bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio-hydrocarbon Production from Sorbitol using FeI2 to accelerate HI regeneration reaction
Authors: Krisnayana Rina , Subagjo  , Rasrendra CB , Hernas Soerawidjaja Tatang
Published: May 2020

Petroleum reserve decrease, while the dominant fuel used for daily needs and industry comes from petroleum. These fossil fuels cause global warming. Because of the above, hydrocarbon fuel from biomass is needed. On the laboratory-scale (1990’s), bio-hydrocarbon can be produced from sorbitol. This was obtained in 2 steps. The first step uses HI and H3PO3 and the second step is heating using KOH-ethanol. In the first step, HI regeneration using H3PO3 produces H3PO4, which is difficult to be reduced back to H3PO3. It makes the process become expensive, so it needs modification. The modification is done by using HCOOH for regenerating iodine into HI. In order to reduce the need for HI in the system, HI regeneration reaction is expected not slower than sorbitol reduction reaction by HI, so it requires FeI2 catalyst. Referring to the previous description, the purpose of this study is to investigate bio-hydrocarbon production from sorbitol using HI for sorbitol conversion, HCOOH for iodine regeneration, and FeI2 as catalyst to accelerate HI regeneration reaction. A sorbitol, HI, HCOOH and FeI2 mixture is refluxed in three-neck flask. Bio-hydrocarbon (C6H12) can be produced from sorbitol. Maximum sorbitol conversion is 85.84%, maximum iodohexane yield is 62.41% and maximum biohydrocarbon (C6H12) yield is 64.2%.
Synthesis of graphene oxide from industrial waste
Authors: Siaw W C , Tsuji T , Abdul Manaf N , Abdul Patah M F , Mohamed Jan B
Published: May 2020

This paper investigates a synthesis of graphene oxide (GO) from industrial waste via leaching and modified Hummers method. In leaching process, most of the impurities were effectively removed by dissolving into 6 M HCl at 70 °C for 210 mins to produce 92.28 % purity graphite residue. Subsequently, GO was synthesis via modified Hummers method with a combination of concentrated H2SO4 and KMnO4. The result from XRD and FTIR analyses confirmed that GO was successfully synthesized. Additionally, a monolayer and multilayer GO with wrinkles surface was observed by TEM which evident the existence of GO surface morphology.
Microwave-assisted Acid Pretreatment of Sago Wastewater for Fermentable Sugar Production
Authors: Illi Mohamad Puad Noor , Madihah Mohd Rashidi Ummul , Suhaida Azmi Azlin , Firdaus Abd Wahab Mohd
Published: May 2020

Sago wastewater (SWW) is one of by-products from sago starch industry. In most practice, SWW is discharged to the nearby rivers. As it contains high amount of organic compounds, usual practice of disposing the wastewater will cause a detrimental impact to the environment. The organic compounds found in SWW such as starch can be utilized as substrate for biofuel and biohydrogen fermentations. However, this starch needs to first undergo pretreatment process to breakdown its complex sugars to the simpler ones. This study aimed to investigate the effect of microwave-assisted acid pretreatment of SWW for fermentable sugar (glucose) production using sulphuric acid (H2SO4). Three parameters that influenced microwave-assisted acid pretreatment were chosen for optimization which are residence time (3-9 min), acid concentration (0.2-0.6 M) and solid loading (5-15% w/v). Faced Centered Central Composite Design (FCCCD) tool under Response Surface Methodology (RSM) in Design Expert v9.0.6.2 software was used for designing the experiments and optimization purposes. The response was the amount of glucose converted (g/L). The maximum fermentable sugar produced was 3.920 g/L, obtained at 9 minutes with 15% solid loading using 0.6 M of H2SO4. Then, the kinetic study of acid hydrolysis was performed by following the first order reaction kinetics. The rate constant of reaction obtained was 0.1684 min−1. It can be concluded that microwave-assisted acid pretreatment of SWW is able to produce high amount of fermentable sugar within a short residence time.
Characterization and Catalytic Activity of γ-Al2O3-ITB on Methanol Dehydration
Authors: Ardy A , Rizkiana J , Gunawan M L , Susanto H
Published: May 2020

National Plan on Energy of Indonesia 2017 states that dimethyl ether (DME, CH3OCH3) will be used as partial substitution of LPG for household fuel. Methanol dehydration using a solid catalyst is a common technology to produce DME. In this research, a catalyst γAl2O3 prepared in our laboratory has been characterized. This catalyst had a surface area of 194.4 m2/g, a total pore volume of 0.55 mL/g, and an average pore diameter of 112, 3 A˙. This catalyst had medium and high acidity sites. Activity tests of this catalyst were carried out in a fixed bed reactor at temperatures of 240, 260 and 280°C. The gas flow rates were related to the gas hourly space velocity of 1500, 2142 and 3000 h−1. Experimentally, the conversions of methanol were closed to that of thermodynamic conversions, i.e about 90% depending on the reaction temperature. The outlet gas was found to contain H2 up to 2% indicating that there were side reactions besides the dehydration of methanol to DME.
Kinetic Study of Simultaneous Ethanol Decomposition and Reduction of Low-grade Iron ore at Transient Temperature
Authors: Kurniawan A , Abe K , Sanada M , Nomura T , Akiyama T
Published: May 2020

An ethanol-assisted ironmaking method had previously been proposed, resulting in a significantly lower temperature of iron reduction. However, the kinetic mechanism remains unknown. A kinetic model for transient temperature condition was introduced, then numerically solved and curve-fitted to the experimental data using MATLAB software. There were 8 main reactions involved: (1) decomposition of ethanol, (2) decomposition of methane, (3) steam reforming of methane, (4) water-gas shift, (5) Boudoard reaction, (6) direct reduction by C, (7) indirect reduction of iron oxide by CO, and (8) iron reduction by H2. Curve fitting methods were successfully conducted with satisfying results (R2> 0.90) calculating three parameters consisting of reaction rate constants, activation energies, and diffusion factors of each reaction. The interpretation of the calculated diffusion factors reveals that the reaction of gases inside pore might be inhibited by carbon deposition on the pore surface of iron ore. It revealed that the direct reduction by C predominates the overall reduction process.
Aspen Plus simulation-based parametric study of Benfield process using hot potassium carbonate promoted by diethanolamine
Authors: Ngu L W W , Mahmoud A , Sunarso J
Published: May 2020

Simulating Benfield process that uses hot potassium carbonate as a chemical absorbent is a challenging task given the absence of the electrolyte system package in the more widely used simulation software such as Aspen Hysys and the fact that all of the existing simulation works have featured either the absorption column or the stripping column as a stand-alone process scenario. In this work, Benfield process is simulated using the Aspen Plus software as a whole process where the absorption column is integrated to the stripping column in a closed-loop mode. The chemical absorbent, i.e., hot potassium carbonate (K2CO3) is promoted by 3 wt.% of diethanolamine (DEA) to enhance the solubility of the carbon dioxide in the absorbent via higher reaction rate. The absorption column is simulated using rate-based approach while the stripping column is simulated using equilibrium approach. The simulation is validated against the industry data. The effects of stripping column boil-up ratio, solvent circulation rate, and K2CO3 concentration on the reboiler duty and the sweet gas CO2 concentration are studied. The lowest reboiler duty of 48 GCal h−1 and the lowest CO2 concentration of less than 50 ppmv are obtained using a boil-up ratio of 0.3, a solvent circulation rate of 35,000 kmol h−1, and K2CO3 concentration of 15 wt.%.
Effect of urea loading on the anodic synthesis of titania nanotube arrays photoanode to enhance photoelectrochemical performance
Authors: Elysabeth Tiur , Mulia Kamarza , Slamet
Published: May 2020

The development of efficient photoanode to improve the photoelectrochemical performance under UV light was investigated. The nitrogen-doped titania nanotube array was prepared by one step anodic oxidation of titanium foil in a solution of electrolyte-containing urea as nitrogen precursor at 50 V for 2h. During the process, the urea was added to the electrolyte solution with different concentrations, 0.1%, 0.2%, and 0.4% based on the weight of electrolyte that containing 25% water, 0.5% ammonium fluoride, and glycerol. The synthesis was followed by annealing at 500°C for 3h under 60ml/min of N2 gas to induce the crystalline phase. SEM analysis showed that titania nanotube was successfully synthesized with average diameter is 72 - 153 nm. Refer to XRD analysis titania nanotube mostly have anatase phase with the crystallite size of 27-37 nm depending on loading of urea. Bandgap energy was determined by UV-DRS analysis and showed that nitrogen-doped titania nanotube arrays have smaller bandgap energy. The photoelectrochemical responses of titania nanotube before and after nitrogen doping were examined by linear sweep voltammetry method. Photocurrent density measurements showed better activity on nitrogen-doped titania nanotube. Nitrogen-doped titania nanotube caused the flatband potential shifted to a negative value and the smaller space charge layer, resulting in the higher photocurrent density and photoconversion efficiency.
Selective Short Chain Carboxylic Acid Production over Fe:Zeolite Nanoparticles from CO2 Hydrogenation Reaction
Authors: Amat Bahari Nurazni , Nor Roslam Wan Isahak Wan
Published: May 2020

In recent years, formic acid become as an alternative fuel that offer useful solution for the efficient energy storage. The formic acid was synthesized by the carbon dioxide hydrogenation reaction by using catalyst. The preliminary study on catalyst between zeolite that act as support while hematite iron oxide (α-Fe2O3) that act as co-catalyst produced a new composite which is Fe-Zeolite. The Fe-Zeolite was synthesized by using sol-gel method with a weight ratio of 1:2 and 2:2. 1:2 of Fe-Zeolite gives the good activity for the production of formic acid which is 1305.41 ppm. The presence of different support material such as zeolite and mesoporous silica nanoparticles (MSN) showed a significant difference in the catalytic performance and formic acid selectivity. The morphological and textural properties of the synthesized catalysts were determined by FTIR, XRD, TEM, and FESEM while the formation of formic acid from CO2 hydrogenation reaction was evaluated using High Performance Liquid Chromatography (HPLC).
A design method for the integration of heat and control in a process of toluene hydrodealkylation
Authors: Kim Nguyen Trung , Khoi Phuc Nguyen Nguyen , Dinh Nguyen Thu , Nguyen Tuan-Anh , Tetsuo Fuchino
Published: May 2020

