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Using of AnyLogic and ExtendSim in modelling of biofuel logistic systems
2008
Dukulis, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Rising oil prices, national security concerns, the desire to increase farm incomes, and a host of new and improved technologies are propelling the European Union to set the directive for the year 2010 – each member state should achieve at least 5.75% biofuel usage of all used transport fuel. The report on the progress made in the use of renewable fuels shows that the average Member State of the EU has achieved only 52% of its target, and biofuels’ share in 2010 will not raise much above 4%. The prices of different biofuels are still not able to compete with oil based fuel prices. One of the possible ways how to solve this problem is to optimize biofuel supply chains using different methods of systems engineering. The aims of this investigation were finding out appropriate simulation tools for biofuel supply chain modelling, development of rapeseed oil supply chains for different production types, and modelling the developed supply chains. As the result of software survey, two packages were chosen – AnyLogic and ExtendSim Suite. Modelling studies showed that rapeseed oil supply chain is very sensitive, because changing just single parameters in a short scale, the actual cost price of 1 litre of oil changes considerably. Comparing the fossil diesel fuel prices with rape oil actual cost from modelling studies, the use of oil as a fuel for farm machinery seems to be profitable. Analysis of costs distribution shows that the greatest part is composed by rapeseed growing expenses.
Show more [+] Less [-]Emission reduction potential of using biofuels
2010
Pirs, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukulis, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
One of the primary reasons for expanding the production and use of biofuels is the potential environmental benefit that can be obtained from replacing fossil fuels with fuels derived from renewable biomass resources. This investigation examines the impact of biofuels on the environment directly from the practical view point analysing how the internal combustion engine emission concentration changes using the most common first-generation biofuels in Latvia – biodiesel, rapeseed oil and bioethanol. Laboratory experiments were performed on a chassis dynamometer Mustang MD1750, but the content of exhaust gases components was determined by the AV L SESAM FTIR measurement system. Investigation shows that the trends of different exhaust gas component changes, which would be the same for all investigated fuels, don't exist, i.e., each vehicle and biofuel type or blend is particular and has to be analysed separately. In comparison with fossil diesel, running the car VW Golf on rapeseed oil the average reduction of NOx was 10%, but SO2 – 59%. The CO, CO2, unburned hydrocarbon and mechanical particle emissions were higher. Running the car Opel Vectra on biodiesel the amount of NOx in comparison with fossil diesel increased in average by about 12%, the amount of mechanical particles and unburned hydrocarbons decreased quite significantly, but just a small increase of CO and SO2 was observed. Testing the car VW Passat on gasoline-bioethanol blends increase of the bioethanol content in the fuel blend increased also the NOx content in exhaust gases, but the content of CO, CO2 and NH3 decreased.
Show more [+] Less [-]Theoretical evaluation of hydrotreated vegetable oil application in diesel engines
2014
Sondors, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukulis, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
A lot of different EU directives and regulations set the targets to decrease greenhouse gas emissions, to increase the share of renewable energy, and to improve energy efficiency. Biofuel usage is directly linked to all of these problems. Since the first generation food-based biofuels should not receive public support after 2020, investigations of next generation biofuels are topical. Hydrotreated vegetable oil (HVO) is one of the most promising next generation biofuels in the near future. This article deals with the results of mathematical modelling to determine the main diesel engine operating parameters (power, torque and fuel consumption) running them on HVO and its blends with fossil diesel fuel. The modelling results of the car Opel Insignia 2.0 CDTi show that every 5% of HVO in fuel blend reduces maximum power and torque of around 0.38% while raising specific fuel consumption by volume of around 0.10%. Analyzing the most realistic scenario in the near future – 7% HVO and 93% fossil diesel blend, the predicted fuel consumption increase (0.14%) and power and torque decrease (0.54%) is inconsiderable for vehicle exploitation, and HVO seems to be a promising biofuel to replace biodiesel in fuel blends and to promote reaching the EU targets.
