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"Telah dilakukan penelitian mengenai proses sintesis polyacrylic acid yang bertujuan untuk mengetahui pengaruh penambahan polimer pada peningkatan kapasitas penyerapan air. Sampel yang digunakan untuk mengetahui kapasitas penyerapan air yaitu produk absorben komersial berupa Disposable Baby Diapers. Proses sintesis polimer dilakukan dengan metode polimerisasi emulsi dengan teknik semi-kontinyu dengan komponen komposisi yaitu aquades, surfaktan anionik SDS, dan larutan PVA terhidrolisis sebagian medium viscosity. Kemudian untuk monomer acrylic acid dan inisiator APS dicampurkan secara kontinyu selama proses sintesis berlangsung pada temperatur ±70°C, kecepatan agitasi 300 rpm, dan waktu sintesis selama 4 jam dengan tiga variasi komposisi yaitu PAA, PAA+SDS, dan PAA+SDS+PVA. Kapasitas penyerapan air dihitung dengan mengikuti standar dari ASTM D570-98 dan diperoleh nilai kapasitas penyerapan air yang meningkat pada semua variasi komposisi dengan dilakukan pelapisan sebanyak 1 gram pada sampel diapers dan diperoleh peningkatan kapasitas penyerapan air pada variasi komposisi satu sebesar 229%, variasi kedua sebesar 206%, dan variasi ketiga sebesar 705%.

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Research has been conducted on the synthesis process of polyacrylic acid to determine the effect of adding polymer on the water absorption capacity. The sample used to determine water absorption capacity is a commercial absorbent product in Disposable Baby Diapers (DBD). The polymer synthesis process utilized the emulsion polymerization method with a semi-continuous technique. The composition included distilled water, SDS anionic surfactant, and partially hydrolyzed PVA solution with medium viscosity. Acrylic acid monomer and APS initiator were continuously mixed during the synthesis process at a temperature of approximately 70°C, an agitation speed of 300 rpm, and a synthesis time of 4 hours. Three composition variations were used, namely PAA, PAA+SDS, and PAA+SDS+PVA. The water absorption capacity was calculated following the ASTM D570-98 standard. The resultsshowed an increased water absorption capacity for all composition variations. Coating 1 gram of the sample diapers resulted in an increase of 229% for the first composition variation, 206% for the second variation, and 705% for the third variation."

"The aim of this study is to evaluate the effects of absorbent flow rate on CO2 absorption through a super hydrophobic hollow fiber contactor. The absorbent used in this study was a physical absorbent, namely a polyethyleneglycol-300 (PEG-300) solution. Meanwhile, the feed gases used in the experiments were pure CO2 and a mixture of 30% CO2 and 70% CH4. Gas absorption using a physical absorbent provides various benefits; for example, it can produce sufficiently high selectivity towards CO2 and it is less corrosive than chemical solvents. Three super hydrophobic hollow fiber contactors, each 6 cm in diameter and 25 cm in lengthconsist of 1000, 3000 and 5000 fibers, respectively, were used in this study. The type ofsuper hydrophobic fiber membrane used was polypropylene-based, with an outer and inner diameter of about 525 and 235 µm, respectively. During the experiments, the absorbent was flowed through the lumen fibers, whilst the feed gas flowed through the shell side of the membrane contactors. The experimental results showed that the mass transfer coefficient, the flux, and the absorption efficiency increased, but the CO2 loading decreased, with increasing absorbent flow rate in the membrane contactor. Meanwhile, it was found that an increase in the number of fibers in the membrane contactor, in general, will increase the absorption efficiency and the CO2 loading, but will decrease the overall mass transfer coefficient and the flux."

"NOx dan SO2 merupakan komponen primer hasil pembakaran bahan bakar fosil. Dengan dihadapinya komitmen serta tantangan dalam pengendalian emisi NOx dan SO2, maka dikembangkannya berbagai teknologi dan metode dalam penurunan tingkat emisi gas NOx dan SO2, salah satu diantaranya yaitu penggunaan metode basah penyisihan gas, yaitu wet scrubbing. Penyisihan pada penelitian ini dilakukan dengan memanfaatkan membran kontaktor serat berongga berbahan dasar PVDF (polyvinylidene fluoride). Larutan absorben yang digunakan yaitu H2O2 dan HNO3, dimana H2O2 berfungsi untuk menyisihkan NOx dan SO2 dengan mengubah gas NOx menjadi gas yang lebih larut dalam air, sedangkan HNO3 digunakan sebagai autokatalis untuk mempercepat laju reaksi penyisihan. Variabel bebas pada penelitian ini yaitu laju alir gas umpan NOx dan SO2 dan konsentrasi H2O2 pada larutan absorben. Variasi laju alir gas umpan yang digunakan yaitu 100, 125, 150, 175, dan 200 mL/menit, sedangkan variasi konsentrasi yang digunakan yaitu 0,02; 0,04; 0,06; 0,08; dan 0,1% b/v H2O2. Penelitian menghasilkan penyisihan gas NOx dan SO2 maksimum berurutan sebesar 98,5% dan 100%, yang didapatkan dengan konsentrasi H2O2 sebesar 0,1% b/v, pada laju alir gas umpan sebesar 100 mL/menit, dengan modul membran sebanyak 50 buah.

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NOx and SO2 are the primary gas components from the combustion of fossil fuels. With the commitment and challenges faced in controlling NOx and SO2 emissions, various technologies and methods were developed to reduce NOx and SO2 gas emission levels, one of which is the use of the wet gas removal method. The allowance in this study was carried out by using a hollow fiber contactor membrane made from PVDF (polyvinylidene fluoride). The absorbent solutions used are H2O2 and HNO3, where H2O2 was used to absorb the NOx and SO2 gases by converting NOx gas into a gas that is more soluble in water, while HNO3 is used as an autocatalyst to accelerate the rate of removal reactions. The independent variables in this study were the feed gas flow rate of NOx and SO2 and the concentration of H2O2 in the absorbent solution. Variations in the feed gas flow rate used were 100, 125, 150, 175, and 200 mL/minute, while the concentration variations used were 0.02; 0.04; 0.06; 0.08; and 0.1% w/v H2O2. The research resulted in maximum NOx and SO2 gas removal respectively 98.5% and 100%, which was obtained with a H2O2 concentration of 0.1%wt, a feed gas flow rate of 100 mL/min, and 50 membrane modules."