Hasil Pencarian  ::  Simpan CSV :: Kembali

"

---

ABSTRACTIn order to respond the global issues regarding climate change and global warming in this new era of globalization, governments and environmentalists set the targets to provide an alternative, sustainable and renewable energy to decrease the pollution emerging from non‐sustainable sources such as a fossil fuels or petrodiesel. The increase in the use of biodiesel fuels is expected to be a better solution to help address the environmental problems impacting on society.Biodiesels are an alternative, environmentally friendly energy resources generated from the transesterification process of animal fats, vegetable oils and other organic resources. The transesterification process of biodiesels can be carried on by using an alkaline as the catalyst to separates the triacylglycerol into an alkyl ester and a glycerol compound. Through this separation, a friendly chemical component similar with a fossil fuel can be produced. Nevertheless, further characteristics of biodiesels need to be observed in order to maximize the performance of biodiesels on the diesel engine.This report will focus on surface tension and density experimental investigations of four biodiesel fuels and nine fractionated methyl ester based on temperature dependency. The results are evidence of the relationship between surface tension and density. Also, the temperature change data characterizes the impact of fatty acid chain length upon density and surface tension."

"Lipase sebagai biokatalis untuk sintesis biodiesel dapat digunakan dalam bentuk lipase intraseluler (whole-cell) dan ekstraseluler. Pada penelitian ini, whole-cell dari Rhizopus oryzae dikultivasi melalui metode single step dan two step. Lipase ekstraseluler yang berupa ekstrak kasar diperoleh dari Aspergillus niger, Aspergillus oryzae, dan Aspergillus awamori. Kinerja biokatalis lipase diuji melalui reaksi interesterifikasi dengan rasio minyak dan metil asetat sebesar 1:12, biokatalis 10% wt pada suhu 35oC selama 48 jam. Hasil biodiesel terbaik diperoleh saat whole-cel free dikultivasi metode one step dengan yield 41%, dan yield lipase ekstraseluler dari Aspergillus awamori sebesar 19%. Kinerja lipase komersial ditinjau sebagai pembanding pada penelitian.

---

Lipase as biocatalyst for biodiesel synthesis can be used in the form of intracellular (whole-cell) and extracellular lipase. In this study, whole-cell from Rhizopus oryzae cultivated with single-step and two-step methods. Extracellular lipase in the form of crude extract obtained from Aspergillus niger, Aspergillus oryzae, and Aspergillus awamori. Performance lipase biocatalyst was tested by interesterification reaction with oil and methyl acetate ratio of 1:12, biocatalyst 10 wt% at a temperature of 35oC for 48 hours. Biodiesel best results are obtained when whole-cell free cultivated single step method with a yield 41% and yield the extracellular lipase from Aspergillus awamori by 19%. Commercial lipases were also reviewed as a comparator in study."

"Mengurangnya cadangan minyak mendorong para peneliti untuk mencari sumber energy alternatif. Biodiesel adalah salah satu solusi untuk mengatasi masalah ini. Microalgae adalah salah satu sumber biodiesel yang baik karena ia memiliki pertumbuhan yang cepat dan tidak perlu mengkhawatirkan akan sumber pangan. Penanaman microalgae dapat dilakukan di air tawar maupun air limbah. Teknik dewatering dibutuhkan untuk memanen microalgae. Namun, proses dewatering membutuhkan biaya yang mahal, maka dari itu, teknik dewatering yang efektif dan efisien sangat dibutuhkan. Eksperimen ini menggunakan teknik Jameson Cell Flotation untuk fase pertama dan pressure filtration untuk fase kedua. Hasil menunjukkan bahwa proses pengurangan kadar air dipengaruhi oleh tekanan dan waktu.

---

The depletion of oil reserve forces people to find alternative source for energy. Biodiesel is one of the alternative solution to overcome the problem. Microalgae has been found as a suitable source of biodiesel because it has a fast growth rate and it does not need to compete with edible crops. The cultivation of microalgae is done in freshwater or wastewater pond. Dewatering is required to harvest the cultivated microalgae. However, the dewatering contributes a significant proportion of production cost and an efficient and effective method of dewatering is desired. The Jameson Cell flotation is chosen to be the initial stage and the pressure filtration is chosen to be the second stage of dewatering process. It is known that the moisture removal is mainly affected by two factors, pressure and time."

"Lipase komersial dari mikroba memiliki kinerja baik dalam mengkatalisis sintesis biodiesel rute non-alkohol. Namun pengembangbiakan kultur mikroba dalam medianya serta pemurnian dari bentuk whole-cell membuat harganya mahal. Getah buah pepaya mentah dengan kandungan lipase yang diproses tanpa permunian rumit yaitu melalui pencucian dengan air dan pengeringan beku, diusahakan sebagai biokatalis alternatif yang harganya lebih terjangkau. Selama sintesis biodiesel rute non-alkohol, pengadukan dalam waktu yang lama dapat menganggu stabilitas biokatalis yang tersuspensi bebas bersama reaktan. Oleh karenanya biokatalis diimobilisasi dengan metode inti-selubung mikrokapsulasi (core shell microcapsulation) menggunakan alginat yang berperan sebagai inti matriks pengikat dan kitosan sebagai selubung yang melindungi inti matriks juga mengatur keluar masuknya substrat dan produk. Kinerja biokatalis getah pepaya tersuspensi dan terimobilisasi diuji dalam reaksi interesterifikasi biodiesel rute non-alkohol pada kondisi suhu 37°C, 1:12 molar, (substrat minyak sawit komersial : reaktan pensuplai alkil metil asetat). Dengan analisa secara kromatografi gas detektor spektrometri massa, didapat konversi biodiesel tertinggi dari masing-masing variasi kondisi reaksi sebesar 73,55% yang dihasilkan oleh 30% (b/b minyak) konsentrasi biokatalis; 30,91% oleh waktu reaksi 28 jam; 70,19% oleh konsentrasi inti alginat 4% (b/v) dan 80,40% oleh konsentrasi selubung kitosan 1,15% (b/v). Dengan menggunakan konsentrasi dan waktu reaksi tersebut dalam satu reaksi utuh, biokatalis dapat menghasilkan 85,47% konversi biodiesel yang dapat digunakan kembali sebanyak 2 siklus. Berdasarkan hasil penelitian, biokatalis getah pepaya terimobilisasi alginat-kitosan dapat berpotensi sebagai biokatalis alternatif lipase komersial dengan saran proses penghilangan metil asetat secara distilasi daripada evaporasi biasa, agar biodiesel lebih murni.

---

Commercial lipase from microorganism has good performance in catalyzing biodiesel non-alcohol route. Yet cultivation on the medium and purification from whole cell form make it costs expensive. Latex from unripe papaya fruit containing lipase processed without complex purification by washing with water and freeze drying, was attempted as more economically reachable alternative biocatalyst. During biodiesel synthesis through non-alcohol route, long time stirring in the reactor could disturb stability of biocatalyst that freely suspended along with reactant. Therefore, biocatalyst was immobilized with core-shell microcapsule method using alginate as linking matrix core and chitosan as core protector also regulate entry-exit of substrate and product. Suspended and immobilized biocatalyst’s performance was tested in interesterification reaction of biodiesel synthesis non-alcohol route under condition of 37°C, 1:12 molar (substrate commercial palm oil : alkyl supplier reactant methyl acetate). From analysis using gas chromatography-mass spectrometry detector, achieved the highest biodiesel conversion from each of every condition reaction variation in the amount of 73.55% by 30% (w/w) biocatalyst concentration; 30.91% by 28 hours reaction; 70.19% by 4% (w/v) alginate core and 80.40% by 1.15% (w/v) chitosan shell. By using those concentrations and time reaction, biocatalyst was set on a run, resulted 85.47% biodiesel conversion which could be reused for 2 cycles. Based on this study’s results, papaya latex immobilized in alginate-chitosan could become a potential alternative to commercial lipase with a suggestion on the methyl acetate removal by distillation instead of rough evaporation to get more purified biodiesel"

