Flask Reactor Research Articles

Comparison of chemical and biological leaching methods with the effect of chloride on the recovery of nickel, cobalt and copper from a pentlandite-pyrrhotite concentrate

In this study, a finely ground nickel sulphide concentrate, consisting mainly of pyrrhotite, pentlandite and chalcopyrite, was leached in shake flask and batch reactor experiments. The objective was to determine the optimal method to recover nickel and cobalt, both hosted in pentlandite, and copper hosted in pentlandite and chalcopyrite respectively. The selected leaching methods tested were sulphuric acid leaching, ferric sulphate leaching and bioleaching. In addition, the effect of chloride ions on the leaching efficiency was evaluated with different concentrations. The results of the chemical leaching experiments showed increase in nickel, cobalt and copper recovery with chloride addition as a result of increased leaching rate for pentlandite and chalcopyrite. The highest yields in the 8-hour reactor experiment (70 % Ni, 66 % Co and Cu 87 %) were obtained in ferric sulphate leaching with chloride concentration of 20 g/L at the temperature of 90 °C. The mineralogical analysis showed that pyrrhotite was dissolved almost completely in all the experiments. Pentlandite and chalcopyrite leaching was clearly improved by the addition of Cl− at similar temperatures.

The study of novelty nutrients supplementary scheme and methodology on advanced carbon sequestration of microalgae

Microalgae has great potential in carbon sequestration and production of biofuel even with a low concentrations of CO2. In this paper, an Andrews based microalgae growth kinetic model and a novel and multiple nutrient supplementary scheme that significantly extends the carbon sequestration period and enhances growth rates of microalgae are proposed. First, the correlation between nutrient concentration and microalgal growth is constructed experimentally. The advanced growth kinetic model incorporating nitrogen and phosphorus consumption is developed. Then, the optimum cultivation conditions including initial nutrients concentration, nutrients supplementary interval and daily nutrients supplementary quantities are obtained in the conical flask reactor. The findings led to a novel nutrient supplementation strategy that initiates with a 0.2BC concentration, followed by a 0.3BC addition at 100 h, with subsequent supplements every 72 h. After adopting this supplementary strategy, the microalgae growth rate is increased by 42.9 % and the carbon sequestration rate is increased by 56.2 % compared with that of the original microalgae cultivation method in one cultivation cycle. Finally, the universal microalgae nutrients supplementary model is proposed in a piecewise model. It can be concluded from the model that in the first cultivation period, microalgae needs a higher affinity for nutrients and after nutrients supplementary, the sensitivity to nutrient inhibition is reduced. The paper is significantly helpful to improve the sustainability of the microalgae growth rate and the carbon sequestration rate.

Catalytic Pyrolysis of Plastic Waste to Liquid Fuel Using Local Clay Catalyst

Plastics are nonbiodegradable, and safe disposal of this waste poses an environmental challenge all over the world. Catalytic pyrolysis is superior to thermal pyrolysis as it uses lower temperatures and hence less energy. The main objective of this study was to produce liquid fuel from plastic waste using indigenous clay as a catalyst through catalytic pyrolysis. The clay from Kisumu County was characterized through an X-ray fluorescence spectrometer (XRFS) and an X-ray diffractometer (XRD). The reaction setup consisted of a round-bottom flask reactor through which plastic feed and catalyst were heated in a temperature-controlled furnace. Vapor product was condensed using a Liebig type water condenser to give pyrolysis liquid product. Solid char was recovered from the flask at the end of the reaction. Optimization studies using central composite design (CCD) and response surface methodology (RSM) were performed in design expert software to predict optimal conditions of the operating variables for maximum yield of the liquid fuel. Results show that clay has a composition of silica and alumina at 64.5 wt% and 16.3 wt%, respectively, indicating high acidity of the clay, being a requirement for a good pyrolysis catalyst. For high-density polyethylene and polypropylene, the highest liquid yield of 87.23 wt% and 60.36 wt%, respectively, was at 300°C and a catalyst concentration of 10 wt%. Indigenous clay was established to be a suitable catalyst for catalytic pyrolysis of plastic waste, with the potential to replace imported catalysts since high yields of liquid fuel were obtained at lower reaction temperatures of 300-450°C, as compared to the 600°C required for thermal pyrolysis. In conclusion, waste plastics can be used to generate alternative fuel for industrial use. The liquid fuel can be used in diesel engines as a transport fuel, in turbines for electricity generation, and as a heating source in boilers and furnaces. Further studies on the modification of the surface and structure of clay are suggested to enhance its catalytic performance in the pyrolysis process for a better fuel yield.

