivity of 0.18 MHz/ppm in VOC sensing and 0.19 MHz/ppm while performing selective binary sensing.

Microwave dielectric relaxation & polarization study of binary mixture of methylethylketone with nitrobenzene

Present paper reveals detailed study of dielectric relaxation and dielectric polarization and physicochemical study of binary polar-polar liquid mixture i.e. dielectric constant, relaxation time, viscosity, density of methylethylketone (MEK) with nitrobenzene (NB) at 303 K. The measured dielectric and physicochemical parameters employed to acquire additional derived properties like Bruggeman factor, molar refraction and excess properties like static dielectric constant, excess inverse relaxation time, excess molar volume, excess viscosity, excess molar refraction, Gibbs free energy, and enthalpy of activation. The variation of this parameters with composition of these quantities has been used to explain the type, strength and nature of intermolecular interactions between MEK+NB binary mixture. Attained results authenticate that there are strong hydrogen-bond interactions between unlike molecules of different groups of MEK+NB mixtures and that 1:1 complexes are produced and strength of intermolecular interaction rises with rise in concentration of MEK. KEY WORDS : Bruggeman factor, Excess inverse relaxation time, Dielectric polarization Bull. Chem. Soc. Ethiop. 2019 , 33(2), 349-358. DOI: https://dx.doi.org/10.4314/bcse.v33i2.15

Determination of methyl ethyl ketone in urine by headspace gas chromatography

Objective: To establish a method for determination of methyl ethyl ketone in urine by headspace gas chromatography. Methods: In the urine sample(hereinafter referred to as urine sample), methyl ethyl ketone is pretreated by headspace technology, and a certain amount of head air is injected into the gas chromatograph, separated by capillary column, detected by hydrogen flame ionization detector, and the retention time is qualitative and the peak height is high. Peak area. Results: Good linearity was in the range of 0.01 to 6.0 μg/ml with a regression equation of y=13.316x+0.8497 and γ=0.9997.The minimum detectable concentration of methyl ethyl ketone was 0.01 μg/ml. The range intra-day RSD and inter-day RSD were 2.2%-5.5% and 2.5%-6.1% respectively. Urine samples can be stored for 20 days in the refrigerator at 4 ℃. Conclusion: The method has a high advantage of sensitivity and accuracy, and also easy to operate. Therefore, it is suitable for the determination of methyl ethyl ketone in urine.

Single‐step Conversion of Methyl Ethyl Ketone to Olefins over ZnxZryOz Catalysts in Water

AbstractIn this study we investigated the conversion of aqueous methyl‐ethyl‐ketone (MEK) to olefin fuel precursors over ZnxZryOz mixed oxide catalysts. Experiments were carried out in water as MEK is intended to be produced from the dehydration of 2,3‐butanediol in fermentation broth which is highly diluted in water. We demonstrated that ZnxZryOz catalysts are highly effective for converting aqueous MEK to C4−C5 olefins. High selectivity to olefins equal to 85 % was reached at 92 % per pass conversion when under H2 atmosphere. Catalyst stability was demonstrated for 60 hours’ time on stream, highlighting the potential for upgrading 2,3‐butanediol contained in fermentation broth without the need for energy‐intensive water separation. Increased concentration of MEK in the aqueous feed results in increased activity towards olefin production. However, water inhibits catalyst deactivation from coking. A mechanistic investigation revealed the impact of the reaction environment (inert or reducing atmosphere) on the reaction pathways. In an inert environment, the mechanism involves consecutive aldol condensation of MEK and 3‐pentanone intermediate. Under reducing conditions two reaction pathways compete with each other as MEK hydrogenation to butenes occurs concurrently with the aldol condensation/decomposition.

Rapid In-situ Analysis for Methyl Ethyl Ketone Dissolved in Transformer Oil Using Surface Enhanced Raman Scattering

Methyl ethyl ketone dissolved in transformer oil is a new chemical mark of thermal insulation degradation. As an effective detection method, Surface-enhanced Raman scattering (SERS) could directly perform rapid detection for methyl ethyl ketone in transformer oil without complex preprocessing steps, which can provide in-situ capability to overcome the shortcomings of traditional method. First, sliver nano-bulks were synthesized on the copper foil surface by the galvanic displacement. silver nanobulks were used as the SERS substrate to detect standard transformer oil samples with different methyl ethyl ketone concentrations. The SERS peak at 763 cm-1 was selected as the characteristic SERS peak for qualitative and quantitative analyses. In addition, the quantitative analysis model was built between the Raman intensity at 763 cm-1 and methyl ethyl ketone concentrations by applying the least square method. Experimental results showed that SERS method could be used to analyze methyl ethyl ketone dissolved in transformer oil quantitatively and effectively. With further improvements of the detection limit, the SERS method will provide a useful approach to achieving rapid in-situ analysis for methyl ethyl ketone dissolved in transformer oil.

Single-phase transesterification of palm oil in the presence of methylethylketone - a study on intrinsic reaction kinetics -

Single-phase transesterification of palm oil with methanol catalyzed by homogeneous alkaline catalyst was carried out in a laboratory scale batch reactor at 298, 308 and 323 K in the presence of methylethylketone (MEK) as a co-solvent. Most of the previous research studies on single-phase transesterification by using a co-solvent were conducted to obtain higher reaction rates than two-phase. In the present study, the authors targeted to investigate the intrinsic reaction kinetics of transesterification of oil with methanol catalyzed by homogeneous alkaline. The reaction experiment was carried out at 0.1, 0.2 and 0.6 mol/L of palm oil initial concentration. The transesterification reaction rate constant behaved in a strange manner with the initial oil concentration: the rate constant increased with a decrease in the initial oil concentration. This may be attributed to size change of palm oil molecule with MEK concentration in palm oil-methanol-MEK system.

One-pot fabrication of multiporous polymer particles by phase inversion in emulsions

Relatively monodisperse spherical poly(styrene-co-acrylonitrile) (SAN) particles may be prepared using phase inversion from water-in-oil (W/O) to oil-in-water (O/W) emulsions containing water-soluble methyl ethyl ketone (MEK) as the oil phase. In this study, we investigate how mixed solvents containing MEK and water-insoluble methylcyclohexane (MCH) affect the shape of SAN particles produced by the same phase-inversion process. We demonstrate that phase separation between MEK-rich and MCH-rich phases in oil droplets of O/W emulsions occurs during phase inversion and that the state of phase separation is controlled by the MCH:MEK ratio and concentration of SAN. In addition, SAN heterogeneously distribute in the oil droplets of O/W emulsions because SAN is soluble in MEK but not in MCH. We show that the uneven distribution of SAN in the oil droplets produces semispherical, disc-like, and multiporous SAN particles.

Kinetic and microbial community analysis of methyl ethyl ketone biodegradation in aquifer sediments.

Methyl ethyl ketone (MEK) is a common groundwater contaminant often present with more toxic compounds of primary interest. Because of this, few studies have been performed to determine the effect of microbial community structure on MEK biodegradation rates in aquifer sediments. Here, microcosms were prepared with aquifer sediments containing MEK following a massive spill event and compared to laboratory-spiked sediments, with MEK biodegradation rates quantified under mixed aerobic/anaerobic conditions. Biodegradation was achieved in MEK-contaminated site sediment microcosms at about half of the solubility (356mg/L) with largely Firmicutes population under iron-reducing conditions. MEK was biodegraded at a higher rate [4.0±0.74mg/(Ldays)] in previously exposed site samples compared to previously uncontaminated sediments [0.51±0.14mg/(Ldays)]. Amplicon sequencing and denaturing gradient gel electrophoresis of 16S rRNA genes were combined to understand the relationship between contamination levels, biodegradation, and community structure across the plume. More heavily contaminated sediments collected from an MEK-contaminated field site had the most similar communities than less contaminated sediments from the same site despite differences in sediment texture. The more diverse microbial community observed in the laboratory-spiked sediments reduced MEK concentration 47% over 92days. Results of this study suggest lower rates of MEK biodegradation in iron-reducing aquifer sediments than previously reported for methanogenic conditions and biodegradation rates comparable to previously reported nitrate- and sulfate-reducing conditions.

Adsorption–desorption characteristics of methyl ethyl ketone with modified activated carbon and inhibition of 2,3-butanediol production

