Differences in raw material sources for biofuel processing

Transcription

1 Differences in raw material sources for biofuel processing Attila J. Kovács, University of West Hungary, Institute of Biosystems Engineering, , Károly Kacz, University of West Hungary, Institute of Biosystems Engineering, , Erika Lakatos, University of West Hungary, Institute of Biosystems Engineering, , Miklós Neményi, University of West Hungary, Institute of Biosystems Engineering, , Overview The Institute of Biosystems Engineering, University of West Hungary (Mosonmagyaróvár, Hungary) has carried out examinations on focusing of the use of plant-based fuels for a long time. First, we examined the rapeseed methyl-ether usage in farm engines. After that, the used cooking (waste) vegetable oil utilization was studied. In this presentation cold-pressed and filtered sunflower and rapeseed oil were investigated aiming to use the oil as biofuel. The study covered more than 30 species of sunflower and 15 verieties of rapeseed, respectively. There are several studies on different oil bearing crops as bio-fule raw materials (Demirbaş, 2003; Zhang et al., 1996; Şensöz, 2006). Significant differences can be detected among different sunflower cultivars and species. Differences can be found from plat production, processing and utilization methods. Seed oil and fatty acid concentrations of sunflower varies greatly depending on the genotype and environmental conditions under wich it develops (Dorell et al., 1978; Seiler, 1985; Seiler, 1994). Selecting the most appropriate verietis or cultivars of plant raw material is crucial for the secure and economicaly viable bio-fule production. Some varieties can be even excluded from biofule production because of e.g. its acid number. Based on the most important parameters of the examined vireties ranking lists presented in this study. Methods The sunflower and rapeseed cultivars and hybrids were under investigation concerning to the possible fuel use which were present at the IKR Corporation s field tests (Bábolna. Hungary). In the first series of examinations 33 plant breaded sunflower materials were tested. After the cold press the samples containing high oleic acid (C18:1 almost 90 %) were selected that were suitable for green fuel without esterification. The selected lines and hybrids were pressed, filtered and mixed (10% and 20%) with gasoline and used in engine break tests. For cold pressing a CSOP-92 type cold press machine (Fig. 1); and for filtration a 10-frame, 3.2 m 2 filter (Fig. 2) were used. The laboratory tests were carried out at the Pannon University, Veszprém (Hungary); meanwhile the engine break test were done at the College of Mezıtúr (Hungary). We took special attention to the pressing characteristics of varieties and hybrids. During cold press infrared images were taken for determination of maximum and average temperature values of the press head. The total oil contents of pressed cakes were also measured. Viscosity measurements of oils were carried out at different temperatures. Scanning electron microscopy was used to study the internal structure of sunflower seed as a function of oil content.

2 Figure 1. The used cold press Figure 2. The 10-framed filter Results Oil seed varieties with the most favorable characteristics for direct use or trans-esterification fuel use were going to be selected by means of pressing tests and analytical analysis. Significant differences were examined among the rapeseed and sunflower varieties in connection to their cold pressing and oil yield characteristics. The yield varied between 28.6% and 38.5% among varieties. The selected varieties had about 90% of oleic acid while in standard varieties this value was only about 26.2%. The

3 3 Intelligent Well Technology: Status and Opportunities for Developing Marginal Reserves SPE linoleic acid content gave reverse result: by the selected varieties it was only %, meanwhile by the standard varieties it was 61.3%. There were differences also in scanning electron microscopic images of different types of sunflower (Fig. 3). a) NOS-1165 b) NOS-1170 Figure 3. Scanning electron microscopic images of sunflower cotyledons (embryo) of low oil yield type (a) NOS-1165, and high oil yield type (b) NOS Magnification: 500X. Scale bars: 50 µm. The varieties with high oleinic acid content did fulfill the standard parameters. Namely, their kinematic viscosity (at 40 C) was 38 mm 2 /s that was slightly above the standard. The iodine-bromide numbers were 80 and 90, the acidic number was higher than 2 mgkoh/g. We examined 15 rapeseed varieties, too. The oil yield was between 24.99% and 36.89%. The higher yield resulted higher pressing temperatures. According to the laboratory tests almost all rape varieties fulfilled the standard requirements as biofuel except the acidic number. There were eight from the 15 varieties that had higher than 2 mgkoh/g of acidic number. The ones with the most favorable characteristics for direct or after-esterification fuel use are going to be selected by means of pressing tests and analytical analysis. Significant differences were examined among the rape and sunflower varieties in connection to their cold pressing and oil yield. The yield varied between 28.6% and 38.5% among varieties. The selected varieties had about 90% of oleic acid while in standard varieties this value was only about 226.2%. The linoleic acid content gave reverse result: by the selected varieties it was only %, meanwhile by the standard varieties it was 61.3%. There were differences also in scanning electron microscopic images of different types of sunflower. The varieties with high oleinic acid content did fulfill the standard parameters. Namely their kinematic viscosity (at 40 C) was 38 mm2/s that was slightly above the standard. The iodine-bromide numbers were 80 and 90, the acidic number was higher than 2 mgkoh/g. We were examined 15 rape varieties, too. The oil yield was between 24.99% and 36.89%. The higher yield resulted higher pressing temperatures (Fig. 4.). According to the laboratory tests almost all rape varieties fulfilled the standard requirements as biofuel except the acidic number. There were eight from the 15 varieties that had higher than 2 mgkoh/g of acidic number. Table 1 shows the ranking lists of rapeseed oils.

4 90 85 Pressing temperature [ C] , , , ,5 40 Oil yield [%] Figure 4. The pressing temparatures meaesured by Infrared camera vs. oil yield of rape seeds Table 1. Ranking of rapeseed oil tested for bio fuel Number Fatty acid content [wet.m.%] Fatty acid content [dry.m.%] Oil yield [%] Remained oil [%] iodinebromide. gi 2 /100 g Acid number. mgkoh/g Ranking

5 5 Intelligent Well Technology: Status and Opportunities for Developing Marginal Reserves SPE Conclusions There are several varieties that their oils are not suitable for biofuel because they did not fulfill the standards. The most important characteristics (concerning bio-fuel utilization) of rape seed is only the acid number. In case of sunflower the most important parameters are the acid number, iodine-bromide number and the kinematic viscosity. We determined the necessary physical treatment of sunflower oils before use them as fuel such as heat treatment, special filtration and/or mixing with alcohol. The resulted rankink lists can secure the bio-fuel raw material production by letting the producers select suitable varieties. These are one of the key points towards increased energy supply security from plant based raw material production point-of-views. References Demirbaş, A., Biodiesel fuels from vegetable oils via catalytic and non-catalytic supercritical alcohol transesterifications and other methods: a survey. Energy Conversion and Management 44: Dorell, D.G., Whelan E.D.P Chemical and morphological characterization of seeds of some sunflower species. Crop Science 18: Seiler, G. J., Evaluation of seeds of sunflower species for several chemical and morphological caracteristics. Crop Science 25: Seiler, G. J., Oil Concentration and Fatty Acid Composition of Achenes of North American Helanthus (Asteraceae) Species. Economic Botany 48(3): Şensöz, S., Kaynar, I Bio-oil production from soybean (Glycine max L.); fuel properties of Bio-oil. Industrial Crops and Products 23: Zhang, H.Y., Hanna, M.A., Ali, Y., Nan, L., Yellow nut-sedge (Cyperus esculentus L.) tuber oil as a fuel. Industrial Crops and Products 5: