bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of ZnCl2 on properties of graphene produced from palm empty fruit bunch
Authors: Sukmana I F , Widiatmoko P , Nurdin I , Devianto  , Prakoso T
Published: May 2020

The production of palm oil in Indonesia is increasing every year. Along with the increase in production, the waste generated by the palm oil mill is also increasing. Waste from the production of palm oil can be used as raw material for high value-added products such as graphene. Graphene is the two dimensional hexagonal lattice of sp2 carbon atoms. Due to its excellent electrical conductivity and high theoretical surface area, graphene has very promising applications in nanoelectronics components including transistors, lithium ion batteries and supercapacitor. This study aims to characterize the effect of activating agent ZnCl2: biomass ratio on the structure and properties of graphene production from palm oil waste with catalyst FeCl3 via two-stage pyrolysis. Experiment results showed that surface properties of graphene sheets depend on the ZnCl2: biomass ratio. The effective surface area increased with increasing ZnCl2: biomass ratio. Graphene sheets shows favourable features such as nanosheet frameworks (2-4 atomic layers), graphite-like interlayer spacing (0.3380 nm) and also high crystalline degree (IG/ID = 9.35).
Effect of different bleaching reagents and process sequences on the properties of steam-exploded empty fruit bunch (EFB) fiber
Authors: Supian M A F , Mohamad S , Amin K N M , Jamari S S , Zakaria J , Ali M F , Mohamad S F S
Published: May 2020

Bleaching reagent process is essential for the production of cellulose, pulp, and paper to increase the appearance and quality of the final products. Empty fruit bunch (EFB) is an agricultural waste with a lignocellulosic constituent. Recently, the conversion of EFB towards pulp for food packaging and paper manufacturing or cellulose-based materials has been actively developed in lab and pilot scales. However, obtaining efficient extraction and bleaching processes is still the main challenge. In this paper, the effect of different bleaching reagent at different sequences towards the brightness properties of the EFB fiber is observed. The EFB fiber was pre-treated using steam explosion process, hot water treatment, and alkaline treatment before undergoing the bleaching process. Four systems of bleaching process were set using NaOCl and NaO2Cl as the bleaching reagents. Two sets of the system are using single reagent and the other two sets are using mixed reagent. In the single reagent bleaching system, four stages of bleaching process were used for each NaO2Cl (C) and NaOCl (H) solution respectively. Meanwhile, the mixed bleaching reagent was conducted with two stages of processes with different sequence of reagents (CH and HC). The bleached cellulose obtained via these two systems were characterized in terms of brightness, chemical composition, thermal characteristic, and degree of crystallinity. The mixed bleaching reagent system the HC has produced the best quality of cellulose with brightness at 77.68%. The chemical and thermal characteristic of the bleached pulp fiber did not change when the bleaching method was applied to the fibers. Even though a single bleaching reagent system with sodium chlorite shows almost similar brightness at 78.66%, the quantity of solvent used is higher compared to the mixed bleaching reagent system. As a conclusion, mixed bleaching reagent system is an efficient system to produce a better quality of cellulose and paper from EFB.
Experimental Densities of Binary mixture of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or sulfolane with monoethanolamine and their molecular interaction by COSMO-RS
Authors: Azlan Kassim Mohd , Asrina Sairi Nor , Yusoff Rozita , Kheireddine Aroua Mohamed
Published: May 2020

Thermophysical properties (densities, ρ) was measured for the binary mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][NTf2] and sulfolane with monoethanolamine (MEA) over the entire range of composition, and at different temperatures from T = (303.15 to 343.15) K. From experimental data of ρ, the excess molar volumes, VE was calculated and fitted to the Redlich-Kister equation. The positive VE values were observed for both of the systems indicating expansion of volume due to breakage of MEA-MEA intramolecular hydrogen bond by addition of [BMIM][NTf2] or sulfolane. Subsequently, a quantum chemical-based COSMO-RS modelling was used to predict the molecular interaction based on non-ideal liquid phase σ-profile and σ-potential for all mixtures. It has been interpreted that weak interaction for [BMIM][NTf2] (1) + MEA (2) and MEA (2) + sulfolane (3) system. A discussion was carried out in terms of interactions and structure factors in these binary mixtures based on results obtained.
Sulfur copolymers (SDIB) from inverse vulcanization of elemental sulfur (S8) for polymer blend
Authors: Parreño Jr Ronaldo P , Liu Ying-Ling , Beltran Arnel B
Published: May 2020

Elemental sulfur (S8) is largely available resource as by-product from petroleum refining process which is causing “excess sulfur problem’ due to its limited usage. The utilization of sulfur as valuable material will not only address environmental concerns but provide cost-effective ways of consuming this huge amount of waste to develop new high-value, high-volume products. One facile synthetic method of utilizing sulfur directly as feedstock to produce polymeric material is inverse vulcanization. In this study, sulfur copolymers (SDIB) was synthesized via inverse vulcanization from S8 and processed into polymer blend with component polymers, polybenzoxazine (PBz) and poly(methyl methacrylate) (PMMA) to show its potential processability into polymer blend. Initially, synthesis of SDIB with varying feed ratios of sulfur to comonomer 1, 3-diisopropenylbenzene (DIB) was evaluated for its resulting properties. Spectroscopy showed copolymerization reactions occurred based on the change in characteristic absorption peaks (C=C-H, C=C, C-H) present in the spectra. Thermogravimetric analysis (TGA) indicated that SDIB is more thermally stable with the increase in onset temperature of degradation. Differential scanning calorimetry (DSC) profile exhibited new single glass transition temperature (Tg) that slightly increased with higher DIB ratio indicating evolution of microstructures of copolymers produced. The processability of SDIB into polymer blend was investigated by using SDIB (50 wt% S) with PBz and PMMA. Blending process using simple mixing technique with solvents was carried out for SDIB/PBz (10/10 wt%) and SDIB/PMMA (7.65/7.65 wt%) blend compositions. The results of this study demonstrated that polymercopolymers interactions influenced the phase structure and behaviour with polymer blend of SDIB/PBz showing higher degree of miscibility with more homogeneous and transparent blend as compared to SDIB/PMMA blend. The suitability of polymer blend in electrospinning of nanofibers could provide variety of new applications for SDIB.
Synthesis of Phenol Formaldehyde Resin with Paraformaldehyde and Formalin
Authors: Kamarudin Nuruldiyanah , Radiah Awang Biak Dayang , Zainal Abidin Zurina , Cardona Francisco , Sapuan Salit Mohd
Published: May 2020

Phenol and formaldehyde are the well-known raw materials used in synthesizing Phenol Formaldehyde (PF) resin. PF resin has been used extensively in various applications including molding and composite laminate industries. This study focused on the synthesizing PF resin using formalin and/or paraformaldehyde for laminate application and assess the physical properties, mechanical properties and fracture toughness of the resins. The density, dynamic viscosity, solid content, gel time, flexural properties, tensile properties and fracture toughness of the synthesized resins were evaluated upon varying the formalin content from 0% to 40% (w/w) in the synthesis process. The result shows that addition of 40% w/w formalin in the PF resin synthesis had increased the fracture toughness and decreased the flexural strength and modulus properties of PF by 97.14% and 97.60% respectively. The tensile stress value was also reduced by 67.80% when the 40% w/w of formalin was added. However, the PF resins that produced by adding formalin up to 20% w/w in the PF resin synthesis, still maintained their flexural and tensile properties within the acceptable range required by EN438 standard for decorative high-pressure laminate (HPL) application. This work shows that paraformaldehyde enhanced the mechanical properties of PF laminate resin compared to formalin.
Effect of forming temperature on properties of biocoke from palm oil residues
Authors: Saisermsak Peeradej , Chaichanawong Jintawat
Published: May 2020

Biocoke is a solid fuel produced from bio-residues such as agricultural residues. Biocoke is expected to use as a replacement for coal coke to reduce CO2 and pollution gases emission. In this research, biocoke was developed from palm oil residue which is one of the main wastes from palm oil industry. The effects of forming temperature on properties of the biocoke such as bulk density, maximum compressive strength and calorific value were investigated. Biocoke from palm oil residue was produced at different forming temperatures (from 140 °C to 190 °C). The forming time was fixed at 20 min. The forming pressure was also fixed at 16 MPa. The bulk density and calorific value of biocoke from palm residue increase with the increase of forming temperature. However, maximum compressive strength of biocoke from palm residue decreases with the increase of forming temperature.
Comparative Study between Avian Cell and Mammalian Cell in Production of Influenza Vaccine Shariah Compliance
Authors: Aliya Mohamad Ros F N , Abd Rahman Norliza , Mohd Ali Jarinah , Anuar Nurina , Sheikh Abdullah Siti Rozaimah Bt. , Fazlim Bin Jusoh Yusoff Amir
Published: May 2020

Nowadays, the manufacturing industry of the influenza vaccine always make the improvement for their production. Most of them are looking for the new production cell line which are easily scalable, high yield production of viral and highly tolerant to multiple viruses. This situations happens as the high demand of the vaccine for every year from around the world. It can be seen that the capacity for the vaccines’ production are really critical in the pharmaceutical industry. However, certain Muslims’ community do not gain a trust from the vaccine’s ingredient itself. This is due to the production process involves blood consist of serum and cell components that may come from the prohibited animals such as pig and dog. Therefore, shariah compliance vaccine has been studied in this research. The avian cell lines are now competing with the mammalian cell currently at advance stage of commercial development for the manufacture of influenza vaccines. Avian cell line chosen are AGE1.CR.pIX cells and DuckCelt-T17 will be compared with the mammalian cells which is Vero and Madin Darby Canine Kidney (MDCK) cells in producing the shariah compliance vaccine. Different type of mediums also will be considered to produce shariah compliance vaccine. The artificial media will be compared with the natural media that contain the non-shariah components. Hence, the shariah status of the enzyme and media will be known in this research. In this study, the production of shariah compliance vaccine mainly focused on the bioreactor and simulated by using a software called SuperPro® Designer. Results gained from the simulation shows the highest yield at 72 hours which is 93.51 % conversion. These study will acknowledge the halal’s status of the vaccine and contribute the development of the halal vaccine processing industry.
A Preliminary Study of Extraction and Purification Processes of Astaxanthin from Haematococcus pluvialisas a Natural Antioxidant
Authors: Dewati P R , Rochmadi  , Rohman A , Budiman A
Published: May 2020

