ANALISIS LAJU ALIRAN RESIRKULASI TERHADAP PRODUKSI BIODIESEL NON-KATALITIK PADA BUBBLE COLUMN REACTOR SKALA PILOT

Abstract

Produksi biodiesel non-katalitik menggunakan bubble column reactor (BCR) merupakan alternatif teknologi yang berpotensi meningkatkan efisiensi proses tanpa penggunaan katalis, namun keberhasilannya sangat dipengaruhi oleh karakteristik aliran fluida di dalam reaktor. Penelitian ini bertujuan menganalisis pengaruh laju aliran resirkulasi terhadap performa produksi biodiesel non-katalitik serta menentukan laju aliran resirkulasi optimum pada BCR skala pilot. Penelitian menggunakan palm fatty acid distillate (PFAD) sebagai bahan baku dan superheated methanol vapor sebagai pereaksi, dengan variasi laju aliran resirkulasi 0,8 m/s, 1,0 m/s, 1,2 m/s dan 1,4 m/s, serta menganalisis karakteristik hidrodinamika, yield, massa dan laju produksi biodiesel, kadar free fatty acid (FFA), estimasi fatty acid methyl ester (FAME), konversi, kebutuhan daya, dan konsumsi energi. Peningkatan laju aliran resirkulasi meningkatkan debit aliran, kecepatan aliran, dan bilangan Reynolds sehingga mendukung perpindahan massa antara uap metanol dan PFAD. Berdasarkan aspek kuantitas produksi, laju aliran resirkulasi 1,2 m/s memberikan hasil terbaik dengan yield sebesar 53,33%, estimasi massa biodiesel sebesar 1.097,39 gram, laju produksi biodiesel maksimum sebesar 7,03 gram per menit, dan estimasi massa FAME sebesar 938,37 gram. Sementara itu, berdasarkan aspek kualitas biodiesel, laju aliran resirkulasi 1 m/s menghasilkan massa FFA terendah sebesar 109,74 gram (kadar FFA 12,63%). Hasil penelitian menunjukkan bahwa laju aliran resirkulasi memengaruhi kuantitas dan kualitas biodiesel yang dihasilkan.

Non-catalytic biodiesel production using a bubble column reactor (BCR) is a promising alternative technology to improve process efficiency without the use of catalysts. However, its performance is strongly influenced by the hydrodynamic characteristics within the reactor. This study aimed to analyze the effect of recirculation flow velocity on the performance of non-catalytic biodiesel production and to determine the optimum recirculation flow velocity in a pilot-scale BCR. Palm fatty acid distillate (PFAD) was used as the feedstock, while superheated methanol vapor served as the reactant. Four recirculation flow velocities were evaluated, namely 0.8, 1.0, 1.2, and 1.4 m/s. The study analyzed hydrodynamic characteristics, biodiesel yield, biodiesel mass and production rate, free fatty acid (FFA) content, estimated fatty acid methyl ester (FAME) mass, conversion, power requirement, and energy consumption. Increasing the recirculation flow velocity increased the volumetric flow rate, flow velocity, and Reynolds number, thereby enhancing mass transfer between superheated methanol vapor and PFAD. Based on biodiesel production quantity, the recirculation flow velocity of 1.2 m/s provided the best performance, yielding a biodiesel yield of 53.33%, an estimated biodiesel mass of 1,097.39 g, a maximum biodiesel production rate of 7.03 g min?¹, and an estimated FAME mass of 938.37 g. In terms of biodiesel quality, the recirculation flow velocity of 1.0 m/s resulted in the lowest residual FFA mass of 109.74 g (FFA levels of 12.63%). The results demonstrate that recirculation flow velocity significantly affects both the quantity and quality of biodiesel produced.