Solid state fermentation of mung beans by Bacillus subtilis subsp. natto on static, shaking flask and soft elastic tubular reactors.

Given that mung beans constitute a significant nutrient source in many cultures, it is worthwhile to investigate ways to improve their nutritional and functional properties. The effect of fermentation of mung beans by Bacillus subtilis subsp. natto was investigated in various reactor designs, including static, shaking flasks, and soft elastic tubular reactors (SETR). The results showed that all three processes might affect the substrate, resulting in changes in the protein and carbohydrate fractions. We noticed an increase in soluble protein and serine levels, which we attribute to the proteases produced during fermentation. Through XRD, FTIR, and DSC analyses, it was also discovered that whereas static and shaking flask fermentation might raise relative crystallinity and peak temperature, fermentation performed on the SETR decreased these values. It was also possible to notice that SETR might induce a change in the particle size distribution of the substrate through a complex impact of mechanical forces, mixing, and microbial activity, which could be helpful to some aspects of the process. To summarize, fermentation of mung beans by Bacillus. subtilis subsp. natto could be an attractive approach for producing a food ingredient with various functional and nutritional properties. Furthermore, the SETR has been shown to be a viable technique for dealing with high solid load substrates, whether as the reactor for the entire process or as a first stage/pre-treatment step, and its applicability in bioprocesses should be explored further.

Synthesis of Zeolite as a Textile Dye Waste Adsorbent from Rice Husk Ash Using Microwave Heating Method

The zeolite was synthesized from rice husk ash with high silica content using the microwave heating method. In the pre-treatment step, the silica content of rice husk ash was extracted by HCl at various concentrations. Zeolite was synthesized by the reaction of rice husk ash, the aqueous solution of NaOH and Al2O3 in the flask reactor, and was treated by microwave heating at various power from 100-200 W. The crystalline phase and the characteristic structure of the product were analyzed by XRD and SEM analysis. Moreover, the surface area of the product was analyzed by BET analysis. The result shows that with 2 M HCl as an acid treatment in the pre-treatment step, the high surface area of the zeolite was obtained, i.e., 266.7 m2/g. The adsorption efficiency of the product was analyzed using methylene blue, methyl orange, and methyl red as the textile dye waste. The result shows that the adsorption efficiency of the product on the methylene blue, methyl orange, and methyl red was 94.2%, 93.89%, and 94.7%, respectively.

Electro-oxidation combined with electro-Fenton for decolorization of caramel colorant aqueous solution using BDD electrodes

This study focused on the effects of the electro-oxidation combined with electro-Fenton process using boron-doped diamond (BDD) electrodes on the degradation of biorefractory food colorant caramel. Aqueous solutions containing Caramel Class IV, Caramel Class III and Acid Orange 7 were comparatively treated by electrochemical advanced oxidation processes, including electro-oxidation (EO), electro-Fenton (EF) and electro-oxidation combined with electro-Fenton (EO + EF). The experiments were performed in a stirred flask reactor using an inflator pump coupled with an undivided cell with BDD and Ti/Pt electrodes. In EF and EO + EF process, Fe2+ was added as catalyst. The independent parameters of air flow rate, Fe2+ concentration and current intensity in the range of 0.5–1.5 L/min, 0.05–0.2 mM and 0.4–1.5 A, respectively, were studied. The effect of electrode material on decolorization was also examined. The decolorization of pigment was enhanced with increasing air flow rate and current intensity due to the greater production of active species. The color decay was fitted to a pseudo-first-order kinetics. Complete decolorization of caramel colorant was realized with BDD electrodes under all experimental conditions and the highest kinetic constant of 2.3*10−2 min−1 was found under these conditions. This study highlighted the potential of EO + EF process with BDD electrodes for efficient degradation of caramel colorant.

Operational Strategies to Selectively Produce Purple Bacteria for Microbial Protein in Raceway Reactors.

Purple non-sulfur bacteria (PNSB) show potential for microbial protein production on wastewater as animal feed. They offer good selectivity (i.e., low microbial diversity and high abundance of one species) when grown anaerobically in the light. However, the cost of closed anaerobic photobioreactors is prohibitive for protein production. Although open raceway reactors are cheaper, their feasibility to selectively grow PNSB is thus far unexplored. This study developed operational strategies to boost PNSB abundance in the biomass of a raceway reactor fed with volatile fatty acids. For a flask reactor run at a 2 day sludge retention time (SRT), matching the chemical oxygen demand (COD) loading rate to the removal rate in the light period prevented substrate availability during the dark period and increased the PNSB abundance from 50-67 to 88-94%. A raceway reactor run at a 2 day SRT showed an increased PNSB abundance from 14 to 56% when oxygen supply was reduced (no stirring at night). The best performance was achieved at the highest surface-to-volume ratio (10 m2 m-3 increased light availability) showing productivities up to 0.2 g protein L-1 day-1 and a PNSB abundance of 78%. This study pioneered in PNSB-based microbial protein production in raceway reactors, yielding high selectivity while avoiding the combined availability of oxygen, COD, and darkness.

Performance of Nitrogen Removal in Ceramic Anammox Reactor with Two-Inflow

Anaerobic ammonium oxidation (anammox) converted ammonium into nitrogen gas using nitrite as an electron donor in anaerobic conditions by anammox bacteria. Granular anammox was used commonly to remove ammonium from wastewater. It easy to be broken and tend to settle in the bottom of the reactor in the application. A pored ceramic carrier was proposed to cultivate anammox bacteria with two-inflow substrate feeding. The carrier with a diameter of 1.0 mm was set up in the center of the 1.0 L conical filtering flask reactor. The substrate with 70 mg-N/L of ammonium-supplemented substate was introduced into the reactor through the center of the ceramic carrier from the bottom and 70 mg-N/L nitrite-supplemented substrates into the outside of ceramic carrier with HRT 3 hours. The influent and effluent concentration measured once a week using ion chromatography. The experiment was conducted in the 35°C controlled temperature room. Anammox bacteria grew by filled and covered the ceramic carrier’s pore, and a flock of anammox settled in the reactor. The reactor’s performance achieved a maximum of 76.496 % NRE and 0.901 kg-N/m3·d NRR, respectively.

Numerical and experimental analysis of optimized conical flask photobioreactor structures to improve liquid–gas two-phase distribution and microalgae carbon sequestration

In this paper, light intensity and gas–liquid distribution of microalgae in the original conical flask photobioreactor with central inlet tube bubbling ventilation are studied by applying both numerical simulation and experimental analysis. The different optimized structures of conical flask photobioreactors are proposed to improve light distribution and microalgae carbon fixation. The advanced effects of light intensity and gas–liquid distribution in advanced conical flask reactors are validation by 5 important parameters. First, the Eulerian gas–liquid two-phase model and DO (Discrete Ordinate) light distribution model of the conical flask reactor are developed. Gas distribution and light distribution are analyzed with different conditions of gas inlet velocity. Second, the optimal gas inlet velocity is evaluated with five vital parameters (average velocity, turbulent kinetic energy, gas holdup rate, average light intensity and velocity of the vertical wall). Then, the optimal CO2 gas inlet concentration is determined by a series of controlled experiment test groups. Finally, based on the numerical simulation and experiment result, three different optimized structures of conical flasks are proposed to prove the effectiveness of optimization, which is named lean-insertion bottle, baffle bottle and cross-nozzle bottle. The results showed that 0.5 m·s−1 gas inlet velocity is the optimal value for the gas–liquid distribution in the 500 ml conical flask reactor. With the increase of CO2 concentration, the growth rate of microalgae biomass concentration increased first and then decreased after the concentration arrives at 4%. At 4% CO2 gas inlet concentration, the highest biomass concentration is increased by 57.4% compared with the lowest ones. The gas distribution and light distribution in the three optimized reactors are significantly improved, and among the three optimizations, the PBR with baffle at 0 mm of the gas inlet pipe is the best one. In conclusion, the cultivation condition of microalgae and the structure of algae photobioreactors are both optimized providing a novel beneficial reference to improve the liquid–gas distribution and carbon sequestration rate of microalgae growth in the laboratory.