The integration of heat and process control, strategies for designing a process that consumes minimum energy and improves controllability has been received an increasing interest by process engineers. The techniques of heat integration to improve efficiency of energy consumption normally consume necessary degree of freedom and raise difficulties in control design. This study aims to develop a method that compromise between heat recovery of a heat exchanger network and control performance of a process by balancing the duties of utility streams. A process without heat recovery should transfer all required energy (Q-Total) using utilities. This study suggested to leave a part of Q-Total as utility streams (Q-Utility) to serve as manipulated variables of a control system. This method can be described in a four-step procedure. In the first step, the Q-Utility of a process is determined. The pinch technology is applied to develop a heat exchanger network for heat recovery in the second step. The streams which relates to the Q-Utility should not be included in the pinch analysis. In the third step, a control system is properly designed by using the Q-Utility streams as manipulated variables. In the fourth step, some disturbances are introduced to the system in the form of pulse inputs to test the controllability and resiliency of the control system. This method was applied successfully to an industrial scale case study which was hydrodealkylation of toluene process. The control system was considered with three levels of Q-Utility which were 5%, 10% and 100% of Q-Total. The dynamic performance results revealed that when disturbances occurred, the process with 100%-Utility was very stable at its designed parameters. However, the alternative with 100%-Utility is not a good option because of its economic waste. Either 5% case or 10% case involved its own benefits and drawbacks. If a plant is well equipped with a good emergency response system and fast troubleshooting, then the 5% case should be chosen. It means the utility percentage for control design can be decreased and economic benefits of heat recovery can be increased. If the 10% case is chosen, the controllability can be improved but it should be compensated by increasing the utility cost.
Parametric and optimization studies for biochar production from municipal solid wastes (MSW) via pyrolysis
Authors: Castillo Katrina Joy T. , Concepcion Maguyon-Detras Monet , Migo Veronica P. , Alfafara Catalino G.
Published: May 2020

The accumulation of municipal solid wastes (MSW) and the negative implications of using fossil fuels are some of the current environmental issues in the Philippines. Hence, this study aimed to utilize MSW by converting it into biochar through pyrolysis and maximize biochar production for energy application. The effects of pyrolysis parameters such as temperature and holding time on biochar yield were initially determined using 2k factorial experiment. Results showed that both factors had negative effects on biochar yield wherein temperature had a relatively higher impact. For the optimization study, Response Surface Methodology (RSM) was performed to determine the optimum pyrolysis conditions for maximum biochar production. The optimum conditions were found to be 300°C and 20 min holding time resulting to maximum biochar yield of 69.64 % by wt. Biochar characteristics were evaluated in terms of higher heating value (HHV), proximate and elemental analyses to determine its suitability as alternative fuel. The HHV of biochar obtained at optimum conditions was about 15.82 MJ/kg which is higher compared to that of the raw MSW (14.42 MJ/kg) and biochar obtained at extreme conditions (13.03 MJ/kg). Moreover, the energy recovery at optimum conditions based on biochar yield was about 76.37% which was also higher compared to that of the biochar obtained at higher temperature and holding time which was about 32.75 %. Using van Krevelen diagram, MSW-derived biochar at the optimum conditions can be classified as lignite, while MSW-derived biochar at extreme conditions is comparable to anthracite coal.
Model predictive control of vinyl chloride monomer process by Aspen Plus Dynamics and MATLAB/Simulink co-simulation approach
Authors: Chinprasit J , Panjapornpon C
Published: May 2020

Characteristics of a vinyl chloride monomer (VCM) process is complex and nonlinear due to interactions between units in a reaction-separation network, multiple process streams, and multiple control loops involved. A fluctuation of the thermal cracking unit could result in a difficulty in maintaining downstream units at the setpoints. In this work, an approach to develop a model predictive control (MPC) for the VCM process by deploying a co-simulation between MATLAB/Simulink and Aspen Plus Dynamics is presented. The co-simulation provides more capability and comfortability to design the MPC controller, and evaluate controllability. The VCM process consisting of thermal cracking, quench and distillation is modelled by Aspen Plus Dynamics. The MPC is developed by integrating the concept of plant-wide control and subsystem partitioning. To reduce the burden of mathematical modeling, the MATLAB system identification toolbox is used to develop a multivariable linear model for the MPC controller by reconciling dynamics data from the VCM plant model. Performances of the developed MPC is evaluated under the regulatory test of the EDC feed disturbance. By comparison with the multiple single-input-single-output proportional-integral controllers through the efficiency indexes—an integral squared error, an overshoot and a settling time. Simulation results supported that the MPC controller outperforms proportional-integral controllers.
Dynamic Multi-Objective Optimization of Autocatalytic Esterification in Semi Batch by Using Control Vector Parameterization (CVP) and Non-Dominated Sorting Genetic Algorithm (NSGA-II)
Authors: Rohman F S , Aziz N
Published: May 2020

