Process optimization for the production of biodiesel from Azolla Microphylla oil and its fuel characterization

The most competent and operative use of renewable feedstock is super critical for the production of biodiesel which has increased attention worldwide pertaining to aquatic fern Azolla. Maximizing the biodiesel yield by optimizing the process parameters of the low-frequency ultrasonic energy-assisted transesterification process of Azolla oil is the need of the hour for minimizing the production cost of biodiesel. Response Surface Methodology (RSM) was applied using central composite rotatable design (CCRD) to find the best optimum reaction parameters for this transesterification process. The optimized reaction parameters arrived from the design of experiments were as following: methanol/Azolla oils molar ratio (A) = 6.49 mole/mole, KOH catalyst concentration (B) = 1.69 (weight% of oil), reactiion time (C) = 34.74 min and reaction temperature (D) = 38.87°C. The best higher theoretical predicted Azolla Fatty Acid Methyl Ester (FAME) yield was Y = 99.76% which is in well coincidence with the actual yield. The extracted Azolla biodiesel was tested for various fuel properties with standard test procedures and found to be in agreement with various Biodiesel standards and the results are promising in terms of utilizing Azolla oil as an inexhaustible and potentially economical source of biodiesel.

Optimasi Sintesis Ligan Diheksilditiofosfat (DHDTP) Menggunakan Response Surface Method (RSM)

Dihexyldithiophosphate (DHDTP) ligand is one of the homologues of dialkyldithiophosphate which is potentially better as an extractant in solvent extraction. The longer the chain in the dialkyldithophosphate compound, ability to dissolve into the organic phase is increasing compared to the shorter chain. The purpose of this study is to synthesize DHDTP ligands and find out the optimum reaction conditions to produce DHDTP ligands with optimal purity using the BoxBehnken (BBD) response surface method (RSM). DHDTP ligands are synthesized from P2S5 by reflux after addition of n-hexanol under a nitrogen gas environment. Ammonium carbonate is added to the reflux to pH 7, then evaporated to remove the solvent. The synthesized DHDTP ligand was then purified by column chromatography with a mobile phase methanol : aquadest (2.5% gradient). DHDTP ligands were examined for purity using a reverse phase HPLC with a mobile phase methanol: aquadest 3: 2. The purity of the best DHDTP synthesis results obtained was 87.34%. The DHDTP ligand formed was characterized to confirm the structure of its ligand compound by using a UV spectrophotometer in which the synthesis product showed maximum absorption at a wavelength of 212 nm and mass spectroscopy ES- with m / z 297.1687.

Production of Biodiesel from Spirogyra elongata, a Common Freshwater Green Algae with High Oil Content

The need for exploring nonfood low-cost sustainable sources for biodiesel production is ever increasing. Commercial and industrial algae cultivation has numerous uses in biodiesel production. This study explores S. elongata as a new algal feedstock for the production of biodiesel that does not compete with food production. The major fatty acids identified in S. elongata oil were oleic (30.5%), lauric (29.9%), myristic (17.0%), and palmitic (14.2%) acids. Transesterification to FAME was conducted using basic (KOH), acidic (HCl), and Zeolitic catalysts for assessment. The yields with acidic (54.6%) and zeolitic (72.7%) catalysts were unremarkable during initial screening. The highest biodiesel yield (99.9%) was achieved using KOH, which was obtained with the optimum reaction conditions of 1.0% catalyst, 60 °C, 4 h, and an oil-to-methanol volume ratio of 1:4. The resulting S. elongata oil methyl esters exhibited densities, CNs, and IVs, that were within the ranges specified in the American (ASTM D6751) and European (EN 14214) biodiesel standards, where applicable. In addition, the high SVs and the moderately high CPs and PPs were attributed to the presence of large quantities of short-chain and saturated FAME, respectively. Overall, the composition and properties of FAME prepared from S. elongaae oil indicate that S. elongata is suitable as an alternative algal feedstock for the production of biodiesel.