Haematococcus pluvialisis is a species of microalgae which contains a prominent natural antioxidant called astaxanthin. However, the thickness of microalgae cell wall hinders the extraction process. This problem (cell wall destruction) can be overcome by implementing one of the efficient methods, microwave assisted extraction. The purpose of this study is to determine the extraction equilibrium constant and simple experiment data on purification process. The extraction was carried out using acetone as the solvent at 50°C under constant stirring speed which was then followed by refinement process. Thin layer chromatography was also performed to select the suitable eluent for purification that drew upon chromatographic column. Based on the experiment, the best eluent from thin layer chromatography was a mixture of acetone and petroleum ether 1:1 (v/v), with the retardation factor (Rf) value of 0.649 under atmospheric pressure. Likewise the highest astaxanthin purity was 6.451mg/L. Meanwhile, the equilibrium constant was investigated by employing the mathematical modeling.
Production of enzymes from pineapple crown and coffee husk by solid state fermentation
Authors: Abu Yazid Noraziah , Razanah Roslan Ainur
Published: May 2020

Agricultural waste had long become an environmental issue since there is no appropriate method for handling these residues. However, most of these wastes are used as animal feed or burned as an alternative for elimination in which it can cause air pollution. The main objective of this study is to produce enzymes from agriculture waste from pineapple plantation (pineapple crown) with coffee husk as co-substrate using solid state fermentation (SSF). The physicochemical properties (carbon, hydrogen, nitrogen, sulphur) of pineapple crown were characterized. During the SSF, the influence of three parameters that were co-substrate ratio, extraction ratio and incubation period were studied for the production of cellulase and bromelain enzymes. Titrimetric Method Assay and Filter Paper Unit Assay were used for the determination of bromelain and cellulase activity, respectively. Pineapple crown contained 39.50% carbon, 5.51% hydrogen, 13.82% nitrogen and 0.46% sulphur. These results proved that the effectiveness of pineapple crown as a substrate in solid state fermentation for production of the enzymes as it contains high C:N ratio (2.86). The optimum result for bromelain and cellulase activity were achieved when using co-substrate ratio 2:1 (w/w) with the presence of sludge, extraction ratio 1:5 (w/v) and incubation period of 4 days which are 1589 ± 9.89GDU/g and 5.5851 ± 0.64 IU/mL respectively. Therefore, the production of hydrolytic enzymes (cellulase and bromelain) from pineapple crown can be accomplished by SSF, thus decreasing the operating cost.
Synthesis of Bioactive Glass using Cellulose Nano Fibre Template
Authors: Sarmast Sh M , George S , AB Dayang Radiah C. , Abdullah N , Kamarudin S
Published: May 2020

Bioactive glass is one of the biomaterials that is used as a bone graft. The important property desired for a bone graft material is to have well suited porosity to enable cell penetration and enhance oxygen and nutrient exchanges. The common methods to produce bioactive glass are melting and sol-gel methods. Melting method is operated at a temperature higher than 1300 °C; the sol-gel method, on the other hand, is usually operated at a much lower temperature, i.e. in the range of 600 – 800 °C. The objective of this study is to evaluate the effect of using cellulose nano-fiber (CNF) template on the properties of the synthesized bioactive glass. Hypothetically, the templating process will create channels within the bioactive glass structures, which improves both its porosity and the interstitial network. In this study, SiO2–CaO–P2O5–Na2O bioactive glass (BG) was prepared via sol-gel method. The effects of the manipulated parameters on the morphology, chemical properties, porosity and crystallinity of BG were assessed by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, Energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). It was found that the sintering temperatures significantly affect the structure and performance of samples. The best property was obtained by sintering bioglass with 10 wt% of CNF at 750 °C.
Study and Experimental Setup of Liquid-Solid Fluidization in Rangsit University
Authors: Chunsawang S. , Ekasilp W.
Published: May 2020

This article explains the basics of fluidization theory and how to construct of liquid-solid fluidization apparatus for the laboratory of the chemical engineering department at Rangsit University. The minimum fluidization velocity of solid particles (calculate from the Ergun equation) is essential for the effective operation and design of fluidized beds. All Chemical engineers need to learn about this technique to apply to the mixing processes, drying process, leaching, and washing processes. In this paper, the apparatus of a fluidized bed constructed with three different diameters of the column; that was 2.7, 5.4, and 10 cm, respectively. The three different diameters of round glass bead were a solid phase; that was 2, 3, and 4 mm, respectively. The parameter in the fluidized bed was the minimum fluidization velocity (Umf). This paper describes the experimental investigation of the liquid-solid fluidized bed. The pressure drops across the fluidized bed measured at a different liquid flow rate. The data analyzed by the graphical method. It found that the minimum fluidization velocity increases with increasing particle size, the height of the bed, and decreasing particle sphericity.
Conceptual Design of a Process Plant for the Production of Natural Dye from Merbau (Intsia bijuga) Bark
Authors: Rahayuningsih E , Mindaryani A , Adriyanti D T , Parthasiwi L D , P Adina H , E Dyah A
Published: May 2020

