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Supported bimetallic ruthenium-tin (denoted as Ru-Sn(x); x = molar ratio of Ru/Sn) catalysts were examined for room temperature (RT) hydrogenation of biogenic platform chemicals of levulinic acid (LA) to g-valerolactone (GVL). Six types of metal oxide support c.a. Nb2O5, TiO2, ZnO, ZrO2, g-Al2O3, active charcoal (AC), were employed as the support for Ru-Sn(x). Ru-Sn(3.0)/Nb2O5 (Ru/Sn = 3.0) that reduced at 500 oC demonstrated the highest yield of GVL (98%) at 30 oC, 30 bar H2 for 3 h. The increase in Sn loading amount (Ru/Sn = 1.5) resulted in decreasing of LA conversion (83%) under the same reaction conditions. Among the studied supported Ru-Sn catalysts, Nb2O5 and ZnO supports exhibited better catalytic performances than that other for RT hydrogenation of LA and various biogenic platform chemicals. The Ru-Sn(3.0)/Nb2O5 catalyst was characterized by means of various adsorption and spectroscopic techniques. The Ru-Sn(3.0)/Nb2O5 catalyst was found to be reusable without any significant loss of its activity. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Hydrogel loading urea has dual functions, namely retaining water and releasing urea in a controlled manner so it can be applied to sandy soil. This study aimed to examine the effect of different additives (CMC and chitosan) in preparing PVA-based hydrogels on the hydrogel properties and characteristics. In the hydrogel preparation, the PVA solution at various concentrations was mixed with chitosan and CMC solutions. The mixture was then irradiated using gamma rays to produce hydrogel. Then, the hydrogel was dried and crushed for analysis. The results showed that PVA/chitosan-based hydrogels had swelling of 7.75–25.16 g/g, water holding of 63.43–65.27 %, water retention of 22.45–26.81 % for 5 days, and urea loading of 76.50–81.43 %. Meanwhile, PVA/CMC-based hydrogels had swelling of 4.75–36.29 g/g, water holding of 63.92–65.74 %, water retention of 31.59–33.88 % for 5 days, and urea loading of 67.21–84.44 %. The PVA/CMC-based hydrogel had a lower crystallinity percentage and smoother surface morphology than the PVA/chitosan-based hydrogel.

Dye-containing wastewater from the textile industry is environmentally harmful. This study investigates the combination of tin oxide and hierarchical zeolite for dye removal through adsorption and photocatalysis. Zeolite has a large surface area; however, it suffers from diffusional limitation due to the small diameter of the micropore. The diffusional problem could be overcome by creating a mesopore using acid treatment. Impregnation of SnO2 using SnCl2 acid solution is estimated to create a hierarchical zeolite, hence the MB removal could improve via adsorption and photodegradation simultaneously. The SnO2-hierarchical zeolites have been prepared using SnCl2 solution in the presence and absence of H2O2. The results show that the acidity of the SnCl2 solution increases the mesopore volume of zeolite from 0.16 to 0.24 mL/g. The SnO2 phase was large and mainly located on the external surface of the zeolite for the sample prepared in the presence of H2O2. In contrast, the SnO2 phase was mainly small and located in the interior, blocking the zeolite's micropore for the sample prepared without H2O2 addition. The sample prepared using H2O2 showed a high MB removal of 97.0 % compared to the sample prepared without H2O2 at 64.4 %, which is not much different from the parent zeolite (52.2 %). The high MB removal can be attributed to the simultaneous removal via adsorption by zeolite and photocatalysis by SnO2 located outside the zeolite's granule, which was exposed to UV-C irradiation. The kinetics follow the Pseudo Second Order model for all samples. The best sample was 0.1 SnO2, with optimized kinetic parameters of qe=29.31mgMBgzeolit and ks=0.08gzeolitmgMB.s. The impregnation method not only spread the tin on the zeolite surface but created a hierarchical zeolite which improved the diffusional transfer and fastened the overall process.

