<p>An accurate kinetic data has been considered as main substance in hydrolysis reaction. This research was conducted at the laboratory of processing of Indonesian Palm Crops Research Institute (IPRI) during June-July 2015. The objective of the research was to obtain the optimum condition of hydrolysis of VCO and the data of reaction kinetics (the reaction rate constant (k), the activation energy (Ea), and the reaction kinetics equation). Virgin coconut oil hydrolysis was done in two stages, the first step was the determination of the ratio of VCO:water (1:3; 1:6; 1:9; 1:12), the second step was the evaluation of reaction temperatures (60°C, 70°C, and 80°C). The determination of the optimum condition was based on the result of free fatty acid content and the values of the reaction rate constant. The free fatty acid content was measured by acid-base titration, meanwhile the reaction rate constant was determined by the equation –ln(1-XA)=kt. The results showed that the hydrolysis of VCO using ratio of VCO:water 1:12 produced higher content of FFA (0.11%) compared than others. The ratio of VCO:water 1:12 was then used to obtain the optimum temperature of hydrolysis. The optimum temperature of hydrolysis was 80°C with 0.14% of FFA, the reaction conversion was 0.88, and the reaction rate constant was 0.27 hour-1. The water consentration and reaction temperature influenced the FFA content, reaction conversion, and the reaction rate constant. The best condition of VCO hydrolysis using 1% of hydrochloride acid catalyst was on ratio of VCO:water 1:12, reaction temperature 80°C for 8 hours. The relationship between the reaction rate constant and temperature, follow Arrhenius equation k = 1,62 x 1015 e -25831/RT. Free fatty acid and glycerol are extensively used as raw materials in the manufacture of products such as detergents, cosmetics, surfactants, and pharmaceuticals.</p><p align="center"><strong>ABSTRAK</strong></p><p>Hidrolisis dapat berjalan baik apabila menggunakan data kinetika yang tepat untuk mendapatkan produk yang diinginkan. Penelitian ini dilaksanakan di Laboratorium Pengolahan Hasil, Balai Penelitian Tanaman Palma pada bulan Juni-Juli 2015. Penelitian bertujuan menentukan kondisi optimum hidrolisis Virgin Coconut Oil (VCO) secara kimiawi dengan katalis HCl dan mendapatkan data kinetika reaksi, yaitu konstanta kecepatan reaksi (k), energi aktivasi (Ea), dan rumusan persamaan kinetika reaksi. Hidrolisis VCO dilakukan 2 tahap, yaitu tahap pertama penentuan rasio VCO:air (1:3; 1:6; 1:9; dan 1:12) dipilih yang menghasilkan kadar ALB terbesar, dilanjutkan pada tahap kedua, yaitu penentuan suhu reaksi (60°C, 70°C, dan 80°C). Penentuan kondisi optimum berdasarkan kadar asam lemak bebas yang dihasilkan dan nilai konstanta kecepatan reaksi. Kadar asam lemak bebas ditentukan dengan titrasi asam-basa, sedangkan konstanta kecepatan reaksi menggunakan rumus persamaan kecepatan reaksi -ln(1-XA)=kt. Hidrolisis VCO menggunakan rasio VCO:air (1:12) menghasilkan kadar asam lemak bebas (ALB) yang lebih tinggi (0,11%), selanjutnya digunakan untuk penentuan suhu optimum hidrolisis. Suhu hidrolisis optimum adalah 80°C dengan kadar ALB sebesar 0,14%, konversi reaksi 0,88 dan konstanta kecepatan reaksi 0,27 jam-1. Konsentrasi air dan suhu reaksi berpengaruh terhadap kadar ALB, konversi reaksi, dan konstanta kecepatan reaksi. Hidrolisis VCO dengan katalis HCl 1% terbaik pada rasio VCO:air 1:12, suhu reaksi 80°C selama 8 jam. Hubungan konstanta kecepatan reaksi dengan suhu reaksi mengikuti persamaan Arrhenius k = 1,62 x 1015 e -25831/RT. Asam lemak bebas dan gliserol hasil hidrolisis banyak digunakan sebagai bahan baku dalam industri deterjen, kosmetik, surfaktan, dan obat-obatan.</p><p> </p>
Site-specific reaction rate constant measurements for various secondary and tertiary H-abstraction by OH radicals