Jurnal Reaktor

261-266

Authors: Erlyta Septa Rosa, Shobih Shobih

This research reports on a fabrication of polymer solar cells based on blends of two widely used polymeric semiconductors i.e. poly(2-methoxy-5-(3,7-dimethyloctyloxy)-para phenylene vinylene) (MDMO-PPV) and the soluble fullerene C60 derivative [6,6 phenyl C61-butyric acid methyl ester] (PCBM). The devices were fabricated on an indium tin oxide (ITO) coated glass substrate. After cleaned and dried, a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in H2O was spin coated onto the freshly prepared substrate and then dried in a vacuum oven at 120°C for 60 minutes. A blend of MDMO-PPV and PCBM in chlorobenzene was spin coated on the top and dried in a nitrogen ambient at room temperature for 24 hours. The devices were transferred to a sputtering system where an aluminum was coated. Some of the devices then were annealed in a vacuum oven at 60°C for 60 minutes. Finally, the devices were encapsulated by placing a sealant between the back of the devices and glass slides and then cured in a vacuum oven at temperature 100°C for 10 minutes. For characterization, the devices were illuminated with a xenon lamp at the intensity of 27 mW/cm2 and the temperature at approximately 25°C. The influence of the annealing treatment and polymer blends on the photovoltaic performance of the devices was also discussed here. The best performance was obtained from the device with a blend ratio of 1:1 MDMO-PPV/PCBM without annealing treatment. The typical power efficiency was 0.01% with open circuit voltage of 0.347 V, short circuit current of 0.064 mA, and maximum power of 0.006 mW.

272-276

Authors: Ery Susiany Retnoningtyas, Antaresti Antaresti, Aylianawati Aylianawati

Tongkol jagung yang melimpah sebagai produk samping dari hasil pengolahan industri jagung pipilan, memberikan peluang untuk dimanfaatkan sebagai substrat dalam produksi crude enzim selulase. Crude enzim selulase dari tongkol jagung selanjutnya diaplikasikan pada produksi etanol dengan memanfaatkan tongkol jagung juga dengan metode simultaneous saccharification and fermentation (SSF). Penelitian ini bertujuan untuk mempelajari pengaruh volume crude enzim selulase terhadap kadar etanol, kinerja crude enzim selulase dalam memproduksi etanol dan membandingkan kinerjanya dengan crude enzim komersial. Penelitian ini terbagi dalam dua tahap yaitu : pretreatment tongkol jagung, dan fermentasi. Tongkol jagung yang sudah dikeringkan, dihaluskan hingga menjadi serbuk dengan ukuran 12 mesh, dan diberi perlakuan hidrolisis dengan uap panas (steam explosion) selama 60 menit. Serbuk tongkol jagung difermentasi,dengan penambahan nutrisi, crude enzim selulase dan jamur Saccharomyces cerevisiae. Proses fermentasi dilakukan pada suhu 30oC selama 120 jam, sedangkan pengamatan dilakukan setiap 24 jam. Hasil penelitian menunjukkan produksi etanol yang dihasilkan dengan menggunakan crude enzim selulase dan crude enzim komersial berturut-turut adalah 1,28 dan 2,89 %.

284-290

Authors: Mubiar Purwasasmita, Petrus Benny Juwono, Aysha Mareta Karlina, Khoiruddin Khoiruddin, I Gede Wenten

Performance of polypropylene hollow fiber ultrafiltration membrane during non-dissolved solids (NDS) removal from palm kernel oil is investigated. The filtration is operated at difference feed temperature and pressure to study the effect of both parameters on membrane performance. From the experimental results, it can be concluded that polypropylene hydrophobic hollow fiber membrane can be used for palm kernel oil NDS removal. Temperature and trans-membrane pressure have proportional effect to permeate flux. In contrast, they have inverse effect to rejection of NDS. During the experiment, permeate fluxes and rejections of NDS varied from 3.4 to 8.7 L/m2.h and from 51% to 94%, respectively. The best operating conditions suggested are feed temperature of 30°C and TMP of 1 bar which produce the highest NDS rejection. In addition, the permeate quality can meet the requirement of standard NDS content even at its lowest rejection level which shows the remarkable performance of membrane filtration.