Activated carbon (AC) is seldom applied for recovering ketone-based volatile organic compounds because of safety concerns. Adsorption of methyl ethyl ketone (MEK) with AC is a highly exothermic reaction that potentially causes fires in AC beds. Moreover, 2,3-butanediol (BDO) is produced in the desorbed solvent, causing yellowing and odor of the recovered solvent. This study applied a continuous adsorption–desorption apparatus for evaluating the operating capacities and BDO concentration in recovered MEK containing modified and original ACs. AC-1 (TAKETA- G2X) was used as the target for modification. The experimental results indicate that using MgO as the modifier increases the ignition point by 12°C and that applying KNO3 as the modifier reduces the AC ignition point by 28°C (compared with AC-1). The BDO concentration of the desorbed MEK solvent can be reduced by increasing the loading of the modifying agent (Ethanolamine) (Im-1: 3.1 wt%; Im-5: 6.2 wt%). Moreover, applying the AC pretreated with nitrogen (Im-6) as adsorbent significantly reduces the BDO concentration (from 0.123 wt% to 0.073 wt%). Because desorption and purging procedures were performed in N2 atmospheres, the BDO concentrations of the desorbed MEK solvents were relatively low and ranged from 0.032 wt% to 0.043 wt%. When the MEK concentration was reduced to 2000 ppm, lower BDO concentrations (0.012–0.022 wt%) were measured in the recovered MEK solvent. The way to modify activated carbon and a better desorbing sequence to effectively inhibit the oxidation of MEK to BDO are developed. The results obtained indicate that the BDO concentration in the desorbed solvent was lower than the original MEK solvent (0.023 wt%). Different approaches can be applied simultaneously to achieve high inhibition effects; however, carbon adsorption performance may be negatively affected.Implications: The study is motivated to improve the quality of recovered solvent and reduce fire hazards, particularly when AC is applied for adsorbing a ketone-based solvent (e.g., MEK). The experimental results indicate that the BDO concentration in the recovered solvent can be reduced and the ignition point of AC can be increased by modifying the AC with an appropriate agent.

Modeling of kinetics approach on the removal in methyl ethyl ketone using pressmud based biofilter systems

The removal of toxic methyl ethyl ketone (MEK) is studied in a lab scale biofilter packed with pressmud as packing materials. The biofiltration operation is divided into 4 phases for a period of 200 days. The maximum removal efficiency of 98 % is achieved during phase I for an inlet concentration of 0.2 g m−3 at a gas flow rate of 0.03 m−3 of MEK. The model simulation results have been reproduced and compared with the above sets of experimental data. Three different model variations are considered: model with low inlet MEK concentration, with high inlet MEK concentration, and with air flow rate modification. A sensitivity analysis has been performed on model to study the effect of important parameters on the removal efficiency. Model limitations and improvements have been highlighted.

β-SiC alveolar foams as a structured photocatalytic support for the gas phase photocatalytic degradation of methylethylketone

Alveolar open-cell self-bonded β-SiC foams with medium specific surface area and large mean cell size were used as high open porosity structured support for TiO2 in the gas phase photocatalytic degradation of methylethylketone. The influence of parameters such as the TiO2 weight content and the foam mean cell size, as well as both methylethylketone concentration and air flow rate was investigated. The structured TiO2/β-SiC foam photocatalytic material takes advantage of the static mixer role played by the β-SiC foam support and of its ability to increase the amount of TiO2 per unit reactor volume. The value of using TiO2/β-SiC foams for structuring flow-through reactors was highlighted in comparison to the commercial Quartzel photocatalytic felt standard and thin film coated wall reactor, the gain in performances being all the more pronounced that the pollutant concentration and the air flow rate were low.

연속식 광촉매반응기를 이용한 MEK 분해특성 연구

methylethylketone(MEK)의 광분해 특성을 연속식 단일관형태의 광촉매반응기를 이용하여 연구하였다. 연속식 광촉매반응기에 적용된 주요 반응변수는 MEK의 초기농도, 광세기, 장기운전의 영향이었다. MEK의 주입농도가 증가할수록 광분해 효율은 감소하였으며, 광분해 감소의 폭은 높은 유속에서 더욱 두드러졌다. 동일한 체류시간의 조건에서 광반응기의 직경과 UV램프의 파장이 증가할수록 MEK제거효율은 감소하였다. 연속식 광촉매반응기를 120시간 연속적으로 운전하여도 MEK 제거효율에서의 감소는 없었다. The degradation of methylethylkeone(MEK) was investigated by the continuous single module photocatalytic reactor. Operational conditions were initial concentration of MEK, intensity of photon flux, and activity change according to the long time operation. The photocatalytic degradation was decreased with the increase of MEK concentration, and the degree of decrease was larger at higher flow rate. Removal efficiency of photocatalytic reactor was decreased with the increase of reactor diameter and lamp wavelength under the same residence time condition. Continuous single module photocatalytic reactor was successfully operated without any activity drop during 120hrs operation.

