Quartz Cell Research Articles

Passively Q-switched nd:YAG laser via a WS2 saturable absorber

In this work, we report a passively Q-switched Nd:YAG laser at 1064nm by using WS2 solution as the saturable absorber (SA). The WS2 solution with different concentrations (0.25, 0.5, and 1mg/ml) were fabricated by the liquid-phase-exfoliated method and injected into quartz cells. Such liquid absorbers have the virtues of adjustable optical absorption, high heat dissipation and non-contact damage. By inserting those WS2 solutions in the laser cavity, stable Q-switched laser operations were obtained. The corresponding pulse duration as short as 922ns was obtained. The result shows that the WS2 material can be act as absorber for solid-state lasers.

圧力振動を用いた壁面近傍に生じる剪断波の実験的検討

We observed 2D flow birefringence profile near a vertical flat walls of an upside-down air tight quartz cell filled with CTAB/NaSal aqueous solution. When a tiny bubble is placed inside the top wall of the cell, an oscillating flow can be generated by pressing a rubber film at the bottom of the cell by a sinusoidal vibrating piston whose vibrating amplitude, frequency and center positon of the cell can be tuned precisely. As the bubble is getting contracting and expanding alternately, shear waves were observed clearly, which was propagated from the vertical wall using the 2D high speed polarization camera. In this study, a correlation of the propagated waves and propagation speed of the shear waves were studied and discussed experimentally.

Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition.

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol. However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr(2+) act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO2 polymorphs and is at the origin of the epitaxial growth.

Generating induced current through the diving-surfacing motion of a stimulus–responsive smart device

Energy conversion from chemical to mechanical forms and then to electricity has experienced an explosive development in recent years. However, most of the current studies are challenged by producing a high output of induced current through cutting the strong magnetic line with a conductive line. Herein, we designed and fabricated a mini-generator to perform a diving-surfacing cycled motion with an intelligent initiation based on pH-responsive materials, and the obtained mechanical energy can be converted into electricity through cutting the strong magnetic line with a conductive line. Under acidic conditions, the device floated on the surface of water, and its locomotion was switched on through the addition of a basic solution. The re-float process was initiated by adding an acid solution and hydrogen peroxide. By investigating the influencing factors of the smart motion, we found that the device that consisted of one pH-responsive part, one hydrophobic part and a quartz cell performed the best under a 0.9% concentration of hydrogen peroxide during the diving-surfacing motion with a high frequency, leading to the highest output of induced current. Moreover, the device with bilateral-pyramidic structure provided the highest diving-surfacing frequency and maximized vertical motion velocity because of its drag-reducing property, achieving the highest output of induced electromotive force.

Diving–Surfacing Smart Locomotion Driven by a CO2‐Forming Reaction, with Applications to Minigenerators

Harvesting energy from environment has attracted increasing attention for its potential applications in fabricating minigenerator. However, most studies in the fabrication of mini‐ or nanogenerators are based on the concept of piezoelectricity or triboelectrification while few of the reports paid attention to the classical theory of Faraday's law. Herein, a pH responsive smart surface is combined with the reaction between CaCO3 and HCl to develop a new minigenerator, which can convert mechanical energy generated from the chemical reaction into electrical energy through cutting magnetic lines with moving conductive lines. The conductive lines are connected with a smart device consisting of a pH‐responsive cube, a hydrophobic cube, and a quartz cell window; the device can perform diving‐surfacing cycled motions with an intelligent initiation through the adjustment of the solution. The device can surface through gathering CO2 bubbles from the reaction between CaCO3 and HCl and dive by releasing the bubbles on the water/air interface. Moreover, the results demonstrate that the inert CO2 was nonhazardous to the smart surfaces, which is meaningful for durable electricity generation.

Magnetic Separation-Assistant Fluorescence Resonance Energy Transfer Inhibition for Highly Sensitive Probing of Nucleolin.

