The Effect of Hydrochloric Acid Solution and Glycerol on The Mechanical, Hydrate Properties and Degradation Rate of Biofilm from Ripe Banana Peels

Banana peel is a biomass waste that has not been utilised optimally, despite its high starch content. Moreover, starch has potential as a raw material for biofilm or edible film production. This research focused on using the starch content from the mature banana peel to create a biofilm. Starch was extracted from the banana peel; then, it was hydrolyzed with a variation of hydrochloric acid solution (HCl) of 0.5 M (0, 2, 4 %-v/v Starch). Glycerol (0, 20, 40 %-w/w starch) was used as a plasticizer. It was found that the formulation of 4%-v/v HCl solution and glycerol 20%-w/w resulted in the highest biofilm’s tensile strength of 4.18 MPa. However, the elongation break percentage achieved the best result at 20,2% when the formulation of 0%-v/v HCl solution and 40%-w/w glycerol was applied. Increasing HCl solution and glycerol was proven to improve the biofilm’s solubility in the water, where 47.9% solubility was attained in the formulation of 40%-w/w glycerol and 4%-v/v HCl solution. The degradation rate of biofilm in the soil was measured using zero- and first-order kinetic rates. The zero-order resulted in the best model with a half-life time (t1/2) between 73 to 108 days.

A Review on the Hydroisomerisasion of n-Parafins over Supported Metal Catalysts

Catalytic hydroisomerization of n-paraffin aims to produce branched paraffin isomers and suppress cracking reactions in the production of the low cloud point of biodiesel. The development of the type of metal and catalyst support, amount of metal loading, and reaction conditions are important to increase the catalyst activity. A high performace catalyst for hydroisomerization bears bifunctional characteristics with a high level of hydrogenation active sites and low acidity, maximizing the progress of hydroisomerization compared to the competitive cracking reaction. In addition, a catalyst support with smaller pore size can hinder large molecular structure isoparaffins to react on the acid site in the pore thus providing good selectivity for converting n-paraffin. Catalysts loaded with noble metals (Pt or Pd) showed significantly higher selectivity for hydroisomerization than non-noble transition metals such as Ni, Co, Mo and W. The reaction temperature and contact time are also important parameters in hydroisomerization of long chain paraffin, because long contact times and high temperatures tend to produce undesired byproducts of cracking. This review reports several examples of supported metal catalyst used in the hydroisomerization of long chain hydrocarbon n-paraffins under optimized reaction conditions, providing the best isomerization selectivity results with the lowest amount of byproducts. The role of various metals and their supports will be explained mainly for bifunctional catalysts.

Modifikasi Proses Pengolahan Boiler Feed Water (BFW) dari All Volatile Treatment (AVT) menjadi Oxygenated Treatment (OT) untuk Produksi Listrik Ramah Lingkungan

