BIOMASS PRODUCTION Chlorella vulgaris BUITENZORG USING SERIES OF BUBBLE COLUMN PHOTO BIOREACTOR WITH A PERIODIC ILLUMINATION

Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2), CO2 transferred rate (CTR), energy consumption for cellular formation (Ex), and cultural bicarbonate species concentration [HCO3] also give better results on series of reactor.Keywords: Chlorella vulgaris Buitenzorg, sunlight, periodic illumination, photo bioreactor, series configuratio

Technoeconomic Analysis of Integrated Bioethanol from Elephant Grass (Pennisetum purpureum) with Utilization of Its Residue and Lignin

Abstract Bioethanol has been developed as an alternative biofuel. Elephant grass is one of the lignocelluloses that can be used as a source of bioethanol. The bioethanol fermentation process should be improved along with its economic competitiveness to promote its wider application. This study aims to investigate and to evaluate the best scheme of biethanol (standalone) and the combination of bioethanol and its by-products through technoeconomic analysis. The method used is collecting data from several previous studies and simulating it with SuperPro Designer. Data from flowsheeting simulation is used as economic simulation data using Microsoft Excel. The results of this study indicate that the processing of biogas and lignin waste as fuel and lignosulfonates can increase the economic value of the bioethanol production process. The best economic value is the bioethanol production process using biogas and lignin as fuel for a Biomass Power Plant which is called Pembangkit Listrik Tenaga Biomassa (PLTBm) with a Net Present Value (NPV) of IDR 364,358,976,036, Internal Rate of Return (IRR) 11.32%, Pay Back Period (PBP) 7.2 years, and Profitability Index (PI) 1.08Keywords: bioethanol, biogas, elephant grass, lignosulfonate, SuperPro Designer AbstrakBioetanol telah dikembangkan sebagai bahan bakar nabati alternatif. Rumput gajah merupakan salah satu lignoselulosa yang dapat digunakan sebagai sumber bioetanol. Proses fermentasi bioetanol harus ditingkatkan seiring daya saing ekonomi untuk mempromosikan penerapannya yang lebih luas. Tujuan studi ini adalah untuk menginvestigasi dan mengevaluasi skema terbaik bietanol (standalone) serta kombinasi bioetanol dan produk sampingnya melalui analisis teknoekonomi. Metode yang digunakan ialah melakukan pengumpulan data dari beberapa penelitian sebelumnya dan disimulasikan dengan SuperPro Designer. Data dari simulasi flowsheeting digunakan sebagai data simulasi ekonomi menggunakan Microsoft Excel. Hasil studi ini menunjukan bahwa pengolahan biogas dan limbah lignin sebagai bahan bakar dan lignosulfonat dapat meningkatkan nilai ekonomi dari proses produksi bioetanol. Nilai ekonomi yang paling baik adalah proses produksi bioetanol dengan pemanfaatan biogas dan lignin sebagai bahan bakar Pembangkit Listrik Tenaga Biomassa (PLTBm) dengan nilai Net Present Value (NPV) Rp 364.358.976.036-; Internal Rate of Return (IRR) 11,32%, Pay Back Periode (PBP) 7,2 tahun, serta Profitability Index (PI) 1,08.Kata kunci: bioetanol, biogas, lignosulfonate, rumput gajah, SuperPro Designer

The Effect of Mass Ratio of Ferrocene to Camphor as Carbon Source and Reaction Time on the Growth of Carbon Nanotubes

This research aims to identify the best reaction time and mass ratio of camphor to ferrocene as carbon source in the growth of carbon nanotube (CNT). Ferrocene is used as carbon source and catalyst with stainless steel (SS)-316 type gauze as substrate.Camphor as alternative carbon source is intended to improve the CNT synthesis results. This research has shown that benzene, toluene, and xylene dominate camphor decomposition, so the addition will produce good quality CNT and increase the yield. The variation of mass ratio of camphor to ferrocene was 3:1, 2:1, 1:2, 1:3 and the variation of reaction time was 10,20,30,40, and 60 min. The synthesis results of the CNT were characterized using FESEM-EDS while the ferrocene and camphor decomposition gas was analyzed by GC-FID. The best quality of CNT was obtained at 1:2 mass ratio with yield 37%, carbon percentage of 76.98% and diameter of 77-151 nm. Increasing the reaction time from 10 to 20 minutes will increase the yield and quality of CNTs. The yield and quality of the CNT decreased after a reaction time of 30 minutes due to the deactivation of the catalyst and the closure of the active sites by nucleation and carbon growth

KINETIKA MIKRO DEKOMPOSISI METANA MENJADI KARBON NANOTUBE PADA PERMUKAAN KATALIS Ni-Cu-Al

MICRO KINETICS OF DECOMPOSITION OF METHANE TO CARBON NANOTUBES OVER NI-CU-AL CATALYST. The main focus of this research was to obtain micro kinetics decomposition of methane producing carbon nanotube on the surface of the Ni-Cu-Al catalyst. Experimental kinetics data collected at a temperature range of 650-750oC and pressure of one atmosphere.&nbsp;The preliminary test was conducted to obtain the kinetics are not influenced by external and internal diffusion limitations as well as inter-phase transfer.&nbsp;Kinetics data were tested by micro kinetic model derived from the catalyst surface reaction mechanism.&nbsp;The most appropriate kinetic model becomes the rate-limiting step of methane decomposition reaction. Results of preliminary experiment showed that the kinetics of the external diffusion effect is negligible at flow rates above 150 mL/min. Internal diffusion can be ignored with a catalyst under 0.25 mm in diameter with a weight of 0.04 grams of catalyst and contact time 2.5x10-4. Rate equation analysis shows that the rate-limiting step is the adsorption which indicates that intermediate consumption (CH4I + I &Ucirc; CH3I + HI) is faster than the formation of intermediate (adsorption of methane, CH4 + I &Ucirc; CH4I).&nbsp;The activation energy obtained for 34.628 kJ/mol and pre-exponential factor of 6.583x106.&nbsp;&nbsp;Fokus utama penelitian ini adalah memperoleh kinetika mikro dekomposisi metana yang menghasilkan Carbon Nanotube pada permukaan &nbsp;katalis Ni-Cu-Al. Data kinetika eksperimen diambil pada rentang temperatur 650-750oC dan tekanan 1 atmosfer. Percobaan pendahuluan dilakukan untuk memperoleh daerah kinetika yang tidak dipengaruhi oleh limitasi difusi eksternal dan internal serta perpindahan antar fasa.&nbsp; Data kinetika&nbsp; diuji dengan model kinetika mikro yang diturunkan dari mekanisme reaksi permukaan katalis. Model kinetika yang paling sesuai menjadi tahap pembatas laju reaksi dekomposisi metana. Hasil percobaan pendahuluan kinetika menunjukkan bahwa pengaruh difusi eksternal dapat diabaikan pada laju alir di atas 150 mL/menit. Difusi internal dapat diabaikan dengan menggunakan katalis berdiameter di bawah 0,25 mm dengan berat katalis 0,04 gram pada waktu kontak 2,5x10-4. Analisis persamaan laju menunjukkan bahwa tahap pembatas laju adalah tahap adsorpsi yang menunjukkan bahwa konsumsi intermediate (CH4I + I &Ucirc; CH3I + HI) lebih cepat dari pembentukan intermediate (adsorpsi metana,CH4 + I &Ucirc; CH4I). Energi aktivasi yang diperoleh sebesar 34,628 kJ/mol dan faktor pre-eksponensial 6,583x106. </p

Adsorption of alkyl benzene sulfonate surfactant on activated carbon for biobarrier purpose

Simultaneous adsorption and biodegradation process in fluidized biobarrier reactor is one of emerging methods for eliminating surfactant in waste water. This paper discusses the adsorption process on activated carbon as a part of a biobarrier system. Surfactant used in these experiments is branched sodium dodecyl benzene sulfonate branched in various concentrations of 400, 700, 1000 and 1500 mg/L placed in 250 mL closed-erlenmeyer container (in batch system). Adsorption took part in a glass column of 30 cm length and 2 cm diameter. Total surfactant concentration was measured with COD-chromate analysis and surface tension measurement. Adsorption equilibrium curves in solid (dC/m) and liquid phase (Ce) as well as surfactant concentration versus surface tension were performed. The results showed that surfactant adsorption equilibrium curve rose within equilibrium concentration (Ce) 0 – 533.4 mg/L, then reached plateau with increasing Ce. Critical Micelle Concentration (CMC) Sodium Dodecyl Benzene Sulfonate was 533.4 mg/L. Freundlich equilibrium constants were (1/n) = 1.91 and Kf = 9.97.10-5 in Ce range of 252.6 to 481.2 mg/L. The equilibrium time for adsorption was 24 hours and the minimum fluidization velocity was predicted to be 0.717 cm/s