Superabsorbent can be used as a carrier for urea-fertilizer which can release urea slowly and can be used as a dry soil moisturizer. The main goal of the current study was to investigate the influence of adding chitosan grafted onto acrylic acid as a superabsorbent base material on the properties and characteristics of the resulting superabsorbents. The method used to prepare the superabsorbent was the gamma irradiation technique. Acrylic acid was neutralized by adding KOH, and then chitosan was added. The mixture was put in a plastic container, followed by irradiation with gamma rays. The formed superabsorbent was washed and dried in an oven, then the dry superabsorbent was analyzed for its properties and characteristics. The results showed that superabsorbent properties such as swelling ratio (from 49.38 g/g to 49.38 g/g), water retention (0.43%-0.89% after 7 days), and urea loading (86.75% to 96.4%) were affected by the amount of chitosan added. However, adding too much chitosan can reduce the superabsorbent properties. The characterization of the superabsorbent revealed a smooth surface with a porous structure, and FTIR analysis showed that chitosan was grafted onto acrylic acid.

The goal of this study was to investigate the effect of the type and dose of coagulants on the color removal of POME through the coagulation process. The coagulants used in this study were alum and poly aluminium chloride (PAC). The dose of coagulants was varied to 2, 4, 6, and 8 g/L. The results of this study showed that the optimum dose for coagulant of alum was 6 g/L and the optimum dose for coagulant of PAC was 8 g/L, in which these doses resulted in color removal efficiencies of 80.65±10.30% and 94.12±1.00%, respectively. The PAC coagulant was more effective than the alum coagulant. The kinetic models used to predict the color removal efficiencies were the first- and second-order kinetic models. Based on the kinetic analysis, the MAPE of the first and second-order kinetic models was 9.17-28.28% and 5.48-21.62%, respectively. It means that the second-order kinetic model can predict with higher accuracy than the first-order kinetic model. By the second order kinetic model, the reaction kinetic constant of the coagulation process at alum coagulant of 6/L and PAC coagulant of 0.021 and 0.057 /min, respectively.

Today, electricity is a very important need so the demand for electricity increases in the world. To meet the electricity needs of the community, the Indonesian government through the state electricity company (PT. PLN) has built electric power networks starting from power plants to transmission lines that can supply electricity to consumers. To reduce power losses along the transmission lines, extra-high-voltage (EHV) is needed. However, the use of this EHV also produces electric and magnetic fields around the conducting wires. This causes anxiety for people, especially people who live in the areas of EHV Airways. The large magnetic field around the conductor wires is feared to have a detrimental impact on people who live near transmission lines. The threshold for the value of the magnetic field that is permitted according to the regulations of MENKES/SK/XI/2002 and SPLN 112:1994 is 500 μT. For this reason, this research was conducted to determine the magnitude of the magnetic field around the conductor wires of the EHV Airway and to determine the effect of the magnetic field on the environment. The methods used in this research were direct measurements and theoretical calculations. The results of the research prove that the value of the magnetic field that appears, both in terms of calculations and in terms of measurements, is still below the allowable threshold both by WHO and IRPA as well as by MENKES/SK/XI/2002 and SPLN 112:1994

Chitin is conventionally isolated under harsh reaction conditions through two constitutive steps deproteinization and demineralization. This paper considers a protocol for chitin's isolation from shrimp shell waste. Ultrasonic irradiation was employed as an effective technique for the isolation process at a mild reaction condition with dilute solvents, a lower temperature and shorter reaction times compared to the conventional one. Shrimp shells wastes were pretreated by washing, grinding and sieving. The grounded shells were deproteinized with 2 M sodium hydroxide solution and followed by demineralization using 1 M hydrochloric acid. The mechanisms by which the demineralization occurs in the deproteinized shells were described using a simple decomposition model. Quantitative mineral analysis was performed by titrimetric at different temperatures 40, 50, 60, and 70 °C under constant ultrasound power and frequency. The results indicated that the protein content significantly reduced to 0.87% w/w when the highest NaOH concentrations were reached. At the same time, the ultrasound assists demineralization, resulting in the lowest mineral content of 1.29% w/w. This work also effectively demonstrates the kinetic model that occurs through the demineralization, in which reaction rate,dCaCO3dt=−k2K1CCaCO3(1+2K1CCaCO3) and k2=Ae−EaRT are an excellent model to describe the process. In this work, the physicochemical characterization showed that the properties of isolated chitin were not much influenced by the ultrasonic treatment, which has the same characteristics as the commercial product.

