Electronic Theses and Dissertation

Preparasi katalis heterogen ZnO/karbon aktif menggunakan zink nitrat heksahidrat sebagai prekursor ZnO dan karbon aktif dari cangkang biji pala (Myristica fragrans Houtt.) untuk sintesis biodiesel telah berhasil dilakukan. Karbon aktif diperoleh melalui proses karbonisasi cangkang biji pala secara termal dan diaktivasi secara kimia menggunakan larutan NaOH. Preparasi katalis ZnO/karbon aktif dilakukan menggunakan metode hidrotermal dan katalis yang diperoleh dikarakterisasi menggunakan X-Ray Diffraction (XRD), spektroskopi Fourier Transform Infra Red (FTIR), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), dan Brunauer–Emmett–Teller (BET). Katalis ZnO/karbon aktif memiliki aktivitas katalitik yang lebih tinggi dibandingkan dengan katalis ZnO pada reaksi transesterifikasi minyak kelapa menjadi metil ester (biodiesel) dengan persen yield 90,40% sedangkan katalis ZnO menghasilkan yield biodiesel sebesar 84,75%. Hasil uji kualitas biodiesel yang meliputi bilangan asam dan viskositas menunjukkan bahwa biodiesel yang dihasilkan memenuhi Standar Nasional Indonesia (SNI) 7182:2015 sedangkan nilai massa jenis yang diperoleh belum memenuhi SNI. Hasil regenerasi dan uji reusabilitas terhadap katalis ZnO/karbon aktif menunjukkan terjadinya penurunan aktivitas katalis ZnO/karbon aktif pada siklus kedua sebesar 2,5% dan yield biodiesel yang dihasilkan adalah 88,14%.

Kata-kata kunci: cangkang biji pala, ZnO, karbon aktif, minyak kelapa, biodiesel.

Preparation of a ZnO/activated carbon heterogeneous catalyst by using zinc nitrate hexahydrate as ZnO precursor and activated carbon from nutmeg shells (Myristica fragrans Houtt.) for synthesis biodiesel has been successfully carried out. Activated carbon is obtained through a thermal carbonization process of nutmeg seed shells and chemically activated using NaOH solution. Preparation of ZnO/activated carbon catalyst was conducted using the hydrothermal method and the catalyst obtained was characterized using X-Ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), dan Brunauer–Emmett–Teller (BET). The ZnO/activated carbon catalyst showed higher catalytic activity than that of bare ZnO catalyst on transesterification reaction of coconut oil to produce methyl ester (biodiesel). The yield of biodiesel obtained by using ZnO/activated carbon catalyst was 90.40%, while using bare ZnO the percent yield was 84.75%. The results of biodiesel quality tests which include acid number and viscosity show that the biodiesel produced meet the requirement of the Indonesian National Standards (SNI) 7182:2015 while the density value obtained does not meet the requirement of SNI. The result of regeneration and reusability tests on the ZnO/activated carbon catalyst showed a decrease around 2.5% in catalyst performance in the second cycle and the yield of biodiesel production is 88.14%. Keywords: nutmeg seed shells, ZnO, activated carbon, coconut oil, biodiesel.