298-304

Authors: Syamsudin Syamsudin, Herri Susanto, Subagjo Subagjo

Kraft pulp mill sludge cake composed of rejected wood fibers and activated sludge microorganisms. With a heating value about 14 MJ/kg (dried basis), this type of biomass had a potential as an alternative energy source. Unfortunately, it had an ash content of 27.6% and a moisture content of 80%. For reducing moisture content with minimum energy consumption, a combination of mechanical dewatering and thermal drying was studied previously. Meanwhile, experiments on isothermal pyrolysis had been carried out for further improvement on ultimate and proximate analysis of solid fuel. Final mass of char obtained from pyrolysis at 500oC was not significantly different from that of 700oC, so pyrolysis was considered to be optimum at 500oC. A char obtained from pyrolysis at temperature of 500oC had a pore surface area of 77.049 m2/g (highest among other temperatures). Kinetic of isothermal pyrolysis was well represented with a first order modified volumetric model with a frequency factor of 0.782 1/s and an activation of 34.050 kJ/mol.

314-323

Authors: Subagjo Subagjo, Maria Ulfah

Evaluasi kinetika reaksi hidrodesulfurisasi (HDS) dibenzothiophene dan simulasi nafta hydrotreater yang berada di PT. PERTAMINA Refinery Unit II Dumai menggunakan katalis NiMo/Al2O3 hasil pengembangan telah dilakukan. Kinetika reaksi HDS DBT dilakukan dalan sistem reaktor batch dengan variasi temperatur 280-320oC dan tekanan 30 bar. Data kinetika diolah dengan persamaan hukum pangkat (law power) dan persamaan kinetik mekanistik (Langmuir Hinshelwood, LH). Berdasarkan model hukum pangkat, kinetika HDS DBT menggunakan NiMo/Al2O3 hasil pengembangan merupakan orde satu terhadap DBT dengan konstanta Arhenius sebesar 165633 detik-1 dan energi aktivasi 69017 J/mol (16,56 kkal/mol). Model LH yang cocok untuk reaksi HDS DBT menggunakan NiMo/Al2O3 hasil pengembangan adalah model LH yang mengilustrasikan adanya kompetisi antara reaktan DBT dan H2 pada tipe pusat aktif yang sama, dengan DBT teradsorb secara kuat sedangkan H2 teradsorpsi secara lemah. Energi aktifasi dan konstanta Arhenius berdasarkan model LH ini ini berturut-turut adalah 81409 J/mol (19,34 kkal/mol) dan 1658133 s-1. Dengan menggunakan persamaan laju reaksi hukum pangkat, model memberikan hasil konversi sulfur yang sama dengan hasil keluaran reaktor nafta hydrotreater RU II-Dumai, yaitu mencapai 98%.

179-186

Authors: Opy Kurniasari, Tri Padmi, Edwan Kardena, Enri Damanhuri

Municipal solid waste (MSW) handling in Indonesia is currently highly dependent on landfilling at the final disposal facility (TPA), which generally operated in layer-by-layer basis, allowing the anaerobic (absent of oxygen) process. This condition will certainly generate biogas in the form of methane (CH4) and CO2. Methane is a greenhouse gas with a global warming potential greater than CO2, and can absorb infrared radiation 23 times more efficient than CO2 in the period of over 100 years. One way that can be done to reduce methane gas from landfills that escape into nature is to oxidize methane by utilizing landfill cover material (biocover) as methane-oxidizing microorganism media. Application of compost as landfill cover material is a low-cost approach to reduce emissions so are suitable for developing countries. The compost used in this study was compost landfill mining, which is degraded naturally in landfill. The purpose of this study was to evaluate the ability of biocover to oxidize the methane on a certain layer thickness with a continuous flow conditions. Three column reactors were used, which were made of flexy glass measuring 70 cm in high and 15 cm in diameter. The methane flowed from the bottom of the reactor continuously at a flow rate of 5 ml/minute. The columns were filled with biocover compost landfill mining with layer thickness of 5, 25, 35 and 60 cm. The results showed that the thicker layer of biocover, the higher the efficiency of methane oxidation. The oxidation efficiency obtained in each layer thickness of 15, 25, 35 and 60 cm was 56.43%, 63.69%, 74.58% and 80, 03% respectively, with the rate of oxidation of 0.29 mol m-2 d-1 and the fraction of oxidation of 99%. The oxidation result was supported by the identification of bacteria isolated in this experiment, namely metanotrophic bacteria that have the ability to oxidize methane through the form of methanol metabolite.

193-198

Authors: Luqman Buchori, Mohamad Djaeni, Laeli Kurniasari

The main problem in corn drying process is the low of energy efficiency (50%) and quality products. Consequently, operating costs in large for fuel consumption and the short shelf life of corn. Zeolite adsorption dryers have the potential to overcome this problem. This research aims to study composition of corn-zeolite and the effect of temperature on drying speed and protein and fat content in corn. Research variables are the ratio of corn and zeolite (1:0, 1:3, 1:1, 3:1) and intake air temperature (room temperature, 30oC, 40oC, 50oC). Sampling for moisture testing performed every 15 minutes. For energy purposes also calculated the energy efficiency (h) based on the amount of heat used to evaporate water from the corn (Qevap) divided by the total heat requirement to regenerate the zeolite and raising the air temperature (Qintr). Profiles of temperature and water in the mixed adsorption dryer are also studied. The results showed that the greater number of zeolite used, the water content of the final outcome a little more drying, protein and fat content of the final result of drying is relatively constant. The larger intake air temperature, the water content of the less drying results, protein content decreases, and the fat content does not change/relatively constant. The best variable was a ratio of corn: zeolite is 1:3 and air temperature was 50oC. While the variables that are suitable and in accordance with ISO standards for dry foods (14%) are air temperature of between 40oC and 50oC with a ratio of corn:zeolite is 1:3. The energy efficiency of 81.23% is obtained. Modeling done with FEMLAB (COMSOL) can describe the moisture content and temperature profiles in the corn and zeolite

204-210

Authors: Darmawan Darmawan, Dyah Tjahyandari Suryaningtyas, Juniska Muria Sariningpuri

Wastewater treatment produces semi-solid residue (sludge) that must be handled carefully during dumping and discharge to avoid polluting the environment. A low cost and easy treatment of dewatering is needed. This research aimed to apply electroosmosis technique for dewatering sludge in order to seek for parameters that can efficiently reduce water content of sludge, including range of voltage, type of electrodes, and distance between electrodes; and to determine the effect of electroosmosis processes on changes of chemical characteristics of sludge. The results showed that: (1) electroosmosis dewatering occurred on the sludge taken from waste water treatment of landfill but not on sludge from water purification plant (PDAM), (2) direct current voltage of 30 volts was the optimum voltage, (3) copper rod cathode provided electroosmosis process as good as stainless steel cathode and both were better than the woven stainless steel cathode, (4) the dewatering time to reduce 1200% (w/w) water content to about 400% was about 40 hours for sludge of 2500 cm3 in volume (laboratory bench scale), (5) the anode need to reinserted gradually approaching the cathode due to current lost when the water content at the anode point reached 400% and sludge at the point shrink, and (6) some chemical elements in the sludge decreased significantly after treatment.

218-224

Authors: Mariana Mariana, Farid Muluna, Purwana Satriyo

Gases produced by garbage burning consist of dangerous gases such as CO, SO2 and other gases. Technology for reducing dangerous gases from incinerator outlet can be done by using a dry or wet process. The dry process is more economical process because of simple process, easy maintenance and no liquid waste as product. However, the weakness of the dry process is low absorption conversion and low gas removal efficiency. One way to overcome these problems is to use sorbent which has high reactivity. An inexpensive sorbent that commonly used is Ca(OH)2. The aim of this research was to increase the reactivity of Ca(OH)2 sorbent by using diatomaceous earth and compost as a source of silica and biosorbent, respectively. Diatomaceous earth contains CaO, SiO2 and Al2O3 and compost contains bacteria as a biosorbent that can convert CO to CO2 and CH4. The reaction between SiO2 and Ca(OH)2 would form calcium silicate hydrate (CaO.SiO2.2H2O) that has a high porosity and reactivity. The results showed that the reactivity of Ca(OH)2 sorbent increased by addition of diatomaceous earth and compost. The results also showed that the sorption of CO gas increases with increasing of height of sorbent bed and temperature. The highest CO gas sorption was obtained at temperature of 150oC and sorbent bed height of 6 cm using the modified sorbent with Ca(OH)2/DE/compost ratio of 3:1:1.

234-241

Authors: Tutuk Djoko Kusworo, Desmile Yusufina, Atyaforsa Atyaforsa

Carbon Nanotubes (CNTs) is one of the most well known nano-technology applications which the most of attracting the attention of researchers, because it has more advantages than other materials. The application of the CNT has extended into various aspects, such as electronics, materials, biology and chemistry. This research uses a system of Catalytic Chemical Vapour Deposition (CCVD), which aims to determine the influence of Co and Fe as a catalyst and zeolite 4A as a support catalyst with acetylene gas (C2H2) as carbon source in the synthesis of Carbon Nanotubes (CNTs). In this experiment, used the ratio of acetylene gas and flow rate of N2 gas is 1:1 by weight of the catalyst Co/Zeolite and Fe/Zeolite amounted to 0.5 grams at the operating temperature of 700oC for 20 minutes. N2 gas serves to minimize the occurrence of oxidation reaction (explosion) when operating. From analysis result by Scanning Electron Microscopy (SEM) shows the CNTs formed a type of MWNT with different of diameter size and product weight, depending on the size of the active component concentration on the catalyst. The larger of active components produced CNTs with larger diameter, whereas product weight syntheses result smaller. Use of the catalyst Fe/Zeolite produce CNTs with a diameter larger than the catalyst Co/Zeolite.

247-254

Authors: Nyoman Jaya Wistara, Gokma Silaban, Gustan Pari

The main goal of the present works was to determine chemical changes, thermal decomposition, and the content of moisture, ash, volatile, fixed carbon and calorific value of soda pulping black liquor of the rice straw. Neutralized black liquor was dried to a moisture content of 10% and then pyrolized at 106oC-750oC. It was found that calorific value, fixed carbon, volatile mater, and moisture content were in the range of 2782-4716 cal/g, 49.2-81.6%, 15.5-47.5%, and 0.2-3.5%, respectively. Ash content was not influenced by the temperature of pyrolysis and was thought to depend on its initial silicate content. The weight loss of pulp was higher than that of black liquor. Extreme weight loss has been found in the temperature of 200-400oC. Noticeable functional groups changes were found with the increasing temperature of pyrolysis. Hydroxyl group completely disappeared at 300oC and above. Carbonyl related groups were also disappeared at 300-500oC, but it was reformed at 650 and 750oC. It might be brought about by the deformation of chemical bonding of oxygen ring in lignin structures.

95-100

Authors: Yulius Deddy Hermawan, Gogot Haryono

The open loop experiment of composition dynamic in a 10 L mixing tank has been successfully done in laboratory. A 10 L tank was designed for mixing of water (as a stream-1) and salt solution (as a stream-2 with salt concentration, c2 constant). An electric stirrer was employed to obtain uniform composition in tank. In order to keep the liquid volume constant, the system was designed overflow. In this work, 2 composition control configurations have been proposed; they are Alternative-1 and Alternative-2. For Alternative-1, the volumetric-rate of stream-1 was chosen as a manipulated variable, while the volumetric-rate of stream-2 was chosen as a manipulated variable for Alternative- 2. The composition control parameters for both alternatives have been tuned experimentally. The volumetric-rate of manipulated variable was changed based on step function. The outlet stream’s composition response (c3) to a change in the input volumetric-rate has been investigated. This experiment gave Proportional Integral Derivative (PID) control parameters. The gain controllers Kc [cm6/(gr.sec)] for Alternative-1 and Alternative-2 are -34200 and 40459 respectively. Integral time constant ( tI) and Derivative time constant (tD) for both alternatives are the same, i.e. tI = 16 second, and tD = 4 second. Furthermore, closed loop dynamic simulation using computer programming was also done to evaluate the resulted tuning parameters. The developed mathematical model of composition control system in a mixing tank was solved numerically. Such mathematical model was rigorously examined in Scilab software environment. The results showed that closed loop responses in PID control were faster than those in P and PI controls.

109-117

Authors: Yuswan Muharam, Chandra Hadiwijaya, Jacquin Suryadi

One of the characteristics of gasoline fuel is anti-knock property represented by its octane number. The determination of octane numbers in Indonesia is by using cooperative fuel research engines. The usage of cooperative fuel research engines in Indonesia has constraints, i.e. the limited number of the units and the old age. This study aims to obtain the octane numbers of commercial fuels by using kinetic models. The kinetics models of the oxidation and combustion of primary reference fuel and multi component hydrocarbons are used to calculate the ignition delay times of primary reference fuel and commercial fuels, respectively. The ignition delay times of primary reference fuel and commercial fuels are calculated at the same initial pressure and temperature, as well as the same equivalence ratio. The octane number of a commercial fuel is known if its ignition delay time agrees with that of PFR possessing a certain volume percentage of isooctane. The model generates the octane numbers of commercial fuels BB-A being 92.5, BB-B being 94.5, BB-C being 89, BB-D being 90.5 and BB-E being 91.5 with the good agreement with those claimed by the fuel producers.

123-128

Authors: Nyoman Puspa Asri, Siti Machmudah, Wahyudiono Wahyudiono, Suprapto Suprapto, Kusno Budikarjono, Achmad Roesyadi, Mitsuru Sasaki, Motonobu Goto

A benign process, non catalytic transesterification in sub and supercritical methanol method was used to prepare biodiesel from vegetables oil. The experiment was carried out in batch type reactor (8.8 ml capacity, stainless steel, AKICO, JAPAN) by changing the reaction condition such as reaction temperature (from 210°C in subcritical condition to 290°C in supercritical state with of 20°C interval), molar ratio oil to methanol (1:12-1:42) and time of reaction (10-90 min). The fatty acid methyl esters (FAMEs) content was analyzed by gas chromatography-flame ionization detector (GCFID). Such analysis can be used to determine the biodiesel yield of the transesterification. The results showed that the yield of biodiesel increases gradually with the increasing of reaction time at subcritical state (210-230oC). However, it was drastically increased at the supercritical state (270-290oC). Similarly, the yield of biodiesel sharply increased with increasing the ratio molar of soy oilmethanol up to 1:24. The maximum yield 86 and 88% were achieved at 290oC, 90 min of reaction time and molar ratio of oil to methanol 1:24, for soybean oil and palm oil, respectively.

135-142

Authors: Elida Purba, Kenjiro Siburian

The determination of salinity and nutrition (NaH2PO4) profile in Nannochloropsis oculata cultivation to gain maximum lipid was investigated. The purpose of this research was to determine the optimum salinity and nutrition (NaH2PO4) to gain maximum lipid in Nannochloropsis oculata. Phosphor can be obtained by adding NaH2PO4 and a salinity enhancement can be applied by adding NaCl to the culture. This research was run by matching each variable of salinity (33, 34, 35, and 36 ppt) to each variable of NaH2PO4 (5, 10 and 15 ppm) randomly. The results show that the percentage of maximum lipid in Nannochloropsis oculata was obtained at 35 ppt and 5 ppm NaH2PO4 (37.68 %). Nevertheless the maximum lipid percentage is low and it can be caused by some factors, such as the drying temperature for preparing the dry microalgae to extract, the cell disruption method and the extraction solvent used. By seeing the results, salinity can affect the total lipid in Nannochloropsis oculata. The greater the salinity in culture the greater the lipid content in Nannochloropsis oculata. Otherwise a different response was obtained by adding NaH2PO4. If NaH2PO4 concentration is greater, the lipid contained Nannochloropsis oculata will be lower

151-157

Authors: Maria Ulfah, Subagjo Subagjo

Effect of surface characteristics of three species of synthesized γ-alumina (alumina-1, alumina-2 and alumina-3) on characteristics NiMo catalysts has been studied. Those aluminas are derived from boehmite Catapal B by varying rasio mol nitric acid to boehmite. A sol-gel method is used to synthesize γ-Al2O3 support. The Nitrogen adsorption, X-ray diffraction (XRD), Temperature Programmed Reduction (TPR) of H2, Temperature Programmed Desorption (TPD) of NH3, and mechanical strength are used to characterize the supports and catalysts. The results showed that the surface area alumina affects the formation of crystalline MoO3 in the NiMo catalyst, while γ-Al2O3-3 support which has the highest surface area (about 195 m2/g) compared to the other two types of alumina (>195 m2/g) does not have a crystalline MoO3. The formation of crystalline MoO3 is not influenced by the acidity alumina. Based on the results of XRD, it is indicated that the supported alumina-3 NiMo catalyst (having the highest acid strength) shows that there is no presence of crystalline MoO3. Pore size distribution of support did not change significantly after the deposition of Ni and Mo oxides. Mechanical strength of support also affects the strength NiMo catalyst. Support alumina-3 which has the highest mechanical strength gives the mechanical strength of the highest NiMo catalyst.

165-172

Authors: Sri Hidayati, Natalia Gultom, Hestuti Eni

An experiment of sulfonation process of methyl ester to produce methyl ester sulfonates (MES) was caried out using waste palm methyl ester and sulfuric acid as sulfonating agent with variation of H2SO4 concentration (60% (K1), 70% (K2), dan 80% (K3)) and sulfonation time (60 minute (L1), 75 minute (L2) and 90 minute (L3)) using factorial on Randomized Complete Design Block. The experiment result showed the best sulfonation condition present in 80% H2SO4 concentration and sulfonation time of 90 minutes. The best characteristic of MES is produced showed surface tension of 27.35 dyne/cm, emulsion stability of 89.44%, acid value of 17.72 mg KOH/g and interfacial tension of 0.0361 dyne/cm at MES concentration of 2% in 10,000 ppm salinity water.

9-16

Authors: M. Faisal, Hiroyuki Daimon, Koichi Fujie

The behavior of heavy metals eluted from the wall of Ni/Fe-based alloy reactors after high-temperature and high-pressure water reaction were studied at temperatures ranging from 250 to 400oC. For this purpose, water and cysteic acid were heated in two reactor materials which are SUS 316 and Inconel 625. Under the tested conditions, the erratic behaviors of soluble metals eluted from the wall of Ni/Fe-based alloy in high temperature water were observed. Results showed that metals could be eluted even at a short contact time. The presence of air also promotes elution at sub-critical conditions. At sub-critical conditions, a significant amount of Cr was extracted from SUS 316, while only traces of Ni, Fe, Mo and Mn were eluted. In contrast, Ni was removed in significant amounts compared to Cr when Inconel 625 was tested. It was observed that eluted metals tend to increased under acidic conditions and most of those metals were over the limit of WHO guideline for drinking water. The results are significant both on the viewpoint of environmental regulation on disposal of wastes containing heavy metals, toxicity of resulting product and catalytic effect on a particular reaction.

25-32

Authors: Teguh Ariyanto, Imam Prasetyo, Rochmadi Rochmadi

Nanoporous carbons, due to high specific surface area, high pore accessibility, and relatively low cost, have been used as material electrode supercapacitors. In this work, the influence of pore structure of nanoporous carbons on the specific capacitance of supercapacitors was examined. Nanoporous carbons with several types of pore structure were prepared by carbonization of phenolic resin produced by polymeric condensation of phenolic compound with formaldehyde. Furthermore, ethylene glycol, as a filler, was added in the phenolic resin polymerization to increase the mesoporosity of nanoporous carbon. The nanoporous carbons produced were characterized for their surface morphology, specific internal surface area (BET method), and pore structure. Samples were used as electrode material in supercapacitor and specific capacitances were characterized by galvanostatic test using 30% KOH aqueous solution as electrolyte. The capacitance test of supercapacitors exhibited that increasing mesoporosity increase specific capacitance value of supercapacitors. The highest specific capacitance of 336 F/g was obtained by using mesoporous carbon produced by carbonization of resorcinol phenol formaldehyde ethylene glycol (C-RPFEG2) as electrode material of supercapacitors.

39-45

Authors: Tjukup Marnoto, Gogot Haryono, Dewi Gustinah, Fendy Artha Putra

Public awareness on using natural dyes has encouraged the extraction of tannins from putrimalu. Extraction was performed continuously using a Soxhlet apparatus. The parameter studied was the influence of solvent polarity on the amount of tannin and mass transfer coefficient. Tannin was extracted from ten grams of dried putrimalu plants using polar solvents (ethanol, acetone and methanol) and a non-polar solvent (n-hexane). Extraction is considered complete when the concentration of tannins in the liquid is no longer changing with time. Liquid samples were withdrawn every 20 minutes interval for tannin analyses using Thin Layer Chromatography (TLC). The results showed that the maximum concentration of tannins in the extract (g/mL) when extraction were performed using n-hexane was 0.0031, acetone (0.016), methanol (0.0274) and ethanol (0.044). From extract yield and mass transfer coefficient point of views, it can be concluded that the best solvent is ethanol. The relationship between tannin concentration in the ethanol 96% solvent and the time was expressed in term of mathematical equations CAL=1.046(1-e-0.0213t) with error was 3.6%. Where CAL is the concentration of tannins in the solvent (g/ml) and t is the extraction time (minutes).

