Judul: Sintesa Metil Ester Sulfonat dari Metil Ester Berbahan Baku PKO pada Skala Pilot Plant
Abstrak: One of the palm oil-based oleochemical industry which has a great prospect to be developed in Indonesia is the surfactant industry. Surfactant is a surface active agent which can be produced by chemical or biochemical synthesis. Surfactant has been widely applied in several kind of industries as adhesive, wetting, foaming, emulsifier, or penetrating material component. One kind of the natural-based surfactant which currently has been researched and developed is the methyl ester sulfonates (MES) surfactant. MES surfactant is one of the anionic surfactant which can be made using the methyl ester from palm oil through the sulfonation process. Research on the MES surfactant production process at the laboratory scale has been conducted many times and it gives product result that can be applied on many kinds of cosmetics, cleaner, and personal care products, and also for enhanced oil recovery (EOR) application on the oil mining. At the upgrading stage of MES surfactant production scale from the laboratory scale to the pilot plant scale, treatment of reaction time and stirring speed on the processing reactor is important to be noticed. The objectives of this research are: (1) to get the process condition which can be used to produce MES surfactant made from PKO-based methyl ester using sulfonation reactor at the pilot plant scale, (2) to obtain the characteristic of the produced MES surfactant product made from PKO-based methyl ester, (3) to get the financial feasibility of the industry of MES surfactant made from PKO-based methyl ester. Sulfonation process of palm kernel oil methyl ester is conducted using batch system in 100 L scale sulfonation reactor tank. Sulfonation process is conducted by mixing the methyl ester and NaHSO3 reactant at reactant mol ratio 1:1.2. Temperature of the process is 100oC. In this research, process variables which are supposed to influence the quality of MES product are the stirring speed at the process and the duration of sulfonation process. The treatment of stirring process consists of 3 grades, those are at the speed of 140, 160 and 180 rpm. The treatment of sulfonation process duration is in every 30 minutes interval in period of 0-360 minutes. Characterization of produced MES product includes test of blue thymol, pH, color (brightness), surface tension decreasing ability, interface tension decreasing ability, emulsion stability, foam stability, and detergency. Determination of relational equation model between product quality parameter and treatment, is using the curve fitting method. Determination of sulfonation process condition, which can be used to produce MES using the existing sulfonation reactor, is conducted using the multi-regression method. The analyzed investment feasibility criteria are Net Present Value (NPV), Internal Rate of Return (IRR), Net Benefit-Cost Ratio (Net B/C), Break Even Point (BEP), Pay Back Period (PBP) and sensitivity analysis. 7 From the result of this research, it can be concluded that the existing sulfonation reactor can be used to produce MES surfactant using batch system with NaHSO3 as the sulfonating agent. The characteristics of the produced MES product are: (1) blue thymol test gives a positive result, (2) pH before purification : 3.53 – 5.94, (3) pH after purification: 5.77-6.21,
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Judul: Kinerja dan Karakteristik Asam Metil Ester Sulfonat dari Metil Ester Crude Palm Oil pada Beberapa Periode Sampling
Abstrak: Methyl Ester Sulphonic Acid (MESA) is a chemical compound that has ability as a surface active agent (surfactant). Surfactant can decrease the surface tension and interfacial tension, so it has been used as adhesives, agent for puffing, wetting, and forming the emulsion. It also has been applied in various fields such as food, pharmaceuticals, cosmetics, agriculture, paint, paper, and mining (as oil well stimulation agent in enhanced oil recovery process). MESA is synthesized through sulfonation of methyl ester. Methyl ester is obtained by esterification-transesterification of triglycerides (oil). If the next process like bleaching and neutralization have been done, the MESA will be converted to MES (Methyl Ester Sulphonate) that known as commercial product. MES has a good detergency (even if it is used in hard water) and good tolerance to the presence of calcium. MES is derived from renewable raw materials that based on oil /fat. One source of oil that can be used is palm oil. This research used Crude Palm Oil (CPO). This raw material is potential to be developed as surfactant because of its supply availability and the suitability of its fatty acid composition. Based on the Foreign Agricultural Service (2009), Indonesia's CPO production increased from 9.1 million tons (year 2002) to 17.82 tons (2008). In the next year, it even reached 20.2 million tons (Department of Industry, 2009). Beside that, based on the fatty acid composition, CPO methyl esters consisted of 46% palmitic acid as C16 carbon chain source and also 3.6% stearic acid, 39% oleic acid, 11% linoleic acid, and 1.5% linolenic acid as C18 carbon chain source (Ketaren, 2005). According to Watkins (2001), MES C16 showed the best detergency, then followed by C18 and C14. Therefore, the MES from vegetable oils containing C16-18 carbon atoms is used for detergent powder and liquid detergents (heavy duty detergent). The main process of MES synthesis was the sulfonation to produce MESA, an addition of sulfonation reactant to make sulfonate group on the methyl ester’s hydrocarbon chain. Sulfonation reactant could be H2SO4, NH2SO3H, H2SO4.nH2O, or which was used in this research, SO3/dry air. SO3/dry air is highly reactive, suitable for continuous production, and can form a sulfonate group optimally. The sulfonation in this research used a Single Tube Falling Film Reactor (STFR) 6 meters in length and 4 liters organic material feed capacity. The temperature of reaction was 100oC with mole ratio of reactants 1:1,3 between methyl ester and SO3. The purpose of this research was to determine the sulfonation period that can produce MESA CPO with the stable performance and characteristics. This research was conducted by complete randomized experimental design with a single factor. The factor studied was sampling period, from 10 minutes up to 100 minutes sulfonation with sampling interval 10 minutes. The synthesized MESA had density value 0.9416-0.9915 gram/cm3, viscosity value 30-102.5 cP, pH 2.98-3.33, and 13.97-21.05% active ingredients.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf