Judul: Delignification of Cacao Pods Husk as a Raw Material for Bioethanol using Alkaline and Microwave Heating Methods
Abstrak: Sebagai negara produsen dan eksportir kakao terbesar di dunia, Indonesia memproduksi kakao sebanyak 720,66 ribu ton per tahun atau 14,34% dari produksi kakao dunia. Sebanyak 74% buah kakao merupakan limbah kulit kakao yang mengandung lignoselulosa dan berpotensi diolah menjadi bioetanol. Dalam memproduksi bioetanol ada beberapa tahapan, seperti pretreatment atau delignifikasi, hidrolisis, fermentasi, dan pemurnian. Tahap pretreatment dilakukan untuk mendapatkan kandungan selulosa/gula yang diproses lebih lanjut pada tahap hidrolisis. Pretreatment dapat dikombinasi seperti penggabungan metode secara fisika dan kimia. Penggunaan metode alkali dan pemanasan microwave merupakan bentuk penggabungan metode fisika dan kimia yang berguna untuk meningkatkan kandungan selulosa dan menurunkan kandungan lignin. Metode ini merupakan metode terbaik yang sudah dilakukan jika dibandingkan dengan metode lain. Larutan alkali yang digunakan yaitu NaOH karena memiliki sifat yang mampu mendegradasi lignin tanpa merusak struktur selulosa. Delignifikasi dilakukan dengan memberikan variasi konsentrasi NaOH 0,75 M; 1 M; dan 1,5 M dan variasi lama waktu paparan panas microwave 5; 7,5; dan 10 menit. Hasil variasi pretreatment diuji secara statistik menggunakan rancangan acak lengkap. Secara statistik, peningkatan konsentrasi larutan NaOH dan lama waktu paparan panas microwave memberikan pengaruh nyata untuk kandungan lignin dan selulosa. Konsentrasi NaOH dan waktu paparan microwave terbaik adalah 1 M dan 7,5 menit., As the largest producer and exporter of cocoa in the world, Indonesia produces approximately 720,66 thousand tons of cocoa per year, which accounts for 14,34% of global cocoa production. About 74% of cocoa fruits consist of cocoa husks, which contain lignocellulose and have the potential to be processed into bioethanol. The production of bioethanol involves several stages, such as pretreatment/delignification, hydrolysis, fermentation, and purification. The pretreatment stage is conducted to obtain cellulose/sugar content that will be further processed in the hydrolysis stage. Pretreatment can be done by combining physical and chemical methods. The use of alkaline methods and microwave heating is a form of combining physical and chemical methods, which is useful for increasing cellulose content and reducing lignin content. This method has been proven to be the best compared to other methods. Alkali solutions, such as NaOH, are used because it can degrade lignin without damaging the cellulose structure. Delignification is carried out by varying the concentration of NaOH at 0,75 M, 1 M, and 1,5 M, and the exposure time to microwave heating at 5; 7,5; and 10 min. The results of the pretreatment variations are statistically tested using a completely randomized design. Statistically, increasing the concentration of NaOH solution and the duration of microwave heating significantly affect the lignin and cellulose content. The optimal NaOH concentration and microwave exposure time are 1 M and 7,5 min.
Keyword: alkaline, bioethanol, cacao pods husk, delignification, microwave heating

Judul: Kajian Pemanfaatan Pod Kakao (Theobroma cacao) melalui Hidrolisis Asam Lignoselulosa untuk Menghasilkan Etanol.
Abstrak: Cocoa is one of commodities that its role is important enough for the national economy. Cocoa commodity exports ranked third in the agriculture sector contributes foreign exchange, after the rubber and palm oil. Currently Indonesian cocoa production ranks third largest after the Ivory Coast and Ghana. In 2006 cocoa exports reached U.S. $ 975 million, an increase of 24.2% over the previous year (Suryani and Zulfebriansyah, 2005). Increased efforts in the field led to increased cultivation of cocoa pod waste. This is a challenge, given the amount of cocoa pod components for 73.73% of the cacao fruit (Siswoputranto, 1983). If the cocoa pod is not handled properly it will result in losses. In the research is studied on the acid hydrolysis using cocoa pod to produce ethanol. In addition to get the best treatment of acid hydrolysis that is affected by acid concentration and hydrolysis time and to get the highest yield of sugar and ethanol. This research was conducted in three main stages that were preliminary treatment of raw material preparation and characterization of raw materials, acid hydrolysis, and fermentation to produce ethanol. Hydrolysis of cocoa pod is done in two stages using sulfuric acid. In the first hydrolysis used sulfuric acid concentration of 1% with a time of hydrolysis for 1, 2, 3, 4, 5, 6, and 7 hours. In the second hydrolysis using acid with higher concentrations of 5, 10, 15, and 20% with hydrolysis time of 1, 2, 3, 4, and 5 hours. Analysis was conducted on the reducing sugar, total sugar, dextrose equivalent, and fiber components of lignocellulose. Fermentation using two different substrates derived from the hydrolysis of the first stage and second stage. In fermentation measured volume of CO2 formed, ethanol content, total residual sugar, the efficiency of substrate utilization and product yield of ethanol. On the characterization of raw materials obtained value of cocoa pod ash content 1.87% (db), fat 3% (db), protein 2.25% (db), carbohydrate 92.89% (db), and 53.82% crude fiber (db). Crude fiber fraction containing cellulose 28.78% (db), hemicellulose 8.70% (db) and lignin 42.90% (db). In the first hydrolysis, the results of analysis showed that the highest reducing sugar of 27.31 mg/ml was produced from treatment of 1% sulfuric acid and hydrolysis time of 4 hours. The highest total sugar also produced from the same treatment with a value of 32.74 mg/ml. Dextrose equivalent values ranged from 50.63% to 84.32%. On analysis of lignocellulose after the first hydrolysis, there is a decrease of lignin content, hemicellulose, and cellulose so that its value in a row to 30.82%, 6.52% and 25.75%. In the second hydrolysis, the best treatment that produces the highest reducing sugar and total sugar by using 5% acid concentration and time of hydrolysis for 4 hours. This treatment produces reducing sugar 15.91 mg/ml and the total sugar 29.26 mg/ml. In the second hydrolysis dextrose equivalent values ranged from 47.08% to 89.67%. Lignocellulose fiber components of cocoa pod is decreasing because the second hydrolysis, so that the lignin content to 28.88%, 4.45% hemicellulose, and cellulose 21.98%.
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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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