51-60

Authors: Kusmiyati Kusmiyati, Puspita Adi Lystanto, Kunthi Pratiwi

Industrial wastewater may contain heavy metals such as Cu and Ag those are harmful to the environment if discharged without pretreatment. One of the methods to reduce heavy metals in wastewater is adsorption, to separate certain components from liquid to the surface of solids. Adsorption is a simple method, but most of the adsorbents are expensive, therefore a cheaper adsorbent is required to reduce the cost of the adsorption process. This work utilized bottom ash as an adsorbent. Bottom ash is a waste of combustion products in the coal industry, which contain potentially harmful materials. Activation of bottom ash was made by soaking in peroxide and continuing by heating at a temperature of 500oC. This study was aimed to determine the influence of process parameters (concentration, pH and processing time) to the percentage of amount heavy metals adsorbed, to study the equation isotherm adsorption using Langmuir and Freundlich models, and to calculate the kinetic constants of adsorption based on pseudo -first- order and pseudo-second-order kinetic model. The experiment was conducted in the batch system, where 10 grams bottom ash was mixed with 400 ml of synthetic waste. AAS was used to determine the heavy metals content in the waste solution. The results showed that bottom ash can be used to reduce heavy metals of Cu2+ and Ag+, the optimum condition when the concentration of 25 ppm under acidic conditions, bottom ash was able to adsorb Cu2+ metals ion by 62.79-80.25% at pH 4, and 65.54-85.98% at neutral pH with the same adsorption time of 300 min. For the ion metals Ag+, at acidic solution the metals ion can be adsorbed by 56.51-82.21%, while at neutral pH conditions 59.92-87.55%. Adsorption of bottom ash follows the model of Freundlich isotherm adsorption at acidic and neutral condition, the correlation coefficient (R2)obtained was 0.994 for Cu2+ metals ion and 0.984 for the Ag+ metals ion at acidic solution, whereas 0.986 for Cu2+ metals ion and 9.69 for the Ag+ metals ion at neutral pH. Kinetic model of second order rate describe the adsorption process well at acidic and neutral conditions. At the optimum conditions, the correlation coefficient (R2) of 0.998 for Cu2+ and 0.999 for the Ag+ at acidic solution, whereas 0.993 for Cu2+ and 9.998 for the Ag+ at neutral pH were obtained.

68-72

Authors: Meiny Suzery, Ely Kusniawati, Dwi Hudiyanti, Bambang Cahyono

Isolation of hyptolide has been done from Hyptis pectinata, and alkene group transformation through oxidation reactions using H3B: OEt2 to the isolated compound was also conducted. Product analyses were carried out using TLC, UV spectrometry, IR, and LC-MS. Pure crystal with melting point of 86-87oC was isolated. The yield was 1.75% (w/w). After analysing and compilating of spectroscopic data it was confirmed as hyptolide compound. Hydroboration of this compound (followed by hydrolysis using H2O2 under alkaline conditions) produce its alcohol derivatives, with 28.9% the percentage of transformation, it was demonstrated by LCMS data. IR spectrum at 3600cm-1, confirming the replacement of hydroxyl bond by alkene. Regioselectivity of addition reaction is proposed through simulation with Chem Office. The reaction product was suspected as 6-hydroxy-7-(6-oxo-3,6-dihydro-2H-pyran-2-yl) heptane-2,3,5-tryil triacetate. Extension of reaction time to 24 hours, has increase hydroboration product to 78.3%. This research has opened other studies of natural materials in accordance to the roadmap set.

79-85

Authors: Indro Sumantri, Sumarno Sumarno, Norma Afiati

Proses konvensional untuk mengolah limbah cair industri urea biasanya menggunakan proses alga mikro atau bakteri heterotropik nitrifikasi-denitrifikasi. Proses alga mikro dapat menggunakan berbagai jenis alga mikro. Keuntungannya adalah murah karena hanya memerlukan nutrien P sedikit tetapi tidak dapat digunakan untuk menyusutkan amoniak. Proses nitrifikasi-denitrifikasi bakteri heterotropik memerlukan asupan karbon yang tinggi sehingga pengolahan menjadi mahal. Tujuan saat ini untuk penelitian adalah untuk mempelajari kombinasi yang potensial untuk proses alga mikro jenis tertentu dengan proses nitrifikasi-denitrifikasi ototrofik. Jenis alga mikro yang digunakan dalam proses alga mikro mempunyai kemampuan baik untuk penyusutan amoniak atau tahan dalam konsentrasi amoniak tinggi. Proses nitrifikasi-denitrifikasi ototrofik menggunakan bakteri nitrifikasi/lumpur sebagai biokatalis. Lumpur nitrifikasi awal adalah lumpur aktif kolam aerasi unit pengolahan limbah cair industri partikel board Pengayaan dan pembibitan lumpur nitrifikasi dilakukan dalam konsentrasi amoniak yang tinggi dan kondisi ototrofik. Berdasarkan penelitian, pengayaan dan pembibitan alga mikro yang mempunyai kemampuan untuk penyusutan amoniak dan tahan konsentrasi amoniak yang tinggi mudah. Evaluasi substrat pembatas penghambat amonium terhadap pertumbuhan alga tidak terbukti. Tujuh variabel yang dipilih lewat penapisan adalah : MLSS, waktu tinggal, konsentrasi NH3-N, laju aerasi, kadar CaCO3, nutrien mikro, rasio N:P. Variabel yang berpengaruhadalah konsentrasi NH3-N, laju aerasi, kadar CaCO3.