For the widely used "off-on" fluorescence (or phosphorescence) resonance energy transfer (FRET or PRET) system, the separation of donors and acceptors species was vital for enhancing the sensitivity. To date, separation of free donors from FRET/PRET inhibition systems was somewhat not convenient, whereas separation of the target-induced far-between acceptors has hardly been reported yet. We presented here a novel magnetic separation-assistant fluorescence resonance energy transfer (MS-FRET) inhibition strategy for highly sensitive detection of nucleolin using Cy5.5-AS1411 as the donor and Fe3O4-polypyrrole core-shell (Fe3O4@PPY) nanoparticles as the NIR quenching acceptor. Due to hydrophobic interaction and π-π stacking of AS1411 and PPY, Cy5.5-AS1411 was bound onto the surface of Fe3O4@PPY, resulting in 90% of fluorescence quenching of Cy5.5-AS1411. Owing to the much stronger specific interaction of AS1411 and nucleolin, the presence of nucleolin could take Cy5.5-AS1411 apart from Fe3O4@PPY and restore the fluorescence of Cy5.5-AS1411. The superparamagnetism of Fe3O4@PPY enabled all separations and fluorescence measurements complete in the same quartz cell, and thus allowed the convenient but accurate comparison of the sensitivity and fluorescence recovery in the cases of separation or nonseparation. Compared to nonseparation FRET inhibition, the separation of free Cy5.5-AS1411 from Cy5.5-AS1411-Fe3O4@PPY solution (the first magnetic separation, MS-1) had as high as 25-fold enhancement of the sensitivity, whereas further separation of the nucleolin-inducing far-between Fe3O4@PPY from the FRET inhibition solution (the second magnetic separation, MS-2) could further enhance the sensitivity to 35-fold. Finally, the MS-FRET inhibition assay displayed the linear range of 0.625-27.5 μg L(-1) (8.1-359 pM) and detection limit of 0.04 μg L(-1) (0.05 pM) of nucleolin. The fluorescence intensity recovery (the percentage ratio of the final restoring fluorescence intensity to the quenched fluorescence intensity of Cy5.5-AS1411 solution by 0.09 g L(-1) Fe3O4@PPY) was enhanced from 36% (for nonseparation) to 56% (for two magnetic separations). This is the first accurate evaluation for the effect of separating donor/acceptor species on the FRET inhibition assay.

Preparation of a novel green optical pH sensor based on immobilization of red grape extract on bioorganic agarose membrane

The development of a novel green optical pH sensor for a wide range pH values is described based on the immobilization of grape extract on an optically transparent agarose biopolymer. Siahe Sardasht grape is a famous variety of grape in Iran that is used for red grape juice concentrate. The anthocyanins of Siahe Sardasht grape were extracted and used as a suitable dye for the preparation of a pH optical sensor, by its immobilization on a transparent agarose film. In an optimized coupling, pH of 10 and a dye concentration of 100mgL−1, a sensitive sensor with long term stability was obtained. The sensor responds rapidly to the pH changes in a range of 1–10 with a response time of 3.0min and repeatability better than 0.3% (RSD). The sensor was mounted in the quartz cells and successfully applied for pH monitoring. No evidence of leaching of the dye or any signal drift was observed.

Development and Validation of UV Spectroscopic First Derivative Method for Simultaneous Estimation of Dapagliflozin and Metformin Hydrochloride in Synthetic Mixture

The Novel, simple, sensitive, rapid, accurate and economical and reliable First derivative spectroscopic method has been developed for synthetic mixture of Dapagliflozin (DAPA) and Metformin hydrochloride (MET). This method involve solving of first derivative method based on measurement of absorbance at two wavelengths 235 nm and 272 nm using UV visible spectrophotometer with 1cm matched quartz cells and methanol solvent were employed in this method. The Developed method obeyed Beer’s-Lambert’s law in the concentration range of 0.5-2.5 μg/ml, having correlation coefficient for Dapagliflozin was 0.984 and 25-125 μg/ml, having correlation coefficient for Metformin hydrochloride was 0.982. A derivative spectrum shows better resolution of overlapping bands than the fundamental spectrum. Different validation parameters like, precision (intra-day and inter-day studies), limit of detection, limit of quantitation were studied and were found to be within the limit. Results of the methods were validated statistically.The validation results showed that the proposed method was sensitive, economical and simple and it could be successfully applied for evaluation and to estimate the amount of synthetic mixture containing Dapagliflozin and Metformin hydrochloride.

Analysis of Glimepiride in Human Blood and Urine by Thin Layer Chromatography and UV Spectrophotometry

Objective: An increasing numbers of cases of poisonings by glimepiride, either attempted suicide or accidental, combined with the absence of reliable methods for the detection and quantitation of glimepiride in biological matrices is the basis for the need for the development of new analytical techniques for forensic analysis.Materials and Methods: Analyses were performed using drug- free biological fluids (whole blood and urine). Specimens were spiked with chromatographically pure glimepiride. After hydrolysis with diluted hydrochloric acid at 50-60 °C for 15-20 min and a double extraction into chloroform, glimepiride was identified by thin-layer chromatography. Standard solution of glimepiride (1 mg/mL) and Sorbfil chromatographic plates were used for thin-layer chromatography. The thin-layer chromatography studies showed that the best mobile phase was chloroform:acetone (9:1), Rf value of glimepiride in five examinations was 0.37±0.02. Visualization of glimepiride was achieved byspraying with Dragendorff’s, Bushard’s, or diphenylcarbazone-chloroform solution followed by mercuric sulphate. The limit of detection of pure glimepiride by thin-layer chromatography was 0.5 p/mL, 1.5 p g/mL in whole blood and 1.0 p g/mL in urine. For spectrophotometric determinations of glimepiride, a UV/VIS spectrophotometer with 1 cm matches quartz cell was used. Standard solutions of glimepiride in ethanol were prepared at concentrations of 1-50 p g/mL and scanned in full-scan mode between 200-400 nm.Results and Conclusion: The wavelength maxima for glimepiride was found to be 227 nm with molar absorptivity of 3.2685x10 4 l/mol/cm. Beer’s law was obeyed in the concentration range of 2-40 p g/mL. The limit of detection and limit of quantification were found to be 0.97 p g/mL and 2.70 p g/mL, respectively. The results have been successfully applied in blood of patients after oral administration and on postmortem blood in an overdose death.Keywords: Glimepiride, Thin-layer chromatography, Spectrophotometry.

FIBER OPTIC DISPLACEMENT SENSOR FOR HONEY PURITY DETECTION USING GLUCOSE ADULTERANT

A fiber optic displacement sensor (FODS) using a transmission technique was developed to determine the purity of honey using glucose adulterant. This was achieved by detecting the output signal of pure honey and adulterated honey with different addition percentage volume of glucose. The honey sample was adulterated with different percentage of glucose ranging from 0-10%. Prior that, the performances of sensor is first demonstrated by sensing output signal without any sample in a quartz cell. The linearity obtained is more than 99% in the range of 0 mm to 2.5 mm and the sensitivity is 32.65 mV/mm. The result from performance of sensor towards pure and adulterated honey showed that the highest sensitivity of all samples was achieved at 10% concentration of adulteration and the lowest sensitivity was obtained at 0% concentration (pure honey). Thus, FODS based on transmission technique has a potential to act as honey purity sensor by detecting the contamination of adulterant substances present in pure honey. The faster, simpler and cheaper devise is a promising technique to be employed in food industrial sector. Fiber optic displacement sensor in detecting honey purity for glucose adulteration.

Optical absorption measurements of hydrogen chloride at high temperature and high concentration in the presence of water using a tunable diode laser system for application in pyrohydrolysis non-ferrous industrial process control.

A tunable diode laser (TDL) was used to measure hydrogen chloride (HCl) spectra at 5747 cm(-1) (1.74 μm) and temperatures of 25-950 °C in a quartz cell. The purpose was to evaluate the capability of monitoring HCl concentration under pyrohydrolysis conditions using a near-infrared (NIR) laser. These conditions are characterized by 20-40% HCl, 2-40% H2O, and the presence of metal chloride vapors at temperatures of 600-1000 °C. Spectral peak area measurements of HCl-N2 mixtures at atmospheric pressure and a path length of 8.1 cm showed linear absorption behavior between concentrations of 5-95% and temperatures of 25-950 °C. Results from the addition of 2-40% water (H2O) indicate that the HCl peak area relationships are not affected for temperatures of 350-950 °C. Evaporating NiCl2 within the cell did not show spectral interference effects with HCl between 650 and 850 °C. The results from this work indicate that a near-infrared optical sensor is capable of measuring high HCl concentrations at high temperatures in the presence of high H2O content during pyrohydrolysis process conditions.

Observing Nitrogen Bubbles in Liquid Zinc in a Vertical Hele-Shaw Cell

Observations of gas bubbles in liquid metal are strongly hindered by the opacity of metals. To circumvent this limitation, the authors recently proposed to study such systems under quasi-2D flow conditions in a Hele-Shaw cell. The current paper presents a successful application of this approach for nitrogen bubbles in liquid zinc at 973 K (700 °C) in a fused quartz cell with a thickness of 1.5 mm. At low oxygen levels, the cell walls are not wetted by the liquid zinc, and bubbles can be observed directly through the transparent cell walls. Furthermore, using a moving high-speed camera that travels upwards with the bubbles, their properties are quantified in detail along the entire trajectory. In the range of equivalent diameters between 5.9 and 9.0 mm, this reveals a single periodic flow regime in which bubbles follow a sinusoidal path with a characteristic frequency of 3.31 Hz. In addition, systematic intermediate accelerations are observed of which the origin remains unexplained. Considering the unprecedented resolution of such observations for bubbles in liquid metals, especially at high temperatures, it is expected that this approach will contribute to a better understanding of the mechanisms that govern gas injection in pyrometallurgy.

