Judul: Aplikasi Response Surface Method untuk Optimasi Kondisi Proses Produksi Biodiesel Jarak Pagar Melalui Transesterifikasi In Situ
Abstrak: A conventional jatropha seeds biodiesel production is conducted through many stages and long time process. It requires high production cost where 70% of production cost is used for extraction and purification. In situ transesterification can be an alternative solution for conventional biodiesel production problems. This study aims to optimize the process conditions of the jatropha seeds biodiesel production through in situ transesterification using RSM, and to determine the influence of the process conditions on the yield and quality of the biodiesel. The variables of process conditions optimized were the ratio of hexane to total solvent (X1), reaction temperature (X2), reaction time (X3), and agitation speed (X4), where the response was yield, viscosity, acid value, saponification value, and ester value. The optimum process conditions for biodiesel yield were obtained on X1= 0, X2= 57.9 °C, X3= 5.4 hours, and X4= 206.5 rpm. The optimum process conditions for biodiesel quality (viscosity; acid value; saponification value; ester value) were obtained on X1= 0.33, X2= 55.8 °C, X3= 3.2-5.2 h, and X4= 300-600 rpm. Polynomial model for biodiesel yield was first order polynomial model or linier and for biodiesel quality was third order polynomial model or cubic. The ratio of hexane to total solvent (X1) affected significantly biodiesel yield and quality. The optimum process conditions with multi response was obtained on X1= 0.06, X2= 53.3 °C, X3= 6 h, and X4= 392.4 rpm, with y1= 81.3%, y2= 0.14 mg KOH/g, and y3= 3.2 cSt. The validation on this optimum process conditions resulted y1= 77.5%, y2= 0.16 mg KOH/g, and y3= 3.6 cSt. The difference between the results of validation and model prediction was less than 5%, the model was thus good.
Keyword: Bogor Agricultural University (IPB), response surface method, optimization, in situ, jatropha seeds, biodiesel

Judul: Kajian Proses Produksi Biodiesel Melalui Transesterifikasi in situ Biji Jarak Pagar (Jatropha curcas L.) Pada Berbagai Kondisi Operasi
Abstrak: Biodiesel production is generally carried out through several stages of process. They are oil extraction, oil purification, and oil transesterification. Several steps that must be passed in the biodiesel production causing low efficiency and high energy consumption, resulting in high cost of biodiesel production. Therefore, it is necessary to develop a process that simplify the steps in biodiesel production, more efficient, low cost and low energy consumption, also be able to produce high quality of biodiesel through in situ transesterification. This study purposes to investigate on in situ transesterification of Jatropha curcas L. under various operating condition by studying the influence of temperature, stirring speed, and reaction time on the yield and quality of biodiesel. In situ transesterification of Jatropha seeds was carried out under the following process conditions : the moisture content of Jatropha seeds less than 1%, the particle size of 35 mesh, the methanol to hexane to seeds ratio of 6:1:1 (v/v/w), and the KOH concentration of 0.075 mol/L methanol. Operating conditions of in situ transesterification was varied at temperature of 40, 50, and 60ºC, reaction time of 3, 4, and 5 hours, and mechanical stirring of 700, 800, and 900 rpm. Analysis of variance showed that temperature, stirring speed, and reaction time did not significantly affected the yield and viscosity of biodiesel. Temperature, reaction time, and interactions between temperature, stirring speed, and reaction time significantly affected acid value of biodiesel. Temperature and interaction between temperature and stirring speed significantly affected saponification value and ester value of biodiesel. The experimental results showed that in situ transesterification conditions which recommended for commercial scale was at temperature of 40ºC, mechanical stirring of 700 rpm, and reaction time of 3 hours (A1B1C1). That condition was choosen because this condition used low energy than other operating condition. This was also supported by the results of statistical analysis showed that the yield and viscosity of biodiesel were not significantly different at all operating conditions, and biodiesel’s characteristics meets Indonesian Biodiesel Standard. The value of acid value, saponification value, ester value, and viscosity at A1B1C1 are 0.49 mg KOH/g, 201.36 mg KOH/g, 200.87 mg KOH/g, and 3.49 cSt.
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Judul: Psittacosis Sebagai Zoonosis Penting Yang Berasal Dari Burung
Abstrak: Psittacosis atau ornithosis adalah penyakit menular dari burung kepada manusia. Agens penyebab psittacosis termasuk ke dalam virus psittacosis-lymphogranuloma venereum group yang disebut Chlamydia psittaci. C. psittaci hanya dapat berkembang biak di dalam jaringan hidup tetapi peka terhadap antibiotik. Penyebaran penyakit ini sangat luas, terdapat hampir di seluruh dunia. Di Indonesia penyakit ini belum pernah di diagnosa, tetapi mengingat terdapat demikian banyaknya jenis burung maka diperkirakan psittacosis ini sudah ada. Kasus pada manusia pertamakali ditemukan oleh Ritter pada tahun 1879, di Eropa. Waktu itu dikenal sebagai pneumotyphus. Chlamydia psittaci tidak hanya sebagai penyebab infeksi pada burung, juga bisa menyebabkan infeksi pada mamalia diantaranya sapi, kerbau, kambing, domba, babi dan kucing. Pada kucing dikenal sebagai feline pneumonitis. Pada domba atau kambing mengakibatkan enzootic abortion. Pada burung, kalkun merupakan unggas paling rentan diikuti oleh burung psittacine dan burung lain di luar famili psittacidae. Virulensinyapun berbeda-beda. Yang berasal dari kalkun bervirulensi tinggi, sedangkan yang berasal dari burung merpati bisa bervirulensi tinggi bisa juga bervirulensi rendah. Penularan terjadi melalui kontak langsung maupun ti- dak langsung. Penularan melalui telur tidak terjadi. Umumnya penyakit ini memperlihatkan gejala klinis berupa deman, lesu, lemah, anorexia, kurus, diarrhea ber- warna kekuningan, discharge dari mata dan hidung, conjunc- tivitis. Gejala khas pada kalkun adalah istirahat dengan sternum sebagai dasarnya, karena adanya tekanan dari bagian perut yang sakit. Sedangkan pada manusia memperlihatkan adanya demam, kadang-kadang merasa dingin, lesu, sakit kepala yang hebat, sakit pada bagian belakang badan dan photophobia…dst
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