The damage to the aquatic life, cancer health effect on humans, and low water quality are the effects caused by the use of synthetic dyes in the textile industry. For this reason, it is necessary to reduce the use of synthetic dyes. By producing the natural dye, people can overcome this problem, and provide a business strategy to improve the country’s economic growth. One of the natural dye substances is tannin, which can be produced from various types of wood bark. Indonesia provides an abundant source of wood and bark waste. One source is Merbau wood from Sinar Wijaya Plywood Industry which is located in Dawai-Serui, Yapen Waropen Regency, Papua Province, and PT Wijaya Sentosa, Teluk Wondama Regency, West Papua Province. Other kind of source is mangrove bark from Bintuni Utama Murni Wood Industry. The other type is mahogany bark from Wonosobo Regency, Central Java. For example, in this paper the technology review is focused on Merbau bark and sawdust, as waste obtained from PT Wijaya Sentosa (PT WS). Based on the research conducted previously, aqueous extraction is known as the most effective method to extract tannin from its biomass source. Because it is waste from the wood industry, the sustainability of the raw material is assured, and we can produce a continuous tannin plant. This paper presents the conceptual design of a process plant for the production of natural dye from Merbau (Intsia bijuga) bark. The process plant consists of a bark size reduction, extraction, evaporation, and drying machines. The design analysis of constituent machines and their performance evaluations were carried out using appropriate design equations. The designed process plant was simulated to ensure its functionality. The results of its performance were analysed and the cost of products was estimated.
Electrospray synthesis and photocatalytic activities of ZnO-SiO2 composites particles
Authors: Qomariyah L , widiyastuti W , Kusdianto K , Nurtono T , Anggoro D , Winardi S
Published: May 2020

A new and rapid method for zinc oxide (ZnO) and ZnO-SiO2 (ZS) composite particles by the simple electrospray method was reported. Free agglomeration and smaller particle size of ZS composite obtained with an increase in the applied voltage that correlates with the charge repulsion within the particles. The presence of silica inhibited the ZnO particles and crystal growth. The XRD and FTIR spectra indicated that silica covered the ZnO particles. Smaller ZS molar ratio with higher applied voltage had a significant role in minimizing the agglomeration of the particle production. This suggested a morphological control of the composite through electrospray. The results of the photocatalytic degradation of methylene blue (MB) in aqueous solution revealed that the presence of silica effectively inhibited the photocatalytic activity of ZnO particles in which the ZnO without and with silica had degradation rate 85% and 63%, respectively. The effect of silica amount to the ultraviolet (UV) shielding property of ZnO particles also examined.
Wetted Wall Photocatalytic Reactor for Methylene Blue Degradation
Authors: Boonying Amornpon , Kasempremsak Artith , Junpirom Supunee , Nuchitprasittichai Aroonsri
Published: May 2020

Titanium dioxide (TiO2) is generally known a good potential of photocatalyst to synthesis hydrogen peroxide (H2O2). The aim of this work is to generate the H2O2 via photocatalysis for further application in a sterilization system. Wetted wall photocatalytic reactor (WWPR) was particularly designed as a prototype for carrying out the experiments of photocatalytic reaction. An advantage of WWPR is a high contact surface area of feed and catalyst mixture with UV light to enhance a high efficiency to produce the H2O2. The TiO2 photocatalyst was prepared via sol-gel method and mixed with rice husk based silica dioxide (SiO2). Properties of photocatalyst were investigated by XRD, SEM and surface area and its photocatalytic performance was tested by methylene blue degradation with reaction measurement using the UV/Vis instrument. Variation of the catalysts loading and methylene blue initial concentration were studied in photocatalytic experiments. In the batch of 0. 25 g of photocatalyst with 80 mg/L methylene blue solution, the results showed that the percentage of methylene blue removal is at 89. 52% within 2 hours of reaction. This removal efficiency of methylene blue is resulted from both mechanisms of degradation by photocatalytic reaction and adsorption by the function of SiO2 modification and the trap-hole of crystallized anatase structure
Lactic Acid Production from High Concentration of Invert Sugar in Semi-Batch Reactor
Authors: Sirisangsawang R , Kitchaiya P
Published: May 2020

The objective in this study is the production of high yield of lactic acid production from invert sugar in alkaline degradation at mild reaction condition. The invert sugar was immediately and continuously added into an alkaline solution in a batch and semi-batch reactor, respectively. The effect of batch and semi-batch, initial concentration of sodium hydroxide and initial of concentrated raw materials were studied. Semi-batch provided better yield than batch reactor. High sodium hydroxide concentration with low invert sugar in semi-batch operation was found to have high lactic acid. The feed concentration of invert sugar at 30, 45 and 70% provided lactic acid yield around 65-68% for excess sodium hydroxide base at 50°C and 10 hr.
Synergistic effect with and without Ni metal over ZSM-5/SAPO-11 catalyst in hydrodeoxygenation of palm oil
Authors: Khan Saima , Fazly Abdul Patah Muhamad , Mohd Ashri Wan Daud Wan
Published: May 2020