The purpose of this study was to determine the encapsulation efficiency and cumulative release of red ginger oleoresin from microcapsules with different wall materials. Red ginger oleoresin was added to the maltodextrin solution, followed by a tween 80. The mixture formed was transferred to a spray dryer for the drying process. Other materials used are carrageenan and a combination of maltodextrin and carrageenan in a ratio of 1:1, 2:1, and 1:2. Red ginger oleoresin microcapsules were analyzed for encapsulation efficiency and release test using phosphate buffer medium pH 7.4, then determine release kinetics using zero-order, first-order, Higuchi model, Korsmeyer-Peppas model, and Peppas-Shalin model. The highest encapsulation efficiency was 78.6%, and the lowest cumulative was 58.46% from microcapsules with a wall material of a mixture of maltodextrin and carrageenan with a ratio of 1:2. The release kinetics best fit the Korsmeyer-Peppas and Peppas-Shalin models with anomalous transport (non-Fickian) and Fickian diffusion release mechanisms. Tujuan penelitian ini adalah menentukan efisiensi enkapsulasi dan kumulatif rilis oleoresin jahe merah dari mikrokapsul dengan bahan dinding yang berbeda-beda. Oleoresin jahe merah ditambahkan ke larutan maltodektrin dilanjutkan denganpenambahan tween 80. Campuran yang terbentuk dialirkan ke spray dryer untuk proses pengeringan. Bahan lain yang digunakan adalah karagenan dan perpaduan maltodektrin dan karagenan dengan rasio 1:1, 2:1, dan 1:2. Mikrokapsul oleoresin jahe merah dianalisis untuk efisiensi enkapsulasi dan uji rilis menggunakan medium buffer fosfat pH 7.4, kemudian menentukan kinetika rilis menggunakan model order nol, order pertama, model Higuchi, model Korsmeyer-Peppas, dan Peppas-Shalin. Efisiensi enkapsulasi tertinggi sebesar 78.6% dan kumulatif terendah sebesar 58.46% dari mikrokapsul dengan bahan dinding perpaduan maltodektrin dan karagenan dengan rasio 1:2. Kinetika rilis dengan fitting terbaik dari model Korsmeyer-Peppas dan Peppas-Shalin dengan mekanisme rilis anomalous (non-Fickian) transport dan Fickian diffusion.

Gasoline is a petroleum-derived liquid that is most typically used in internal combustion engines, especially those utilizing spark ignition. Gasoline is a hydrocarbon blend that contains sulfur, nitrogen, oxygen, and other metals. Olefins, aromatics, paraffin, and naphthenes are the four main components of gasoline. An octane number is a unit of measurement for the ignition quality or flammability of gasoline. It is frequently referred to as the research octane number (RON), and it is calculated using a ratio of isooctane to n-heptane. The octane number can be decreased by lengthening the hydrocarbon molecule chain and increasing by branching the carbon chain. Another method is to use an octane number increaser for gasoline as an addition. These are classified as oxygenate, ether, antiknock agent, nanoparticles, and aromatic compounds. Numerous studies have been conducted to establish the influence of additives in gasoline on engine performance metrics such as braking power, thermal brake efficiency, volumetric efficiency, fuel consumption efficiency, and their impact on the environment. This review article aims to assess and compare the effects of various gasoline additives on the performance and emission characteristics of ignition engines. Bensin adalah cairan yang berasal dari minyak bumi yang paling banyak digunakan sebagai bahan bakar di mesin pembakaran internal, khususnya mesin menggunakan percikan pengapian. Bensin adalah campuran hidrokarbon dengan beberapa kontaminan, termasuk belerang, nitrogen, oksigen, dan logam tertentu. Empat kelompok penyusun utama bensin adalah olefin, aromatik, parafin, dan naften. Angka oktan adalah ukuran kualitas pengapian atau mudah terbakarnya bensin, biasa disebut Research Octane Number (RON) yang dapat diukur menggunakan perbandingan antara campuran isooktana dengan n-heptana. Angka oktan dapat berkurang dengan bertambahnya panjang rantai dalam molekul hidrokarbon sedangkan angka oktan dapat meningkat dengan membuat percabangan rantai karbonnya. Cara lain untuk meningkatkan angka oktan adalah ditambakan peningkat angka oktan bensin sebagai aditif, yang terbagi pada kategori oxygenat, eter, agen antiknock, nano partikel dan senyawa aromatik. Banyak penelitian tentang penggunaan aditif dalam bensin untuk menentukan pengaruhnya terhadap ukuran kinerja mesin seperti daya pengereman, efisiensi rem termal, efisiensi volumetrik, efisiensi konsumsi bahan bakar, dan efeknya terhadap lingkungan. Tujuan dari artikel review ini adalah untuk mengevaluasi serta membandingkan berbagai aditif pada bensin dan pengaruhnya terhadap kinerja dan karakteristik emisi mesin pengapian.

This study aimed to investigate the effects of volume ratio in the continuous phase and the dispersed phase (CP/DP) and stirring speed on yield, water absorption, particle size, morphology surface, and cumulative release of nitrogen from the chitosan microsphere. The chitosan microsphere preparation method was emulsion cross-linking with glutaraldehyde saturated toluene (GST) as the cross-linking agent. Urea was mixed with chitosan solution and put into the oil. It was then stirred to form an emulsion. Glutaraldehyde saturated toluene (GST) was added slowly, followed by 2 ml glutaraldehyde, stirred continuously for 2 h. The formed chitosan microsphere was eventually washed and dried to be analyzed. The yield obtained was about 87.01%-96.71%, the water absorption was 79.77%–89.25%, and the diameter size of chitosan microspheres was from 153.66 ± 26.35 μm to 179.39 ± 34.95 μm. The chitosan microspheres morphology were good sphericity even though there were irregular size. Cumulative release analysis was obtained from 32.38%–37.69% by release mechanism such as anomalous behavior (non-Fickian kinetics)

Sandy soil has a low ability to absorb and store low water, low nutrient content, and a high water evaporation rate, so it is not suitable to be used as agricultural land. Superabsorbents can be used to overcome these weaknesses. The purpose of this study was to measure the abilities of the superabsorbents, including water holding, swelling, and water retention of sandy soil enriched with superabsorbent, and to analyze the chitosan-graft-poly(acrylic acid) superabsorbent characteristics. The superabsorbent was prepared by mixing a chitosan solution with ammonium persulfate as an initiator and acrylic acid, which had been neutralized with KOH. Then, the mixture was cross-linked with N,N′-methylenebisacrylamide (MBA). The resulting superabsorbent gel was dried in an oven and then crushed for analysis. The results showed that an increase in chitosan concentration increased the gel fraction, swelling, reusability, and water holding. Meanwhile, an increase in chitosan concentration decreased water retention in sandy soils. The swelling kinetics can be predicted using the pseudo-second-order model with high accuracy (R2 value of 0.99).

The mathematical model was developed analytically to describe the release of red ginger oleoresin (Zingiber officinale var. rubrum) from microcapsules prepared by cross-linking emulsion method with chitosan as wall material. The model of release used a reservoir system, where red ginger oleoresin diffused through the chitosan membrane (wall material) to the solution medium. The assumption was that the microcapsule diameter was much larger than the wall thickness; therefore the mathematical equation was approximated by diffusion through the slab. Comparison between experimental data and calculated data of red ginger oleoresin concentration in buffer solution (CAw) was used to verify the suitability of the mathematical model. Mathematical models for controlled release was in good agreement with experimental data which was indicated by the value of R2 = 0.76–0.86. Keywords: Chitosan, Diffusion coefficient, Red ginger oleoresin, Emulsion crosslinking, Reservoir system

This research was conducted to study the effect of various additions of synthetic nutrient into Spirulina platensis growth medium containing tofu wastewater 8%v/v. Synthetic nutrient was varied at 50, 75, 100%. Based on abservation, the OD680 (Optical Density at 680 nm) increased until in the end of cultivation time with final OD680 of 0.381, 0.392, 0.189 for variable of 50, 75, 100% respectively. Meanwhile, the growth rate value was 0.0743, 0.0759, 0.0354/day. The best protein content was obtained at nutrient synthetic of 75%, which was 91,27%. The good growth and protein content of S. platensis obtained at nutrient synthetic of 75%, which had C:N:P ratio of 128:12:1.

Background: Encapsulation is one of the methods used to trap active ingredients in the wall material of microparticles. Aim: The aim of this study was to evaluate the encapsulation of red ginger oleoresin using an emulsion crosslinking method with chitosan as the wall material. Methods: Emulsions were formed of red ginger oleoresin with chitosan in concentrations of 1%, 2%, 3%, and 4% (w/v), respectively. The emulsions were then mixed with corn oil and stirred for one hour to obtain a second set of emulsions, and glutaraldehyde saturated toluene (GST) was added dropwise in quantities of 20, 10, 6.7, and 5 ml, respectively. This was followed by the addition of 2 ml of 25% glutaraldehyde and the emulsions were stirred for two hours. The resulting microcapsules were washed with petroleum ether followed by hexane and then dried in an oven at 70 o C. Results: The emulsion crosslinking method used to trap the red ginger oleoresin in chitosan produced microcapsules of good spherical geometry with the mean diameter ranging from 75.61 ± 11.8 µm to 178.65 ± 40.7 µm. The highest yield was 98.93% and encapsulation efficiency was 83.1%. Thermogravimetric and differential thermal analysis showed that the melting point was at a temperature between 120 and 130 o C. Conclusion: Chitosan concentration has little effect on encapsulation yield, whereas the amount of GST tends to strengthen the crosslinking bonds of chitosan and reduces the mean diameter of microspheres.

Degradasi fenol menggunakan reaktor berbuffle telah dilakukan. Limbah yang digunakan adalah limbah fenol sintetik yang terbuat dari serbuk fenol (Merck Pro Analys). Fotokatalis yang digunakan adalah TiO2 Degussa 25. dengan variasi pengaruh penggunaan buffle dan pH. Konsentrasi awal limbah yang digunakan yaitu 10 ppm, 20 ppm dan 40 ppm, sedangkan loading katalisnya yaitu 0.5 gr/L, 1 gr/L dan 1.5 gr/L. Analisa konsentrasi fenol Spectrofotometer Hach. Hasil penelitian menunjukkan bahwa buffle mempunyai peranan penting dalam hal pengontakkan antara limbah, energi foton dan katalis lebih baik dibandingkan dengan tidak menggunakan buffle. Persen penyisihan dengan tidak menggunakan buffle diperoleh 50.1% dan untuk menggunakan buffle diperoleh persen penyisihan sebesar 79.07%. Sedangkan loading katalis optimum untuk mendegradasi senyawa fenol adalah sebesar 1gr/L dengan pH terbaik yaitu pada pH 7. Pada kondisi optimum ini, dengan konsentrasi awal limbah 10 ppm diperoleh konsentrasi akhir sebesar 2,022ppm setelah degradasi selama 5 jam.

Septic tank merupakan salah satu pengelolaan limbah sederhana dan merupakan sumber dari limbah domestik. Limbah septic tank dapat mempengaruhi sumber air bersih seperti sumur, sehingga posisi sumber air harus benar supaya terbebas dari kontaminan BOD dari septic tank. Tujuan dari artikel ini adalah mengembangkan model transport kontaminan sumur resapan septic tank untuk memberikan rekomendasi jarak aman antara sumur dengan septic tank. Model transport kontaminan dibagi menjadi dua zona yaitu zona unsaturated dan saturated yang keduanya dipengaruhi oleh proses adveksi, dispersi dan biodegradasi. Berdasarkan hasil perhitungan dengan menggunakan model yang dikembangkan menunjukkan bahwa pada model zona unsaturated dengan kedalaman 7 meter dengan waktu kurang dari 5000 hari mengandung BOD dibawah ambang batas, sedangkan pada zona saturated pada jarak 10 meter dengan waktu dibawah 3000 hari kandungan BOD masih aman, tetapi jika waktu diatas 5000 hari untuk zona unsaturated dan diatas 3000 hari untuk zona saturated konsentrasi BOD diatas ambang batas yang dikeluarkan oleh Pemerintah Republik Indonesia.