Single-Step Green Synthesis of Iron Nanoparticles in the Aqueous Phase for Catalytic Application in Degradation of Malachite Green

The goal of the research was to devise a simple and environment-friendly approach to synthesize iron nanoparticles (FeNPs) and evaluate the catalytic activity of biosynthesized FeNPs for the degradation of the cationic dye Malachite Green (MG) in the presence of Peroxomonosulphate (PMS). Different instrumental approaches were used to characterize green produced FeNPs, and the results show that the NPs are spherical and 48 nm in size. Increasing the concentrations of nanoparticles (0.5 × 10-8 - 2.0 × 10-8 mol/dm3), Peroxomonosulphate (1.0 × 10-4 - 5.0 × 10-4 mol/dm3), dye (1.0 × 10-5 - 5.0 × 10-5 mol/dm3), pH (5), and high temperature (25-35 °C) enhanced the degradation kinetics of Pseudo-first-order kinetics were used to describe the degradation of MG in the FeNPs/PMS system, and activation parameters were derived. The maximum MG degrading efficiency for the FeNPs/PMS system was 88% in 60 minutes under optimum reaction conditions. The structure of intermediates formed by MG degradation by FeNPs/PMS was determined using UV-vis spectrum analysis. The application of synthesized FeNPs to improve Peroxomonosulphate oxidation potential for MG degradation is a unique, efficient, promising, and eco-friendly technology because it does not require any expensive reagents.

Simplified Method to Optimize Enzymatic Esters Syntheses in Solvent-Free Systems: Validation Using Literature and Experimental Data

The adoption of biocatalysis in solvent-free systems is an alternative to establish a greener esters production. An interesting correlation between the acid:alcohol molar ratio and biocatalyst (immobilized lipase) loading in the optimization of ester syntheses in solvent-free systems had been observed and explored. A simple mathematical tool named Substrate-Enzyme Relation (SER) has been developed, indicating a range of reaction conditions that resulted in high conversions. Here, SER utility has been validated using data from the literature and experimental assays, totalizing 39 different examples of solvent-free enzymatic esterifications. We found a good correlation between the SER trends and reaction conditions that promoted high conversions on the syntheses of short, mid, or long-chain esters. Moreover, the predictions obtained with SER are coherent with thermodynamic and kinetics aspects of enzymatic esterification in solvent-free systems. SER is an easy-to-handle tool to predict the reaction behavior, allowing obtaining optimum reaction conditions with a reduced number of experiments, including the adoption of reduced biocatalysts loadings.

Phenylalanine, Tyrosine, and DOPA Are Bona Fide Substrates for Bambusa oldhamii BoPAL4

Phenylalanine ammonia-lyase (PAL) links the plant primary and secondary metabolisms, and its product, trans-cinnamic acid, is derived into thousands of diverse phenylpropanoids. Bambusa oldhamii BoPAL4 has broad substrate specificity using L-phenylalanine, L-tyrosine, and L-3,4-dihydroxy phenylalanine (L-DOPA) as substrates to yield trans-cinnamic acid, p-coumaric acid, and caffeic acid, respectively. The optimum reaction pH of BoPAL4 for three substrates was measured at 9.0, 8.5, and 9.0, respectively. The optimum reaction temperatures of BoPAL4 for three substrates were obtained at 50, 60, and 40 °C, respectively. The Km values of BoPAL4 for three substrates were 2084, 98, and 956 μM, respectively. The kcat values of BoPAL4 for three substrates were 1.44, 0.18, and 0.06 σ-1, respectively. The major substrate specificity site mutant, BoPAL4-H123F, showed better affinity toward L-phenylalanine by decreasing its Km value to 640 μM and increasing its kcat value to 1.87 s-1. In comparison to wild-type BoPAL4, the specific activities of BoPAL4-H123F using L-tyrosine and L-DOPA as substrates retained 5.4% and 17.8% residual activities. Therefore, L-phenylalanine, L-tyrosine, and L-DOPA are bona fide substrates for BoPAL4.

