Journal of Engineering and Technological Sciences
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Removal of Reactive Yellow 4R Azo Dye from Synthetic Aqueous Solution by Alkali Hydrothermally Activated Fly Ash
Get PDFDye-containing wastewater affects the aesthetic quality, transparency and gas solubility of natural water bodies, hence colored wastewater must be treated before being discharged. Physical removal of dyes from wastewater can be achieved using activated carbon. However, this technique is expensive, so there is a need to find less expensive alternatives. A waste product generated from coal-fired plants known as fly ash is a sorbent that can be used to remove pollutants from solution. This study investigated the effectiveness of using alkali (NaOH) hydrothermally activated fly ash to remove Reactive Yellow 4R azo dye from synthetic aqueous solution. Na2O in alkali hydrothermally activated fly ash increases thirteen-fold. SEM observations revealed that the raw fly ash consisted of smooth round shaped particles, whereas the activated fly ash was composed of granular crystalline particles. Batch adsorption experiments of the dye at 25 °C showed that increasing the activated fly ash quantity (0.5 to 3.5 g) increased the removal efficiency from 30% to 39.3%. The Freundlich isotherm adsorption model best described the adsorption of Reactive Yellow 4R dye by alkali hydrothermally activated fly ash with KF = 1.49 x 10-21 mg/g. The dye adsorption kinetics by activated fly ash followed the Lagergren pseudo second order model, with calculated qe = 2.65 mg/g; k2 = 0.06 g/mg; and calculated h = 0.42 mg/g min‑1. Dye removal occurred primarily through surface adsorption and very little through intra-particle diffusion
An Environment-Friendly Rock Excavation Method
Get PDFBlasting is used as an economical tool for rock excavation in mines. However, part of the explosive energy is converted into elastic waves, resulting in ground vibration and excessive vibration, which may cause damage to nearby buildings. Meanwhile, toxic gases are also produced during the explosion. In this paper, an environment-friendly method for rock excavation is proposed. A series of vibration tests were conducted, and the peak particle velocity was monitored. The results showed that the proposed method can replace the conventional blasting method in mines. Besides that, the vibration caused by the proposed method is much smaller than by the conventional method. By adjusting the direction of the high-pressure gas injection, buildings around the mine can be protected well from vibration. Also, the production of toxic gases during excavation will no longer be a problem. Thus, a milder environmental impact can be achieved. However, the rocks excavated by the proposed method are relatively large, which still need to be broken further. On this issue, further study is required
Kinetics and Characterization of Microalgae Biofuel by Microwave-assisted Pyrolysis Using Activated Carbon
Get PDFThe reaction kinetics and the effect of power on microwave-assisted pyrolysis (MAP) in converting microalgae to biofuel were investigated to determine the decomposition mechanism and then characterize the best product. The resulting product consisted of three phases, namely liquid phase (bio-oil), solid residue (char), and uncondensable gas products. The results showed that the optimal increase in microwave power obtained was 20.57% with a 600-watt microwave power condition, a reaction time of 20 minutes, a microwave absorber to microalgae ratio of 1:6, and a heating rate of 25.96 K/min (600 watts). The reaction kinetics evaluated in the best condition showed a second-order reaction with activition energy (Ea) and pre-exponential factor (A) at 35.5971 kJ/moles and 2,606.75/minute, respectively. The characteristics of the biofuel product obtained were 1.01 gr/mL density, viscosity 10.97 cP, and pH 9.30. In addition, based on GC-MS analysis, the bio-oil contained aliphatic, aromatic, phenol, FAME, and polycyclic aromatic hydrocarbon (PAH) organic compounds. These results indicate that MAP has the potential to be developed as an alternative production process for biofuels
A New Mechanical Analysis of a Crankshaft-connecting Rod Dynamics Using Lagrange’s Trigonometric Identities
Get PDFThe main objective of this study was to conduct a new and simple but accurate analysis of the dynamics of a crankshaft-connecting rod system based on Lagrange’s trigonometric identities. Actual and equivalent connecting rod mass approximations of single- and multi-cylinder reciprocating engines were studied. Several examples were studied to demonstrate the dynamics of the system. Lagrange’s trigonometric identities were used to simplify the model, while MATLAB was used to obtain the results. For both the proposed reduced model and the full model, the resultant forces and torques of an actual and an equivalent connecting rod mass were compared. The results showed that the proposed reduced model gives force and torque results that match the results of the full model very well. It was shown that the largest torque imbalance resultant on the crankshaft was exerted by the two-cylinder engine. In addition, it was shown that the largest external forces resultant acting in the x-direction was exerted by the one-cylinder engine. The results also revealed that the resultant of external forces acting in the y-direction was zero for multi-cylinder engines. The relative error, which mainly occurred at the points of maximum force and torque, ranged from about 1% to about 15%
The Effects of Long-Term Storage on the Quality of Palm Oil Biodiesel and Canola Oil Biodiesel
Get PDFEffective storage of biodiesel has proven to be a challenge, which the Indonesian government has invested billions of Indonesian rupiahs (IDR) in to overcome. It is thus important to investigate how different storage methods can affect the quality of biodiesel. The purpose of this study was to determine how storage at room temperature in the dark affects the quality of palm oil biodiesel (POB) and canola oil biodiesel (COB). POB and COB were stored in closed containers at 22 °C in the dark for 12 months. The results showed that POB was more significantly damaged than COB. This study found increases of density (POB by 51.52 kg/m3 and COB by 17.52 kg/m3), kinematic viscosity (POB by 0.67 mm2/s and COB by 0.32 mm2/s), acid value (POB by 0.27 mg-KOH/g and COB by 0.25 mg-KOH/g), total glycerol (POB by 0.58%-mass and COB by 0.60%-mass), and peroxide value (POB by 48 meq-O2/kg and COB by 54 meq-O2/kg), whereas there were decreases in fatty acid methyl esters (POB by 7.11%-mass and COB by 9.36%-mass). Gas chromatography-mass spectrometry results for POB and COB showed decreases in 9-octadecenoic acid methyl ester and 9,12-octadecadienoic acid (Z,Z)-methyl ester, and increases in 9-octadecenoic acid and 9,12-octadecadienoic acid (Z,Z). Fourier transform infrared spectroscopy (FTIR) results revealed the presence of methyl ester functional groups. The storage of biodiesel in a closed container at 22 °C in the dark can minimize biodiesel oxidation, as evidenced by the findings of this study, namely, the insignificant formation of ketone and aldehyde groups in the biodiesel oxidation process during storage, based on the results of FTIR
Land Subsidence Susceptibility Projection for Palembang Slum Area by Complex MCDM-AHP Technique
Get PDFLand subsidence is a geomorphological event that affects Earth’s structure and physiognomy. This phenomenon occurs when the groundwater volume changes and results in the movement and sinking of sediment. Several studies have been conducted to identify major causes or factors that may lead to land subsidence. It was found that land subsidence intensity is influenced by several factors, i.e. terrain slope and aspect, land use, soil moisture content, and distance to a river. Population density contributes to continuous changes in land use. Deep investigation of factors that contribute to land subsidence such as population density is important. This study investigated the relationship between land subsidence and population density contributing to continuous land-use changes. The study area was a highly populated slum area along the Musi River in Palembang, Indonesia. Factors that have high contribution to land subsidence were considered in developing a land subsidence susceptibility map. Susceptibility analysis was done using the Analytical Hierarchy Process (AHP) method. Land subsidence features were associated with slum features and the result revealed a significantly high correlation (r = 0.844) between actual land subsidence areas and the developed susceptibility map
Carbon Black and Lignin Hybrid Filler in Designing NR Based Cushion Gum Composite Formulation
Get PDFLignin has high potential to be used as rubber cushion gum compound ingredient due to its unique properties. Cushion gum is an adhesive used to bind a new tread to the surface of used tires in a retread tire factory. An experiment was carried out to evaluate the performance of hybrid filler consisting of carbon black and lignin in affecting the physical and mechanical properties of natural rubber (NR) based cushion gum composite. The composition of carbon black/lignin was arranged at 40/10 phr and 35/15 phr. Carbon black grade N220, N330, and N550 were used in this research. Meanwhile, the lignin was specifically in the form of sodium lignosulfonate. The cushion gum compound was also formulated with the addition of pine tar oil as bio-based plasticizer. Commercial cushion gum was used as a comparison. The result showed that the hybrid filled NR cushion gum composite with N330/lignin at 40/10 (coded as SP2) was the most appropriate formula. Compared to commercial cushion gum, the SP2 hybrid filled cushion gum had comparable or even better processability and mechanical properties, attributed to high crosslink density. The excellent adhesive strength of the SP2 NR cushion gum composite was due to the presence of high content of the phenolic functional group in lignin and pine tar oil
Production of Biogasoline via Pyrolysis of Oleic Acid Basic Soaps
Get PDFIn this study, an investigation on the effect of the Ca/Mg/Zn mixing ratio on gasoline-range hydrocarbon production by oleic basic soap pyrolysis was carried out. The ratios of calcium to magnesium used were 15%, 35%, 50%, 65%, and 85% with constant Zn. Oleic basic soap was obtained by saponification with the modified fusion method. Pyrolysis experiments were carried out at 450 °C using a semi-continuous reactor with a feed flow rate of 5 g/15 min. The process produced three fractions, i.e., gas, solid, and liquid (bio-hydrocarbon + water). The gas products were characterized by GC-TCD, and the results showed the presence of carbon dioxide, hydrogen, nitrogen, oxygen, and methane. Based on the GC-FID and FT-IR results, the bio-hydrocarbon comprised mainly homologous hydrocarbon from carbon number C7 to C19 containing n-alkanes, alkenes, various iso-alkanes, and some oxygenated compounds. All calcium ratios in the oleic basic soap produced hydrocarbon in the range of gasoline (C7-C11) as the dominant product. The maximum yield of gasoline (74.86%) was achieved at 15% calcium