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%.
Keyword: 

Judul: Kajian teknologi produksi poligliserol dari hasil samping industri biodiesel
Abstrak: The transesterification process in biodiesel production, produces main product (90% methyl ester) and by product (10% glycerol). The glycerol from the biodiesel process consists of 40-90% glycerol, 8-50% water content, and methanol less than 5-10%. The pure glycerol had been produced by the glycerol purification process when the crude glycerol had been separated from impurities (Idaho, 2006). Glycerol purification process by using H3P04 was carried out to neutralize and separate the fatty acid. The colour and minerals are absorbed by the active carbon. The polymerization of glycerol is one of the alternative process in order to reuse the by product of biodiesel industry. Polyglycerol could be used as emulsifier, emollient, disperant, spreading agent, and solubilizer. The polyglycerol and derivative could be used in many industry such us polymer additive, lubricant, drilling fluid, hydraulic fluid, cutting oil, etc. The objectives of this research is to find out the right process of polyglycerol production froin by-prod~~ocft biodiesel industry (glycerol). The treatments of the process were temperature (200,225, and 245 OC), heating time (6, 8, and 10 hours), and type of catalyst (KOH and NaOH) which has concentration 0,5 and 1 %. The result of this research showed that the higher temperature and the longer heating time can increase the viscosity and density of the product as well as the darken of the colour. Hydroxyl value was used to determine degree of polymerization. The degree of polymerization has value r 5. According to analysis of density, viscosity, boiling point, hydroxyl value and functional group, the best process of polymerization is reached at temperature 200 and 225oC.
Keyword: 

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%.
Keyword: