MODEL KESEIMBANGAN EKSTRAKSI MINYAK TEMULAWAK MENGGUNAKAN PELARUT ETANOL

In the design or operation of mass transfer equipment, it always needs equilibrium data. The aim of this research was to find the suitable equilibrium model on temulawak oil extraction using ethanol 95 % weight as the solvent. The extraction was carried out in closed erlenmeyer of room temperature and equipped by magnetic stirrer for agitation. The extraction was run about 2 hours and the equilibrium state was attained. The concentrations gf oil were measured at various weight ratio solid-ethanol. Three models were propos"f:d, namely Henry model, Langmuir model, and Freunlich model. Based on experimental data and the mathematical model, the equilibrium constants were evaluated nUf[1erically least square. The results showed that the Langmuir equilibrium model waf fit with the experimental data. Key words: equilibrium model, extraction

Peningkatan Kualitas Biodiesel dari Minyak Biji Karet dengan Hidrolisis dan Acid PreTreatment

Pemberdayaan biodiesel sebagai bahan bakar alternatif di Indonesia terbentur pada beberapa kendala. Salah satunya adalah masalah bahan baku yang bersaing dengan kebutuhan pangan. Diversifikasi bahan baku sangat mungkin dilakukan mengingat Indonesia adalah negara yang sangat kaya akan sumber minyak nabati. Tujuh puluh persen biaya produksi biodiesel berasal dari bahan baku. Untuk itu perlu diupayakanpenggunaan bahan baku yang murah serta proses produksi yang sederhana untuk menghasilkan biodiesel berkualitas baik. Bahan baku murah dapat diperoleh dengan menggunakan minyak nabati kasar (unrefined vegetable oil), minyak goreng bekas, serta produk samping proses hidrolisis minyak, yang berupa asam lemak. Dengan pre-treatment yang sesuai, dapat dihasilkan biodiesel berkualitas baik. Indonesia sangat berpotensi menggunakan minyak biji karet menjadi bahan baku biodiesel karena memiliki 3,4 juta hektar lahan perkebunan karet (terbesar di dunia). Di samping itu, kadar minyak biji karet tinggi serta belum termanfaatkan secara optimal. Penelitian pada tahun kedua ini bertujuan untuk memproduksi biodiesel dengan 2 macam pre-treatment,yakni hidrolisis dan acid pre-treatment. Kedua produk biodiesel tersebut dianalisis karakteristiknya dengan standar ASTM dan disesuaikan dengan Standar Nasional Indonesia (SNI). Proses pembuatan biodiesel dilakukan dengan kondisi operasi optimal yang telah dihasilkan pada penelitian tahun pertama. Pretreatment dengan asam dilakukan dengan metanolisis minyak biji karet menggunakan katalis H2SO42,5% volume minyak, rasio metanol : minyak 1 : 6 mgek, waktu reaksi 2 jam dan suhu 60 o C. Sedangkan pre-treatment secara hidrolisis dilakukan dalam multi tahap dengan katalis HCl, rasio minyak : air 1 : 1 dan suhu 80 o C pada tekanan atmosfir. Berdasarkan data percobaan diperoleh informasi bahwa biodiesel dari asam lemak jenuh minyak biji karet memiliki keunggulan dari segi angka setana, angka iod, angkaasam, viskositas dan titik tuang. Sementara itu biodiesel dari minyak biji karet dengan acid pre-treatment lebih unggul dari sisi kadar residu karbon yang rendah dan titik nyala yang tingg