Pseudo flow-injection ESR technique combining spin-trapping and application to the evaluation of superoxide scavenging capacity of phenolic compound

Evaluation methods of superoxide scavenging capacity have been studied by many researchers. One of the methods is a spintrapping electron spin resonance (ESR) technique, in which 5,5-diemthyl-1-pyrroline 1-oxide (DMPO) was usually used as a spintrapping reagent. In previous reports, the evaluation method based on a competition reaction and spin-trapping ESR technique were proposed. However, a big key issue and unavoidable problem remained in this evaluation. This is the rapid decrease of DMPO-O2 adduct by the following chemical reactions. Therefore, the initial signal intensity of DMPO-O2 has to be estimated with an approximation from a decreasing curve. This approximation, however, includes at least a thirty-second time lag before starting an ESR measurement. So, the measurement of a shorter time lag is required to obtain a more accurate initial intensity of DMPO-O2 - adduct. In this study, the pseudo flow-injection ESR method using a peristaltic pump was adopted to inject the test solution directly into a quartz cell in ESR cavity. This method achieved a 10 times shorter time lag (ca. 3 seconds) compared with the previous method (ca. 30 seconds) using a hematocrit capillary. As a consequence, the initial signal intensity within 10 % error was obtained without any estimation. The second-order rate constants of the reaction between various phenolic compounds and superoxide were obtained as one of the applications of this method.

Method Development for Quantification of Donor-Acceptor Complexes of Alverine Citrate and Tapentadol by Visible Spectrophotometry

In this present work two colorimetric methods were developed based on donor-acceptor complexes of alverine citrate (ALV) and tapentadol (TAP) with cobalt thiocyanate. These methods were developed on Perkin Elmer LAMBDA 25 UV–VIS spectrophotometer with 1cm quartz cells. The colored species formed are the coordination complexes of the drugs (electron donor) and the central metal atom of cobalt thiocyanate (electron acceptor) which is extractable into nitrobenzene from aqueous solution. The reaction conditions were optimized and validated to achieve maximum colour intensity. The colored complexes show maximum absorbance measured at 625 nm for both ALV and TAP. The absorbances were found to increase linearly with an increase in concentration which was corroborated by the calculated regression coefficients (0.9998-0.9999). Linearity was obeyed in the range of 100-600 µg/ml for both ALV and TAP, respectively. The molar absorptivity, sandell’s sensitivity, LOD, LOQ and other validation parameters have been evaluated extensively as per ICH guidelines and all the parameters were found within the acceptance criteria for both methods. The proposed methods were proven to be more accurate, simple, precise and rapid by statistical validation of recovery studies and could be suitable for regular analysis.

Pressure broadening and frequency shift of the 5S1/2 → 5D5/2 and 5S1/2 → 7S1/2 two photon transitions in 85Rb by the noble gases and N2

Doppler free two photon absorption spectroscopy was employed to measure the pressure broadening and frequency shift rates of the 5S1/2 (F = 3) → 5D5/2 (F = 5, 4, 3, 2, 1) (778.105 nm) and the 5S1/2 (F = 2) → 7S1/2 (F = 2) (760.126 nm) two photon transitions in 85Rb by the noble gases and N2. To our knowledge, these rates are reported on for the first time. The self-broadening and shift rate of the 5S1/2 (F = 3) → 5D5/2 (F = 5, 4, 3, 2, 1) transition and self -broadening rate of the 5S1/2 (F = 2) → 7S1/2 (F = 2) transition were also measured. The temperature dependence of the self-frequency shift (Rb-Rb collisions) of these transitions is presented. Helium diffusion rates through Quartz and Pyrex cells are also calculated and the implication of helium diffusion through glass vapor cells is discussed in regards to atomic frequency standards based on these transitions. Experimental pressure broadening and shift rates are compared to theoretically calculated rates assuming a 6, 8 or 6, 8, 10 difference potential and pseudo potential model. Reasonable agreement is achieved between experimental and theoretical values.

Light-Mediated Thiol-Ene Polymerization in Miniemulsion: A Fast Route to Semicrystalline Polysulfide Nanoparticles.

Historically, the synthesis of aqueous polymer dispersions has focused on radical chain-growth polymerization of low-cost acrylate or styrene emulsions. Herein, we demonstrate the potential of UV-initiated thiol-ene step-growth radical polymerization, departing from a nontransparent difunctional monomer miniemulsion based on ethylene glycol dithiol and diallyl adipate. Performed without solvent and at ambient conditions, the photopolymerization process is energy-effective, environmentally friendly, and ultrafast, leading to full monomer consumption in 2 s, upon irradiating a miniemulsion contained in a 1 mm thick quartz cell microreactor. The resultant linear poly(thioether ester) particles have an average diameter of 130 nm. After water evaporation, they yield a clear elastomeric film combining chemical resistance and high degree of crystallinity (55%).

Note: A quartz cell with Pt single crystal bead electrode for electrochemical scanning tunneling microscope measurements.

In this paper, we provide and demonstrate a design of a unique cell with Pt single crystal bead electrode for electrochemical scanning tunneling microscope (ECSTM) measurements. The active metal Pt electrode can be protected from air contamination during the preparation process. The transparency of the cell allows the tip and bead to be aligned by direct observation. Based on this, a new and effective alignment method is introduced. The high-quality bead preparations through this new cell have been confirmed by the ECSTM images of Pt (111).

Effect of Coupling Electrochemical and Ozonation Methods on the Degradation of Phenol

Introduction Currently various industries exhibit high pollution potential because their production processes generate large volumes of refractory type effluents. These effluents are problematic, mainly due to the presence of compounds which are harmful and recalcitrant. Biological processes generally do not remove this type of compounds. In fact, high concentration of these compounds can inhibit the performance or be toxic to biota which is responsible for the removal of pollutants. Advanced Oxidation Processes represent a technological alternative with great potential for the treatment of biodegradable effluents. In this study compared two methods are compared in the degradation of phenol: ozonation and coupled electrochemical-ozonation. Methods Solution of Phenol was prepared using Phenol supplied by Merck and deionized water at a concentration of 1000 mgL-1. Then aliquots of 100 ml were used in 1000 ml of Na2SO4 0.1 M solution to obtain a concentration of 100 mgL-1. Ozonation. The ozonation experiments were conducted in an up-flow glass bubble column reactor. The gas mixture ozone/air was continuously fed with a flow rate of 0.04 Lmin-1 through a gas diffuser with a 2 mm pore size at the bottom of the reactor. Analysis. Concentration of phenol was determined by UV/vis spectrophotometry technique. Samples absorbance was scanned from 200 to 900 nm, and a maximum absorbance at 270 nm was observed. The samples were scanned in a quartz cell. In order to establish the mineralization degree of phenol, Chemical Oxygen Demand of samples was determined by means of the American Public Health Association standard procedures. Electro-oxidation reactor: The reactor cell contains a pair of BDD electrodes (BDD film supported on a niobium substrate), each electrode was 20.0 cm by 2.5 cm with a surface area of 50 cm2. Batch volumes of 0.90 L were treated in the 1.00 L reactor. A direct-current power source supplied the system with 1.0, 2.0 and 3.0 A corresponding to current densities of 20, 40, and 60 mA/cm2. All the experiments were carried out at room temperature (20ºC), pH was adjusted at 3.0, 7.0, 9.0 and 12.0 with analytical grade H2SO4 and NaOH. O3-electrochemical coupled process: For the combined system the pair of BDD electrodes from the electrooxidation reactor were installed in the ozonation reactor. Ozone was introduced at the same rate and the BDD electrodes were given the same current densities as in the individual reactors. Treated samples were taken at the same intervals and analyzed the same way. Results This study shows a synergistic effect on the degradation of phenol by combining two advanced oxidation processes: ozone and electrochemical. Figure 1 shows the efficiency of degradation of each process. It is worth noticing that the best efficiency is obtained by a combination of processes, obtaining 99.98% in 1 hour. Figure 2 shows the effect of pH on the treatment in relation to the formation of the main products of mineralization of the molecule. Both technologies, ozonation and electrochemical, remove 97.90% and 99.88%, respectively in a time of 120 minutes. The combined treatment, however, reduces the time down to 60 minutes with a removal of 99.98%. Although ozonation possess characteristics that make it more versatile to be implemented on a larger scale as a single processing system or coupled to biological processes, the use of the electrodes is an effective option because it has a wide potential window, making it more efficient. Conclusions Recalcitrant compounds such as phenol require effective combination of advanced oxidation processes to achieve its complete mineralization. The combination of the processes ozone/electrochemical leads to the complete degradation of phenol after 1 hour. The decrease in pH observed in the process suggests the formation of carboxylic acids.

