Engineering Chemistry Vol. 2

Abstract: Two new copper-based metal organic frame work (Cu-MOF21 and CU-MOF-22) was synthesized using bromo malonaldehyde and terephthalic an amino terephthalic acid. They synthesized CU-MOFs were characterized by FT-IR, UV-Visible spectroscopy. The XRD diffraction pattern indicated 2 θ at 17.3° and 26.8°. The Tauc’s method was employed to calculate the band gap of Cu-MOFs and was found that Cu-MOFS-21 exhibited 3.14 eV and Cu-MOF-22 with average bandgap energy at 3.61 eV attributed to the ligand-metal charge transfer. The results indicate that both Cu-MOFs can be further modified by suitable dopants to enhance the conductivity and reduce the band gap energy. Keywords: Metal organic frameworks, Copper metal, Bandgap energy, photoluminescence,

Abstract: Metal organic frameworks are the materials of today’s generation and are widely used for their various physicochemical properties. MOFs are synthesized by various methods such chemical precipitation method, solgel method, hydrothermal method etc. To attain the required optoelectronic properties of MOFs, synthetic methods play a important role. In the present work, the synthesis of Cu-MOFs was carried out at 80 °C and 120 °C. The synthesized Cu-MOFs were labeled as RIT 62-Cu-MOF-1 and RIT 62-Cu-MOF-2. Both the Cu-MOFs were characterized by FTIR, UV-visible spectra. The FESEM of both Cu-MOFs indicated that spherical particles with 120 to 200 nms. of particle size. Tauc’s method was employed to compute the band gap of both Cu-MOFs. RIT 62-Cu-MOF-1 imparted 2.67 eV while RIT 62-Cu-MOF-2 imparted average of 2.06 eV off bandgap. 2.35 eV due to ligand-metal charge transfer observed through UV-visible spectra. Further, optimization of synthetic procedures to enhance the optical properties of Cu-MOFs.

Abstract: Coconut shell waste causes environmental pollution around the community. Therefore, it is necessary to have more optimal processing to produce valuable products using a microwave-assisted pyrolysis process. This study uses microwave-assisted pyrolysis (MAP) for the production of liquid smoke from coconut shells using different power (300, 450, 600 W) and sizes (1 mm, 2 mm, 3 mm). The results of this study show that the highest yield for 300 W power at 2 mm size by 22.85%, for 450 W power at 3 mm size by 28.52%, for 600 W power size 3 mm by 28.67%, while the optimal size for liquid smoke is 3 mm size by 31.95% at 450 W power.

Abstract: The addition of zinc oxide (ZnO) as impregnation for activated carbon (AC) with the hydrothermal method has been performed in this research. Vetiver distillation waste has been used as a precursor for activated carbon synthesized with pyrolisis methods. Carbon is activated by a chemical process using KOH. Enhancement of amorph structure and function group by addition of zinc oxide has been characterized by Raman Spectroscopy, Fourier Transform Infra-Red (FT-IR), and X-Ray Diffraction (XRD). Furthermore, cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) has been done to show the electrochemical properties enhancement of the ZnO/AC compared to pristine AC. At the current density of 1 A/g, the specific capacitance of VRW-ACM has a value of 277 F/g. After the impregnation process, the specific capacitance of VRW-ACM-ZnO has been improved by 44.4% compared to VRW-ACM. The result showed that the activated carbon-based vetiver root waste impregnated with ZnO has the potential to be applied as supercapacitors electrodes.

Abstract: This study focused on the optimization of methylene blue removal on a magnetic activated carbon from the carbon-rich agro-industrial residue, sugarcane bagasse, synthesized by microwave method. The adsorption process was assisted by ultrasound. The magnetic sugarcane bagasse activated carbon (MSB) was characterized by FTIR and SEM-EDX. Based on FTIR results, the functional groups found in magnetic sugarcane bagasse activated carbon are O-H, C=C, C-O, and Fe-O. The SEM results show that MSB is porous with a rough surface. In addition, EDX data found the presence of three main elements, namely C, O, and Fe. Response Surface Methodology (RSM) Box-Behnken Design was applied to analyze the effects of three parameters, including adsorbent dosage (50-100 mg/L), ultrasonic power (100-200 W), and contact time (30-60 min). The obtained optimum conditions of the adsorption process were the sonication power of 155.65 W, the adsorbent dosage of 89.77 mg/L, and the sonication time of 57,81 minutes. The results indicated that the parameters of adsorbent dosage, ultrasonic power, and contact time influenced the response (qe and methylene blue removal).

Abstract: Plastic industry development has increased the amount of plastic waste, including LDPE plastic film, therefore LDPE waste processing becomes essential, such as thermal or catalytic cracking. Cracking is the breakdown of complex hydrocarbons into simple and commercial hydrocarbons (C₃-C₄₀). The catalytic cracking is preferred due to lower temperatures, which is 200-300°C instead of 500-700°C. In this study, catalyst selection, acid impregnation of catalyst, catalyst loading (wt%), N₂-gas-purging, feed-to-solvent weight-ratio, temperature, and reaction time were studied to determine the most suitable process condition to obtain the highest liquid fraction. In this study, the catalytic cracking was conducted at 20 bar with kerosene as solvent, with and without N₂-gas-purging at several temperatures (265 and 295°C), solvent-to-feed weight-ratios (5:1 and 4:1), catalyst types (bentonite, SiO₂ and ZSM-5), catalyst loading (wt%) (1.0wt%; 5.0wt%; 7.0wt%; 9.0wt%; 10.0wt%), and reaction time (1-3 hours). The best results were with N₂-gas-purging using 10.0wt%-bentonite in (5:1) solvent-to-feed weight-ratio for 1 hour at 295^οC produced 54.9wt% of liquid fraction and without N₂-gas-purging at 265°C produced 54.5wt% of liquid fraction, indicating the possibility of N₂-gas-purging exclusion in future studies. Additionally, this study has promoted bentonite as a potentially viable catalyst for LDPE plastic waste catalytic cracking.

Abstract: The titled mononuclear complex [Cu (L)] with the formally tetradentate schiff base ligand, [N,N’-bis (2-hydroxy-3-methoxybenzylidene)-1,3-diaminopropan-2-ol] has been synthesized and characterized using IR spectroscopy and elemental analysis. Crystal structure has been determined by XRD which reveals the pseudo octahedral complex geometry and the use of hydroxo bridges between two neighbor units to form a 1D coordination polymer. The use of this complex as a catalyst for the degradation of two textile dyes, in the presence of the appropriate amount of H₂O₂ and a UV light source has given very good results with yields exceeding 98% after 50 minutes.