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Production of Biopolymer Polyhydroxyalkanoates (PHA) by Extreme Halophilic Marine Archaea Haloferax mediterranei in Medium with Varying Phosphorus Concentration Melanie, Susiana; Winterburn, James B.; Devianto, Hary
Journal of Engineering and Technological Sciences Vol 50, No 2 (2018)
Publisher : ITB Journal Publisher, LPPM ITB

The development of plastics production from biodegradable resources such as polyhydroxyalkanoates (PHAs) is important due to the increasing demand for plastics. PHAs occur as intracellular solid materials produced by microorganisms as a result of an excess of carbon source and a limitation of nutrients. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV, as one of the PHAs, is a combination of two homopolymers, namely poly-3-hydroxybutyrates (PHB) and poly-3-hydroxyvalerates (PHV). This study aimed to investigate the effect of the phosphorus concentration on the production of PHAs by Haloferax mediterranei. It is possible that phosphorus deficiency may affect the length of the HV chains in the copolymer structure and thus influence the copolymer properties. The experiment was done in triplicate at laboratory scale by culturing H. mediterranei in medium with phosphorus limitation using various phosphorus concentrations. During cultivation, the optical density, phosphorus concentration, pH, and dry cell weight were observed. The PHBV product was collected and analyzed using gas chromatography. The result shows that medium with a phosphorus concentration of 0.5 g/L produced higher PHAs than the other phosphorus concentrations. The accumulated PHA was 0.95 g/L with 15.6% of dry biomass and yield YPHA/S of 0.1 g/g.

Influence of Electrode Distance on Electrical Energy Production of Microbial Fuel Cell using Tapioca Wastewater Harimawan, Ardiyan; Devianto, Hary; Al-Aziz, Rd. Habib R. M. T.; Shofinita, Dian; Setiadi, Tjandra
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB

Microbial fuel cell is one alternative technology that can be used to simultaneously solve problems related with wastewater production and energy demand. This study investigates the influence of electrode distance on power density in microbial fuel cell using tapioca wastewater. Graphite sheet without metal catalyst was used for both electrodes, separated by Nafion membranes. Four variations of electrode distance were used. MFC with highest electrode distance give the highest equilibrium OCV (676 mV), while the MFC with shortest electrode distance give the highest power density (7.74 mW/m2). EIS measurement suggested that the charge transfer resistance is dominant in all MFC configuration. Wastewater COD removal were in the range of 35-46 %, which were in accordance with the power density for all MFC.

The Effect of Carbon Nanotube Composite Addition on Biomass-Based Supercapacitor Widiatmoko, Pramujo; Devianto, Hary; Nurdin, Isdiriayani; Yandra, Ridho Eka
Journal of Engineering and Technological Sciences Vol 48, No 5 (2016)
Publisher : ITB Journal Publisher, LPPM ITB

Electric vehicles are set to become a most attractive alternative transportation mode due to their high efficiency and low emission. Electric vehicles require an efficient energy storage system, e.g. a supercapacitor. Coconut shells have high lignocellulosic content and are not being fully utilized in Indonesia. The lignocellulose could be converted into activated carbon for use as the electrode on a hybrid supercapacitor. This research focused on studying the effect of the addition of carbon nanotube (CNT) composite to porous graphene-like nanosheets (PGNS) as the electrode on a hybrid supercapacitor. The PGNS and CNT composite were synthesized via simultaneous activation and carbonization. Nickel oxide was used as the counter electrode. The CNT composite had a large surface area of 1374.8 m2g-1, pore volume of 1.1 cm3g, and pore size of 3.2 nm. On the other hand, the PGNS had a surface area of 666.1 m2g-1, pore volume of 0.47 cm3g, and pore size of 2.8 nm. The electrode pair between the NiO and the activated carbon achieved 5.69 F/g and 94.1% cycle durability after 10 charging and discharging cycles. The composite had an energy density of 0.38 W h kg-1. The aim of this research was to provide an alternative formula for producing high-performance supercapacitor materials.

DEVELOPMENT OF ELECTRODE DEPOSITION METHODS FOR SCALE-UP OF DYE SENSITIZED SOLAR CELLS Mutiari, Anies; Ananda, Wisnu; Widiatmoko, Pramujo; Devianto, Hary; Nurdin, Isdiriayani; Adriaan, Adriaan; Utomo, Mhd Ridho; Koto, Hilham Zamriko
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar

This research studied the effect of electrode deposition method on the performance of dye-sensitized solar cells (DSSCs). Four deposition methods (bar coating, doctor blade coating, screen printing, and spray coating) were compared. For commercial production purposes, applicability of the methods to a scaled-up DSSC was studied. In order to minimize the production cost, commercial activated carbon was utilized as counter electrode. The experimental results showed that the doctor blade technique provided the best DSSC performance among the investigated methods. Based on the study of cell I-V characteristics, the photoelectric conversion efficiency of the DSSC with an electrode active area of 70 cm2 was significantly lower than with 5 cm2 despite using the same deposition method. The electrochemical characteristics of the cells were further studied using electrochemical impedance analysis.

EVALUATION OF BIO-CORROSION ON CARBON STEEL BY BACILLUS MEGATERIUM IN BIODIESEL AND DIESEL OIL MIXTURE Pusparizkita, Yustina Metanoia; Schmahl, Wolfgang; Setiadi, Tjandra; Ilsemann, Bork; Reich, Mike; Devianto, Hary; Harimawan, Ardiyan
Journal of Engineering and Technological Sciences Vol 52, No 3 (2020)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2020.52.3.5

Biodiesel can act as carbon source for bacterial metabolisms, leading to corrosion of carbon steel. In this study, the corrosion of carbon steel by biodiesel blends (B15, B20, B30) was observed in the presence of Bacillus megaterium. The effect of biodiesel concentration on microorganism-induced corrosion was investigated by electrochemical impedance spectroscope (EIS), scanning electron microscope (SEM) and digital microscope. The results showed that under various biodiesel concentrations, Bacillus megaterium can grow and form biofilm on carbon steel. Based on the impedance analysis, their presence can increase the corrosion rate and cause pitting corrosion because the biofilm can change the electrochemical reactions in the metal or the interface solution and the kinetics of the anodic cathodic reactions. Also, Bacillus megaterium produces acid metabolites and can oxidize iron. Besides being influenced by Bacillus megaterium activities, the pitting formed on carbon steel depends on the biodiesel concentration. The results showed a great deal of shallow pit formation in B30, exacerbating the severity of metal roughness.

Synthesis and Characterization of Hydrochar and Bio-oil from Hydrothermal Carbonization of Sargassum sp. using Choline Chloride (ChCl) Catalyst Rustamaji, Heri; Prakoso, Tirto; Rizkiana, Jenny; Devianto, Hary; Widiatmoko, Pramujo; Guan, Guoqing
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42595

The purpose of this study is to alter the biomass of Sargassum sp. into elective fills and high valuable biomaterials in a hydrothermal process at 200oC for 90 minutes, using ZnCl2 and CaCl2 activating agents, withChClas a catalyst. This method generatedthree primaryoutputs: hydrochar, bio-oil, and gasproducts. ChCl to water ratio varies from 1:3, 1:1, and 3:1. The hydrochar yield improved when the catalyst ratio was increased, but the bio-oil and gas yield declined. The highest hydrochar yields were 76.95, 63.25, and 44.16 percent in ZnCl2, CaCl2, and no activating agent samples, respectively.The porosity analysis observed mesopore structures with the most pore diameters between 3.9-5.2 nm with a surface area betweenÂ 44.71-55.2. The attribute of interaction between activator and catalyst plays a role in pore formation. The hydrochar products with CaCl2 showed the best thermal stability. From the whole experiment, the optimum hydrochar yield (76.95%), optimum surface area (55.42 m2 g-1), and the increase in carbon content from 21.11 to 37.8% were achieved at the ratio of ChCl to water was three, and the activating agent of ZnCl2. The predominant bio-oil components were hexadecane, hexadecanoic, and 9-octadecenoic acids, with a composition of 51.65, 21.44, and 9.87%, respectively the remaining contained aromatic alkanes and other fatty acids. The findings of this study reported that adding activating agents and catalysts improve hydrochar yield and characteristics of hydrochar and bio-oil products, suggesting the potential of hydrochar as a solid fuel or biomaterial and bio-oil as liquid biofuel

KETAHANAN KOROSI PADUAN Al-Mg 5052 DI DALAM AIR PENDINGIN NETRAL MENGANDUNG KLORIDA Dicky Tri Jatmiko; Isdiriayani Nurdin; Hary Devianto
Urania : Jurnal Ilmiah Daur Bahan Bakar Nuklir Vol 21, No 2 (2015): Juni 2015
Publisher : website

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/urania.2015.21.2.2263

KETAHANAN KOROSI PADUAN Al-Mg 5052 DI DALAM AIR PENDINGIN NETRAL MENGANDUNG KLORIDA. Paduan Al-Mg 5052 adalah material yang biasa digunakan untuk kelongsong elemen bakar nuklir karena serapan fluks netronnya rendah dan tahan korosi di dalam air demineralisasi pada kondisi operasi reaktor. Makalah ini difokuskan untuk mengetahui ketahanan korosi paduan Al-Mg 5052 di dalam air dengan pH netral dan mengandung klorida sebagai pengganti air demineralisasi pendingin primer Reaktor Serba Guna GA Siwabessy (RSG-GAS). Penelitian mencakup pengukuran laju korosi menggunakan metode Tafel, prediksi mekanisme korosi menggunakan metode voltametri siklik dan analisa produk korosi dengan metode difraksi sinar X. Percobaan dilakukan dengan variasi temperatur 30°C, 35°C, 40°C, dan 45°C, serta variasi konsentrasi larutan natrium klorida 0,05 M, 0,25 M, dan 0,5 M. Hasil penelitian ini menunjukkan bahwa paduan Al-Mg 5052 terkorosi dengan kategori “dapat diabaikan” hingga “sedang” dalam larutan natrium klorida menjadi produk yang larut dalam air pada satu tahap reaksi oksidasi irreversible. CORROSION RESISTANCE OF Al-Mg ALLOY 5052 IN CHLORIDE CONTAINING NEUTRAL COOLING WATER. Al-Mg alloy 5052 is a material used as nuclear fuel element cladding due to its low neutron flux absorption and high corrosion resistance in demineralized water. This research is focused to know of the corrosion resistance of Al-Mg alloy 5052 in chloride containing neutral water used as demineralized primary cooling water substitute in GA Siwabessy Multi Purpose Reactor (RSG-GAS). This research covers the corrosion rate measurement using the Tafel method, corrosion process prediction using cyclic voltammetry method and corrosion product analysis using X-Ray Diffraction method. The experiments are carried out at temperature variation of 30°C, 35°C, 40°C and 45°C, as well as sodium chloride concentration of 0.05 M, 0.25 M and 0.5 M. The research results show that Al-Mg alloy 5052 is insignificantly to moderate corroded in chloride containing water by single step irreversible oxidation reaction.

The Effect of Carbon Nanotube Composite Addition on Biomass-Based Supercapacitor Pramujo Widiatmoko; Hary Devianto; Isdiriayani Nurdin; Ridho Eka Yandra
Journal of Engineering and Technological Sciences Vol. 48 No. 5 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.5.7

Electric vehicles are set to become a most attractive alternative transportation mode due to their high efficiency and low emission. Electric vehicles require an efficient energy storage system, e.g. a supercapacitor. Coconut shells have high lignocellulosic content and are not being fully utilized in Indonesia. The lignocellulose could be converted into activated carbon for use as the electrode on a hybrid supercapacitor. This research focused on studying the effect of the addition of carbon nanotube (CNT) composite to porous graphene-like nanosheets (PGNS) as the electrode on a hybrid supercapacitor. The PGNS and CNT composite were synthesized via simultaneous activation and carbonization. Nickel oxide was used as the counter electrode. The CNT composite had a large surface area of 1374.8 m2g-1, pore volume of 1.1 cm3g, and pore size of 3.2 nm. On the other hand, the PGNS had a surface area of 666.1 m2g-1, pore volume of 0.47 cm3g, and pore size of 2.8 nm. The electrode pair between the NiO and the activated carbon achieved 5.69 F/g and 94.1% cycle durability after 10 charging and discharging cycles. The composite had an energy density of 0.38 W h kg-1. The aim of this research was to provide an alternative formula for producing high-performance supercapacitor materials.

Influence of Electrode Distance on Electrical Energy Production of Microbial Fuel Cell using Tapioca Wastewater Ardiyan Harimawan; Hary Devianto; Rd. Habib R. M. T. Al-Aziz; Dian Shofinita; Tjandra Setiadi
Journal of Engineering and Technological Sciences Vol. 50 No. 6 (2018)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2018.50.6.7

Microbial fuel cell is one alternative technology that can be used to simultaneously solve problems related with wastewater production and energy demand. This study investigates the influence of electrode distance on power density in microbial fuel cell using tapioca wastewater. Graphite sheet without metal catalyst was used for both electrodes, separated by Nafion membranes. Four variations of electrode distance were used. MFC with highest electrode distance give the highest equilibrium OCV (676 mV), while the MFC with shortest electrode distance give the highest power density (7.74 mW/m2). EIS measurement suggested that the charge transfer resistance is dominant in all MFC configuration. Wastewater COD removal were in the range of 35-46 %, which were in accordance with the power density for all MFC.

Production of Biopolymer Polyhydroxyalkanoates (PHA) by Extreme Halophilic Marine Archaea Haloferax mediterranei in Medium with Varying Phosphorus Concentration Susiana Melanie; James B. Winterburn; Hary Devianto
Journal of Engineering and Technological Sciences Vol. 50 No. 2 (2018)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2017.50.2.7

The development of plastics production from biodegradable resources such as polyhydroxyalkanoates (PHAs) is important due to the increasing demand for plastics. PHAs occur as intracellular solid materials produced by microorganisms as a result of an excess of carbon source and a limitation of nutrients. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV, as one of the PHAs, is a combination of two homopolymers, namely poly-3-hydroxybutyrates (PHB) and poly-3-hydroxyvalerates (PHV). This study aimed to investigate the effect of the phosphorus concentration on the production of PHAs by Haloferax mediterranei. It is possible that phosphorus deficiency may affect the length of the HV chains in the copolymer structure and thus influence the copolymer properties. The experiment was done in triplicate at laboratory scale by culturing H. mediterranei in medium with phosphorus limitation using various phosphorus concentrations. During cultivation, the optical density, phosphorus concentration, pH, and dry cell weight were observed. The PHBV product was collected and analyzed using gas chromatography. The result shows that medium with a phosphorus concentration of 0.5 g/L produced higher PHAs than the other phosphorus concentrations. The accumulated PHA was 0.95 g/L with 15.6% of dry biomass and yield YPHA/S of 0.1 g/g.

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