Judul: Kendali Proses Deasidifikasi dalam Pemurnian Minyak Sawit Merah Skala Pilot Plant
Abstrak: Deacidification is one of the steps of palm oil refining process which is carried out using alkali solution such as NaOH (sodium hydroxide). Carotenoids in palm oil is affected by the process of deacidification that has to be controlled to minimize the destruction of carotenoids during processing. The objective of this research was to improve deacidification process in pilot plant scale so that the process can produce low level free fatty acids (FFA) and higher carotene recovery in high yield neutralized red palm oil (NRPO). Characterization of physical and chemical properties of crude palm oil (CPO) such as moisture content, FFA, carotene content, saponification number, iodine value, peroxide value, and color were determined before processing. Excess NaOH was found in the trial of deacidification in the pilot plant scale and it gave 17.5% excess NaOH. The degumming was done before deacidification process. The optimization of temperature and time for deacidification process were using central composite design (CCD). Response surface method (RSM) was used to observe the influence of treatments on reduction of FFA, carotene recovery, and yield of NRPO. The result showed that the optimum condition of deacidification process was at 61 ± 2oC in 26 minutes, and strength of NaOH 16oBe with 17.5% excess of NaOH. In this optimum condition, the process could achieve reduction level of free fatty acid was about 96.35%, recovery of carotene was 87.30%, and yield was 90.16%.
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Judul: Kajian Proses Deguming Minyak Sawit Kasar (Crude Palm Oil) dengan Menggunakan Asam Sitrat
Abstrak: PT. Sinar Meadow International Indonesia, Jakarta, rnerupakan salah satu perusahaan yang rnengolah GPO rnenjadi rninyak rnakanlgoreng. PT. SMll rnengolah CPO dengan cara rafinasi fisik, pada saat degumming (dry) PT. SMll rnenggunakan asarn phosphat 85% sebagai bahan penolong dengan konsentrasi 700 pprn. Pada penelitian ini digunakan asam sitrat (larutan dan kristal) sebagai bahan penolong dengan konsentrasi 100, 200 dan 300 pprn, dan rnetode degumming yang digunakan adalah dry dan wet degumming. Tujuan penelitian ini adalah rnelihat pengaruh penggunaan asam sitrat dibandingkan dengan asarn phosphat serta rnencari rnetode, dan penggunaan asam sitrat yang optimal untuk mendapatkan rnutu rninyak yang baik dengan rnelihat warna, kadar ion logarn Fe, Cu dan Mg, bilangan peroksida, bilangan iod, kadar asarn lernak bebas, fraksi tak tersabunkan dan rendernen. Metode degumming yang digunakan, yaitu dry dan wet degumming, tidak berpengaruh nyata terhadap ion logarn Mg, kadar phosphor, bilangan iod dan kadar asarn lernak bebas; berpengaruh nyata terhadap fraksi tak tersabunkan; dan berpengaruh sangat nyata terhadap warna, ion logarn Fe dan Cu, kadar nitrogen, bilangan peroksida dan rendemen.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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