In power plant industries, boiler feed water (BFW) quality becomes the main parameter for steam generation, which is used for electricity production. To generate standard BFW for power plants, each impurity within water resources should be removed to prevent corrosion and scale deposition by several processes such as sedimentation, coagulation, polishing, and deaeration. Operation conditions that involved high temperature would trigger corrosion as a crucial factor in the maintenance and practical lifetime of the equipment. In the beginning of the operation, PT. Cirebon Electric Power (CEP) used All Volatile Treatment–Reduction (AVT-R) by injection of both ammonia and hydrazine. In order to optimize the operation, the BFW treatment was changed to All Volatile Treatment–Oxidation (AVT-O) that only uses of ammonia and deaerator for removing the dissolved gas. Based on the actual evaluation, AVT technology showed less performance related to corrosion prevention and high chemical consumption. Therefore, PT. CEP tried to implement modification in the BFW treatment, which is AVT technology to Oxygenated Treatment (OT). This paper is to evaluate the effect of those modifications on corrosion prevention and resource-energy saving. The modification into OT showed valuable results that decrease concentration of dissolved Fe from 1 ppb to 0.1 ppb in the deaerator outlet stream. This data reveals that good corrosion prevention can be achieved through the creation of passive layers, hematite Fe2O3. Oxygen injection into the water circulation system yielded an oxidation atmosphere so that the passive layer, Fe2O3, was formed. In addition to corrosion prevention, this modification also cut the amount of ammonia injection into the system from 2 ppm to 0.12 ppm. Reduction of that ammonia injection provides other benefits such as decreasing the volume of resin regeneration, which becomes only twice a month. This situation also created other benefits such as reducing the regeneration water, chemicals, and wastewater. Thus, the modification could establish the electricity production by PT. CEP more environmentally friendly and sustainable.A B S T R A KPada operasi PLTU, kualitas boiler feed water (BFW) menjadi parameter yang krusial untuk menghasilkan steam yang akan digunakan untuk memproduksi listrik. Untuk mendapatkan BFW sesuai dengan standar yang ada, maka pengotor di dalam air baku industri harus dihilangkan karena dapat menyebabkan korosi dan pembentukan kerak, baik pada pipa maupun peralatan. Kondisi operasi yang melibatkan steam pada suhu tinggi menyebabkan korosi menjadi masalah yang krusial terutama terkait dengan maintenance dan umur efektif pabrik. Pada awal berdirinya, PT. Cirebon Electric Power (CEP) menggunakan teknologi All Volatile Treatment–Reduction (AVT-R) dengan injeksi amonia dan hidrazin. Selanjutnya, dilakukan optimasi melalui perubahan proses menjadi All Volatile Treatment–Oxidation (AVT-O) dengan hanya menginjeksikan amonia dan mengoptimalkan fungsi deaerator untuk menghilangkan pengotor dissolved gas. Berdasarkan data lapangan, teknologi AVT yang digunakan kurang memberikan pencegahan korosi yang baik dan juga jumlah bahan kimia yang digunakan masih relatif banyak. Agar lebih ramah lingkungan dan handal, PT. CEP berusaha untuk melakukan modifikasi terhadap pengolahan boiler feed water (BFW) dari yang semula menggunakan teknologi AVT-O menjadi Oxygenated Treatment (OT). Penelitian ini bertujuan untuk mengevaluasi dampak modifikasi sistem AVT menjadi OT pada pencegahan korosi dan juga penghematan sumber daya. Modifikasi sistem AVT-O menjadi OT berhasil menurunkan konsentrasi dissolved Fe dari 1 ppb menjadi 0,1 ppb pada BFW. Hal ini menunjukkan terjadinya peningkatan pencegahan korosi melalui pembentukan double protective layer yang merupakan kombinasi magnetite (Fe3O4) dan hematite (Fe2O3). Injeksi oksigen ke dalam sistem mengubah kondisi air menjadi suasana oksidasi sehingga mampu mengubah dan membentuk lapisan baru sebagai pencegahan korosi. Selain pencegahan korosi, modifikasi ini juga berhasil menurunkan jumlah injeksi amonia dari 2 ppm menjadi 0,12 ppm dalam siklus air yang ada. Penurunan jumlah injeksi amonia ini akan memberikan keuntungan beruntun berupa berkurangnya frekuensi regenerasi resin dari semula 8 menjadi 2 kali perbulan. Kondisi ini akan menghasilkan penghematan sumber daya berupa kebutuhan air untuk regenerasi, bahan kimia amonia, dan beban pencemaran. Oleh karena itu, modifikasi ini telah membuat proses produksi listrik di PT. CEP lebih ramah lingkungan dan berkelanjutan.Kata kunci: All Volatile Treatment (AVT); efisiensi energi; korosi boiler; Oxygenated Treatment (OT)

Pemanfaatan Jerami Padi (Oryza Sativa L.) Sebagai Bahan Baku Dalam Pembuatan CMC (Carboximetil Cellulose)

Rice straw is a waste from rice plants that contains 37.71% cellulose, 21.99% hemicellulose, and 16.62% lignin. High cellulose content in rice straw can be used as raw material for the manufacture of Carboxymethyl Cellulose (CMC). CMC is a cellulose derivative widely used in food, pharmaceutical, detergent, textile and cosmetic products industries as a thickener, stabilizer of emulsions, or suspensions and bonding. This study aims to process rice straw waste into CMC with variations in sodium monochloroacetate of 5,6,7,8 and 9 grams. The method used in this research is by synthesis using 15% NaOH solvent, with a reaction time of 3.5 hours and 5 grams of rice straw. The results showed that the best CMC was obtained at a concentration of 9 grams of sodium monochloroacete with a yield characterization of 94%, pH 6, water content of 13.39%, degree of substitution (Ds) of 0.80, and viscosity of 1.265 cP.

Penyisihan Kontaminan dari Air Limbah Hasil Daur Ulang Baterai LiFePO4 (LFP) Menggunakan Penukar Ion Resin Kation Amberlite HPR1100 Na dan Resin Anion Dowex Marathon A

Pada tahun 2025, diperkirakan kebutuhan baterai Li-ion akan mencapai 400.000 ton. Upaya strategis diperlukan untuk mewujudkan pemakaian baterai Li-ion yang berkelanjutan. Setelah siklus pemakaian baterai Li-ion berakhir, baterai Li-ion akan diproses kembali untuk diambil kandungan logam-logam penting yang terkandung di dalam katoda, terutama litium. Secara umum, proses recycle tersebut dilakukan dengan metode hidrometalurgi yang terdiri atas rangkaian leaching dan presipitasi. Namun demikian, dalam proses pemurnian tersebut dihasilkan air limbah yang mengandung beragam logam dengan konsentrasi yang berbeda. Untuk baterai LFP, logam-logam tersebut berasal dari katoda yang mengandung Li, Na, Si, dan PO4. Proses pelindian dan pencucian serbuk katoda membutuhkan air dalam jumlah yang relatif besar. Pengolahan air limbah hasil proses daur ulang baterai diharapkan dapat secara signifikan meningkatkan efisiensi penggunaan air. Pada eksperimen ini, metode adsorpsi batch dengan ion-exchange resin kation Amberlite HPR1100 Na dan resin anion Dowex Marathon A digunakan untuk menghilangkan ion logam dari air limbah artifisial. Pengambilan sampel air limbah yang diolah diambil pada menit ke-3, 6, 10, 20, 30 dan hari ke-3. Berdasarkan pada hasil removal percentage, diperoleh bahwa pengolahan air limbah artifisial metode adsorpsi dengan menggunakan ion-exchange resin kation Amberlite HPR1100 Na dapat mengurangi kadar ion litium dan natrium sampai 100% pada menit ke-20 dengan variasi dosis adsorben 10 g/100 mL, sedangkan penggunaan ion-exchange resin anion Dowex Marathon A dapat mengurangi kadar ion fosfat sampai 100% pada menit ke-30 dengan dosis adsorben 10 g/100 mL. Dengan adsorpsi isotherm didapat model Langmuir lebih sesuai dengan data eksperimen dengan nilai parameter Qm dan KL untuk ion litium sebesar 1,16 mg/g dan 2,57 mg/g, ion natrium sebesar 74,62 mg/g dan 0,04 mg/gL/mg, dan ion fosfat sebesar 208,33 mg/g dan 0,06 mg/g. Selain itu, studi kinetika menunjukkan bahwa model pseudo second-order memiliki kesesuaian data yang lebih baik daripada pseudo first-order.

Effect of Surfactant Type on Synthesis and Characteristics of Nanonickel Hydroxide

Nickel hydroxide has a vital role in various applications, especially as a support material for energy storage materials. Nickel hydroxide can be synthesized through the hydroxide precipitation method. However, the product formed by this method may be large or more than 100 nm because the agglomeration step can occur easily. This present work aims to study the effect of surfactant types in the synthesis and characterization of nickel hydroxide nanoparticle. Nickel sulfate (NiSO4) solution was used as a precursor solution, while 5M sodium hydroxide (NaOH) solution was used as a precipitation agent. The surfactants studied were alkyl benzene sulfonate (ABS), sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and polyvinylpyrrolidone (PVP). The nickel hydroxide synthesis process was carried out at 50 oC for 1 hour. The surfactant concentration used was at the critical micelle concentration (CMC), where the CMC for ABS, SDS, CTAB, and PVP were 0.01; 0.05; 3; and 0.5 %w/v, respectively. The synthesis of nickel hydroxide nanoparticle was carried out successfully precipitated almost 100% of Ni2+ ions. The product characterization that has been carried out shows that ABS surfactant produces the best nickel hydroxide nanoparticle product where the particle size is 3.12–4.47 nm.

Evaluasi Manfaat Penggantian Chemical Amine N1800 menjadi N1805 dalam rangka Pengurangan Jejak Karbon

Inovasi berkelanjutan pada alat dan atau proses di dalam industri kimia untuk mencapai efisiensi dan industri yang ramah lingkungan wajib dilakukan. Dalam mendukung hal ini PT. KMI melakukan modifikasi proses dengan mengganti bahan neutralizing amine yang digunakan pada sistem boiler feed water. Penggantian amine dilakukan pada pertengahan tahun 2017, dari amine N1800 menjadi N1805. Data konsumsi amine dan air pelarut tahun 2015-2020 digunakan sebagai dasar evaluasi. Estimasi jumlah emisi juga dilakukan dengan menghitung kebutuhan air pelarut, drum kontainer bahan amine dan juga transportasi bahan dari produsen ke PT. KMI. Dari hasil perhitungan, dapat disimpulkan bahwa penggantian bahan amine dari N1800 ke N1805 memberikan benefit yang baik, yaitu: (1) menurunkan biaya tahunan untuk konsumsi amine, (2) menurunkan kebutuhan air pelarut dan beban pencemar air dan (3) menurunkan emisi secara signifikan. Penurunan emisi sebagian besar berasal dari penghematan penggunaan drum kontainer dan transportasi, sedangkan dari penurunan penggunaan air kurang signifikan.

