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This paper simulates a process for recovering dimethylnaphthalene isomers (DMN) from light cycle oil (LCO), a by-product in cracked gasoline manufacture.The process involves a multistage emulsion liquid membrane permeator for separating aromatics from paraffins in LCO and four distillation towers of which two towers are used to recover solvent from raffinate and permeate and the others are used to separate DMN from other aromatics in permeate. Stirred vessels are employed as contactors.Prior to the simulation, a series of continuous experiments on emulsion liquid membrane permeation were conducted to collect permeation coefficient data. The permeation coefficient data obtained was thereafter used to develop an empirical correlation needed for the simulation.During the simulation, the effects of permeator variables on the energy demands of the distillation towers and on the yield of DMN were investigated at a fixed DMN concentration in the product.The permeator variables studied included solvent-to-feed ratio, stirring rate, number of stages, permeator reflux ratio, and stage volume, as well as the kinds of solvents.DMN yield increased with stirring rate, number of stages, and stage volume, decreasing with permeator reflux ratio, and not affected significantly with solvent-to-feed ratio. The lighter the solvent, the lower were the energy demand and DMN yield. In the conditions of the study, about 80% of DMN in LCO could be recovered.Most of the energy consumed was used to recover the solvent. A quick analysis showed that the energy demands might be met by utilizing the raffinate obtained.

Oil palm empty fruit bunches (OPEFB) as one of lignocellulosic biomass, consists of three main components: cellulose, lignin, and hemicelluloses. Cellulose may occur in a crystalline form in addition to amorphous form. Cellulose and hemicelluloses can be converted into fermentable sugar, i.e. glucose and xylose, by chemical or enzymatic hydrolysis. This sugars is usually used as a feedstock for bioethanol production. Lignin and high-crystallinity of cellulose inhibit the performance of enzymatic hydrolysis process. Therefore pretreatment is necessary to remove lignin, decrease the crystallinity and improve the yield of enzymatic hydrolysis. One of the developed pre-treatment processes is soaking with aqueous ammonia solution or called by SAA process. In this study, the advantage of SAA pre-treatment process was investigated using ammonium solution prior to the enzymatic hydrolysis. The pre-treatments were carried out in various ammonium concentrations (5%, 7.5%, and 10%) at mild conditions (25 o C and 1 atm) for 24 hrs, and with or without a following additional diluted-acid pre-treatment (92-98 o C and 1 atm for 1 hour). The pre-treated materials were then enzymatically hydrolyzed by cellulose and β-glycosidase for 96 hrs and anaerobically digested by inoculums microbial. The changes in cellulose crystallinity were analyzed by FTIR Spectroscopy. The OPEFB pre-treated by 10% ammonium solution without a following dilute-acid pre-treatment shows low crystallinity with a crystallinity index (CI) of 0.80 compared to that of the untreated material (2.11). The method could increase the yield of hydrolyzed glucose to 79% compared with that of untreated material (13 g/g glucan added). The results also show increasing the methane production from 0.18 Nm 3 /g volatile solid to 0.35 Nm 3 /g volatile solid via anaerobic digestion.

An extrusive cooker prototype for stabilizing rice bran has been developed and tested at various flow rate, moisture, and die diameter. The effectiveness of stabilization was observed from measurement of free fatty acid in rice bran oil. The results showed that extrusive cooking achieved steady state condition in 15 to 20 minutes. The smaller the size of die or the higher the flow rate of fed rice bran, the higher the cooking temperature could be achieved. In the range of values tried, moisture was found not affect cooking temperature significantly. Stable rice bran pellets could be produced if extrusive cooking was carried with moisture of 15% to 20% resulting cooking temperature of 110to 130oC. At this condition, free fatty acid content of oil from extrusive cooked rice bran could be maintained at 8% to13% (free fatty  acid content of oil from fresh rice bran is 5% to 6%), for storage of rice bran pellets in three months. Compared to extraction of raw rice bran, extraction of extrusive cooked rice bran was found to be faster. Solvent absorbed by extrusive cooked rice bran was also less than that was absorbed by raw rice bran.Keywords: Extrussive Cooking, Rice Bran, Stabilization AbstrakSebuah prototipe  pemasak  ekstrusif untuk stabilisasi  dedak padi telah dikembangkan  dan diuji pada  berbagai laju alir,  kelembaban  dan diameter  die. Efektifitas  stabilisasi  diamati  melalui pengukuran  kadar asam lemak bebas dalam minyak dedak padi. Hasil-hasil menunjukkan bahwa pemasakan  ekstrusif mencapai keadaan  tunak  dalam waktu  15 hingga 20 menit. Semakin kecil diameter die atau semakin  besar laju alir dedak yang  diumpankan,  semakin tinggi temperatur pemasakan  yang  dapat  dicapai.  Pada  rentang  nilai yang  dicoba,  kelembaban diketahui  tidak mempengaruhi  temperatur pemasakan  secara  berarti. Pelet dedak stabil  dapat  dihasilkan jika pemasakan  dilakukan dengan kelembaban 15% hingga 20% yang akan menghasilkan temperatur pemasakan  110 hingga 130oc. Pad a kondisi tersebut, kadar asam lemak bebas minyak dari pelet dedak padi hasil pemasakan ekstrusif dapat dipertahankan sebesar 8% hingga 13% (kadar asam lemak bebas minyak dari dedak segar adalah 5% hingga 6%),pada penyimpanan pelet dedak padi selama tiga bulan. Tambahan pula, ekstraksi minyak dari pelet dedak padi hasil pemasakan ekstrusif telah dikaji dan dibandingkan dengan ekstraksi dedak padi tanpa mengalami pemasakan, dengan heksan sebagai pelarut. Ekstraksi minyak dari pelet dedak padi hasil pemasakan ekstrusif diketahui berlangsung lebih cepat. Pelarut yang diserap oleh pelet dedak padi hasil pemasakan ekstrusif juga lebih sedikit dibandingkan dengan dedak padi tanpa mengalami pemasakan.Kata Kunci: Dedak Padi, Pemasakan Ekstrusif, Stabilisasi

