Biodiesel dari Transesterifikasi Minyak Jarak Pagar(Jatropha Curcas) Ber-Asam Lemak Bebas 7,78% dengan Katalis Asam Polistirena Sulfonat(PSS) 1% dan 4% dalam Waktu 6 Jam terhadap Sifat Fisika

Abstract

Production of castor oil biodiesel has been done by transesterification process. The castor oil was previously tested for titration and produced 7.78% free fatty acid. The process was done in an autoclave by mixing the materials of castor oil to methanol in 1:6 mole. 1% and 4% of PSS catalyst. The reaction proceed in 80oC for 6 hours. The solution was neutralized by ammoniac and estracted by n-Hexane. The transesterification resulted in 2 layers ; upper layer containing methyl ester (FAME) and the lower layer containing residual glycerol and methanol and then separated. The upper layer of the separating funnel contained FAME added sufficiently by n-hexane, and then washed by aqueous repeatedly. The fraction of hexane was added by anhidrate Na2SO4 and then filtered. The filtrate was distillated by an usual distillation and then vacuumed and the residue weighted. The physical features such as viscosity, density, Iod grade, fogging point and the water content were then tested. Of 50 grs of the transesterificated castor oil for 6 hours in concentration of catalyst 1%, it had resulted in 28 grs crude FAME, converted methyl ester of 53.73%, viscosity of 20.76cSt, density of 0.91 gr/cm3, fogging point of 8.00 C, Iod grade of 67.65 grI2/100 gr, water content of 0.083% and flaming point of 35oC For 4%, it has resulted in 40.4 gr crude FAME, converted methyl ester of 77.53%, viscosity of 19.76 cSt, density of 0.90 gr/cm3, fogging point of 1.00oC, Iod grade of 67.14 grI2/100gr, water content of 0.096% and flaming point of 35oC. The more increased is the catalyst of reaction, the higher is converted methyl ester. The physical features showed that the castor oil-derived biodiesel may be used to be one alternative of substituting solar fuel.

Telah dilakukan pembuatan biodiesel minyak jarak pagar (jatropha curcas) melalui proses transesterifikasi.Minyak jarak pagar sebelumnya di uji titrasi diperoleh asam lemak bebasnya 7,78% Proses ini dilakukan dalam autoclave dengan campuran minyak jarak pagar : methanol sebanyak 1:6 mol. Katalis PSS 1% dan 4% Reaksi ini berlangsung pada suhu 80oC dalam waktu 6 jam.Larutan di netralkan dengan amoniak, dan diekstraksi dengan n-Hexana Transesterifikasi ini menghasikan 2 lapisan: lapisan atas mengandung metil ester (FAME) dan lapisan bawah gliserol dan metanol sisa, kemudian dipisahkan. Lapisan atas dalam corong pisah mengandung FAME ditambahkan n-heksan secukupnya kemudian dicuci dengan aquadest berulangkali. Fraksi heksan dibubuhi dengan Na2SO4 anhidrous kemudian disaring . Filtrat dimurnikan dengan destilasi biasa,kemudian divakum dan residu ditimbang, Sifat fisisnya seperti viscositas, densitas, titik kabut, bilangan Iod, kadar air dan titik nyala selanjutnya diuji. Dari 50 gr minyak jarak pagar yang di transesterifikasi, selama 6 jam dengan konsentrasi katalis 1% diperoleh bahan FAME kasar 28 gr, konversi metil ester53,73%,viscositas 20,76 cSt, densitas 0,91 gr/cm3 ,titik kabut 8,00oC, bilangan Iod 67,65 grI2/100gr, kadar air 0,083% dan titik nyala 350C.Untuk 4% diperoleh bahan FAME kasar 40,4 gr, konversi metil ester 77,53%, viscositas 19,76 cSt, densitas 0,90 gr/cm3 , titik kabut 1,00oC, bilangan Iod 67,14 grI2/100gr , kadar air 0,0906% dan titik nyala 350C.. Makin bertambah konsentrasi katalis reaksi makin tinggi konversi metil ester. Sifat fisis hasil ini menunjukkan biodiesel minyak jarak pagar dapat dipakai sebagai salah satu alternatif pengganti bahan bakar solar.