Modeling of the photocatalytic degradation of methyl ethyl ketone in a fluidized bed reactor of nano-TiO2/γ-Al2O3 particles

Gas phase photocatalytic degradation of methyl ethyl ketone (MEK) using nano-TiO2 supported γ-Al2O3 adsorbent was studied in a Fluidized Bed Photo-Reactor (FBPR). The objective was to simulate photocatalytic degradation of MEK in the FBPR. The experiments were conducted in order to investigate the effect of operating parameters such as relative humidity (RH), MEK concentration, and superficial gas velocity on MEK degradation. In order to simulate the performance of the FBPR, the kinetic sub-model and the hydrodynamic sub-model were coupled together and solved simultaneously. The Langmuir–Hinshelwood (LH) kinetic model was adopted for photocatalytic degradation of MEK and its kinetic parameters were determined experimentally. The simple two-phase and dynamic two-phase models were considered as the hydrodynamic sub-models and their validity was investigated through comparing the simulation data and the experimental results. It was observed that the dynamic two-phase model has more validity than the simple two-phase; therefore, the dynamic two-phase model was selected as the hydrodynamic sub-model to predict the performance of the FBPR. The model predictions were compared with the experimental results of this study and the experimental data reported in the literature. Close agreement was found between the model and the experimental data. The modeling and simulation results of this study can be used to predict the performance of the fluidized bed photo-reactor.

회분식 광촉매반응기를 이용한 아세트알데하이드와 MEK 제거특성 연구

본 휘발성유기화합물인 아세트알데하이드와 MEK(methylethylketone)의 광촉매분해특성을 회분식 광반응기를 이용하여 연구하였다. 광촉매분해반응의 주요 반응변수인 아세트알데하이드와 MEK의 초기농도, 수분함량, 그리고 반응온도의 영향을 조사하였다. 아세트알데하이드와 MEK의 광촉매 분해속도에서 어느 일정농도까지는 초기농도가 증가할수록 증가하나, 그 이상에서는 완만한 증가형태를 보이며, 분해반응형태는 Langmuir-Hinselwood 모델이었다. 아세트알데하이드와 MEK의 광분해반응에 있어 수분은 inhibitor 역할을 수행하였다. 그리고 아세트알데하이드와 MEK 분해반응에 있어 최적의 반응온도는 <TEX>$45^{\circ}C$</TEX>이었다. The kinetics of photocatalytic degradation of gaseous acetaldehyde and methylethylketone(MEK) were studied by the batch scale of photo-reactor. Variable parameters were initial concentration of acetaldehyde and MEK, water vapor content, and temperature. The photocatalytic degradation rate was increased with increasing concentration of acetaldehyde and MEK, but maintained gentle increase beyond a certain concentration. The Langmuir-Hinselwood model was successfully applied to correlate experimental data. Water vapor inhibited the degradation reaction of acetaldehyde and MEK. The optimum reaction temperature was <TEX>$45^{\circ}C$</TEX> for acetaldehyde and MEK.

Biodegradation of Volatile Organic Compounds from Paint Industries

Methyl ethyl ketone (MEK) and methyl iso-butyl ketone (MIBK) constitute significant proportion of the total VOC emissions from manufacturing and application processes of surface coatings. Biodegradation of MEK and MIBK using an acclimatized mixed culture was evaluated, under aerobic condition. Biodegradation studies were carried out using MEK and MIBK as single substrates and in combination. Mixed-pollutant studies were conducted in MEK-dominated system, MIBK-dominated system, and MEK-MIBK equi-concentration systems to understand the concentration-dependent interaction of these compounds in a biosystem. Experimental data obtained from single-pollutant system was used to estimate the biokinetic parameters, viz. μ(max), K(s), K(i), and Y(T), for these compounds. Among the several bio-kinetic models tested, Monod inhibition model was best suited for predicting the biodegradation of these two VOCs. Four multiple-substrate models, viz. no-interaction, competitive, un-competitive, and non-competitive were used to study the nature of inhibition for different combinations of these compounds. The biodegradation of MEK and MIBK mixtures was found to be best described by competitive inhibition model. However, the predictions were not very good for systems where MEK concentration was higher than MIBK concentration.

Compounds interaction on biodegradation of toluene and methyl ethyl ketone mixtures in a composite biofilter

Compounds interaction on biodegradation of toluene and methyl ethyl ketone (MEK) mixtures in a composite bead biofilter was investigated. The biodegradation rate of two compounds in the exponential growth phase and stationary phase for the single compound and two compounds mixing systems was determined. For the single compound system, the biodegradation rate of two compounds in the microbial growth phase and stationary phase was inhibited with increasing inlet compound concentration. The inhibitive effect resulting from increasing the inlet compound concentration was predominated at higher inlet compound concentrations. For the two compounds mixing system, the microbial metabolic activity of biodegraded toluene in the microbial growth process and biochemical reaction process was inhibited as MEK was introduced. The inhibitive effect resulting from compounds interaction was more pronounced at higher inlet concentrations of both compounds. The maximum elimination capacity of toluene was reduced as MEK was introduced and that of MEK was not affected as toluene was introduced. Increasing concentration of MEK in the influent mixture strongly suppressed the biodegradation efficiency of toluene, while increasing concentration of toluene in the influent mixture had no effect on the biodegradation efficiency of MEK.

PMMA Modified PVDF Hollow Fiber Ultrafiltration Membranes

Polymethylmethacrylate (PMMA) modified poly(vinylidene fluoride) (PVDF) hollow fiber ultrafiltration membranes were prepared by wet spinning method using polyvinylpyrrolidone (PVP) as pore-foaming agent and mixture of dimethyl formamide (DMF)/methyl ethyl ketone (MEK) as solvent. The effects of PVDF, PMMA, PVP, and solvent ratios in the spinning solution on the permeation properties of the formed membranes were studied. The results showed that the performance of the membrane is the best with a pure water flux of 117 L/m2•h and rejection rate of 82% to bovine serum albumin (BSA), when the concentrations of PVDF, PMMA, PVP, DMF and MEK are 17, 3, 3, 60 and 17 wt%, respectively.

Pervaporation of methyl–ethyl ketone and water mixture: Determination of concentration profile

Experimental studies were conducted to separate methyl–ethyl ketone (MEK) from water through pervaporation using poly di-methyl siloxane (PDMS) and poly (ether) block amide (PEBA) membranes. Experiments were carried out at different feed MEK concentrations (10, 15, and 20 wt.%), temperatures (40–60 °C), and downstream pressures (3–7.5 mm Hg), and their influences on flux and selectivity were observed. The selectivity of MEK–PDMS was found to be around 100 for 10 wt.% MEK–water solution at 40 °C with 3 mm Hg downstream pressure, whereas it was 13.5 for MEK-PEBA under the same conditions. However, PEBA membranes offered much higher fluxes. For the PEBA membrane, a flux of around 0.12 kg m − 2 h − 1 was typically observed under the same conditions, whereas this value was 0.06 kg m − 2 h − 1 for the PDMS membrane. The selectivity of MEK–PDMS was 7.4 times higher than that of MEK-PEBA, but in terms of flux, the PEBA membrane offered almost double the flux of the PDMS membrane. Concentration profiles across the PDMS membrane were determined based on an earlier published work (Mulder and Smolders, 1984). Concentration profiles were developed under the following two conditions: (i) apparent diffusion coefficients independent of concentration and (ii) doubling the apparent diffusion coefficients. Analysis of transport across membranes for an MEK-water mixture by pervaporation required efforts beyond the usual consideration of concentration-independent diffusion coefficients. Accordingly, concentration profiles across the membrane were obtained using the determined values of polymer–liquid and liquid–liquid interaction parameters.

Elimination of Methyl Ethyl Ketone in Air Streams by a Biofilter Packed with Fern Chips

A biofilter packed only with fern chips is developed for the removal of air-borne low-concentration volatile organic compounds emitted from copper clad laminate manufacturing processes using methyl ethyl ketone (MEK) as a solvent for resin lamination. The fern chip biofilters can sustain continuous operation for at least 4 years without turnover maintenance and avoid traditional media shortcomings such as compaction, drying, and breakdown, which lead to the performance failure of biofilters. Performance of biofiltration for the removal of MEK in a waste gas stream was studied in a pilot-scale biofilter that consisted of two compartments (each 40 cmW × 40 cmL × 70 cmH) arranged in one acrylic column. Each compartment was packed with fern chips to a volume of around 56 L (0.40 m2 × 0.35 mH). Experimental results indicate that using volumetric organic loadings of 60–115 g m−3 h−1, MEK removal efficiencies of over 91% were maintained for an operation period of over 120 days. Instant milk powder was essential for the good and stable performance of the biofilter for MEK removal. Economic analysis showed that for treating a gas flow rate of 12,000 N m3 h−1 with an average MEK concentration of 700 mg N m−3, the total cost of using the proposed biofiltration approach was less than 20% that of using the regenerative thermal oxidation method.