Judul: Studi Kelayakan Pendirian Industri Surfaktan Metil Ester Sulfonat Berbasis Minyak Kelapa Sawit (Studi Kasus : Untuk Aplikasi Enhanced Oil Recovery)
Abstrak: One of the solutions to increase the crude oil production is to implement the technology of Enhanced Oil Recovery (EOR) by using Methyl Ester Sulfonate (MES) surfactant. The purpose of this research is to study the feasibility for establishing a palm oil MES surfactant industry. The market share for the MES surfactant produced is an oil field that needs 18 tons surfactant/day. The capacity of the MES surfactant industry understudy is 20 tons MES/day locating at PT. Mahkota Indonesia, Jakarta. The investment required is about 29 billions rupiah that consist of fixed capital investment of 18 billions rupiah and working capital of 11 billions rupiah. The result of feasibility indicates that this MES surfactant industry is feasible to be built if there is establishment a chemichal flooding formulation company. The investment criteria show that Net Present Value is Rp. Rp 19.420.228.000, Internal Rate Return is 22%, Benefit/Cost Ratio is 1,53, and Pay back period is 5 years over 4 months. The sensitivity analysis shows that Industry feasible to build if the maximum increase of transaction value of dollar to rupiah is equal 7,7%, the maximum of decrease of selling price MES is equal 4,5%, and the maximum of decrease of production capacity is equal 70 %. The break even point analysis shows that at the first year must be produced at least 2.118 ton. The exchange rate risk shows that The appreciation of rupiah increase profit and asset eventhought the depereciation of rupiah decrease profit and asset.
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Judul: Production and formulation of methyl ester sulfonate-based surfactant from palm olein for enhanced oil recovery application
Abstrak: The remaining oil in a reservoir that cannot be produced using the natural driving force (primary recovery) is about 50 to 80% of the initial oil volumes (IOIP). A secondary recovery technique such as waterflooding can only increase the recovery as much as 5 to 20% of the IOIP. Therefore, a method known as Enhanced Oil Recovery (EOR) has to be implemented in the reservoir in the effort to recover much more oil. One of the EOR methods is surfactant injection. The injection of surfactant solution is aimed to significantly reduce the capillary forces in the reservoir by lowering the oil-water interfacial tension within the pore spaces. Once the capillary force is diminished, the reservoir oil is much easier to be displaced and moved toward the production wells. This is an excellent opportunity to develop a type of vegetable oil-based surfactants. One of potential surfactant types to develop is methyl ester sulphonate surfactant (MES). This study was aimed at producing MES surfactant and formula-based methyl ester sulfonate surfactant from palm olein to be applied for in the process of improving oil recovery using carbonate formation fluids. Results of the study showed that the best condition was achieved in a sulphonation process done in 3-4 hours with the flowrate of dry air of 1.8 kg/hour and a purification performed without the addition of methanol in a pH of 8. The best MES surfactant-based formula for EOR applications on the formation of carbonate was the one with the composition of 0.3% MES surfactant, 0.3% Na2CO3, and 15,000 ppm salinity. MES surfactant produced from this formula had more heat resistance, higher salinity, and higher hardness than the commercial surfactants did. Results of the performance test of surfactant-based formula showed that the MES surfactant formula was compatible with formation water and injection water. The formed phase was a lower phase which was relatively stable on a heating up to day 77 (reservoir temperature of 70 and 112 °C) with a range of interfacial tension of 10-2 dynes/cm. The adsorption reached 152.86 μg active matter/g core and the incremental oil recovery using synthetic core of 8-19% and using native core of 9.1%. Surfactant solution coreflooding test with bottom-up flow direction resulted in a greater oil recovery (16%) than that with top-down flow direction. This was caused by the influence of gravity.
Keyword: Palm Olein

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