Judul: The Utilization of Kemiri Sunan Fruit Peel as Heterogeneous Catalyst in Biodiesel Production through Trans-esterification Reaction
Abstrak: Penggunaan buah kemiri sunan sebagai bahan baku pembuatan biodiesel dapat menghasilkan limbah berupa kulit buah yang dapat mencemari lingkungan dan mengganggu estetika lingkungan. Kulit buah kemiri sunan tersebut berpotensi dimanfaatkan sebagai katalis heterogen dalam proses transesterifikasi pada produksi biodiesel. Katalis kalium oksida (K2O) yang terdapat pada kulit buah kemiri sunan dapat diaktivasi melalui proses kalsinasi, dengan berbagai suhu yaitu 650 oC, 800 oC dan 950 oC selama 4 jam. Proses pembuatan biodiesel dilakukan menggunakan hotplate dengan suhu 60 oC dengan perbandingan mol metanol 1:6 dengan waktu reaksi transesterifikasi selama 2 jam. Konsentrasi katalis yang digunakan yaitu 2%, 2,5% dan 3%. Hasil rendemen terbaik yaitu 82,67%. Selain rendemen, penelitian ini juga menganalisis viskositas, densitas, angka asam dan stabilitas oksidasi. Rancangan percobaan yang digunakan pada penelitian ini yaitu rancangan acak lengkap faktorial dua faktor dan dianalisis dengan ANOVA (α=0,05) serta uji duncan. Penelitian ini dapat disimpulkan bahwa suhu kalsinasi dan konsentrasi katalis sangat mempengaruhi proses pembuatan biodiesel., The use of Kemiri Sunan as raw material for biodiesel production can produce waste in the form of fruit peel, which pollute the environment and can impair the aesthetics of the environment. The fruit peel of the Kemiri Sunan has the potential to act as a heterogeneous catalyst in the trans-esterification process in biodiesel production. The potassium oxide (K2O) catalyst contained in the fruit peel of the kemiri sunan can be activated by the calcination process at different temperatures, namely 650 oC, 800 oC and 950 oC for 4 hours. The process of producing biodiesel was carried out using a hot plate with a temperature of 60 oC with a mole ratio of 1:6 methanol with a trans-esterification reaction time of 2 hours. The concentration of the catalyst used was 2%, 2.5% and 3%. The best yield was 82.67%. In addition to the yield, the viscosity, density, acid number and oxidation stability were also analyzed in this study. The experimental design used in this study was a fully randomized two-factorial factorial design and was analyzed by ANOVA (α=0.05) and Duncan's test. From these investigations it can be concluded that the calcination temperature and catalyst concentration have a major influence on the production process of biodiesel.
Keyword: biodiesel, heterogeneous catalyst, K2O, calcination, concentration

Judul: Pemanfaatan Kulit Buah Kola Sebagai Katalis Heterogen Untuk Produksi Biodiesel Dari Minyak Goreng Curah
Abstrak: Energi merupakan kebutuhan yang tidak dapat dipisahkan dari kehidupan manusia. Sumber energi yang sering digunakan seperti minyak bumi, batu bara, dan gas memiliki cadangan yang terus berkurang berbanding terbalik dengan penggunaanya. Salah satu sumber energi terbarukan adalah biodiesel. Dalam prosesnya diperlukan katalis untuk mempercepat reaksi pembentukan biodiesel. Jenis katalis yang dapat digunakan adalah katalis heterogen. Katalis ini dapat berasal dari limbah pertanian seperti kulit buah kola. Katalis yang berasal dari kulit buah kola dibuat melalui proses kalsinasi pada berbagai suhu yaitu 550 °C, 625 °C, dan 700 °C selama 4 jam. Konsentrasi katalis yang digunakan pada pembuatan biodiesel yaitu 2%, 3%, dan 4%. Proses pembuatan biodiesel menggunakan suhu reaksi sebesar 60 °C dengan waktu reaksi transesterifikasi selama 2 jam. Hasil dari analisis katalis seperti Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Atomic Absorption Spectroscopy (AAS), dan penggunaan ulang katalis. Biodiesel yang telah diproduksi juga dianalisis seperti rendemen, densitas, angka asam, bilangan penyabunan, gliserol total, dan kadar metil ester. Hasil terbaik diperoleh pada suhu kalsinasi terbaik yaitu 550 °C dengan konsentrasi katalis sebesar 3%. Rancangan percobaan yang digunakan pada penelitian ini yaitu rancangan acak lengkap faktorial dua faktor dan dianalisis dengan ANOVA (α = 0,05) serta uji lanjut Duncan. Penelitian ini dapat disimpulkan bahwa suhu kalsinasi dan konsentrasi biodiesel mempengaruhi hasil biodiesel., Energy is a necessity that cannot be separated from human life. Energy sources, such as petroleum, coal, and gas, have reserves that continuously decrease inversely with their usage. One of the renewable energy sources is biodiesel. In its production process, a catalyst is needed to speed up the biodiesel formation reaction. The type of catalyst that can be used is a heterogeneous catalyst. This catalyst can be derived from agricultural waste, such as kola nut pod husk. Catalysts derived from kola nut pod husk are produced through calcination processes at various temperatures, namely 550 °C, 625 °C, and 700 °C for 4 hours. The catalyst concentration in biodiesel production is 2%, 3%, and 4%. The biodiesel production process uses a reaction temperature of 60 °C with a transesterification reaction time of 2 hours. The results of catalyst analysis include Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Atomic Absorption Spectroscopy (AAS), and catalyst reusability. The biodiesel is also analyzed for yield, density, acid number, saponification number, total glycerol, and methyl ester content. The best results are obtained at the optimum calcination temperature of 550 °C with a catalyst concentration of 3%. The experimental design used in this research is a two-factor full factorial design, and it is analyzed using ANOVA (α = 0.05) and the Duncan post hoc test. This study can be concluded that calcination temperature and biodiesel concentration affect biodiesel yield.
Keyword: biodiesel, calcination, kola pod husk, concentration, heterogeneous catalyst

Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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