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The secondary raw materials of fish can be used for various purposes in food industry, agriculture, etc. No less important way for usage of secondary raw fish, dead fish and fish farming sludge is the utilization of mentioned feedstocks for energy purposes, i.e. biofuels production. In this reearch, the possibilities of the consumption of dead fish and fish farming sludge for biodiesel and biogas production has been studied. The influence of the basic biodiesel production parameters, including the methanol to oil molar ratio, amount of catalyst, temperature and process duration on transesterification yield was determined. The guantitative and gualitative research of biogas production using different substrates such as fish waste, fish farming sludge and substrates composed of fish waste (de-oiled and non de-oiled biomass)+fish farming sludge and fish farming sludge+wastewater sludge was performed. The biodiesel yield higher than 96.5% could be achieved under the following process conditions: methanol/oil molar ratio - 4:1, amount of enzyme content - 7% from oil mass, temperature - 40 ° C, reaction time - 24 hours. The highest biogas yield (1224 ml/gVS) was determined using wet fish waste biomass and mixed substrates consisted of fish waste and fish farming sludge. The results of qualitative biogas research revealed, that biogas produced from both homogeneous and heterogeneous substrates contained more than 60% of methane. The highest calorific value (app. 70% of methane) had biogas gained from fish waste biomass. [ABSTRACT FROM AUTHOR]

Rapeseed is currently the main raw material for biodiesel production in Europe. The search for new raw materials is very important for the increase of biodiesel fuel production volume. Microalgae are one of alternatives for biodiesel fuel production. In this research, transesterification of microalgae Chlorella sp. oil with ethanol by applying the biotechnological method has been studied. The effectiveness of seven commercial lipases was evaluated. The most effective lipase Lipolase 100 L was selected for optimization of reaction conditions. The influence of main process parameters, including the ethanol to oil molar ratio, lipase amount and process duration on transesterification yield was evaluated. The results revealed, that process duration and amount of lipase affected the transesterification yield mostly. The biodiesel yield higher than 96.5% could be obtained when ethanol and oil molar ratio in reaction mixture is 8:1, process duration - 24 hours, lipase amount - 8%. [ABSTRACT FROM AUTHOR]

As the production of biodiesel fuel increases, the demand of raw material for its production - rapeseed oil - continuesly rise. In EU countries, including Lithuania, the amount of land available to grow rapeseed is limited because of the need for crop rotation and the suitability of the soil for rapeseed growing. Cyperus esculentus seeds have potential for the production of biodiesel fuel, since the seeds contain not only a significant amount of oil (28.1 %), while their productivity is about 4 times greater than that of rapeseed. The fatty acid methyl esters of Cyperus esculentus oil meet the equirements of the Standard that defines biodiesel fuel quality, except for the cold filter plugging point, which is only +1.4 oC. The cold filter plugging point of fatty acid methyl esters produced from Cyperus esculentus oil can be reduced to -5.5 °C by adding 1250 ppm of the depressant Wintron XC-30 or 1800 ppm of Infineum R-442. In Lithuania, such a product can be used as fuel during the summer period [ABSTRACT FROM AUTHOR]

Taking into account the perspectives of manufacturing of biofuels and potential of raw materials, it was determined that the potential growing areas of rape in our country are not sufficient for supply with raw materials. Thus it is necessary to start growing new cultures, such as Camelina saliva, as an undersowing in the areas of corn and leguminous plants, as well as to use waste fat and oil. The biocatalyst transesterification is the most suitable for fatty waste of poor quality containing a lot of free fatty acids, when the immobilized lipases are used. The multistage transesterification was investigated using lipases at various ratios of triglycerides and methanol. It was determined that the process lasts for more than 20 hours although the transesterification degree of 96.5% specified in the standard is not reached. Contrary to the popular opinion, the immobilized lipases are inactivated by glycerol; therefore the researches were done, how to eliminate glycerol with the help of adsorbents. The adsorption capacity of 5 adsorbents (TRISYL, ENGELHARD F-105 SF, TONSIL-OPTIMUM 214 FF, silica gel of LIFOSA Ltd., JELTAR-100) was analyzed. It was determined that glycerol is best adsorbed by TRISYL in the following conditions: amount of adsorbent -45 % of biodiesel fuel's weight, temperature -40 °C, time - 120 mm. There was created the technology that allows supplying continuously methanol to the reaction mixture and eliminating glycerol with the help of adsorbents. It was determined that the 89.4% transesterification degree may be achieved when 10-12% immobilized lipases in Lipozyme TL 1M are used for 7 hours, although the transesterification degree increases only by 7 % in the last 3 hours. [ABSTRACT FROM AUTHOR]