Hydrodeoxygenation (HDO) of palm oil by catalytic for biofuels has attracted the researchers in the recent years. Currently available catalysts are typically intensive on sulfided CoMo and NiMo catalysts, which certainly modeled by the sulfur contamination in the final liquid product. Consequently, exploring the non-sulfured catalyst is still vulnerable challenge and has ultimate importance. In this paper, sulfur free catalyst with and without Ni based SAPO-11/HZSM-5 is synthesized according to incipient wetness impregnation method. The prepared catalyst was tested by performing HDO of palm oil for product selectivity. Different analytical techniques were used like: XRD, FESEM, Pyridine-FTIR and H2-TPD to explore the physicochemical properties of the novel catalyst. In addition, Ni supported ZSM-5/SAPO-11 catalyst with medium acidity showed greater properties because of the synergistic effect of Ni metal and acidic support than the catalyst without Ni support. The results showed that the, catalyst acidity has suggestively inclined the catalytic performance and product selectivity. The maximum selectivity of biofuel was achieved with ZSM-5/SAPO-11 over Ni support under the mild reaction condition at 350°C is indicating its auspicious part in this reaction. The acquired results determined that the metal and acid sites showed crucial role for the development of an effective catalyst for HDO of palm oil over Ni supported catalyst.
Comparative Performance of Catalytic and Non-Catalytic Pyrolysis of Sugarcane Bagasse in Catatest Reactor System
Authors: Faraheen Kabir Ahmad Syahirah , Fazara Md Ali Umi , Md Isa Khairuddin , Rahayu Mohamed Alina , Sataimurthi Omneswary
Published: May 2020

Catalytic pyrolysis is a favourable process used to enhance the quality of bio-oil. Based on reviews from previous research there are only scarce of studies on the comparison of catalytic and non-catalytic pyrolysis of biomass such as rice husk, olive husk and corncob. In this study, sugarcane bagasse was selected as it has not been explored much yet. The target of this research is to compare the impact of catalytic and non-catalytic pyrolysis of sugarcane bagasse in terms of the yield, properties, and also the compositions of bio-oil. Catalytic and non-catalytic pyrolysis was executed in catatest bed reactor at temperatures 400°C to 550°C with the aids of ZSM-5 zeolite catalyst. Bio-oil from catalytic and no-catalytic pyrolysis which gives the maximum yield was used to be studied further in terms of the properties and chemical compositions. The result shows that the maximum yield of bio-oil was accomplished from catalytic pyrolysis at temperature 500°C which was 21.4%. The properties and composition of bio-oil from catalytic pyrolysis shows better result compare to non-catalytic pyrolysis.
Optimization of Agitation and Kinetic Studies on Proanthocyanidin Compound Extraction from Red Sorghum Grains in Agitated Vessel
Authors: Susanti D Y , Sediawan W B , Fahrurrozi M , Hidayat M
Published: May 2020

Proanthocyanidin extraction for antioxidant material from intact red sorghum grains in agitated vessel had been investigated. The optimization and the appropriate kinetic evaluation were useful to conduct the engineering design of the developed process. Concentrations of the proanthocyanidin compounds in the aqueous extract were affected by the agitation speed and extraction time. The objectives of this research were to determine the optimum values of agitation speed and time for getting maximum extraction performance and to develop the appropriate kinetic model for illustrating the extraction phenomena. This research also evaluated the characteristics of the obtained extract. The optimum conditions of extraction were determined using Response Surface Methodology. The concentration of proanthocyanidin compound in the extract was predicted to be maximum at 405.05 rotations per minute (rpm) of agitation speed and 133.03 minutes of extraction time. The values of R2 of the regression equations were 99.45%. In the kinetic modeling, the mechanistic model turns to be much more accurate than the second order kinetic. The extract from the optimum process had 0.837 mg/ml of proanthocyanidin concentration and was proven to be effective in scavenging 64.02% of free radicals in the 100 μM DPPH in 30 minutes.
Modelling and optimization of the heat pump system for the usage of swimming pool
Authors: Lau M J , Zanil M F , Choong S Y , Tan J
Published: May 2020

Heat pump is a device which being used to transfer heat energy from one or more heat sources at low temperature to one or more heat sinks at high temperature simultaneously through pumping. The heat pump system used in swimming pool is an air –to-water heat pump that made up of four elements, which are evaporator, compressor, condenser and expansion valve. The overall efficiency of the heat pump in recovering the heat energy with the least of work done needed is defined as Coefficient of Performance (COP). A calculation software interface is designed using programming language of Visual Basic in Microsoft Visual Studio software to model, simulate the operation of heat pump product in actual industrial application and aid the optimization of heat pump system. The calculation software interface developed generates high accuracy COP value at 4.90, which has only 0.62% difference compared to actual COP of the heat pump product at 4.87. In order to optimize the performance of heat pump, the number of turns of outer and inner coil in condenser and the water flow rate pumped into the condenser are changed to maximize the COP within allowable cost increment. The COP is improved from 4.90 to 5.52, 5.13 and 6.89 based on each respective optimizations with cost increment controlled in between 0.5 to 2%. The final COP improved is obtained at 8.06 through combined optimization.
The Effect of Clay Content in the Adsorption of Surfactant by Reservoir Rock in the Enhanced Oil Recovery Process
Authors: Nurmayanti L , Dewi S Y P , Murachman B , Purwono S
Published: May 2020