The Effect of Nutrients Mixture on The Biomass and Lipid Production from Microalgae Botryococcus braunii Mutated by UV-C Rays

Nutrient is one of the most important factors in the growth of microalgae. This research was conducted to study the effect of nutrient mixture on the biomass and lipid production of Botryococcus braunii. Microalgae B. braunii was cultivated in the commercial nutrient medium of agricultural fertilizer combinations of ammonium sulphate (ZA), urea, and triple superphosphate (TSP). Before the cultivation process, B. braunii was exposed to UV-C rays (254 nm) for 3 minutes. The concentration and type of fertilizer as a nitrogen source divided into four types of mixtures, namely FM-1, FM-2, FM-3, and FM-4 were compared with Walne nutrients to study their effects on microalgae growth and lipids. FM-1 consisting of 150 mg/L of ZA, 7.5 mg/L of urea, and 25 mg/L of TSP led to the best growth for native and mutated microalgae strains compared to Walne nutrients and other nutrient mixtures. The mutated microalgae showed less growth than the native microalgae strains. However, the mutation process significantly increased the lipid content in the microalgae. In native microalgae strains, FM-4 consisting of 136.3 mg/L of urea and 50 mg/L of TSP produced the lowest lipid at 8.96%. After being exposed to UV-C rays, the lipids in FM-4 medium increased to 55.11%. The results show that the use of commercial fertilizers and exposure to UV-C rays on microalgae have high potential in preparing lipids as raw material for biodiesel which can be effectively applied in large-scale microalgae cultivation.

Characteristics and Kinetics Study of Glycerolabietate from Glycerol and Abietic Acid from Rosin

Rosin is a natural resin from the coniferous tree sap, which separated from its oil content (terpenes). Rosin is brittle. Therefore modifications are needed to improve its mechanical properties. The main content of rosin is abietic acid which has a carboxylic group, so it can form an ester group when reacted with polyhydric alcohol (polyalcohol) such as glycerol. The research aimed to study the kinetics of the esterification reaction between the hydroxyl group in glycerol and the carboxylic group in abietic acid from rosin at various reaction temperatures and reactant compositions. This reaction is carried out in a three-neck flask at atmospheric pressure without a catalyst. The reaction temperatures used were 180˚C, 200˚C, and 220˚C, and the ratio of rosin and glycerol was 1:1, 1:3, and 1:5. The reaction kinetics calculations were analyzed with acid number data over the reaction time using three different models. The calculations showed that this reaction involves positioning a hydroxyl group on glycerol, which the primary and secondary hydroxyl groups contribute to forming a rosin ester (glycerolabietate). The rate of reaction constants of primary hydroxyl of glycerol and abietic acid were in the range 6.25x10-4 - 3.90x10-3 g/(mgeq.min), while reaction rate constants of secondary hydroxyl and abietic acid were in the range 1.06x10-5 - 1.15x10-4 g/(mgeq.min). FTIR analysis showed a change in the hydroxyl, carboxylate, and ester groups which were assigned by a shift of wavenumber and a difference of intensity at 3200-3570 cm-1, 1697.36 cm-1, and 1273.02 cm-1.

Separation of 6-Gingerol in Zingiber Officinale Rubrum Varieties Using an Ultrasonic Assisted Extraction Method

Gingerol is a chemical compound found in red ginger, with pharmaceutical use as an analgesic drug. Generally, gingerol separation in ginger uses the Soxhlet extraction method, but this process has a weakness. It requires a long process and unsatisfactory yield. This research aims to study ultrasonic frequency effect on increasing gingerol yield in the extraction process. The variables studied were extraction times with variations of 30, 60, 90, and 120 minutes. In addition, the ultrasonic effect was also observed with variations in the ultrasonic frequency of 40 and 50 kHz compared to the solvent extraction method. This study used 70% (v/v) ethanol as a solvent and an operating temperature of 50 ºC as fixed variables.Furthermore, it used a rotary vacuum evaporator at a pressure of 350 mmHg to separate the resulting gingerol extract. Qualitative sample analysis used Thin Layer Chromatography (TLC) and scanning electron microscope (SEM) while quantitative analysis used high-performance liquid chromatography (HPLC), Waters Alliance e2695 brand with X-Terra RP18 column 100 x 4.6 mm, five μm to determine the total gingerol extract. The results showed that ultrasonic power had a significant effect on the results obtained, with the highest yield was 24.71% at the ultrasonic frequency of 50 kHz with an extraction time of 120 minutes.