Catalyzed Esterification of sec-butyl propionate in semi batch reactor prefers to be solved by dynamic-nonlinear programming (NLP) based optimization for determining optimal temperature and feed flowrate trajectories. In this autocatalytic esterification process, there are contrary objective functions, i.e. maximum productivity and minimum process time. Simultaneous optimization of these objectives yields in a dynamic multi-objective optimization (DMOO) problem, which is characterized by a set of multiple solutions, known as non-dominated or Pareto solutions. In this work, a control vector parameterization (CVP) and non-dominated sorting genetic algorithm (NSGA-II) approach were used to generate the Pareto solutions for two objectives: maximize conversion and minimize process time. Each point of Pareto solutions consists of different optimal temperature reactor and feed rate profiles, which lead to a variation combination of conversion and process time. These solutions give multiple alternatives in evaluating the trade-offs and selecting the most suitable operating policy.
Optimal Control of Carbon Dioxide Exchange Process in a Membrane Oxygenator Using Particle Swarm Optimization Approach
Authors: Hazfiza Manap Hany , Khairi Abdul Wahab Ahmad , Mohamed Zuki Fathiah
Published: May 2020

The aim of this study is to evaluate the performance of Zeigler-Nichols continuous cycling and particle swarm optimization (PSO) method in tuning the optimal gains for Proportional-Integral-Derivative (PID). PID controller is implemented to control the rate of CO2 elimination from a membrane oxygenator during extracorporeal blood purification process. The sweep gas flow rate is chosen as the manipulated variable to control arterial CO2 partial pressure (pCO2) in blood. The Zeigler-Nichols continuous cycling tuning method is employed for tuning purpose and the performance of each controller (P-only, PI and PID) are evaluated based on three performance indices, namely integral absolute error (IAE), integral squared error (ISE) and integral time absolute error (ITAE). Next, the optimization algorithm known as PSO is used to calculate the gain parameter that can produce the best control action. The robustness of these tuning methods is assessed for set point tracking and load disturbance rejection tests. Results indicated that the PID is seen as the best controller compared to the classical controllers such as P and PI when Zeigler-Nichols continuous cycling as the tuning method is implemented. However, further tests highlighted the PSO-PID strategy (PID parameters that are optimized by PSO) showed even better control responses compared to PID alone. Thus, it can be concluded that optimization strategy by PSO method is the best tuning method to be used in determining the controller parameters for the automation of extracorporeal circulation control for both set point tracking and load disturbance rejection tests.
Artificial Neural Network Topology Optimization using K-Fold Cross Validation for Spray Drying of Coconut Milk
Authors: Lee Kar Ming Jesse , Saleena Taip Farah , Shamsul Anuar Mohd , Bahari Mohd Noor Samsul , Abdullah Zalizawati
Published: May 2020

In this study, the development of an optimized topology neural network model for spray drying coconut milk is investigated using K-fold cross validation technique. Performance between standalone ANN and ANN with K-fold cross validation is compared, as K-fold cross validation method is integrated into neural network to overcome the limitations of restricted dataset. With inlet temperature (140 °C-180 °C), concentration of maltodextrin and sodium caseinate (0 w/w %- 10w/w %) are established as the input parameters, while moisture content (3.64%-5.1%), outlet temperature (76.5 °C-104.5 °C) and surface free fat percentage (0.35%-34.51%) are the output parameters for the neural network. Experimental data from the spray drying process is used to develop the neural network. Selection from the best training algorithm (gradient descent backpropagation, gradient descent with momentum, resilience backpropagation, conjugate gradient backpropagation with Polak-Riebre restarts, conjugate gradient backpropagation with Fletcher-Reeves, scaled conjugate gradient, Broyden-Flectcher-Goldfard-Shanno backpropagation algorithm and Levenberg-Marquardt backpropagation), transfer function (tansig, logsig, purelin and satlin), number of training runs (1000-5000), number of hidden layers (1-3) and nodes (5-15) have significant effect on the performance of the ANN models based on the lowest MSE values and R2 values. Overall, the optimum topology ANN model with k-fold cross validation outperformed the recorded lowest MSE value of 0.064 and highest R2 value of 0.855 compared to the optimum standalone ANN model with MSE value of 0.082 and R2 value of 0.832. The optimum ANN with K-fold cross validation implements the Levenberg-Marquart training algorithm with hyperbolic tangent sigmoid transfer function using 4500 times training runs with optimal topology configuration of 3-8-2-3. Result concludes that the developed neural network using K-fold cross validation represents the spray drying process as a highly reliable model with high degree of accuracy.
Supply chain pinch analysis to optimal planning of biogas production
Authors: Kow Z Y , Tan Jully , Kiew P L , Zanil M F
Published: May 2020

Supply chain is essential for an organization as it helps to maximize the operations which are profitable through the production, capacity, subcontracting, inventory and stock outs optimum levels. The traditional supply chain involves high documentation cost, with data involved that are mostly inaccurate and useless. In supply chain, the system of production plays an important role. The pinch analysis concept is initially used in the approach of energy conservation, and has extended to the optimization of resources and process integration. This paper presents the application of supply chain using pinch and cascade analysis for biogas production from palm oil mill effluent (POME). Biogas falls under the renewable energy where it can be produced via anaerobic digestion of POME. POME contributes to huge environmental impact mainly due to its high organic content. Supply chain via pinch analysis is used targeting to eliminate or reduce the difficulties faced in conventional supply chain. In this biogas supply chain analysis, it aims to meet the demand in a specific time frame. Minimum production rates are determined as accordance to the demand of electricity from 2020 to 2050. The pinch points are the points where the supply and demand are at the minimum, which the optimum production rate of electricity is able to determine from supply chain via pinch analysis. Monte Carlo Simulation tool is involved in the later stage of the study. It is used in the findings of analysing the increment of more than 10% of up-scale and down-scale production demand for each year for 35 years. The simulation is done from 2016 to 2035 of every five years interval. At the end of the study, the optimization of biogas production was achieved with the application of supply chain via pinch analysis. The supply and demand of biogas to electricity projection from 2020 to 2050 is forecasted. The optimal planning of electricity production from biogas was indicated in the supply chain cascade analysis.
Improvement of Gasification Efficiency with Consideration for Microwave Input Power on Biogas Reformulation by Microwave Plasma Assisted Combustion
Authors: Yamamoto T. , Uchiyama S. , Matsune H. , Kishida M.
Published: May 2020

Extended Abstract

In recent years, the effective use of low grade fossil fuel and the diversity of fuels are required due to the exhaustion of fossil fuels, global warming and the nuclear accident caused by the Tohoku earthquake in Japan. The studies of brown coal, biomass, biofuel, etc. are being conducted to expand the use of these fuels throughout the world. We have paid attention to biogas among such low grade fuels. Biogas is a carbon neutral fuel to be generated from garbage, livestock manure, sewage sludge, etc. CO2 emitted by its combustion is not converted to greenhouse gases. On the other hand, biogas is primarily composed of 60% CH4 and 40% CO2, and has a low calorific value. Low calorific value does not make biogas easy to apply to a conventional energy utility system. To utilize biogas, it is necessary to develop the combustion promotion technology of biogas or upgrade biogas.
Application of Surfactant-Polymer Flooding for Improving Oil Recovery in the Indonesian Oil Field
Authors: Hasokowati W , Rochmadi  , Purwono S , Murachman B , Wintoko J , Yuliansyah A T , Azis M M
Published: May 2020

The goal of this research is to investigate the effect of surfactant and polymer found in the market and developed in the laboratory such as Sodium Ligno Sulfonat, Poly Vynil Alcohol (PVA) and Partially Hydrolyzed Polyacrylamide (HPAM) polymer on the oil recovery which can be used to optimize recovery and minimize residual oil in the reservoir by: lowering the oil / water interfacial tension and improving mobility ratio. The effectiveness of chemicals was tested through micro displacement using artificial reservoir as porous medium. The procedure of operation is as follows: initially the reservoir model was filled with brine until it was 100 % saturated. Then to represent oil migration, oil was injected into the medium until minimum water saturation (Swc) of about 30 % is reached. After this, the medium was flooded by the same brine until minimum oil saturation, Sor, was reached, which was about 10 %. The oil remaining in the reservoir model after this water flood was then subjected to the injection of various chemicals for additional oil recovery. A set of mathematical model of oil displacement from porous media using water and polymer flooding has also been developed, based on fundamental theories of two phase flow. Since the model includes the material balance of the water, surfactant and polymer, the concentration of the surfactant and polymer at any position and time can be predicted. The oil displacement experiments show that as much as 20 % to 60 % of remaining oil can be recovered by flooding it with the chemical developed in the laboratory. The results also show the oil recovery depends on chemical, chemical concentration, pressure and temperature in the model reservoir, and crude oil. It turns that the mathematical models proposed were in a good agreement with the experimental data.
Agile solar roof tile HVAC
Authors: Sinha S , Abdul Manaf N , Pethe K , Tri Luu M , Milani D , Abbas A
Published: May 2020

This paper studies the technical feasibility of a novel solar roof tile (SRT) to be used for HVAC (heating, ventilation and air conditioning) in buildings. The SRT utilizes a phase change material (PCM) for thermal storage. The SRT works like a conventional thermal storage tank while featuring compact size and lower cost. Two heat exchangers are connected one each on the top and bottom of the PCM matrix. The top heat exchanger functions as an absorber of solar heat. Aqueous sodium hydroxide passes to the top heat exchanger from a storage sump. The bottom heat exchanger is the condenser and evaporator with water passing through the heat exchanger. The cooling system is integrated inside the customised roof tile interlocking system. This system uses roof tiles that have higher performance during extreme weather conditions and lower maintenance costs. In this paper, we have investigated the thermal performance and technical feasibility of the proposed solar SRT-HVAC system. This proposition eliminates conventional thermal storage tanks used in solar thermal collectors. The dynamic performance of the SRT under transient conditions is evaluated using the TRNSYS modelling package, which shows the influence of design variables like insulation points and charging/discharging durations on thermal storage performance.
Synthesis of Biodiesel from Kapok Seed Oil using CaO/Dolomite Catalyst and Its Comparison with Homogeneous Catalyst
Authors: Sutrisno Bachrun , Dysca Sanada Maydina , Kurniawan Winarto , Hidayat Arif , Hinode Hirofumi
Published: May 2020

Biodiesel as renewable energy resources has been attracted more intense study because of the alternative effort to reduce dependency of fossil fuel. Commonly biodiesel production is produced using edible oils as feedstock. However, the problems related to the competition between foods versus energy supply have been concerned in the past few decades. The dependency on edible oils as biodiesel feedstock could be reducing by using non edible oils. Furthermore, using non edible oil as feedstock will make the biodiesel prices appropriate to compete with fossil fuel prices. In this research, synthesis of biodiesel from kapok seed oil using CaO/Dolomite catalyst as heterogeneous catalyst and its comparison with homogeneous catalyst was studied. The properties of CaO/Dolomite catalysts were determined in term of porosity analysis (adsorption and desorption of N2), crystaline structure (X-Ray Diffraction), and analysis of element compositons (X-Ray Fluorescence). The biodiesel yield as high as was 92.9% achieved at following reaction conditions: 60°C of reaction temperature, 3:1 methanol to KSO mass ratio, and catalyst amount 10 wt. % of KSO.
Pyrolysis and Carbon Dioxide Gasification Kinetics of Pine Cones and Lignite Blends
Authors: Ang Janica Y. , Dee Perry C. , Tan Amos B. , Bungay Vergel C.
Published: May 2020

This study determines the kinetic parameters of blended Pinus kesiya, Pinus elliottii, and Indonesian lignite in co-pyrolysis and co-gasification. Nine binary blends and three ternary blends were tested using a thermogravimetric analyzer. Pyrolysis was carried out in an argon atmosphere and DTG plots showed that Pinus kesiya had the highest maximum pyrolysis rate while Pinus elliottii had the lowest starting decomposition temperature. Similarly, blends with Pinus elliottii had lower maximum pyrolysis rates and lower starting decomposition temperatures than those with Pinus kesiya. Ternary blends, however, have starting decomposition temperatures and maximum pyrolysis rates close to those of pure Pinus elliottii. The Kissinger-Akahira-Sunose (KAS) model was used to obtain the reaction rate constants and activation energies of the pyrolysis reactions of various blends. Co-gasification of the mixtures was also done in a CO2 environment at gasification temperatures of 700°C, 800°C, and 900°C. The conversion-time data obtained were fitted using five different gas-solid reaction models.
Biogas production from cassava waste: effect of concentration
Authors: Kohmuean P , Boonrod N , Wongkoblap A
Published: May 2020

In the lactic acid production from cassava, there is cassava waste generated from saccharification process. This study intends to investigate the effects of substrate concentration on fermentative methane and carbon dioxide from cassava waste using activated sludge obtained from the cassava production plant and the biogas production was determined in batch experiments. The ratio between cassava waste and sludge of 1:1, 1:2, 2:1 and 1:0 at 34°C were used in this investigation. The rate of fermentation and methane yield were observed during the fermentation. First, we investigated whether the biogas can occur without the additional microorganism. It was found that methane can occur within 6 days for the batch adding the biological sludge, while it cannot be observed in the case of the reactor free of adding the microflora. The suitable ratio in this study was found that cassava waste and sludge of 1:1 can produce the greatest biomethane in biogas. The quality of biogas occurred in batch reactor composed of 63.1% CH4, 34.4% CO2, 2.2% of oxygen and 0.3% of other gases. It is noted that at this ratio, the hydrogen sulfide (H2S) was not detected while it was 4 ppm in the case of higher sludge added in the reactor.
Process Design and Steady State Simulation of Natural Gas Dehydration Using Triethylene Glycol (TEG) to Obtain The Optimum Total Annual Costs (TAC)
Authors: Kharisma N , Arianti P S D , Affandy S A , Anugraha R P , Juwari  , Renanto
Published: May 2020

Natural gas is one of the most desired raw materials which can be used in petrochemical industries or as energy resource. Natural gas usually obtained from underground reservoirs and it must go through purification process so it can be utilized. All acid gas compounds such as H2S, CO2 and all liquids including H2O must be removed. Most industries use triethylene glycol (TEG) dehydration unit to absorb water from natural gas streams. Therefore, further research about design and optimization of dehydration unit using TEG should be conducted since the optimization of dehydration unit using TEG affects to safety, operability, and stability of the process. In this study, the optimization of TEG Dehydration Unit process is conducted to minimize the Total Annual Costs (TAC) and improve the efficiency of the process. Aspen Plus software is used to perform the simulation of TEG dehydration process. Optimization is conducted by changing several of the base case operating conditions which have been created using existing condition to obtain the optimum conditions with minimum TAC on the existing circumstances. The variables that are used in this research is absorber column pressure (35-45 barg with 2.5 barg interval) and lean TEG temperature (39-49°C with 2°C interval). The constrain of the absorber column pressure is less than 45 barg, since the natural gas feed pressure from well is 45.16 barg. The results show that by changing some operating conditions can reduce the size of the column, reduce the energy costs including steam, cooling water, and electricity costs. Therefore, it can reduce the TAC of the natural gas dehydration unit. The validation simulation results of the steady state of the TEG Dehydration Unit using Aspen Plus and the real plant produces relatively small % error, so it can be used to create a base case using the existing data. The mole fraction of H2O in dehydrated gas after optimization using Aspen Plus is 0.000178 while in real plant the result is 0.000200. The simulation results can reduce the TAC from 3, 416, 739 USD to 2, 973, 219 USD.
Optimization of Small-Scale Natural Gas Liquefaction using Nitrogen Expander with Precooled Cycle
Authors: Henryawan M A , Purwanto W W
Published: May 2020

Nitrogen expander is the liquefaction process which suitable for small scale liquefied natural gas plant because its characteristic. However, the major issue of technology is low energy efficiency. In this study, optimization of small-scale natural gas liquefaction process using nitrogen expander with precooled cycles were conducted. The specific energy consumption is chosen as an objective function with decision variables are natural gas pressure after compression, nitrogen pressure after compression, inlet temperature of high pressure expander, evaporation temperature in precooling cycle, and type of precooling refrigerant. The refrigerant used for precooling cycle are propane, cyclopropane, isobutane, butane, and neopentane. The simulation and optimization processes are are performed by UniSim and GAMS software. The results show that integrating precooling cycle to the nitrogen expander system can reduce specific energy consumption up to 25, 24% and propane is the most effective precooling refrigerant.
Incineration of Ammonia Wastewater and The Effect to The Environment
Authors: A Rahim B Norman A. , Noorhidayah Bt Hussein B. , Fadzrul Izwan B M Ali C.
Published: May 2020

Wastewater containing ammonia is normally sent to the wastewater treatment system in a chemical plant for the removal of ammonia compound. Alternatively, it is proposed to remove the ammonia compound by incinerating the wastewater using the existing incinerator system. However, it is essential to ensure that the gaseous and aqueous emission produced by the incinerator system do not exceed the Clean Air Regulations (CAR) 2014 and Industrial Effluent Regulations (IER) 2009 limits, especially the nitrogen oxides (NOx) content and unburnt ammonia compound. A process simulation model of the incinerator system was developed using a Gibbs energy minimization reactor approach coupled with Gasification property package to predict the products of the incineration process. Two case study runs were conducted to evaluate the impact of incinerator operating temperature and ammonia concentration in the wastewater feed. Theoretically, there are two causes of NOx production; from thermal NOx (oxidation of nitrogen at high temperature) and fuel NOx (oxidation of liberated nitrogen from ammonia). The study showed that the thermal NOx effect is significantly higher than fuel NOx effect through this study. This is because the total liberated nitrogen molecules from the intended concentration of ammonia in the aqueous water is comparatively small when compared with the amount of nitrogen molecules in the combustion air. Based on the case study results, there is very minimal impact of ammonia injection on total NOx production as the incinerator temperature is commonly controlled on a fixed set point. There is also opportunity to reduce fuel gas requirement because the heating value of the waste streams increases through the combustion of hydrogen molecules in ammonia.
Treatment and Recycling of Wastewater From Food Industry using Fixed-Bed Adsorption Treatment on the Tertiary Stage
Authors: Haslija Abu Bakar Ayu , Thaarani Priya
Published: May 2020

Water pollution occurs when toxic pollutants of varying kinds (organic and inorganic) are directly or indirectly discharged into water bodies without adequate treatment to remove such potential pollutants. Today’s sources of these potential pollutants, which cause high deterioration of freshwater quality, are industrial waste discharge, and industrial waste disposal practices. Therefore, the development of wastewater treatment processes to alleviate water pollution has been challenging and demanding. Food wastewater was characterized using COD, DO, Turbidity, pH, TS, TDS, and TSS. Comprising a mixture of areas including physical, and chemical methods to remove various potential pollutants. In this study, coagulation, sedimentation, and adsorption treatment were used to remove the pollutants contained in wastewater and also the treated water recycled back to the food processing industry. In addition, Superpro Designer Software was used to design a water recycling system that successfully meets the requirements of the standard A Regulation on Malaysia Environmental Quality.
COD Treatment of Printing Ink Wastewater by Column Adsorption using Activated Carbon
Authors: Haslija Abu Bakar Ayu , Elvira Veni
Published: May 2020

Direct discharge of untreated industrial effluents containing high COD is hazardous to the environment. This study explores the efficiency of commercial activated carbon to uptake of the organic components responsible for the chemical oxygen demand of ink wastewater by column adsorption. The main objective of this research is to reduce the COD of ink wastewater to below its predetermined standard adopted from WHO and Environmental Quality Regulation 2009. For this purpose, the wastewater was investigated by analyzing its characteristic including pH, TSS, TDS, BOD, colour, turbidity and COD. Meanwhile, activated carbon used is PKSAC (Palm Kernel Shell Activated Carbon). COD adsorption studies with this activated carbon were carried out under different conditions and influence by different parameters such as pH and bed height in column adsorption. The performance study showed the condition in which pH does not show significant effect on the COD removal and the highest percentage of COD removal were found at bed height 3 cm with the percentage removal of 65%. This indicate, % of COD removal increase with increasing in bed height. Furthermore, the minimum bed height required to treat the water sample was recorded to be 0.8 cm analyzed by BDST model. The present study prove that the activated carbon was one of the effective ways in removal of COD.
Immobilization of cadmium (Cd2+) in contaminated soil using biochar derived from Calophyllum inophyllum (bitaog) seed husks
Authors: Oblepias J L , Pana T N , Villanueva M , Dimaano M N
Published: May 2020