Oleoresin kayu manis adalah hasil ekstraksi menggunakan pelarut etanol yang berwarna merah kecoklatan, kental, dan beraroma tajam khas kayu manis. Tujuan dari penelitian ini adalah menentukan kondisi operasi ekstraksi berdasarkan berat rendemen maksimum dan mengetahui komponen-komponen kimia dalam oleoresin kulit kayu manis menggunakan analisa GCMS QP.2010S SHIMADZU. Penelitian ini dibagi menjadi dua tahap. Tahap pertama adalah ekstraksi 20 gram kulit kayu manis kering yang sudah dihaluskan dengan ukuran -20+30 mesh, -40+50 mesh dan -80+90 mesh menggunakan pelarut etanol. Perbandingan berat partikel kulit kayu manis dan etanol sebesar 1 : 4, 1 : 5, 1 : 6, suhu ekstraksi adalah 40oC, 50oC, 60oC dengan kecepatan pengadukan sebesar 700 rpm selama 6 jam. Tahap kedua adalah proses pemurnian dengan distilasi pada suhu 78C selama 6 jam. Berdasarkan hasil penelitian yang telah dilakukan, rendemen terbesar adalah 36% pada perbandingan berat kayu manis dan pelarut 1:5, suhu ekstraksi sebesar 60C dan ukuran partikel sebesar -50+60 mesh. Komponen kimia yang terdeteksi adalah 26 senyawa dan komponen kimia terbesar adalah 9,12-octadecadienoic sebesar 41,297%, hexadecanoic acid 15,311% dan octadecadien sebesar 14,9401%.

Sumber energi minyak dan gas bumi tidak dapat diperbaharui kembali, persediaanya semakin menipis dan pengembangan produksinya terbatas, sebelum krisis minyak bumi terjadi, hendaknya harus ada bahan bakar alternatif yang dapat dikembangkan dan dimanfaatkan, salah satunya adalah minyak nyamplung. Kendala penggunaan minyak nyamplung yaitu bilangan asam dan viskositas yang cukup tinggi. Bilangan asam minyak nyamplung yang tinggi harus diturunkan agar biodiesel yang dihasilkan memenuhi standar mutu SNI maupun ASTM. Tujuan penelitian ini adalah untuk mendapatkan perbandingan rasio molar metanol dengan minyak dan jumlah katalis KOH terbaik untuk memperoleh biodiesel yang berkualitas (bilangan asam, kadar FFA, viskositas, densitas serta kadar air). Penelitian ini dilakukan dengan mengkombinasikan proses produksi biodiesel yaitu metode esterifikasi-transesterifikasi. Kondisi operasi dan variabel yang digunakan adalah pada suhu reaksi 60°C dengan katalis KOH 1%, 1,5% dan 3% serta perbandingan rasio mol minyak terhadap metanol yaitu 1:4 dan 1:5 selama 60 menit pada tahap transesterifikasi. Perlakuan terbaik yang memenuhi standar SNI adalah pada rasio molar methanol 5:1 katalis KOH 1,5% dengan bilangan asam 1.48 mg KOH/g sampel, viskositas 3,26 cSt, densitas yaitu 0,8365 gr/ml, kadar air 0.046% dan rendemen 62% (v/v).

Pembuatan biodiesel sebagai salah satu bauran energi menghasilkan produk samping berupa gliserol. Dengan mereaksikan antara gliserol dengan sodium karbonat menjadi gliserol karbonat dapat memberikan nilai tambah pada industri biodiesel. Penggunaan katalisator yang ekonomis dan ramah lingkungan mutlak diperlukan untuk mengurangi dampak polusi lingkungan. Untuk itu, penelitian ini dilakukan dengan maksud untuk mengetahui seberapa besar konversi gliserol yang dihasilkan dengan pengunaan katalisator resin penukar ion berupa indion 225 Na dalam proses reaksi antara gliserol dan sodium karbonat. Percobaan dilakukan dalam reaktor batch, kecepatan pengadukan 600 rpm, perbandingan pereaksi 3 gmol gliserol/gmol sodium bikarbonat, konsentrasi pelarut 3gmol,waktu reaksi 90 menit, suhu reaksi 60- 100oC, konsentrasi katalisator 1-9 % massa gliserol, dan dimeter partikel 0,0456-0,0912 cm . Pengambilan sampel dilakukan setiap 15 menit untuk dilakukan analisa gliserol sisa (Gb)dan gliserol awal (Go) sebelum katalisator dimasukan. Hasil percobaan menunjukan dengan semakin meningkatnya suhu reaksi dan semakin kecil ukuran katalisator konversi yang dihasilkan mengalami peningkatan, tetapi mengalami penurunan dengan meningkatnya konsentrasi katalisator. Kondisi terbaik diperoleh pada diameter katalisator 0,0645 cm, konsentrasi katalisator 1% massa gliserol, suhu 100oC, dan pada waktu reaksi 60 menit yaitu dengan perolehan konversi sebesar 30,28% atau 90,84% berbasis sodium bikarbonat.