Comparison of Profiling of Hairy Root of Two Tibetan Medicinal Plants Przewalskia tangutica Maxim. and Anisodus tanguticus Maxim.

Tropane Alkaloids (TAs) are important drugs for curing many diseases in the medical industry. To sustainably exploit TA resources in endangered traditional Tibetan herbs, the hairy root (HR) systems of Przewalskia tangutica Maxim. and Anisodus tanguticus Maxim. were compared under the same culture conditions. The results indicated that both the Agrobacterium rhizogenes strains and explants affected the HR induction frequency, MSU440, A4 and LBA9402 strains could induce hairy roots following infection of cotyledon and hypocotyl of A. tanguticus while LBA9402 could not induce HR on either explants of P. tangutica. The efficiency of LBA9402 was higher than A4 and MSU440 on A. tanguticus and A4 was better strain than MSU440 on P. tangutica. The hypocotyl explant was more suitable for P.tangutica and cotyledon explant was better for A.tangutica with a transformation frequency of 33.3% (P. tangutica) and 82.5% (A. tanguticus), respectively. In a flask reactor system, both the growth curves of HR for two species both appeared to be "S" curve; however, the HR of P. tangutica grew more rapidly than that of A. tanguticus, and the latter accumulated more biomass than the former. As the culture volume increased, the HR proliferation coefficient of both the species increased. HPLC analysis results showed that the content of TAs in the HR of P. tangutica was 257.24mg/100g·DW, which was more than that of A. tanguticus HR (251.08mg/100g·DW), and the anisodamine in the Pt- HR was significantly higher than that in At-HR. Moreover, tropane alkaloids in the HR of the two species were all significantly higher than that of the roots of aseptic seedlings. Our results suggest that HR of P. tangutica and A. tanguticus both could provide a useful platform for sustainable utilization of two Tibetan medicinal plants in the Qinghai-Tibetan Plateau in the future.

Transesterification of Palm Oils Catalyzed by Ionic Liquid in Microwave Heated Reactors

Biodiesel is a renewable, carbon neutral liquid fuel produced from vegetable oils or animal fats with alcohol via catalytic transesterification reaction. Conventionally, alkaline-catalysed transesterification using convective heating takes long time to complete. Alkaline catalysts used are usually non-recyclable, environmentally unfriendly and could react with free fatty acids to form soap. Recently, ionic liquids have been shown to be effective in catalyzing transesterification. Furthermore, microwave irradiation has been shown to boost heat transfer to the reactants, making the reaction time shorter than the conventional heating. In this work, biodiesel production from microwave-irradiated transesterification of palm oils with methanol using a green ionic liquid was investigated. The ionic liquid (ChOH) was synthesized from choline chloride (ChCl) with potassium hydroxide (KOH) and characterized by Fourier transform infrared spectroscopy. The batch experiments were setup and carried out in an 800 W microwave oven with a flask reactor connected to a condenser. The continuous experiments were setup and carried out with a polytetrafluoroethylene (Teflon) tubing connected to a Teflon valve and a pump. Operating condition was oil to methanol ratio (1:15), reaction time (8 min), power of microwave (800 W), and catalyst loading (4 wt%). Methyl ester content was determined by gas chromatography and mass spectrometer. From the findings, it was shown that the ionic liquid was effective in catalysing transesterification of palm oils. Microwave heating proved to accelerate the reaction in short time. The methyl ester content was found to be 87 and 82 % for the batch and continuous experiments. The ester content was quite low, compared to the conventional heating. Further investigation was needed to find high biodiesel yield. The ChOH could also be reused several times but its effectiveness to produce biodiesel may be degraded, in comparison with the fresh catalyst.