Show more [+] Less [-]Development of experimental equipment for vegetable oil fuel research
2011
Birkavs, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukulis, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
The European Parliament and Council Directive 2003/30/EK ‘On the promotion of the use of biofuels and other renewable fuels for transport’ determines that pure or straight vegetable oil, produced from oil plants by pressing, extracting or comparable procedures, crude or refined but chemically unmodified, compatible with common engines, and corresponding to emission requirements, is also considered as biofuel. The biggest problems imposed by these conditions are directly associated with the carrying-out of the emission requirements, because when using vegetable oil as a fuel, usually increases the composition of the solid particles and nitrogen oxides in exhaust gases, that not only adversely affect the environment, but also is a serious threat to human health, and as a result trying to save the world from the global warming, human health continues to deteriorate. It is therefore necessary to carry out studies and find solutions to reduce harmful emissions from diesel engines when using vegetable oil fuel. For more qualitative and effective research on vegetable oil fuel emissions, the equipment for vegetable oil fuel testing has been developed. This equipment allows fast checking of theoretically proposed hypotheses and detailed calculations for vegetable oil fuel combustion processes and objective data acquisition. The equipment consists of the classic diesel engine adapted for work with vegetable oil and is equipped with several high-precision devices to get and store the measuring data. During pilot tests the optimal measuring modes (engine rotation frequencies, number and duration of repetitions) for further research are estimated.
Show more [+] Less [-]Changes in cold pressed rapeseed oil quality in different packaging materials during storage
2007
Bluka, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Cakste, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
The dynamic of rapeseed oil oxidizing processes under the influence of light in brown glass, colourless glass, and colourless PET bottles during storage at 18+-2 deg C were investigated. The changes in A and E vitamins content in rapeseed oil packed in colourless PET packaging materials were determined after 4 months storage at 18+-2 deg C at daylight. The connection between different packaging materials' transparency and oxidizing of oil were observed.
Show more [+] Less [-]Dynamics of peroxide value in flavoured rapeseed oil
2005
Kruma, Z.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:zanda.kruma@llu.lv | Kreicbergs, V.(Latvia Univ. of Agriculture, Jelgava (Latvia)) | Karklina, D.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:kada@cs.llu.lv
Spices are used to season food products. Investigations were carried out to determine dynamics of primary oxidation products in flavoured rapeseed oil depending on used spice, its concetration, storage duration, and sample preparing method. The oil was flavoured with winter savoury Satureja Montana L., hyssop Hyssopus officinalis L., and marjoram Oreganum vulgare L. Results showed that dynamics of peroxide value in flavoured oils were influenced significantly (p is less than 0.05) by all investigated factors - used spice, its concentration, storage duration, sample preparing method, and interaction of these factors, too. Heating of oil in particular cases caused unusual, hard explainable dynamics of peroxide value. It is necessary to investigate optimal conditions of flavouring of oils and components of spices which can influence oxidation of flavoured oils.
Show more [+] Less [-]Volatile compounds in aromatised oils with basil, oregano and thyme
2006
Kruma, Z. | Kreicbergs, V. | Adams, A.
During processing of aromatized rapeseed oils, volatiles from the added spices migrate in oil and give specific taste and aroma to oils, but there are no investigations about volatile compound migration in oil. The aim of this research was to determine volatile compounds in oils aromatized with basil, oregano, and thyme. In basil 43 volatile compounds, in oregano - 39, and in thyme - 37 volatile compounds were identified. In oil aromatized with basil - 8, in oil aromatized with oregano - 20, and in oil aromatized with thyme 11 volatile compounds were identified. From the total amount of identified compounds in spices, 23-30% of volatiles found in thyme migrated in oil aromatized with thyme, from oregano in oil migrated 12-15% of volatiles, but from basil in oil aromatized with basil - only 5% of volatiles. More volatile compounds as camphene, alpha-pinene, and alpha-thujene migrate in oil better than less volatile compounds like methyl chavicol, and thymal. Migration of the same compound in oil from various spices differed. It could be explained by the location of the volatile compound in plant structure.
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