Yoeswono Yoeswono
Pusdilat Migas, Jl. Sorogo No. 1, Cep, jawa Tengah, Indonesia

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PEMANFAATAN LIMBAH ABU TANDAN KOSONG SAWIT SEBAGAI KATALIS BASA PADA PEMBUATAN BIODIESEL DARI MINYAK SAWIT Yoeswono, Yoeswono; Triyono, Triyono; Tahir, Iqmal
Jurnal Manusia dan Lingkungan (Journal of People and Environment) Vol 14, No 2 (2007)
Publisher : Pusat Studi Lingkungan Hidup Universitas Gadjah Mada

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Abstract

Pemanfaatan limbah abu tandan kosong sawit (TKS) sebagai sumber katalis basa telah dilakukan untuk aplikasi pada proses pembuatan biodiesel dari minyak biji sawit. Kadar logam kalium untuk mengetahui kadar basa dalam abu TKS dianalisis dengan AAS dan kadar ion karbonat diuji dengan uji alkanalis. Komposisi asam lemak dalam bahan minyak biji sawit  dianalisis dengan GC-MS. Abu TKS direndam dalam metanol untuk mendapatkan senyawa kalium metoksida yang selanjutnya digunakan untuk transesterifikasi minyak biji sawit. Rasio persentase berat abu terhadap minyak pada reaksi transesterifikasi tersebut divariasi kemudian persentase konversi biodiesel ditentukan dengan spektrometer 1H NMR. Hasil penelitian menunjukkan bahwa kadar kalium dalam abu TKS = 29,82 % b/b, dan kadar ion karbonat = 19,63 % b/b, sehingga konversi (%) dimungkinkan kalium tersebut dalam bentuk karbonat. Konversi biodiesel meningkat dengan peningkatan persentase berat abu terhadap minyak. Kondisi optimum dicapai pada persentase berat abu terhadap minyak = 6 % b/b dengan diperoleh konversi biodiesel 69,67 %.  
EFFECT OF TEMPERATURE AND SPEED OF STIRRER TO BIODIESEL CONVERSION FROM COCONUT OIL WITH THE USE OF PALM EMPTY FRUIT BUNCHES AS A HETEROGENEOUS CATALYST Pratama, Luthfi; Yoeswono, Yoeswono; Triyono, Triyono; Tahir, Iqmal
Indonesian Journal of Chemistry Vol 9, No 1 (2009)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (779.06 KB) | DOI: 10.22146/ijc.21562

Abstract

Biodiesel synthesis by transesterification reaction of coconut oil with methanol by using ash of palm empty fruit bunches (EFB) as base catalyst has been conducted. Sample of ash was prepared through heating, screening, reashing, and finally determining of potassium content. Sample of coconut oil was analyzed by GC-MS. A certain amount of ash was extracted in methanol with mixing for about 1 h at room temperature and a result was used for reaction of transesterification. The studied variables were effect of temperature and speed of stirrer. The composition of the methyl esters (biodiesel) was analyzed using GC-MS and 1H NMR, whereas characters of biodiesel were analyzed using ASTM methods. The results showed that potassium content in ash of EFB could be extracted by methanol and it could be used as base catalyst in the biodiesel synthesis. The value increasing of both variables enhanced the biodiesel conversion. The properties of biodiesel were relatively conformed to specification of biodiesel.   Keywords: biodiesel, coconut oil, base catalyst, temperature, stirring
KINETICS OF PALM OIL TRANSESTERIFICATION IN METHANOL WITH POTASSIUM HYDROXIDE AS A CATALYST Yoeswono, Yoeswono; Triyono, Triyono; Tahir, Iqmal
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (172.786 KB) | DOI: 10.22146/ijc.21625

Abstract

A study on palm oil transesterification to evaluate the effect of some parameters in the reaction on the reaction kinetics has been carried out. Transesterification was started by preparing potassium methoxide from potassium hydroxide and methanol and then mixed it with the palm oil. An aliquot was taken at certain time interval during transesterification and poured into test tube filled with distilled water to stop the reaction immediately. The oil phase that separated from the glycerol phase by centrifugation was analyzed by 1H-NMR spectrometer to determine the percentage of methyl ester conversion. Temperature and catalyst concentration were varied in order to determine the reaction rate constants, activation energies, pre-exponential factors, and effective collisions. The results showed that palm oil transesterification in methanol with 0.5 and 1 % w/w KOH/palm oil catalyst concentration appeared to follow pseudo-first order reaction. The rate constants increase with temperature. After 13 min of reaction, More methyl esters were formed using KOH 1 % than using 0.5 % w/w KOH/palm oil catalyst concentration. The activation energy (Ea) and pre-exponential factor (A) for reaction using 1 % w/w KOH was lower than those using 0.5 % w/w KOH.   Keywords: palm oil, transesterification, catalyst, first order kinetics, activation energy, pre-exponential factor
EFFECT OF PALM EMPTY BUNCH ASH ON TRANSESTERIFICATION OF PALM OIL INTO BIODIESEL Sibarani, Johan; Khairi, Syahrul; Yoeswono, Yoeswono; Wijaya, Karna; Tahir, Iqmal
Indonesian Journal of Chemistry Vol 7, No 3 (2007)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (174.977 KB) | DOI: 10.22146/ijc.21675

Abstract

Biodiesel conversion from transesterification reaction palm oil with methanol was studied by using an ash of palm empty bunch as a base catalyst. Atomic absorption spectroscopy (AAS) and indicator titration analysis were used as tools for characterization of ash sample. Chemical structure of biodiesel was analyzed by GC-MS. The effects of ash sample weight (5, 10, 15, 20 and 25 g) immersed in 75 mL methanol and the methanol-palm oil mol ratio (3:1; 6:1; 9:1 and 12:1) toward the conversion of biodiesel were investigated. Biodiesel was prepared by refluxing palm oil and methanol containing ash sample. The reflux was done at room temperature for 2 h. Ester layer was distillated at 74 oC, extracted with aquadest and then dried using Na2SO4 anhydrous. The product was characterized by GC-MS, ASTM D 1298 (specific gravity 60/60 °F), ASTM D 97 (pour point), ASTM D 2500 (cloud point), ASTM D 93 (flash point), ASTM D 445 (kinematics viscosity 40 °C) and ASTM D 482 (ash content). The result of GC-MS analysis showed that methyl palmitate is primary content of biodiesel product. A 15 g weight of ash sample gave the maximum biodiesel conversion. By increasing methanol mole quantity, biodiesel conversion increased progressively and maximum at 9:1 methanol-palm oil ratio (84.12 %) and decreased on 12:1 ratio (75.58 %). Most of the biodiesel products were similar to those of the diesel physical characters.   Keywords: Biodiesel conversion, transesterification, palm oil, palm empty bunch