Krisis energi dunia yang terjadi pada dekade terakhir ini mendorong pengembangan energi alternatif dengan pemanfaatan sumber daya energi terbarukan (rewenable resources). Bentuk energi alternatif yang mulai dikembangkan adalah biofuel yang mempunyai tingkat kelayakan teknologi cukup tinggi dimana dapat berupa bioethanol untuk menggantikan bensin, biodiesel menggantikan solar atau minyak bakar. Indonesia merupakan Negara agraris yang kaya akan bahan baku biodiesel dan bioethanol sebagai energi terbarukan. Tujuan penelitian ini adalah mencari kondisi operasi optimum dalam pembuatan biodiesel dari minyak nyamplung dengan menggunakan katalis asam-basa. Dalam proses pembuatan biodiesel dari Minyak nyamplung melewati tahapan proses, yaitu proses esterifikasi dan transesterifikasi. Variasi katalis yang di gunakan sebanyak 1.5%, 2% dan 2.5% dengan lama waktu reaksi 30 menit, 60 menit, dan 75 menit, temperature reaksi 60C. Kondisi maksimum penelitian ini berdasarkan kualitas biodiesel yang memenuhi standar SNI adalah menggunakan katalis NaOH 2,5% waktu reaksi 75 menit dengan Cetane number 53.32 ,bilangan asam 0.72mg NaOH/g sampel ,viskositas 5.78 cSt ,densitas 0.88g/ml, dan rendemen 66.5% .

Asap cair merupakan hasil dari pembakaran proses pirolisis yang dikondensasi. Asap cair mengandung senyawa asam dan turunannya serta senyawa fenol, sehingga dapat dijadikan sebagai pengawet alami. Penelitian ini bertujuan untuk menentukan % yield maksimum dan karakterisasi asap cair tempurung kelapa seperti viskositas, densitas, dan pH. Penelitian ini dibagi menjadi dua tahap yaitu tahap pirolisis tempurung kelapa pada suhu 300, 400 dan 500oC, waktu pirolisis yaitu 2, 3 dan 4 jam, serta ukuran tempurung kelapa 6 – 10 mm, 4 – 6 mm, dan 1.6 – 4 mm. Tahap ini menghasilkan cairan berwarna merah kehitaman, sehingga dilakukan tahap kedua yaitu proses destilasi untuk mendapatkan asap cair yang murni. Berdasarkan penelitian yang telah dilakukan persen yield maksimum asap cair sebesar 37,35% pada temperatur pirolisis 500oC, selama 4 jam dengan ukuran tempurung kelapa sebesar 1.6 – 4 mm. Analisa karakteristik asap cair pada suhu 500C memiliki pH 2, densitas sebesar 1,084 gr/ml. viskositas kinematik sebesar 1,62 mm2/s.

Oleoresin pala adalah cairan berbentuk kental yang berbau khas dan banyak dimanfaatkan untuk bahan-bahan kosmetik dan makanan. Tujuan penelitian ini adalah memperoleh besarnya rendemen maksimal berdasarkan kondisi operasi ekstraksi maserasi.Penelitian ini dibagi menjadi dua tahap. Tahap pertama adalah ekstraksi 20 gram biji pala kering yang sudah dihaluskan dengan ukuran 20+30 mesh, -40+50 mesh dan -60+80 mesh menggunakan pelarut metanol. Perbandingan berat partikel pala dan metanol sebesar 1 : 4, 1 : 5, 1 : 6, suhu ekstraksi adalah 40oC, 50oC dengan kecepatan pengadukan sebesar 700 rpm selama 6 jam. Tahap kedua adalah proses pemurnian dengan distilasi pada suhu 62oC – 65oC selama 6 jam. Berdasarkan hasil penelitian yang dilakukan, % rendemen oleoresin pala terbesar adalah 3,2 gram dengan kondisi ektraksi maserasi pada suhu 40C, ukuran partikel -40+50 mesh dan perbandingan berat partikel dengan metanol adalah 1 : 6.