Carrageenan Properties Extracted From Eucheuma cottonii, Indonesia

Abstract—The effect of extraction solvent upon properties of carrageenan from Eucheuma cottonii was studied. The distilled water and KOH solution (concentration 0.1- 0.5N) were used as the solvent. Extraction process was carried out in water bath equipped by stirrer with constant speed of 275 rpm with a constant ratio of seaweed weight to solvent volume ( 1:50 g/mL) at 86o C for 45 minutes. The extract was then precipitated in 3 volume of 90% ethanol, oven dried at 60o C. Based on experimental data, alkali significantly influenced yield and properties of extracted carrageenan. The extracted carrageenan was found to have essentially identical FTIR spectra to the reference samples of kappa-carrageenan. Increasing the KOH concentration led to carrageenan containing less sulfate content and intrinsic viscosity. The gel strength increased along with the increasing of KOH concentration. The decreasing of intrinsic viscosity value indicates that a polymer degradation occurs during alkali extraction. Keywords— gel strength, sulfate, intrinsic viscosity, Eucheuma cottoni

Sintesis Katalis Heterogen Nanokomposit ZnO/Fe 2O3 untuk Reaksi Trans-Esterifikasi pada Pembuatan Biodiesel Berkualitas Tinggi

The increasing of the price and the decreasing of the resources of petroleum have to be anticipated by finding alternatives energy resources, especially the renewable energy resources. Biodiesel, one of the alternative energy, have many advantages. The advantages of the use of biodisel are renewable energy, lower emission, able to be used as petrosolar adititive, as wel as non-toxic Biodiesel is usualy made from vegetable oil by esterification proce ss. The esterification for producing biodiesel was much carried out using homogeneous catalyst (acid/base). These process had many disanvantages such as high energy consumption, side product formed and complicated separation among product, side product and catalyst. Because of these, it is needed a heterogeous catalyst which is able to give a high reaction yield and is easily separated from biodiesel product. ZnO as transesterification catalyst has given high yield (86.1%) and high content of methyl ester (98.9%) of biodiesel product. To improve the catalytic performance, the catalyst specific surface must be increased by, such as, decreasing the size of particle. To ease the separation between product and catalyst, the magnetic characteristic should be added to the catalyst. The aim of the research were to obtain nanocomposite ZnO/Fe 2O3 and determine physical characteristic as well as catalytic and separation performance of nanocomposite ZnO/Fe 2O3. In the first two years of the research, the nanocomposite catalyst of ZnO/Fe2O3 had been produced and characterized its physical properties. The research had also determined the best operating conditions of manufacturing nanocomposite catalyst of ZnO/Fe2O3, i.e.,ratio of Zn(NO 3)2 and Fe(NO 3)3 in precursor solution 1:1.; Flowrate of LPG 0,3 L/minute; Carrier gas flowrate 1 L/menit. At those conditions nanocomposite of ZnO/Fe 2O3 obtained had 50-100 nm in size and 45-55 m 2 /gram of specific surfaceas well as a property of attracted by magnet. In the last year of the research, the research was focused on the determination of catalytic performance of nanocomposite of ZnO/Fe 2O3 as catalyst on transesterification reaction for producing biodiesel. Here, Waste of Cooking Oil, instead Crude Palm Oil as planned before, was used as reactant on transesterification reaction. Besides that the reaction condition was also modified from temperature 200 o C to 65 o C. The consequency of changing the reaction condition were the catalyst must be first activated through impregnation and the conversion of reaction might be lower. This changing had to be taken as transesterification reaction at 200 o C were very dangerous, very expensive and very difficult to be handled because of its high pressure (5 atm). An equal ratio of Zn(NO 3)2 and Fe(NO3)3 were dissolved in water with 2 molar of concentration as precursor solution. Assisted by carrier air precursor solution was nebulized in an ultrasonic nebulizer, OMRON NEU-17 and the droplet formed was flowed to the inner tube of the burner. LPG gas dan oxidant air were flowed to the inner annulus and outer annulus, respectively. The solid produced was separated from gas by particle filter. Solid particle obtained was then activated through calcination and impregnation. The impregnated particle was later called activated catalyst of nanocomposite of ZnO/Fe 2O3. It was then determined its catalytic performance on transesterification reaction for producing biodiesel. The activated catalyst of nanocomposite of ZnO/Fe 2O3 was mixed with methanol and the mixture was then filled into reactor while being stirred and heated till temperature 65 o C. Concurrently, Waste Cooking Oil was heated until the temperature reached 65 o C and then filled into reactor. The reactor was continuously stirred and kept temperature at 65 o C. during 3 hours. The products of reaction were then separated. Catalyst particle was separated using magnet in which it attached on the magnet surface and it was collected as catalyst recovery. Glycerol was separated from methyl ester through decantation.The glycerol was then analyzed to determine reaction conversion, and the other one was determined its methyl ester content using GC -MS. The result of the research showed that the higher the weight ratio of catalyst/waste cooking oil the higher the catalyst recovery and the higher the reaction conversion. The highest catalyst recovery occurred at 3.5% of weight ratio of catalyst/ waste cooking oil, i.e., 76.5%.The conversion slightly increased, with the average increase of 1.3% for every 0.5% weight ratio increase, from 13.3% on weight ratio of 0.5% to 21,28% on weight ratio of 3% and noticeably inclined to 24,47% on weight ratio of 3.5%. This conversion was still lower than the previous research result because of the lower the reaction temperature. T he examination using GC-MS showed that transesterification reaction using nanocomposite of ZnO/Fe 2O3 catalyst produced methyl ester, the main substance on biodiesel. The kinds of methyl ester produced was suitable with triglyceride contained in waste cooking oil. On the other word, nanocomposite of ZnO/Fe 2O3 was proven that it had a good cataytic property so that could be used as heterogenuous catalyst on transesterification reaction for producing biodiese

BIODELIGNIFIKASI BATANG JAGUNG DENGAN JAMUR PELAPUK PUTIH Phanerochaete chrysosporium

The crisis of energy and enviromental problems has led the inovation of the paper manufacturing process that enviromentall- friendly and energy saving. Biological systems can be used for this purposed. The most commonly utilized fungus is the white-rot fungus Phanerochaete chrysosporium. The goal of this research is to determine the lignin degradation in the corn stalk using Phanerochaete chrysosporium. Dried corn stalk with 40 mesh size was soaked in the medium culture, adding with glucose and the pH was adjust at 4. These corn stalk were then sterilized in the autoclaf at 121 o C. Inoculation was done by adding 5 mL fungus suspension. Six flask containing the stalk were placed in the incubator at 38 o C. The culture then incubated for 30 days. The lignin and cellulose content were analyzed every 5 days. A control witrhout adding fungus was treated with same condition. The results show that the longer incubation time, the lower lignin content. At 30 days incubation, 81,4% of lignin degradation were achieved. The degradation of lignin occured together with degradation of cellulose but the degradation of cellulose is less then the lignin. At 30 days incubation, 22,3% of cellulose degradation were achieved. Keywords : Biodelignification, white rot fungus, corn stal

TINJAUAN REAKSI HOMOGEN PADA HIDROLISA MINYAK BIJI KARET

Abstract: Fatty acids wereproduced by hydrolysisof rubber seed oil in the presence of HCI as catalyst. The aim of this research was to estimate the reaction rate parameters. The experiment was carried out in a stirred-batchreactor equipped with condensor and temperature controller to maintain it isothermally. The equivalent ratio of water/oil was fixed at 10 times and the catalyst was set 0.4 g /100 g 0/7based. This hydrolysisreaction was observed in a homogen reaction and temperature vaty at 323 - 363 oK. Temperature absolutely affected the reaction rate constant. It developed on the- In k = 0,8735 + 2327, 9692/RT equations. Keywords: Omega-3, fattyacids, hydrolysi

PENGARUH KONDISI PROSES PADA PENGOLAHAN EUCHEUMA COTTONII TERHADAP RENDEMEN DAN SIFAT GEL KARAGENAN

Since natural carrageenan are mixtures of different sulfated polysaccharides, their composition differs from batch to bacth. Chemical used in seaweed processing effects on yield and gelling properties of carrageenan from Eucheuma cottonii seaweed, largely sourced from Indonesia. The properties differ from batch to batch. Therefore, the quantitative analysis of carrageenan batches is important. The carrageenan was prepared by alkaline extraction, followed by alcohol precipitation. The effect of extracting alkali concentration ( NaOH 0.05 – 0.2N and KOH 0.13 – 0.36N), alcohol concentration (ethanol 70 – 90% v), and bleaching treatment of seaweed ( bleached and unbleached seaweed ) on yield and gelling properties were investigated. The higher yield could be reached in KOH solvent and concentrated alcohol. The higher alkali concentration enhanced carrageenan gel strength and melting and gelling temperature. Besides, bleaching seaweed reduced both the yield and gelling properties. Keywords: carrageenan, alkaline extraction, alcohol precipitation, gelling properties

PENGARUH RASIO BERAT RUMPUT LAUT-PELARUT TERHADAP EKSTRAKSI AGAR-AGAR

Although seaweeds of Glacilaria species are cultivated in Indonesia, study of this extraction rate is scare. The mass transfer process on batch extraction of agar was studied by extracting seaweed using water as the solvent. The effect of seaweed-water ratio on yield and the parameters which appeared in the mathematical model proposed were investigated. Seaweeds, glacilaria from Bali, were soaked in an aquoeus acetic acid solution of 0.6N. After being neutralized, the seaweeds were extracted using hot water of 95 o C in a closed tree necks bottle in water bath. The bottle was equipped by a water condenser and a mercury stirrer for agitation. Some of extract samples at various time were dried dan weighed. Based on the experimental data and the mathematical model proposed, the mass transfer coefficient were evaluated by numerically least square. The mathematical model turned out to be able to simulate the mass transfer process. There were found that equilibrium constant was 0.0662 g seaweed/ mL solvent. The yield increases with the decreasing of seaweed-water ratio. The faster rate of extraction would be obtained by extraction with higher the seaweed-water ratio. Keywords : extraction, seaweed-water rati

Preparation and Characterization of Glutaraldehyde-Crosslinked Kappa Carrageenan Hydrogel

Glutaraldehyde-crosslinked kappa carrageenan hydrogel was prepared using glutaraldehyde (GA) as the crosslinking agent. Kappa carrageenan film obtained from extraction of Kappaphycus alvarezii seaweed was immersed in GA solution (1 - 5 wt%) for 2 min and then cured at 110oC for 25 min. The obtained crosslinked film was washed and soaked in the ethanol to remove the unreacted GA. The obtained film was air dried at room temperature to a constant weight. The infrared spectra, thermal analysis, and the value of swelling degree of obtained hydrogel showed that kappa carrageenan was able to be crosslinked using GA by film immersion and high temperature curing method without catalyst presence. GA concentration less than 0.027 g GA/g polymer was not able to crosslink hydroxyls group of carrageenan. The swelling degree in water media decreased up to 60% with increasing GA concentration from 3% to 5%. The kappa carrageenan hydrogel was found to be pH sensitive

PENGARUH PENAMBAHAN GLUKOSA DAN EKSTRAK YEAST TERHADAP BIODELIGNIFIKASI AMPAS BATANG AREN

Biological system offers more enviromentally friendly and energy saving in the paper making technology. One of the most preferred was using white rot fungi Phanerochaete chrysosporium. The objective of this research was to study the effect of glucose and yeast extract to the amount of the degraded lignin in the solid waste of starch aren industry. The dried solid wastes weres added with culture medium, glucose or yeast extract and then sterilized. All systems was adjusted at pH 4. A portion of fungi suspension then mixed with the substance then it incubated at 40 o C for 30 days. The lignin and cellulose content were analysis every five days. It observe that the lignin content decreases with incubation time. The cellulose content also decreses with incubation time too, but less quantity than the lignin. More glucose and extract yeast added to the waste, more lignin can be degraded but less in losing cellulose. Key words: Phanerochaete chrysosporium, lignin content, glucose, yeast extract