EXTRACTION OF FREE FATTY ACID FROM RICE BRAN OIL USING ETHANOL-WATER IN A STIRRED TANK. This research was aimed to study the extraction of free fatty acid (FFA) (0,5-1,9)10

Hydrazine is commonly used as an oxygen scavenger in boiler feed water treatment. However, this compound is very flammable and is a carcinogenic substance. The industries in developed countries has studied the alternatives for hydrazine since long time ago and started to replace hydrazine. Carbohydrazide is known to be a good alternative for hydrazine. This research is aimed to understand the synthesis routes of carbohydrazide and to determine the best route as well as to develope a detail procedure of carbohydrazide preparation for local application. Literature study showed that carbohydrazide can be made by reacting hydrazine and cyanuric acid, phosgene, dimethyl carbonate or diphenyl carbonate. The synthesis path which is appropriate to be applied in Indonesia is that via cyanuric acid. From laboratory testing, a detail procedure for making carbohydrazide from hydrazine and cyanuric acid has been developed. In the range of experimental conditions studied, carbohydrazide with purity of 90-92% could be obtained with yield of 20-60%.Keywords: Carbohydrazide, cyanuric acid, hydrazine AbstrakHidrazin umumnya digunakan sebagai pengikat oksigen dalam pengolahan air umpan boiler. Akan tetapi, senyawa ini merupakan bahan kimia yang mudah terbakar dan bersifat karsinogenik. Industri-industri di negara maju sudah lama mengkaji alternatif pengganti hidrazin sebagai pengikat oksigen dan sudah mulai meninggalkan hidrazin. Senyawa yang diperkirakan potensial untuk menggantikan hidrazin adalah karbohidrazida. Tujuan  penelitian ini adalah untuk memahami rute sintesis karbohidrazida dan menentukan rute yang tepat serta menyusun langkah-langkah detil proses pembuatan karbohidrazida untuk penerapan lokal di tanah air. Studi literatur menunjukkan bahwa karbohidrazida dapat diperoleh dengan mereaksikan hidrazin hidrat dan asam sianurat, fosgen, dimetil karbonat atau difenil karbonat. Alur yang diperkirakan tepat untuk dikembangkan di Indonesia adalah alur melalui asam sianurat. Melalui uji coba di laboratorium, prosedur pembuatan karbohidrazida dari hidrazin dan asam sianurat yang detil telah disusun. Pada kondisi yang dikaji, karbohidrazida dengan kemurnian90-92% dapat disintesis dengan perolehan pada rentang 20-60%.Kata kunci: karbohidrazida, asam sianurat, hidrazin.

This work is aimed to measure the liquid-liquid equilibria of rice bran oil-fatty acid-aqueous alcohols using fatty acid mixtures derived from rice bran oil as solutes and to calculate the number of equilibrium stages required for the extraction process. Renewable alcohols, ethanol and isopropanol in aqueous form were used as solvents. The liquid-liquid equilibrium data were measured at 25 °C and presented as ternary diagrams. It was found that ethanol gave a lower distribution coefficient than isopropanol. For the same solvent, increasing the water content resulted in a lower distribution coefficient. For the free fatty acid contents of 30% in the feed and of 10% to 2.5% in the raffinate, the minimum solvent-to-feed ratio was found to be in the range of 1 to 5. Using solvent-to-feed ratios from 2 to 4, the number of extraction stages required was in the range of 1 to 8. Based on the minimum solvent-to-feed ratio and number of equilibrium stages, isopropanol was found to be better than ethanol.

This research was aimed to evaluate the synthesis of mercaptoethyl ester of palm fatty acid distillate (PFAD) where water as a byproduct was removed by using vacuum distillation and azeotropic distillation. The reactions were done in a batch reactor using para-toluene sulfonic acid (pTSA) as a catalyst. The performances of the synthesis were evaluated by measuring the sulfhydryl content and yield of the product. Compared to dehydration by vacuum distillation, dehydration by azeotropic distillation gave lower sulfhydryl content and yield but faster reaction completion. Azeotropic distillation gave sulfhydryl content and yield in the range of 6–7% and 57–74%, respectively. Vacuum distillation gave sulfhydryl content and yield in the range of 7–9% and 75–85%, respectively.