Electrochemical Degradation of Azo Dyes using Graphene/Fto As Cathode and Platinum/Ti As Anode

One of the most water polluting impact on the environment are dyes produced in various industries, mainly textile. An estimated 10-15% of the dyes used in these industries are thrown in the waste water. Chemicals containing dyes (including azo) are related to the presence of toxic compounds with chromophores groups of high molecular weight which to accumulate in lakes and rivers causing decrease in the brightness of the water and consequently induce the decrease of photosynthetic activity and decrease in available oxygen content in the water. In this work the electrochemical degradation of organic azo dye (Disperse Blue 3) will be presented. The degradation is carried out using the technique of chronoamperometry, calculating the anodic and cathodic potential of the system using calomel reference electrode. Phosphate buffer solution (1M) at pH 7.4 will be used as a supporting electrolyte. Graphene oxide supported on tin oxide dopped with fluor (FTO) will be use as cathode active electrode and platinum on titanium as anode active electrode. All systems of electro degradation will be built inside the 1cm x 1cm x 5cm quartz cell of the ultraviolet-visible spectrophotometer and measurements will be taken insitu during the process of electrochemical degradation. The cathode and anode are in separate cells joined by a salt bridge. Experiments are performed by applying an anodic potential before and after the production of oxygen at the anode, employing a power supply after the porduction of oxygen. The authors are grateful to CONACYT and CONCYTEG for the economic support via the projects FOMIX GTO-2012-C04-195057REFERENCES1. - A Comparative study on oxidation of disperses dyes by electrochemical process, ozone, hypochlorite and fenton reagent by Lidia Szpyrkowicz.2. - A comparative study of platinised titanium and niobe/synthetic diamond as anodes in the electrochemical treatment of textile wastewater by Anastasios Sakalis. Chemical Engineering Journal - CHEM ENG J 01/2006; 119(2):127-133. DOI:10.1016/j.cej.2006.02.0093.- Bechtold T. Cathodic decolourisation of textil waste water containing reactive dyes using a multicathode elctrolyser. Journal of chemical Technology and Biotechnology, 76 pp 303-311, 2001.4.- Evaluation of a novel electrochemical pilot plat process for azodyes removal from textile wastewater, Chemical Engineering Journal, Volume 111, Issue 1, 1 July 2005, Pages 63-70.

STUDIES ON PYROLYSIS OF SPENT ENGINE OIL IN A QUARTZ LOAD CELL

Every year gallons of waste automobile lubricating oil are generated in India. With the rapid growth of automobile industries, volume of waste lubricating oil is increasing at a high rate. The regeneration of these waste oils depends on its PCBs and PCTs value. If the value is lower than 50 ppm then legally the waste oil can be used otherwise it must be incinerated. In very recent years, pyrolysis method has been practiced to remove the pollutants from waste oil. Pyrolysis method has also been applied due to the production of either char or oil or gases at a time and these pyrolysis products may be maximized by the adjustment of process conditions. Under the present investigation, spent engine oil is pyrolysed in a 30 mm diameter and 195 mm long quartz load cell placed in a tubular furnace from 573K to 873K in a nitrogen atmosphere. The calorific value of this oil sample is 46 MJ/kg, determined in a bomb calorimeter. The spent engine oil sample is also pyrolysed in a Thermogravimetric analyzer (TGA) under the same experimental conditions. The TGA analysis has been performed at constant heating rate, 10 O C/min. A kinetic scheme has been proposed where two parallel reactions occur simultaneously to produce volatiles and char. The kinetic rate constants of both the reactions have been determined in the temperature range under study. Reaction kinetics of formation of pyro-oil and gaseous product from feed material has also been determined in present range of reaction temperature. The activation energies and pre-exponential factors of all products (volatile, char, pyro-oil and gas) have been determined. The calorific values of pyrooil obtained from pyrolysis of spent engine oil at temperature of 673K, 773K and 873K have been determined to be values 56 MJ/kg, 62 MKJ/kg and 58 MJ/kg respectively.