211-219

Authors: Margono Margono, Rochmadi Rochmadi, Siti Syamsiah, Muhamad Nurcahyanto

One of the technical approaches to get improvement of PHB productivity was a process simulation by using mathematical modeling. The objective of this research was to develop mathematical model which could be used to simulate fermentation of polyhydroxybutyrate production by Bacillus cereus IFO 13690 using tapioca substrates. Three different experiments with initial ammonium of 0.286, 0.566, and 1.203 g/L were carried out in 5 L fermentor and 500 rpm of agitation speed. The pH medium was controlled at 5.6 after it came down from the initial pH of 6.8. Meanwhile, the initial doT was 70% air saturation and also came down to and maintained at doT of 5% air saturation. PHB accumulation was growth associated product. Model of bacteria mechanism on utilizing tapioca and the mathematical model were proposed. The proposed model was suitable with the experimental phenomena. However, the rate of fermentation process was the controlling rate for overall PHB synthesis.

225-230

Authors: Heri Rustamaji, Hary Sulistyo, Arief Budiman

Sulfated zirconia has been prepared and characterized by X-ray diffraction, infrared spectroscopy, BET surface area, and BJH pore distribution methods. XRD patterns reveal that the sulfated zirconia mainly consists of tetragonal crystalline zirconia with average size of about 9.8 nm. N2 adsorption data show that the nanosized sulfated zirconia has high surface area (109.4 m2/g) and shows the uniform pore distribution aggregated by zirconia nanoparticles. Sulfated zirconias were used as catalysts in the alcoholysis of jatropha oil. The conversions of jatropha oil alcoholysis under good conditions (120oC, 2 h, 3 wt% of catalyst and 1000 rpm agitation speed) were 79.65%.

237-241

Authors: Tony Handoko, Sherly Octavia Rusli, Isabella Sandy

As a maritime nation, Indonesia produced fresh fish products up to 4,408,419 tons in 2005. Mackerel fish is one of them. Its bone waste has an economic value as a source for fish glue production. The purpose of this research was to determine the optimum conditions in fish glue processing. Preliminary research was done to determine the acid type (CH3COOH and HCl) and its concentration (4%, 5%, and 6%) in soaking process. While the main research was then done to determine the best temperature (45oC, 60oC, and 75oC) and time of extraction (4 hrs, 5 hrs, 6 hrs). The fish glue products were analyzed their adhesion and physical characteristics, such as density, viscosity, pH, and water content. The results showed that weak acid (CH3COOH) of 5% concentration is the best solution in soaking process and extraction in 4 hrs at 45oC has given the optimum condition for producing fish glue. The glue has a nice odor but its adhesion strength remains poor.

248-253

Authors: Herti Utami, Arief Budiman, Sutijan Sutijan, Roto Roto, Wahyudi Budi Sediawan

Indonesian turpentine contains 65-85% α-pinene, 1% camphene, 1-3% β-pinene, 10-18% 3-carene and limonene 1-3%. In order to obtain more valuable products, α-pinene can be hydrated in dilute acid solutions to produce terpineol, which can be used as perfume, insect repellent, antifungal, disinfectant etc. The aim of this research was to study kinetics of terpineol synthesis from α-pinene, the main component of turpentine Turpentine was introduced into a batch reactor (tree neck flask) equipped with condenser, thermometer, stirrer and was warmed up to the desired temperature with the reaction time of 420 minutes. The study investigated the effects of temperature, catalyst amount, and the stirring rate on the hydration of α-pinene. The heterogeneous kinetics model was proposed to quantitavely describe the hydration process of α-pinene. The results of this study showed the relationship of the constants of the reaction rate and temperatures. The equations can be written as follow and . The relative errors were 2.80% and 2.19%, respectively. It was found that the chemical reaction step controlled the hydration process. The results of this study show that the proposed heterogeneous kinetics model can quantitatively describe the hydration of α-pinene using chloro acetic acid as catalyst very well.