"Sebagai program peningkatan penyediaan energi bersih secara berkelanjutan dan upaya mengurangi impor solar di tengah situasi global yang terancam krisis energi, Presiden Republik Indonesia, Joko Widodo mengeluarkan mandatori Instruksi Presiden Nomor 1 Tahun 2006 Tentang Penyediaan dan Pemanfaatan Bahan Bakar Nabati (biofuel) Sebagai Bahan Bakar Altarnatif. Karena jumlah bahan bakar fosil terbatas maka pemerintah membuat instruksi untuk mencampurkan bahan bakar fosil dengan minyak nabati. Biodiesel adalah bahan bakar nabati untuk aplikasi mesin/motor diesel berupa ester metil asam lemak (fatty acid methyl ester/FAME) yang terbuat dari minyak nabati atau lemak hewani melalui proses esterifikasi/transesterifikasi. Untuk saat ini, di Indonesia bahan baku biodiesel berasal dari Minyak Sawit (CPO). Biodiesel siap digunakan oleh mesin diesel biasa dengan sedikit atau tanpa penyesuaian. Penyesuaian dibutuhkan jika penyimpanan atau wadah biodiesel terbuat dari bahan yang sensitif dengan biodiesel seperti seal, gasket, dan perekat terutama mobil lama dan yang terbuat dari karet alam dan karet nitril. Biodiesel tidak berbahaya, tetapi biodiesel yang terdegradasi dapat menjadi sangat berbahaya bagi kumponen rubber dan metal yang berhubungan langsung dengan bahan bakar. Oleh sebab itu saya melakukan praktek keinsinyuran untuk mengurangi dampak biodiesel terhadap mesin diesel. Pekerjaan telah diselesaikan secara professional dengan menjalankan prinsip dasar kode etik insinyur dan senantiasa memperhatikan Keamanan, Keselamatan, Kesehatan, Lingkungan Hidup (K3L) menggunakan standar–standar keamanan yang harus terus dijaga oleh setiap produsen mesin diesel.

---

As a program to increase the provision of clean energy sustainably and an effort to reduce diesel imports amidst a global situation threatened by an energy crisis, the President of the Republic of Indonesia, Joko Widodo issued a mandatory Presidential Instruction Number 1 of 2006 concerning the Provision and Utilization of Biofuels (biofuel) as Alternative Fuels. Because the amount of fossil fuels is limited, the government has issued instructions to mix fossil fuels with vegetable oil. Biodiesel is a vegetable fuel for diesel engine/motor applications in the form of fatty acid methyl ester (FAME) made from vegetable oil or animal fat through an esterification/transesterification process. Currently, in Indonesia, the raw material for biodiesel comes from Palm Oil (CPO). Biodiesel is ready to be used by ordinary diesel engines with little or no adjustment. Adjustments are needed if the biodiesel storage or container is made of materials that are sensitive to biodiesel such as seals, gaskets, and adhesives, especially old cars and those made of natural rubber and nitrile rubber. Biodiesel is not harmful, but degraded biodiesel can be very harmful to rubber and metal components that are in direct contact with the fuel. Therefore, I practice engineering to reduce the impact of biodiesel on diesel engines. The work has been completed professionally by implementing the basic principles of the engineer's code of ethics and always paying attention to Security, Safety, Health, Environment (K3L) using safety standards that must be maintained by every diesel engine manufacturer. "

"Untuk menghadapi tantangan perubahan iklim dan makin meningkatnya permintaan energi, juga untuk menjaga supply energi di masa yang akan datang, konsep "renewable energy" mulai dikembangkan, dimana salah satunya adalah biodiesel. Biodiesel merupakan alternative bahan bakar yang paling efektif dan siap untuk digunakan dalam skala besar global untuk menghadapi berbagai tantangan krisis energi yang ada. Biodiesel merupakan sebuah senyawa mono alkyl ester yang diproduksi melalui sebuah reaksi transesterJlcation, dimana bersama methanol menjadi methyl ester dan glycerol dengan catalic assistance. Biodiesel memiliki 12 sampai 20 rantai kanbon dan mengandung oxygen. Biodiesel memiliki beberapa kualitas khusus antara lain mudah digunakan, biodegradable, tidak beracun, tidak mengandung logam berat, sulfur dan senyawa aromatic chemical dan memiliki titik bakar lebih tinggi dari pada petroleum diesel sehingga aman untuk digunakan. Sejak tahun 2004, Indonesia mulai mengimport minyak bumi, dan pada tahun 2005, sebesar 30% konsumsi bahan bakar diesel diperoleh melalui impor. Sejalan dengan kenaikan harga bahan bakar minyak global, maka subsidi minyak bumi mencapai Rp.54 triliun dan pada tahun 2008 meningkat menjadi Rp.126 tniliun. Dengan per-timbangan tersebut, Indonesia mulai mempromosikan penggunaan bahan bakar alternatif termasuk biodiesel. PT. RI sebagai perusahaan engineering dan construction telah mulai aktif berperan dalam pengembangan biodiesel maupun bioethanol di Indonesia semenjak tahun 2004, dan mulai menjajaki investasi di industri biodiesel sebagai bentuk dukungan terhadap program pemenintah yang sejalan dengan clean development mechanism (GDIvI program Kyoto Protocol dan sekaligus menjadikan investasi pabrik biodiesel sebagai bentuk diversifikasi usaha perusahaan. Dalam melakukan investasi biodiesel dilakukan analisa kelayakan dari beberapa aspek khususnya finansial dan aspek penunjang Iainnya yaitu aspek pasar, aspek teknis, aspek produksi, dan aspek sumber daya manusia sebagai dasar pengambilan keputusan. Analisis kelayakan finansial investasi industri biodiesel dilakukan berdasar konsep capital budgeting dengan menggunakan metode Net Present Value (NPV), Internal Rate of Return (IRR), Profitability Index (P1), dan Paybak Period dengan tingkat diskonto berdasarkan hasil perhitungan Weighted Average Cost of Capital (WACC), mengingat sumber dana investasi diperoleh dari hutang dan kekayaan sendiri. Dari hasil analisis kelayakan finansial terhadap proyek biodiesel dengan kapasitas produksi 100,000 ton per tahun dengan bahan baku crude palm oil menunjukkan bahwa proyek biodiesel layak untuk dijalankan dengan nilai expected scenario NPV USD 4,755,201, IRR sebesar 23.38% lebih besar dibandingkan weighted average Cost of capital investasi yaitu sebesar 18,31%, PT sebesar 1.23, dan payback period selama 5 tahun 2 bulan (kurang dari sepuluh tahun), dengan asumsi harga dasar bahan baku crude palm oil USD 500 per ton dan harga jual biodiesel USD 710 per ton dengan proyeksi eskalasi harga 4% per tahun.

---

To face up to the challenge of climate change and to meet the increase in demandfor energy, as well as to safeguard the energy supply in the future, the concept of "rewenable energy" is being developed, one of which is biodiesel. Biodiesel is the most effective alternative fuel and ready for large-scale global use to face up to any existing challenges. Biodiesel is mono alkyl ester produced through a transesterJIcation reaction between tiygliceride found in vegetables oil, like palm oil, castor oil, etc. That with methanol becomes methyl ester and glycerol with catalic assistance. Biodiesel has a carbon chain between 12 through 20 and contains oxygen. The oxygen in biodiesel tells it apart from petroleum diesel the chief component of which only consists of carbon and hydrogen. Biodiesel has several special qualities, including easy to use, biodegradable, nonpoisonous, free of heqiy metals, sulfur and aromatic chemical compounds and has a higher flash point rate than petroleum diesel so it is safer to keep and use. Since 2004, Indonesia has started to be importing country for natural oil fuel. In 2005, some 30% consumption of dieselfuel was met from import. In line with global price oil fuel increase, the subsidized oil fuel has reached Rp. 54 trillion and in 2008 it has increased until Rp. 126 trillion, considering the above condition, Indonesia is now starting to promote the use of alternative fuel, including biodiesel. Since 2004, PT. RI as an engineering and construction company has actively been a part of biodiesel and bioethanoi development in Indonesia, and start looking forward an investment in biodiesel industry to support and in line with the government 's policy related to clean development mechanism (CDM) program of Kyoto Protocol, and also performing business divers/Ication through biodieseiplani. In the biodiesel plant investment need to be analyzed in several aspects including potential market, technical, production, and human resources as the basis of the investment feasi bully. The basis offinancialfeasibility analysis is capital budgeting concept using mehod of Net Present Value (NPV), Internal Rate of Return (TRR), Profitabililty Index (P1), and Payback Period with discount rate calculation base on Weighted Average Cost of Capital (WA CC), due to the inveslement budget resources consist of debt and equity. Financial feasibility analysis of biodiesel project with its capacity 100,000 ton per year and crude palm oil as the raw material shows that the project is feasible to perform with NPV USD 4,755,201, IRE? 23.38% > weighted average cost of capital of the investment that is 18.31%, P11.23, and Payback Period within 5 years and 2 months (less than ten years), with assumption that the raw material crude palm oil base price is USD 500 per ton and selling price of biodiesel is USD 710 per ton with price escalation projection 4% per year."

"Biodiesel merupakan salah satu solusi bahan bakar alternatif yang tepat digunakan di Indonesia karena Indonesia merupakan salah satu produsen Crude Palm Oil CPO terbesar di dunia. Saat ini, Biodiesel digunakan sebagai campuran dari diesel dari minyak bumi Solar. Masalah utama yang terjadi adalah kecenderungan biodiesel untuk teroksidasi sehingga menurunkan storage life. Masalah tersebut dapat diatasi dengan penambahan aditif antioksidan seperti tert-Butylhydroquinone TBHQ yang harganya murah dan banyak tersedia di pasaran. Performa TBHQ kurang memuaskan karena dispersinya yang buruk saat dicampur pada biodiesel. Oleh karena itu, TBHQ dicampurkan kedalam biodiesel dengan bantuan surfaktan Sorbitan monooleate yang bertujuan untuk meningkatkan dispersi sehingga performanya sebagai antioksidan lebih baik. Pencampuran tersebut dilakukan dengan beberapa langkah, yaitu pertama-tama mencampurkan TBHQ dengan surfaktan, kemudian dicampurkan kedalam biodiesel, serta dilakukan uji dispersi. Biodiesel diuji ketahanan oksidasinya sebelum dan setelah dicampurkan TBHQ dan surfaktan dengan bilangan asam dan bilangan iodin. Pengujian tersebut menunjukkan bahwa penambahan surfaktan Sorbitan Monooleate mampu meningkatkan dispersi TBHQ pada biodiesel. Peningkatan ketahanan oksidasi pada biodiesel paling baik terjadi setelah penambahan surfaktan Sorbitan Monooleate 300 ppm dan TBHQ 2000 ppm.

---

Biodiesel is one of the best alternative fuels solutions to be used in Indonesia because Indonesia is one of the largest producers of Crude Palm Oil CPO in the world. Currently, Biodiesel is used as a mixture of diesel from petroleum Solar. The main problem that occurs is the tendency of biodiesel to oxidize, thus lowering the shelf life. The problem can be solved by the addition of antioxidant additives such as tert Butylhydroquinone TBHQ which is cheap and widely available in the market. TBHQ performance is less satisfactory because of poor dispersion when mixed in biodiesel. Therefore, TBHQ is incorporated into biodiesel with the help of Sorbitan monooleate surfactant which aims to increase dispersion so that its performance as an antioxidant is better. Mixing can be done with several steps, namely first mixing TBHQ with surfactant, then mixed into biodiesel, and conducted by dispersion test. Biodiesel tested its oxidation resistance before and after mixed TBHQ and surfactant with acid number and iodine number. The tests showed that the addition of Sorbitan Monooleate surfactant increased the dispersion of TBHQ antioxidant additive in biodiesel. The best improvement of oxidative stability of biodiesel occur after adding the Sorbitan Monooleate 300 ppm and TBHQ 2000 ppm to the biodiesel."