Influence of Pd and Pt Promotion in Gold Based Bimetallic Catalysts on Selectivity Modulation in Furfural Base-Free Oxidation

Furfural (FF) has a high potential to become a major renewable platform molecule to produce biofuels and bio-based chemicals. The catalytic performances of AuxPty and AuxPdy bimetallic nanoparticulate systems supported on TiO2 were studied in a base-free aerobic oxidation of furfural to furoic acid (FA) and maleic acid (MA) in water. The characterization of the catalysts was performed using standard techniques. The optimum reaction conditions were also investigated, including the reaction time, the reaction temperature, the metal ratio, and the metal loading. The present work shows a synergistic effect existing between Au, Pd, and Pt in the alloy, where the performances of the catalysts were strongly dependent on the metal ratio. The highest selectivity (100%) to FA was obtained using Au3-Pd1 catalysts, with 88% using 0.5% Au3Pt1 with about 30% of FF conversion at 80 °C. Using Au-Pd-based catalysts, the maximum yield of MA (14%) and 5% of 2(5H)-furanone (FAO) were obtained by using a 2%Au1-Pd1/TiO2 catalyst at 110 °C.

Determination of Relationship between Higher Heating Value and Atomic Ratio of Hydrogen to Carbon in Spent Coffee Grounds by Hydrothermal Carbonization

This study was a preliminary investigation of solid recovered fuel production from spent coffee grounds using the hydrothermal carbonization (HTC) technique. The spent coffee grounds (SCGs) were subjected to HTC at 170 to 250 °C. The biochar was characterized by proximate analysis, ultimate analysis, capillary suction time, time to filter, suspended solids, and particle size distribution. The biochar yields decreased with increasing HTC temperature and time. However, the higher heating value (HHV) of biochar increased with the HTC temperature and time. The H/C slop relative to the O/C atomic rate of spent coffee grounds was 0.10 with low decarboxylation selectivity. Considering the HHV of biochar and dehydration capacity depend on ratio of H/C vs. O/C, the optimum reaction temperature of HTC was 200 °C, and the biochar from SCGs is an attractive biochar.

Extraction of cellulose from oil palm empty fruit bunch using eco-friendly solvents for preparation of transparent cellulose thin film

The purpose of this research is to extract the cellulose using eco-friendly reagents of hydrogen peroxide and formic acid and determine the optimum reaction time for delignification process. The extracted cellulose and characterised using FTIR, TGA and PSA. The percentage yield of extracted cellulose were calculated. The highest yield was found to be 65.78 % at reaction time 120 min. The FTIR spectral studies confirm the removal of lignin from the delignified cellulose at peak 1613 cm−1 and the TGA result shows the thermal degradation of extracted cellulose at 329.04, 329.92 and 330.99 °C at reaction time 60, 90 and 120 min. The PSA studies provided the evidence of extracted particle size of the cellulose become finer as the reaction time increase. The particle size observed for delignified cellulose at 60, 90 and 120 min are 68.4, 64.6 and 57.3 μm. The extraction of cellulose and characterization to determine the optimum reaction time was able to obtain. From the result obtained, it can be concluded that the longer the reaction time, the higher the percentage yield of cellulose extracted. Film formation was later carried out using the extracted cellulose from different reaction time.

Enhanced aquathermolysis of extra-heavy oil by application of transition metal oxides submicro-particles in relation to steam injection processes

In order to investigate the catalytic effects of transition metal oxides submicro-particles on aquathermolysis of Liaohe extra-heavy crude oil, the catalysts NiO, α·Fe2O3 and Co3O4 are used and evaluated during the experiments. The optimum mass fraction of the catalyst and water was determined to be 5.0 wt% and 30 wt%, respectively. The optimum reaction time for aquathermolysis was 24 h, and the optimum reaction temperature was 240 °C. The analysis results showed the heavy oil was upgraded dramatically by addition of the catalysts based upon viscosity reduction, saturate/aromatics/resins/asphaltenes analyses, elemental analysis, Fourier transform infrared spectroscopy and gas chromatography. All results show the heavy oil is in situ updated dramatically by catalytic aquathermolysis under the optimum operating conditions. A five-lump model is proposed for estimating kinetic parameters of aquathermolysis and agrees well with the experimental data.