Judul: Pemucatan Gliserol Kasar Hasil Samping Pembuatan Biodiesel Menggunakan Adsorben
Abstrak: Glycerol compound is a byproduct the making of biodiesel that high economic value. Glycerol with various levels of quality are needed as raw materials in industry. Glycerol used in the food industry, cosmetics industry, pharmaceutical industry, tobacco processing industry, industrial lubricating, and also oleochemical industry. In the future when the demand of biodiesel is increasing along with population growth, it also increases the production of glycerol. The use of glycerol especially pure glycerol in a various of products have been developed. But before the process of making a compound glycerol derivatives of glycerol refining process takes most of which crude glycerol was mixed with other materials. The purpose of this research is to determine the effect of adsorbent concentration on the purification of glycerol in order to determine the type and combination of effective adsorbent to produce pure glycerol. The treatment tested in this study is the type of adsorbent (activated carbon and bentonite) and a combination of both adsorbent added. The ratio of activated carbon and bentonite added is 4: 4 (adsorbent total is 8 %), 4: 6 (adsorbent total is 10%), 4: 8 (adsorbent total is 12%) and 4: 10 (adsorbent total is 14%) of the weight of crude glycerol. The results showed that the concentration of adsorbent used in the bleaching have significant effect on water content, ash content and color of glycerol produced but did not have real impact on the number of acid. The use of adsorbent with a total of 14 % to produce glycerol with water content and ash content lower than most others. Based on absorbance values, the adsorbent total 14 % are also more effective in absorbing the colors then the color of the resulting glycerol is clearer. The influence of the total of adsorbent to the water content is higher the amount of adsorbent is added, then the value of water content lower glycerol. Neither the value of ash content nor the lower absorbance with increasing number of adsorbent used. The ratio of the use of adsorbent (activated carbon: bentonite) is the best ratio of 4:10 with the lowest water content value (0.663%), the lowest ash content (0.0543%), transmitance (low absorbance value of 1.987) and 8.74 glycerol levels %. Glycerol analysis using GC-MS (Gass Chromatography Mass Spectrometry) showed that glycerol before and after the purification process still contains the methyl esters of glycerol so that low purity. This is because the reaction is not perfect at the time of the process of making biodiesel. But after the purification process of glycerol content increased from 0.85% to 8.74%.
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Judul: Kajian Pemurnian Gliserol Hasil Samping Biodiesel Jarak Pagar Menggunakan Asam Nitrat, Sulfat, dan Fosfat
Abstrak: About ±10% glycerol is produced as byproduct in KOH alkali-catalysis transesterification of Jatropha curcas oil and methanol. The glycerol contains some soluble impurities such as catalyst, soap, excess methanol, water, and other substances. The glycerol needs purification treatment so that glycerol can be utilized into other products. The first step in the glycerol purification is mineral acid addition to neutralize the base content and to split the soap content into salt and free fatty acid that are more easily separated from glycerol. The purposes of this research are to select the kind of acid that could separate the glycerol from the base catalyst and soap, to study the effect of the molar amount of added acid, and to identify the quality of salt as byproduct of glycerol purification with the best treatment. The experiments conducted in complete randomized factorial design, consisted of two treatment factors: kinds and molar amount of mineral acids. Kind of acids were HNO3 15.27 M, H2SO4 18.01 M, and H3PO4 14.74 M. Molar amount of acids were 54 mmol, 90 mmol, 126 mmol, 162 mmol, and 198 mmol (added into 200 g of glycerol). The observed response variables were pH of glycerol, glycerol content, and ash content of glycerol. The crude glycerol from KOH alkali-catalysis of Jatropha curcas biodiesel production contained: glycerol (40.48%), KOH (2.39%), soap (7.82%), evaporated compounds at 1050C (46.81%), and ash (5.16%). The kind and molar amount of mineral acid significantly affected the pH-value, glycerol content, and ash content. The treatment with 126 mmol H3PO4 14.74 M, in 200 grams glycerol, resulted highest glycerol content (78.77%), lowest ash content (1.085%), and pH-value 6.63. Precipitated salt produced from the best treatment contained (based on dry base, except evaporated compounds): K2O (13.17%), P2O5 (20.14%), chloride (2.67%), free acid (26.18%), and evaporated compounds at 1300C (33.93%).
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Judul: Indexing Spatio-Temporal Pada Data Hotspot
Abstrak: The spatial information of hotspot is always changing over time. The recording of these changes makes it necessary to add dimension of time (temporal) into database. The database which is capable to store spatial and temporal information is known as spatiotemporal database. This database is bigger than a normal database because it stores all versions of an object over time and not allowed data to be physically deleted. A large database size causes it’s search time increases. It makes an access structure is needed in spatiotemporal database. Indexing is one of the access structure applied in the spatiotemporal database that accelerates data searching process. Spatiotemporal indexing method consists of two parts namely spatial indexing which is based on geographical information, and temporal indexing which is based on data timing information. The process of hotspot data indexing will be done in this research by using R-Tree approach for spatial data and Change Temporal Index (CTI) for temporal data. R-Tree is a hierarchical, height-balanced external memory data structure for multidimensional object. The hierarchical of R-Tree based on list of administrative such as regency, provinces and island. Change Temporal Index makes indexed data based on temporal side like valid time. CTI keeps valid data in current database and previous data according to interval valid time in historical database. This research is expected to accelerate the retrieving process in spatiotemporal databases. Spatial indexing makes searching faster up to 70%, temporal indexing makes searching faster up to 35% and spatiotemporal indexing makes searching faster than without indexing up to 50%.
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