Many heavy metals such as cadmium found in contaminated soil naturally leach out and seep in groundwater through time. Natural leaching is further accelerated in acidic conditions specifically with acid rain. This study investigated the effectiveness of biochar derived from Calophyllum inophyllum (Bitaog) seed husks as an immobilizing agent through a simulated acid rain leaching test (equivalent to 100 years of acid rain) using artificially contaminated soil. Furthermore, magnetization and phosphoric acid treatment were utilized to produce modified biochar where Thermo-gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) analyses revealed that the modifications led to the enhancement of physiochemical properties such as fixed carbon content, surface morphology, and surface chemistry respectively. Walkley-Black Loss on Ignition test showed that all the biochar amendment increased the organic matter content of soil making it attractive for in-soil applications. Adsorption kinetic and isotherm models were used to describe the adsorption mechanism of cadmium onto the soil amended with modified and unmodified biochar where experimental results showed that the adsorption best fitted the pseudo-second order kinetic and Langmuir isotherm models. The leaching test results showed that the soil amended with magnetic and phosphoric acid modified biochar were not suitable as immobilizing agents especially in highly acidic conditions. Whereas the unmodified biochar significantly reduced leached cadmium concentration by 40.02% than in unamended soil as shown by the AAS results. Bitaog derived biochar was affirmed to be potentially effective for the long-term immobilization of cadmium in contaminated soil while may simultaneously increase soil fertility.
The Steps in Preventing, Monitoring and Removing of Fouling Scale on Operation of Evaporator
Authors: Salimin Zainus , Kistriyani Lilis , Ratiko
Published: May 2020

Concentrating of solution by evaporation with tubular heating surface evaporator is the effective method for decontamination of radioactive waste. Radioactive matter was concentrate with decontamination factor 104-105 for Cs-137. The evaporation of liquid waste from Serpong Nuclear Facilities having the permanent hardness of CaSO4 and MgSO4 with ratio of 2:1 generates fouling scale. The presence of scale on the evaporator gives the additional cost i.e. increasing of the capital investment cause of oversize of heat transfer surface area, increasing of energy cost for same evaporator capacity due to the presence of fouling heat transfer resistance, the presence of time loosing for maintenance and descaling, the chemical cost for descaling, and decreasing of the production capacity cause of decreasing of production time comparing the condition without the presence of fouling scale. For the problem solution, it is necessary to perform the sequence action starting the prevention of fouling scale formation, than monitoring of the fouling factor (Rd), and finally removing of fouling scale by chemical descaling. The prevention of fouling scale formation is performed by separation of soluble and suspended solid and utilization of chemical inhibitor before evaporation operation. The monitoring of fouling factor is performed during evaporation operation by reading the operating parameter of evaporation on the control panel i.e. mass flow rate of heating steam, mass flow rate of liquid waste, the input and output of steam temperature, and the input and output of liquid waste temperature. The energy for evaporation can be calculated, than the clean and dirty overall heat transfer coefficient can be calculated, so the fouling factor can be obtain. The removing of fouling scale or descaling process is performed by immersion of evaporator circuits using nitric acid solution of 10% weight concentration, and by mechanical brushing during maintenance activity. The prevention, monitoring, and removing of scale fouling on the operation of evaporator is described on the paper.
Bio-remediation of palm oil mill effluent (POME) using Aspergillus niger immobilized on coconut husk and free cell fermentation
Authors: Thegarathah P , Jewaratnam J , Simarani K
Published: May 2020

Aspergillus niger which is ubiquitous and acts as good biological agent has been chosen to treat POME in this study. Use of, free cell fermentation limits the uptake of substrate as compared to immobilization method which provides larger surface area for cell growth. Therefore, the idea of using coconut husk as immobilization medium has been proposed. Coconut is widely available in Malaysia almost at no cost. Hence, the purpose of this study is to evaluate the bio-degradation of palm oil mill effluent by Aspergillus niger through immobilization on coconut husk and free cell fermentation. Substrates from different types of POME such as. raw, sterile, treated using Aspergillus niger through free cell fermentation and treated with Aspergillus niger cells which are immobilized on coconut husk were prepared at different concentration range from 0 to 100%. Aspergillus niger cells (1 X 105 cells per ml were inoculated into Erlenmeyer flasks and incubated at 30 ± 2 °C and 150 rpm for seven days. Fermentation slurry were used to analyse for turbidity, COD and pH. The results were compared with free cell fermentation method. Raw POME has significantly low turbidity as compared to sterile and treated POME. Autoclaving POME increases the turbidity. 100% sterile POME shows the highest turbidity which is 979.5 FAU and 100% POME which was treated by immobilization on coconut husk shows a reduction in turbidity which gives 900.5 FAU. The presence of coconut husk has significantly increased the COD value as 0% POME (distilled water) with coconut husk shows 3320 mg/l of COD. However, at the end of seven days of treatment, 100% POME which was treated through immobilization shows lower COD as compared to free cell fermentation. pH reading is a concern as treatment method might influence the pH of POME. Range of pH for POME throughout the experiment was between 7.1 and 9.6. Degradation of POME using Aspergillus niger immobilized on coconut husk provides additional incentive that is cheap and sustainable.