Surfactant flooding aims at lowering the interfacial tensions between the oil and water phases to improve the displacement efficiency during oil recovery. However, high adsorption of surfactant by reservoir core is undesirable since it could decrease the ability of surfactant to reduce the interfacial tension between oil and brine which makes injection ineffective. This study was done to get better understanding of the effect of clay content on oil displacement. The procedures of adsorption process are as follows: crushed core were put into flasks wich filled with surfactant and heated up at different temperature for three days operation. The clean solution was then measured its absorbance using UV spectrophotometer. The result of adsorption experiments show that the adsorption decreasedup to 25 % when temperature was increased from 25 to 70oC. The experimental for studying the effect of clay content on the adsorption also shows the right behavior. The experimental results also show that adsorption of surfactant is higher in the clean core than in the core filled with oil. This phenomenon is true since the contact area between surfactant and core is much higher when the core is clean. The oil displacement experiments show that the oil recovery also depends on type of reservoir rock used in the process.
Fabrication of ZnO-SiO2 Nanocomposite Materials Prepared by a Spray Pyrolysis for the Photocatalytic Activity under UV and Sunlight Irradiations
Authors: Kusdianto K , Widiyastuti W , Shimada M , Qomariyah L , Winardi S
Published: May 2020

ZnO is the most widely used for photocatalytic application among various semiconductor materials. The photocatalytic performance of ZnO can be enhanced by doping with other materials. In this study, ZnO-SiO2 nanocomposites have been successfully fabricated by gas-phase method via spray pyrolysis. The effect of temperature of spray tubular furnace reactor ranging from 300 to 600 °C on the photocatalytic activity of ZnO-SiO2 nanocomposites were investigated. Colloidal SiO2 with concentration at 1 %wt was used as dopant to ZnO particles. The pristine ZnO was also synthesized at temperature of 400 °C for comparable. Zinc acetate and water glass were used as the precursors for fabrication ZnO-SiO2 nanocomposites. At first, the water glass was synthesized by sol-gel method to produce colloidal SiO2 nanoparticles and then mixed with zinc acetate before subjecting to the spray reactor. The produced nanocomposite materials were collected by an electrostatic precipitator. Scanning electron microscopy and energy-dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) were used for characterization the products. While UV-Vis spectrometry was used to measure the concentration of methylene blue (MB) before and after irradiations. SEM images indicated that the morphology of particles was as sphere-like structures with interwoven nanoplate and the agglomeration of particles can be suppressed by adding SiO2. The average particle size of the produced nanocomposite decreased with increasing synthesis temperature. XRD analysis also confirmed that the crystallite size increased with increasing temperature. Finally, the photocatalytic activity of the ZnO-SiO2 nanocomposites were calculated by evaluating the methylene blue degradation aqueous solution under UV and sunlight irradiations. MB degradation efficiency under UV light was much lower than that of under sunlight irradiation. It also showed that the best photocatalytic performance reached 96 % when the synthesis temperature was set as high as 400 °C with SiO2 concentration at 1 %wt under sunlight irradiation.
Biodiesel Synthesis over Biochar-based Catalyst from Sengon (Paraserianthes falcataria L. Nielsen) Sawdust using Palm Fatty Acid Distillate as Low-Cost Feedstock
Authors: Taufiq Agus , Arista Sari , Sutrisno Bachrun , Hidayat Arif
Published: May 2020

Biodiesel is mostly made from trans-esterification reaction using homogenous catalysts. Problems related to homogenous catalysts are the difficulty to separate the final product and the toxic that the waste contains. To prevent this negative effect, it is suggested to use heterogeneous catalysts. The heterogeneous catalysts have been considered to apply on biodiesel production associated with homogeneous catalysts limitations. Many advantages coul be provided by heterogeneous catalysts including easily separated from reaction product, can be used repeatedly, generate less waste water, and environmentally friendly operations. In this paper, the Palm Fatty Acid Distillate (PFAD) esterification to form biodiesel was studied using biochar-based catalyst from sengon (Paraserianthes falcataria L. nielsen) sawdust as heterogeneous catalyst. Reaction parameters such as temperature, molar ratio of oil to methanol, and amount of catalyst percentage were varied to achieve the highest conversion. The highest free fatty acids (FFAs) conversion of 89.71%, was obtained by using 60°C of reaction temperature at 12:1 molar ratio of methanol to PFAD and 3% catalyst amount.
Sensitivity analysis of small scale biomass gasification-based CHP system: A way forward for sustainable urban waste to energy technology
Authors: Rasid A R , Abdullah I H , Siaw C W , Zanil M F , Mohd Shadzalli Z F , Abbas A , Abdul Manaf N
Published: May 2020

