Kinerja Mesin Diesel Memakai Bahan Bakar Biodiesel Biji Karet dan Analisa Emisi Gas Buang

Abstract

ABSTRAK Penelitian pengembangan proses produksi biodiesel (B-100) dari minyak biji karet atau rubber seed oil (RSO) yang diproduksi secara non-katalis superheated metanol di dalam sebuah bubble column reactor (BCR) tekanan atmosfir telah dilaporkan. Spesifikasi B-100 tersebut dipergunakan sebagai bahan bakar dalam penelitian ini yaitu: densitas 882 g/ml; viskositas kinematik 5,19 cSt; calculated cetane index (CCI) 47,5; titik tuang –6 o C; flash point 200 o C; residu karbon mikro dalam sampel asli 0,126% massa dan dalam 10% ampas distilasi 2,87% massa; sedimen 0,01% volume; temperatur distilasi 347 o C; kandungan sulfur 0,72 ppm; angka asam 0,01 mgKOH/g; serta nilai kalor rendah 9184,43 kkal/kg. Biodiesel dicampur dengan solar (B-0) pada tingkat perbandingan tertentu sehingga diperoleh B-5, B-10, B-15, dan B-20 (B-5 adalah campuran antara biodiesel 5% serta solar 95%, dst) dipergunakan sebagai bahan bakar pada mesin diesel stasioner. Kinerja mesin diesel dan emisi gas buang dibandingkan dengan mesin yang memakai solar (B-0). Mesin dioperasikan pada putaran konstan 1350, 1750, 2150, 2550, dan 2950 rpm. Hasil penelitian menunjukkan bahwa bahan bakar B-10 menghasilkan kinerja mesin terbaik pada putaran 2550 rpm. Pada putaran ini diperoleh daya maksimum sebesar 36,95 PS, konsumsi bahan bakar spesifik terendah sebesar 0,256 kg/(PS.jam), efisiensi termal 58,44%, kandungan CO terkecil sebesar 0,4%, dan opasitas gas buang 58,6% HSU memenuhi Peraturan Menteri Negara Lingkungan Hidup Nomor 5 tahun 2006, dan tidak perlu memodifikasi mesin. Jika dibandingkan dengan solar murni (B-0), B-10 lebih baik dari pada B-0 karena pada kondisi optimum menghasilkan kenaikan daya sebesar 1,8%, konsumsi bahan bakar spesifik sama 0,256 kg/(PS.jam), efesiensi termal naik 2,4%, kadar CO gas buang turun 80%, serta CO2 turun 55%. Kata kunci: Biodiesel, RSO, non-katalis, mesin diesel. ABSTRACT The research about development of biodiesel (B-100) production process from RSO which is produced in the non-catalyst superheated methanol in a bubble column reactor (BCR) atmospheric pressure has been reported. The fuel which is used in this research has the following specifications: density 882 g/ml; kinematic viscosity 5.19 cSt; calculated cetane index (CCI), 47.5; pour point -6 o C, flash point 200 o C; micro carbon residue in the original sample 0.126% of mass and the 10% distillation residue is 2.87% of mass; sediment 0.01% of volume; destilation temperature 347 o C; sulfur content 0.72 ppm; acid number 0.01 mgKOH/g; and low heating value 9184.43 kcal/kg. Biodiesel (B-100) was blended with diesel fuel (B-0) at a certain level of comparison in order to obtain B-5, B-10, B-15, and B-20 (B-5 is a mixture of 5% biodiesel and 95% diesel fuel, and so on) and then it is used as fuel in diesel engine stationary. Engine performance and exhaust emissions are compared with engines that use diesel fuel (B-0). The machine is operated in constant rotation in 1350, 1750, 2150, 2550, and 2950 rpm. The results showed that B-10 produced the best engine performance at 2550 rpm. In this rotation, the maximum power obtained was 36.95 PS, the lowest specific fuel consumption was 0.256 kg/(PS.hr), the thermal efficiency 58.44%, the lowest CO content 0.4%, and flue gas opacity 58.6% HSU in accordance with the State Minister of Environment Regulation Number 5/2006, and no modification of engine needed. Compared with diesel fuel (B-0), B-10 was better than B-0 because it produced power increase 1.8%, same specific fuel consumption 0.256 kg/(PS.hr), rising thermal efficiency 2.4%, CO content decreased 80.0%, and CO2 content decreased 55.0% at optimum condition.