14 research outputs found
PEROLEHAN SILIKAT DARI ABU SEKAM PADI DALAM SPOUTED-BED: EFEK PERPINDAHAN MASSA
No full textA 5 cm diameter spouted-bed reactor has been applied for solid-liquid reaction, paddy ash and NaOH producing Na-silicate. Hydrodinamics of spouted-bed reactor was studied by using paddy ash-water system. Correlation for minimum superfisial spouting (Ums) was determined and follows the equation. ( in cgs unit)The spouted bed (SB) operates under transition regime i.e. Reynold number particle range 7-25 or Re number fluid ranging from 19 to 254. The mass transfer is the controlling step for this system as for all solid-liquid reactions are very fast. So, a model of mass transfer has been derived and mass transfer correlation in SB follows equations Sh = 191,34 + 0,6325 Sc0.35 Re1.89 Above correlation shows high mass transfer at stagnant fluid compared to other mass transfer correlations which is due to reacting system involved.Kata kunci : sunbungan adhesives, perfonnansi kekakuan. performansi perpindahan panas
Characterization of Biocomposites from Polylactic Acid and Cellulose of Oil Palm Empty Fruit Bunch
No full textBiocomposites are polymers reinforced with natural fibers, such as cellulose. This research aims to synthesize cellulose from Oil Palm Empty Fruit Bunch (OPEFB) and biocomposites from PLA and cellulose. In this study, cellulose was obtained through alkalization, hydrolysis, and bleaching of OPEFB. Biocomposites production was carried out by mixing PLA and cellulose using the extrusion method. In the extrusion method, PLA and cellulose of OPEFB were mixed using an extruder above the melting point of PLA of 170°C. The output product of an extruder was then pressed using a compression moulding machine to form biocomposites. The tensile strength of biocomposites had a smaller value than pure PLA, whereas the modulus young of biocomposites with 5% by weight of cellulose had a higher value than pure PLA. The decrease in the mechanical properties of biocomposites was caused by poor adhesion between PLA and cellulose. The water absorption of biocomposites was greater than pure PLA, which was influenced by cellulose's characteristics as hydrophilic and PLA is hydrophobic. Also, the higher water absorption in biocomposites accelerated the weight loss of biodegradability
Karakterisasi Nanokomposit Poly(Lactic Acid)-Spent Bleaching Earth Regenerasi Termodifikasi: Characterization of Nanocomposite of Poly(Lactic Acid)-Modified Regenerated Spent Bleaching Earth
No full textDevelopment of renewable resource-based polymers attracts attention to solve environmental problems due to the build up of polymer (plastic). Poly(lactic acid) (PLA) is one of the most widely used polymers which have good biodegradability and processability. The addition of fillers to the PLA matrix aims to improve the characteristics of the PLA, such as mechanical properties of nanocomposites of PLA. Thus, PLA can be use as substitution of fossil fuel-based polymer. Spent Bleaching Earth (SBE) can be used as a filler after regeneration process. SBE was extracted and oxidized to take its oil content. Then, SBE was modified with urea solution to increase the interlayer distance. In this study, structure of nanocomposites was characterized using X-Ray Diffraction and mechanical properties of nanocomposites were characterized using Universal Testing Machines. X-Ray Diffraction characterization results show that PLA-SBE nanocomposite and PLA-modified regenerated SBE nanocomposites do not form new peaks, so SBE and modified regenerated SBE is intercalated and partially exfoliated in the PLA matrix. The degree of intercalation/exfoliation is indicated by the results of characterization of mechanical properties. The mechanical properties of PLA-SBE nanocomposite are lower than neat PLA, whereas the mechanical properties of PLA-modified regenerated SBE nanocomposites are higher than neat PLA. The best mechanical properties of nanocomposites were obtained for PLA-5% modified regenerated SBE, with elongation and tensile strength, 3.26%, and 42.22 MPa, respectively.
Keywords: nanocomposites, poly(lactic acid), regeneration, spent bleaching eart
Penerapan Spouted-ben dalam Pembuatan Natrium Silikat dari Abu Sekam Padi: Hidrodinamika, Perpindahan Massa, dan Perolehan Silikat
No full textSari. Telah dilakukan satudi awal penerapan spouted-bed untuk menyelenggarakan reaksi cair-padat, NaOH-abu sekam padi guna memperoleh natrium silikat yang mencakup studi hidrodinamika, perpindahan massa, dan perolehan silikat. Korelasi kecepatan minimum spouting dan kriteria kestabilan spouting telah diperoleh lewat pengematan sistem tak bereaksi air-abu sekam padi. Korelasi untuk koefisien perpindahan massa pada rezim transisi, Re partikel 7-25 atau Re fluida 19-254, diperoleh lewat penerapan model reaksi cair-padat dengan anggapan laju difusi NaOH dari bulk ke permukaan partikel sebagai pengendali. Konversi SiO2 tertinggi yang diperoleh mencapai 62% dengan pemakaian larutan NaoH yang relatif encer, yaitu 0,8 M. unjuk kerja ini lebih baik dibandingkan dengan hasil yang telah diperoleh peneliti terdahulu. Tawar-menawar antara konversi SiO2 dengan perolehan rasio SiO2/Na2O dalam produk perlu diperhatikan berdasarkan hasil studi ini. Spouted-Bed Reactor in Producing Sodium Silicate from Paddy Husk Ash: Hydrodynamics, Mass Transfer, and Silicate YieldAbstract. A laboratory-scale spouted bed reactor has been applied for producing sodium silicate from paddy husk ash and NaOH. The study covered hydrodynamics, mass transfer, and silicate-yield in the reactor. The correlation of minimum superficial velocity was determined by using nonreacting paddy ash-water system. Mass transfer correlation is spouted-bed which is valid for transition regim, i.e. Reynold particle range 7-25 or Reynold fluid number 19 -254, was derived from a simple model assuming the diffusion rate of NaOH from bulk to the particle surface as a determining step. Conversion of SiO2, equivalent to Na-silicate yield, is up to 62% using 0.8 M NaOH. This performance is significantly better than the other previous research. The study found that in producing silicate pay-off between SiO2 conversion and SiO2/Na2O mol ratio should be considered
Production of Methyl Laurate From Coconut Cream Through Fractionation of Methyl Ester
No full textThis paper concerns the production of methyl laurate from coconut cream through fractionation of methyl esters. Coconut oil was produced by wet processing of coconut cream. The esters were prepared by reacting coconut oil and methanol using homogeneous catalyst KOH in a batch reactor, followed by fractionation of fatty acid methyl esters (FAME) at various reduced pressures applying differential batch vacuum distillation. Experimental data were compared with simulation of a batch distillation employing the simple Raoult's model and modified Raoult's model of phase equilibria. Activity coefficients (γi) were determined by optimization to refine the models. The modified Rault's model with activity coefficients gave better agreement with the experimental data, giving the value of γi between 0,56-0,73. For a given boiling temperature, lower operating pressure produced higher purity of C10 and C12 FAME for respective distillates
SIFAT POLIMER DAN KEMAMPUAN TERBIODEGRADASI BLEND BIODEGRADABLE POLYMER POLI (L-ASAM LAKTAT) (PLLA)
No full text Poly(D,L-lactic acid) (PDLLA) and poly(ethylene glycol) (PEG) was used to modify mechanical and biodegradability properties of poly(L-lactic acid) (PLLA) through solution blending method using solvent mixture of dichloromethane-ethanol. Polymer samples were then characterized using FTIR, DSC, UTM, and enzymatic degradation test. FTIR spectrum of pure PLLA showed specific IR absorption peaks at wavenumber of 3504 cm-1 (-OH), 1757 cm-1 (-C=O), and 1381 cm-1 (-CH3 symmetric). Further, polymer blend samples showed absorption peak shifts at 1755 cm-1 and 1382 cm-1 for PLLA/PDLLA due to stereocomplex interaction and at 3429 cm-1 due to hydrogen bond interaction. DSC results showed that there was melting temperature depression for all polymer blend samples compared to pure PLLA with increasing of either PDLLA or PEG composition. In PLLA/PDLLA, two melting points were discovered because of homocrystallite and stereocomplex phase formation. While PLLA/PEG samples showed increasing crystallinity to 69% at 20%-wt PEG composition. Mechanical analysis showed that 10%-wt of PDLLA addition in PLLA produced better mechanical performance than pure PLLA while 20%-wt of PEG addition showed highest elongation at break with the value of 89%. Polymer blend samples were degradable during enzymatic degradation test represented by percent weight loss with maximum value of 21% for PLLA/PEG sample. Keywords: polymer properties, solution-blending, Poly(lactic acid), polymer blend, enzymatic degradation </p
Evaluation and Modification of Processes for Bioethanol Separation and Production
No full textThis paper concerns on process evaluation and modification for bioethanol separation and production by applying pinch technology. Further, the paper is also focused on obtaining a most energy-efficient process among several processes. Three basic process configurations of bioethanol separation and production were selected for this study. The three separations and production systems are Othmer process, Barbet process and a separation process that operates under vacuum condition. Basically, each process is combination of Danish Distilleries process with a separation system yielding 95% (v/v) bioethanol. The production capacity of the plant is estimated about 4 x 107 litre of bioethanol 95% (v/v) per year. The result of the studies shows that the most energy efficient process among the three processes evaluated is the Othmer process, followed by the Barbet process and the process involving vacuum operation. The evaluation also shows that further energy saving can be carried for Barbet and Othmer process configuration when Tmin = 10oC for heat exchange possible
Synthesis and Characterization of 2-monoacylglycerols from Canarium Oil (Canarium Indicum)
No full textAbstractThis paper studies synthesis and characterization of 2-monoacylglycerols (2-MAGs), generally used for structured lipid production. Synthesis used canarium oil by enzymatic reaction using immobilized lipase from Mucor miehei that has a specific activity on the sn-1 and 3 of the triacylglycerol structure. Characterization of 2-MAGs by thin layer chromatography using a standard of 2-oleoylglycerol followed by isolation and purification to determine the fatty acids composition.The highest composition of fatty acids on 2-MAGs were unsaturated fatty acids, namely oleic acid (939.8ppm) and linoleic acid (445.5ppm), therefore it could be used for the synthesis of structured lipid
STUDI METODE-METODE EKSTRAKSI PEWARNA MAKANAN ALAMI ANNATTO DARI BIJI KESUMBA (Bixa orellana)
No full textAnnatto is natural food colorant extracted from Bixa orellana seeds. The main constituent of annatto is bixin, a carotenoid having carboxylic acid groups at both ends of its molecular chain and one of these is methyl-esterified. The carboxylic acid groups of bixin and norbixin cause the molecule to dissolve in aqueous bases. The methyl ester structure causes the molecule dissolving in oil and other organic solvents. The double bond conjugated chain causes bixin dissolved in most organic solvents. These characteristics are mainly bases for extraction solvent selection. The objectives of this research are to evaluate the performance of ethyl acetate and acetone as solvents for annatto extraction with different method of extraction and to obtain a procedure for preparing general purpose annatto extract having the highest possible of bixin yield. Two methods of extraction are carried out using Soxhlet method (at solvent boiling temperature) and ultrasonic bath extraction at room temperature. The selected solvents are ethyl acetate and acetone that have medium polarity index and low boiling point. The bixin quality is examined by measuring pigment content with spectrophotometer at certain wavelength. Two types of seeds from different places in Indonesia will be the investigated as sources of annatto. Experimental results for extraction with Soxhlet method shows that yield of bixin (upon seed) from ultrasonic bath extraction is higher that is 0.584% (w), compared to Soxhlet extraction 0.443% (w). For ultrasonic bath extraction, yield of bixin (upon seed) with ethyl acetate as solvent is 0.602%, much higher compared to that from acetone 0.565%. Extraction with Soxhlet method gives different results. Yield of bixin (upon seed) with acetone as solvent is higher which is 0.460%, compared to ethyl acetate which is 0.427%. Seeds from Bandung (West Java) and Duri (Riau) do not give significant difference of bixin yield from two methods of extraction. Annatto merupakan pewarna alami makanan yang didapatkan melalui ekstraksi dari biji pohon kasumba (Bixa orellana) dengan komponen pewarna utamanya adalah bixin. Keberadaan ikatan rangkap terkonjugasi menyebabkan bixin dan norbixin larut dalam sebagian besar pelarut organik. Ciri struktur kimia dari bixin ini yang menjadi dasar dalam pemilihan pelarut untuk ekstraksi pewarna annatto. Tujuan makalah ini adalah studi metode-metode ekstraksi terhadap perolehan bixin, metode Soxhlet pada temperatur didih pelarut dan metoda ultrasonic bath pada temperatur kamar, dengan dua tempat sumber biji kasumba, Bandung dan Duri. Pelarut yang digunakan adalah etil asetat dan aseton. Pengujian dilakukan dengan mengukur kadar pigmen yang dihasilkan menggunakan spektrofotometri pada panjang gelombang tertentu. Dari penelitian ini, didapatkan data yield (perolehan bixin) dari berbagai variasi percobaan. Perolehan bixin (terhadap biji) yang didapat dari ekstraksi ultrasonic bath lebih tinggi yaitu rata-rata sebesar 0,584%, dibanding dengan metode soxhlet yang rata-rata sebesar 0,443%. Ekstraksi menggunakan metode ekstraksi ultrasonic bath, dan menggunakan pelarut etil asetat lebih tinggi yaitu rata-rata 0,602% daripada menggunakan aseton yang rata-rata 0,565%. Sedangkan dengan metode soxhlet menunjukkan perolehan bixin berbeda, dengan pelarut aseton 0,460%, sedangkan untuk pelarut etil asetat adalah 0,427%. Biji yang berasal dari 2 tempat berbeda, ketika diekstraksi dengan dua metode tersebut tidak memberikan perbedaaan hasil bixin yang signifikan</p
Synthesis of Structured Triglycerides Based on Canarium Oil for Food Application
No full textThis paper concerns the synthesis of structured triglycerides containing different proportions and positions from medium- (M) and long-chain (L) fatty acids on a glycerol backbone. Structured triglycerides of MLM type were synthesized by utilizing canarium oil and incorporating caprylic acid (C8:0) as a source for the medium chain (M) fatty acids. Synthesis was performed through a two-step enzymatic reaction, with ethanolysis as the first step and esterification as the second step. Both reactions use the sn-1,3 specific lipase as a catalyst, which has specific activity at positions sn-1 and sn-3 of the triglyceride structure. The results from high-performance liquid chromatography showed that the stereospecific distribution of fatty acids in the structured triglyceride was 29.52±0.59 and 44.28±0.88 mol% of caprylic acid in the positions of sn-1,2,3 and sn-1,3, respectively. Furthermore, analysis of the physicochemical properties of both the native canarium oil and the structured triglycerides using an independent-sample t-test at p < 0.05 indicated that the two samples were significantly different for saponification number, iodium number, and average molecular weight. The results of this study showed that canarium oil can be exploited as a starting material for functional food application