A biomass gasification-based combined heat power (CHP) system emerges as a potential sustainable urban waste-to-energy (WtE) technology that can offer solutions to the excessive anthropogenic CO2 emissions and the escalation of energy demand as well as to the incremental of domestic and agriculture wastes. In this work, a steady state flowsheet model of 25 kW APL power pallet is developed by Aspen Plus software. The developed power pallet model integrates physical and chemical processes which involves pyrolysis, combustion, and gasification processes. The developed gasification model is validated with experimental data using biomass woodchip as a feedstock. This study focuses on the gasification of biomass to produce syngas (mainly H2 and CO) which subsequently converts to electric power. As an initial study towards large scale WtE plant, a detailed parameter sensitivity analysis is performed by analysing variables effects on syngas production subjected to the manipulation of gasification temperature, pressure and air-to-biomass ratio. The results show that the elevation of air-tobiomass ratio and gasification temperature contribute to the high conversion of CO subsequently enhance the potential of electrical power load. Moreover, power pallet exhibits optimal operation at 3.9 of air-to-biomass ratio with gasification temperature approximately at 1200 K. The initial results obtained in this study are valuable in determining the feasibility of biomass gasification-based CHP system as a sustainable and robust WtE technology.
Adsorption of copper, nickel and chromium ions using silica aerogel synthesized by ambient-pressure drying and modified with EDTA
Authors: Pornchuti B , Pongpattananurak B , Sutthiard D , Singtothong P
Published: May 2020

Adsorption of heavy metal ions was studied widely since it is one of the promising methods for treating wastewater. Silica aerogel was selected as an adsorbent in this study because it was easy to modify surface. Although most of aerogels were synthesized by supercritical drying, the silica aerogel in this work was dried at atmospheric pressure which safer. It was modified further with APTES (Aminopropyltriethoxysilane) and EDTA (Ethylenediaminetetraacetic acid) to increase adsorption capacity. The modified silica aerogels were used to adsorb copper, nickel and chromium ions from aqueous solution. It was found that efficiency of heavy metal removal in case of EDTA modified silica aerogel was better than those of APTES modified silica aerogel and unmodified adsorbent. The adsorption data agreed well with Langmuir isotherm model than Freundlich isotherm model. The maximum adsorption capacities of copper, nickel and chromium on EDTA modified silica aerogel were found to be 94.34, 84.75 and 169.49 mg/g, respectively.
The Effect of Leachate Resirculation on The Greenhouse Gases Emission from Municipal Solid Waste (MSW) Landfill in Tropical Climate Region
Authors: Ali Q H , Sugihen S R , Munawar E , Adisalamun
Published: May 2020

Indonesia is facing serious problem with huge amount of Municipal solid waste (MSW), whilst landfilling still the main option to dealing with it. The landfilling of the MSW is associate to the environmental issue, especially due to the leachate and landfill gas emissions. The leachate produces which is containing hazardous materials, while the landfill gas which mainly containing CO2 and CH4 that categorized as greenhouse gases. The leachate and landfill gas emissions were influenced by many factors, including climatic condition. This research was aimed to determine the effect of leachate recirculation on leachate production and landfill gas emissions of MSW landfill in tropical climate region. The experiment was carried out by using 2 landfill simulator reactors (LSRs) made of high density polyethylene (HDPE) pipe with 50 cm OD and 150 cm length. The sample used was collected from the Blang Bintang landfill, a regional landfill constructed to accept MSW from Banda Aceh municipality and Aceh Besar District. The LSRs were operated under difference operation mode, the first LSR were operate without leachate recirculation, however a certain amount of water was added to simulated the MSW landfill operated under conventional method. While the second LSR were operate with leachate recirculation to represent the MSW landfill operated under bioreactor landfill mode. Results of this study show the leachate recirculation has in significant affects on the rate of waste degradation and the landfill gas production. The highest CH4 concentration in landfill gas emission first and second LSRs were about 58% and 59%, respectively. This relatively small difference is probably due to the high rainfall in the tropics region. This results indicated that the potential of MSW landfill in tropical climate region as renewable energy, either operated under conventional or bioreactor landfills.
Life Cycle Assessment of Refuse Derived Fuel (RDF) for Municipal Solid Waste (MSW) Management: Case Study Area Around Cement Industry, Cirebon, Indonesia
Authors: Anasstasia T T , Lestianingrum E , Cahyono R B , Azis M M
Published: May 2020

Life Cycle Assessment (LCA) is a useful tool to evaluate the environmental impact of Municipal Solid Waste (MSW) processing. Here, a BUMDES (village owned enterprise) converted MSW to Refuse Derived Fuel (RDF) in the area around a cement plant in Cirebon, Indonesia. The RDF that is produced is used as a partial substitutiton fuels for the kiln in the cement industry. The purpose of present study was to evaluate the environmental impacts of RDF production through an attributional LCA study. The results were compared with the current practice of MSW treatment system. The waste management system that will be compared includes RDF and direct combustion. LCA simulation was conducted in the OpenLCA software, which is equipped with ecoinvent database as well as primary data from the field. The company treated about 2, 259.96 kg of waste / day. The results showed that the production rate of RDF is about 966 kg / day. The analysis shows that the conversion of combustible municipal solid waste into RDF is more environmentally friendly than direct combustion with environmental impacts as follows: GWP 8.40E-01 kg CO2eq., Acidification 4.36E-04 kg SO2eq., Eutrophication 7.18E-04 kg PO4eq., ODP 3.59E-09 kg CFC-11 eq., And Human toxicity 2.27E-01 kg 1.4 dichlorobenzene eq. The use of RDF as a substitute fuel for the cement industry is economically advantageous if: there are no restrictions on processed waste, the RDF product sales to the cement industry is ensured, and the RDF product price should be economically viable. The initial investment costs and high operating as well as the maintenance costs could be a challenging issue when dealing with MSW processing to RDF.
Evaluation of Hydrocarbon Gas Dispersion and Explosion in a Gas Processing Plant
Authors: Rismayasari D , Budhi Y W , Rizkiana J , Cahyono T , Khairunnisa
Published: May 2020