Biogasoline synthesis via fluid catalytic cracking of waste cooking oil using treated eggshell

This paper reports on preparation and characterization of eggshell for fluid catalytic cracking (FCC) reaction of waste cooking oil (WCO) to produce biogasoline. Hydrocarbon from condensate of gas emitted from a spherical flask reactor was agitated at 350, 400 and 450 resolution per minute (rpm) under 350, 400 and 450 °C reaction temperature by the one-factor- at-a-time (OFAT) approach was analyzed by using a gas chromatography mass spectrometer (GC-MS). Acid compounds were also recorded. Earlier, the eggshell was ground, calcined at 900 °C for three hours and sieved into 250 – 425 μm range of particle size before being analyzed using Fourier-transform-infrared-spectroscopy (FTIR) for calcium oxide content. About 30 wt% of biogasoline ranged from C4 to C12 of alkanes and alkenes was obtained from the 350-°C hydrocarbon condensate after 30, 45 and 60 min of which aromatic compounds increased with the reaction temperature. However, the biogasoline compounds decreased with the reaction temperature. More than 20 wt% was esters and free fatty acids of carbon number greater than 20 were also formed, respectively. Stirring speeds generally increased condensate yield but the increment does not have pattern due to various volatility of the content. The highest biogasoline yield through the FCC reaction was 4.5 wt% at 350 0C at 400 rpm stirring speed, and the product was found comparable with previous research and commercial gasoline.

Modulation of fungal biofilm physiology and secondary product formation based on physico-chemical surface properties.

Relative to the amount of knowledge concerning bacterial biofilms, little is known about the impact of physico-chemical properties of support material on fungal biofilm adhesion and physiology. In the field of industrial fermentation, large-scale production of low-cost fungal secondary product is a challenging area of research. In the present work, the effect of physico-chemical surface properties of five different materials (Teflon, glass, Viton™ rubber, silicon rubber, and stainless steel) on the production of class II hydrophobins (HFBI and HFBII) from Trichoderma reesei (HFB2a-2) and Trichoderma harzianum) was evaluated. Two culture systems (shake flask and drip flow reactor (DFR)) were used in this study to promote biomass growth and the production of hydrophobins. Furthermore, the effect of physico-chemical surface properties (hydrophobicity, surface energy) and surface texture (roughness) of support material on the initial colonization and attachment of the fungal biofilm was evaluated. Maximum biofilm productivity was obtained using Viton™ rubber for T. reesei and Viton™ rubber and stainless steel as support materials for T. harzianum. Scanning electron microscope (SEM) revealed that fungal biofilm adhesion was higher on the rough hydrophobic Viton rubber surface as compared to the smooth hydrophobic Teflon surface. Initial colonization initiated because of surface irregularities and holes in the material as hyphal filaments. Moreover, compared to traditional submerged fermentation, a significant increase in biofilm productivity for both strains (T. reesei, T. harzianum) in all five materials was obtained.

Synthesis of Triacetin Catalyzed by Activated Natural Zeolite Under Microwave Irradiation

Esterification of glycerol with acetic acid under microwave irradiation in the presence of activated natural zeolite was investigated. Natural zeolite was collected from Ujung Pancu (Aceh Besar) and chemically activated with hydrochloric acid. The reaction was carried out in a stirred glass flask reactor placed inside microwave oven. Experimental variables include microwave transmission time, molar ratio of glycerol to acetic acid, and catalyst loading. XRD profile of activated zeolite showed an increase of Si/Al ratio to 6.042 and the crystallinity decreased slightly by 12.23%, mainly due to dealumination during chemical treatment. Qualitative analysis by FTIR shows that the reaction product obtained by microwave heating contains ester group (triacetin) at wavelength 1706.669 cm-1, while the quantitative analysis by acidi-alkalimetry titration indicates the highest glycerol conversion of 93.033% at the reaction condition of the molar ratio of 1:9, catalyst loading of 3%, and microwave transmission of 10 minutes. The present work suggests that microwave can be utilized as efficient heating technique in esterification of glycerol to triacetin.

Biodiesel Production from Palm Methyl Ester (PME) –Review

In the era of the increase in globalization, this led to increase in industrialization and motorization. It’s obvious that with the increase in motorization the consumptions of auto fuels had been increased since long. This may lead to a reduction of fuels (diesel & petrol). Also, environmental issues have arisen from the emissions of toxic pollutants and greenhouse gases. Hence, it is necessary to look for an alternate energy source to respond this problem. To overcome this problem the replacer of fuel in CI engines had been introduced, i.e. “biodiesel”. Biodiesel is composed of fatty acid and some vegetable oils. This review paper briefly describes different biodiesel production methods, especially the production of biodiesel using palm methyl ester (PME) oil, by transesterification process. In addition, it also compares the yield of biodiesel produced form mill effluents and palm oil by-products using flask and batch reactor.

Facile development of medium optimization for antibody production: implementation in spinner flask and hollow fiber reactor.

Most bio-industrial mammalian cells are cultured in serum-free media to achieve advantages, such as batch consistency, suspended growth, and simplified purification. The successful development of a serum-free medium could contribute to a reduction in the experimental variation, enhance cell productivity, and facilitate biopharmaceuticals production using the cell culture process. Commercial serum-free media are also becoming more and more popular. However, the cell line secrets its own recombinant product and has special nutritional requirements. How can the composition of the proprietary medium be adjusted to support the specific cell's metabolism and recombinant protein? This article uses statistical strategies to modify the commercial medium. A design of experiments is adopted to optimize the medium composition for the hybridoma cell in a serum-free condition. The supplements of peptone, ferric citrate, and trace elements were chosen to study their impact on hybridoma growth and antibody production using the response surface methodology. The stimulatory effect of the developed formulation on hybridoma growth was confirmed by the steepest ascent path. The optimal medium stimulated the hybridoma growth and antibody production in three diverse systems: a static plate, an agitated spinner flask, and a hollow fiber reactor. The cells in the developed serum-free medium had a better antibody production as compared to that in the commercial medium in the hollow fiber reactor. Our results demonstrated that the facile optimization for medium and antibody production was successfully accomplished in the hybridoma cells.

Morphology Control of CdSe Nanoparticles via Two-Step Segmented Microreactors

Morphology control of CdSe nanoparticles was essential for their potential applications. Different shapes of CdSe nanoparticles could be synthesized in flask reactors. However, there were few researches using microreactors to control the morphologies of CdSe nanoparticles. In this article, a microfluidic approach was developed to synthesize anisotropic CdSe nanoparticles. The nucleation stage (or seed preparation stage) and crystal growth stage were separated, and PFPE was used to form segmented microreactors for the growth stage. The influence of different conditions, such as nucleation temperatures, crystal seeds concentration, the overall ratio of Cd to Se, and monomer concentration for growth stage, on the shape control of CdSe nanoparticles was studied. Branched shape CdSe nanoparticles with high monodispersity were obtained.

Palm-Based Neopentyl Glycol Diester: A Potential Green Insulating Oil.