Indonesia merupakan salah satu penghasil minyak atsiri terbesar di Dunia, salah satu tumbuhan penghasil minyak atsiri adalah nilam. Tujuan dari penelitian ini adalah menentukan % rendemen terbesar dan menentukan standarisasi minyak sesuai dengan SNI yang dihasilkan dari proses penyulingan uap. Daun nilam kering seberat 1,5 kg yang sudah bersih dari kotoran dimasukkan dalam ketel suling dan ditutup dengan rapat. Steam dari boiler dialirkan ke ketel suling dengan tekanan 0,5 barG, 1 barG dan 1,5 barG selama 4, 5 dan 6 jam. Campuran minyak dan air yang keluar dari kondenser ditampung dan diamkan selama 24 jam untuk memisahkan air dan minyak. Minyak daun nilam dimurnikan dengan bentonit 10% dari berat minyak pada suhu 50 yang telah terpisah dari bentonit ditambahkan Na2SOo 4C sambil diaduk selama 1 jam. Minyak daun nilam anhidrat dan diamkan selama 15 menit kemudian pisahkan air dan Na2SO dalam minyak. Sampel dengan % rendemen terbesar dianalisa kualitasnya sesuai dengan SNI. berdasarkan hasil penelitian menunjukan kondisi penyulingan pada tekanan 1 bar dan waktu 4 jam diperoleh rendemen tertinggi sebesar 1.82 % dengan berat jenis (0,943-0,983), indeks bias (1,504-1,514) dan bilangan asam (3,79-4,14). Karakterisasi minyak nilam yang dihasilkan sesuai dengan SNI.

Chitosan is a natural polymer derived from different starting materials such as fish scales, crab and shrimp shells. Due to the advantages like biocompatibility and biodegradability, chitosan has been widely used in hydrogel development. This current study aims to make chitosan from shrimp shells, synthesize hydrogel from chitosan, and observe the effect of various chitosan preparation treatments on the properties of the hydrogel. The preparation of chitosan was carried out through demineralization, deproteinization, and deacetylation process. HCl concentration during demineralization and NaOH concentration during deproteinization were varied (1; 1,5; 2) M and (1; 1,5; 2) M, respectively. Chitin deacetylation was conducted using 60% (w/v) of NaOH at the temperature of 90°C for 120 min, and chitosan was resulted. Chitosan based hydrogel was then synthesized with the addition of alginate and glutaraldehyde. The effect of HCl and NaOH concentrations during demineralization and deproteinization on the deacetylation degree of chitosan was observed. The effect of deacetylation degree of chitosan on the degree of crosslinking and swelling property of the hydrogel were also evaluated. Chitosan resulted from this study has the optimum degree of deacetylation at 57.28 %, resulting from demineralization by using HCl 2M and deproteinization with NaOH 2 M. Higher deacetilation degree of chitosan causing the increase of the degree of cross-linking and decrease of the swelling capacity of the hydrogel. The highest degree of cross-linking is 78.85 %, and the swelling capacity is 47 %. [ABSTRACT FROM AUTHOR]

Global food security will be a major concern because it involves the availability of food that is not able to meet human needs. The decline in food production is caused by the low efficiency of fertilizer absorption by plants because it uses conventional fertilizers. One solution to increase crop productivity is to use slow-controlled release fertilizers. This technology can improve the nutrient use efficiency (NUE) and reduce the negative impact on the environment due to chemical fertilization and by inadequate disposal or reuse of agricultural waste. This study provides information about the design and use of slow-controlled release fertilizer that can control nutrient release and enhance NUE as a solution to food security problems. [ABSTRACT FROM AUTHOR]

The effect of spray dryer inlet temperature on characterization and total phenolic content of palm sugar has been studied. The spray dryer operating conditions used were 160° 220°C inlet temperature with a feed flow rate of 2 L/h, while for outlet temperature was 85°C. The high inlet temperature produced a higher crystallinity of sucrose and did not agglomerate and not sticky. However, the high temperature of the spray dryer inlet produced palm sugar that was browner than the low temperature one. The effect of increasing temperature of spray dryer produced irregular total phenolic. The total phenolic at 220°C was higher than 200°C. Likewise, the temperature of 180°C generated total phenolic was higher than the temperature of 160°C. The total phenolic of palm sugar analyzed in this study was quite large within the range of 49 ± 0.01 to 63.6 ± 0.01 mg of GAE/100 g samples. [ABSTRACT FROM AUTHOR]