Gas leakage is one of hazard sources in a gas processing plant, where the released gas may form vapor cloud, which is dispersed or accumulated. At certain concentration, the vapor cloud may induce fire and explosion, which could harm people, equipment and environment. The effects of the incidents can be estimated to determine the consequences and to improve the plant design. Due to several complexities including congestion of plant equipment, 3D CFD model was developed to represent real configuration. In this study, the as-built 3D plant geometry and FLACS software were utilized to run the CFD model simulation to evaluate the quantity and placement of the existing gas detectors. The recommendation given according to evaluation results was to install two additional gas detectors. Thereby, in the case of gas leak, the gas detection system may alarm personnel and preventive action may be taken into consideration. The effects of explosion result from the selected scenario were predicted to not be able to cause steel frame distortion or eardrum rupture. These demonstrated that the evaluation of release consequence using 3D CFD model gave more advantage than 2D method by representing accurately physical characteristic of gas dispersion and explosion, which could eventually improve the plant safety strategy.
Gold Leaching from Printed Circuit Boards (PCBs) as one of the Urban Mine Resources using Thiosulphate: Optimization using Response Surface Methodology (RSM)
Authors: Petrus H B T M , Putra A E , Gustiana H S A , Prasetya A , Bendiyasa I M , Astuti W
Published: May 2020

Along with the decrease of metal resources in the natural ores, urban mine comes up as an alternative with two aspects of both resource and environmental protection due to recycle. Broken printed circuit boards (PCBs) as one of the urban mine resources contains valuable metals, such as, Au, Ag, and Ti, with high concentration, however, it has not been seriously managed in some developing countries, such as Indonesia. Focusing on gold extraction, safer leaching agent using thiosulphate has been applied in this study and scrutinized the optimum leaching conditions with respond surface methodology. Temperature and concentration of thiosulphate were varied and designed in accordance with three factorial. Leaching time was set for two hours and the shaking speed of waterbath was set at fixed value of 200 rpm. In order to quantify the final concentration of gold in the solution, Atomic Absorption Spectroscopy (AAS) was applied for all samples. Response Surface Method (RSM) is utilized to know the optimum result of Au extracted. The result shows that the optimum result of Au extracted by using ammonium tiosulphate is 0.5114 mg/L respectively with correlative equation as follow;

Gold Concentration = 0, 127+0, 00268*T+0, 66*C-0, 000021*T2+1, 74*C2- 0, 0038*T.C.

With T = temperature (°C) and C = thiosulphate concentration (M)

The obtained R2 is 0.94 and the p-value is 0.037 showing the significance of the variable correlation in the equation.
Carbon dioxide adsorption using biomass-based activated carbon functionalized with deep eutectic solvents
Authors: Hussin F , Aroua M K , Roziki M Z A , Yusoff R
Published: May 2020

The biomass-based activated carbon can be synthesized into green solvent to mitigate disposal problems and enhance production efficiency. The green solvent known as deep eutectic solvents (DES), which exhibits unique characteristics can be used to enhance the performance of the activated carbon and results in high CO2 adsorption capacity. In this study, new approaches involving the modification of low-cost biomass-based activated carbon with green solvent functionalization agent is proposed. The DES produced will be characterized for their physical properties such as pH, density and viscosity. The modified adsorbents were studied for their surface morphology and element composition using field emission scanning electron microscope and energy dispersive X-ray spectroscopy techniques. Further to this, in order to evaluate the CO2 adsorption characteristic, breakthrough curve was studied in a packed-bed adsorption reactor. The effects of temperature were used as a parameter for examining the breakthrough time performance. The results revealed that, the breakthrough time decreases with increasing column temperatures. The results indicated that the breakthrough time was longer at a lower adsorption temperature (30°C) for modified activated carbon with DES, which was 5 min. Maximum high adsorption capacity of 11.05 mg/g at lower adsorption temperature was achieved using modified activated carbon with DES.
Review: A Comparison of Conditions for The Extraction of Vegetable and Essential Oils Via Microwave-Assisted Extraction
Authors: Haffizi Mohd , Sulaiman Sarina , Noraini Jimat Dzun , Amid Azura
Published: May 2020

Microwave Assisted Extraction (MAE) has been utilized in extracting a myriad of phytochemicals, lipids, carbohydrates, and proteins. This extraction method essentially takes advantage of water present inside cells by exciting the molecules hence increasing the internal temperature and pressure till the cells bursts. MAE is studied extensively due to its advantages over other typical extraction methods; especially in essential oil extraction. However, there is not many researches on using MAE to extract vegetable oil. Essential and vegetable oils are both derived from plants, but the characteristics of both oils differs. Therefore, the proper conditions for MAE extraction of the oils are different. This paper reviews the MAE conditions such as extraction time, power of microwave, solvent to feed ratio, and the set-up of microwave equipment. This paper attempts to show the differences between the MAE conditions between vegetable and essential oil extraction. The challenges faced by MAE is also discussed briefly with suggestions to overcome them. The Internet of Things is also discussed for its implementation in a scaled up MAE reactor.