The transesterification of high oleic palm oil methyl ester (HOPME) with neopentyl glycol (NPG) has been investigated. The present study revealed the application of low-pressure technology as a new synthesis method to produce NPG diesters. Single variable optimization and response surface methodology (RSM) were implemented to optimize the experimental conditions to achieve the maximum composition (wt%) of NPG diesters. The main objective of this study was to optimize the production of NPG diesters and to characterize the optimized esters with typical chemical, physical and electrical properties to study its potential as insulating oil. The transesterification reaction between HOPME and NPG was conducted in a 1L three-neck flask reactor at specified temperature, pressure, molar ratio and catalyst concentration. For the optimization, four factors have been studied and the diester product was characterized by using gas chromatography (GC) analysis. The synthesized esters were then characterized with typical properties of transformer oil such as flash point, pour point, viscosity and breakdown voltage and were compared with mineral insulating oil and commercial NPG dioleate. For formulation, different samples of NPG diesters with different concentration of pour point depressant were prepared and each sample was tested for its pour point measurement. The optimum conditions inferred from the analyses were: molar ratio of HOPME to NPG of 2:1.3, temperature = 182°C, pressure = 0.6 mbar and catalyst concentration of 1.2%. The synthesized NPG diesters showed very important improvement in fire safety compared to mineral oil with flash point of 300°C and 155°C, respectively. NPG diesters also exhibit a relatively good viscosity of 21 cSt. The most striking observation to emerge from the data comparison with NPG diester was the breakdown voltage, which was higher than mineral oil and definitely in conformance to the IEC 61099 limit at 67.5 kV. The formulation of synthesized NPD diesters with VISCOPLEX® pour point depressant has successfully increased the pour point of NPG diester from -14°C to -48°C. The reaction time for the transesterification of HOPME with NPG to produce NPG diester was successfully reduced to 1 hour from the 14 hours required in the earlier synthesis method. The main highlight of this study was the excess reactant which is no longer methyl ester but the alcohol (NPG). The optimum reaction conditions for the synthesis were molar ratio of 2:1.13 for NPG:HOPME, 182°C, 0.6 mbar and catalyst concentration of 1.2 wt%. The maximum NPG diester yield of 87 wt% was consistent with the predicted yield of 87.7 wt% obtained from RSM. The synthesized diester exhibited better insulating properties than the commercial products especially with regards to the breakdown voltage, flash point and moisture content.

FTIR as an easy and fast analytical approach to follow up microbial growth during fungal pretreatment of poplar wood with Phanerochaete chrysosporium

Since the determination of the fermentation kinetics is one of the main challenges in solid state fermentation, the quantitative measurement of biomass growth during microbial pretreatment by FTIR spectroscopy in Attenuated Total Reflectance mode was evaluated.Peaks at wave numbers of 1651 cm−1 and 1593 cm−1 showed to be affected during pretreatment of poplar wood particles by Phanerochaete chrysosporium MUCL 19343. Samples with different microbial biomass fractions were obtained from two different experiments, i.e., shake flask and fixed-bed reactor experiments. The glucosamine concentration was compared to the normalized absorbance ratio of the 1651 cm−1 to 1593 cm−1 peak, measured by FTIR-ATR, and resulted in a linear relationship. The application of a normalized absorbance ratio in function of time provided a graph that was similar to the microbial growth curve.Application of FTIR in ATR mode to follow-up kinetics during solid state fermentation seems to be a fast and easy alternative to laborious measurement techniques, such as glucosamine determination.

PEMBUATAN BIOADITIF TRIACETIN DENGAN KATALIS PADAT SILICA ALUMINA

Triasetin is a bioaditif to increase the octane number of the gasoline. Triasetin was generated from the reaction between giserol and acetic acid. Glycerol is a byproduct of biodiesel production. Triasetin production can reduce glycerol which is actually a waste by converting it into bioaditif having higher value. The reaction can be accelerated by addition of catalysts either solid or liquid catalyst. The reaction in this study used a solid catalyst types Silica Alumina. The reaction takes place in the three-neck flask reactor which is equipped with heating unit, mixers, and tools to take samples at regular intervals. Variables used in this research is the variety of reaction time and the reaction temperature (70, 80, 90, 100, and 1100C). The concentration of triasetin obtained will be known through the analysis of Gas Chromatography - Mass Spectrometry (GC-MS). The results of the analysis of GC or GC-MS treated or counted so getting glycerol conversion and selectivity of triasetin. The highest glycerol conversion 8,45% occurs at a temperature of 700C the reaction time of 90 minutes with triasetin selectivity 100%.