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[en] The synthesis and application of a hybrid catalyst for the esterification of free fatty acids (FFA) in Jatropha oil is reported. Three catalysts, namely silica sulfuric acid, silica supported boron trifluoride and a combination of the two in the weight ratio of 1:1, the hybrid catalyst, were investigated. Jatropha oil samples with a wide range of FFA values i.e. 6.64 to 45.64% were prepared and utilized for the experimental work. This study revealed that silica sulfuric acid and silica supported boron trifluoride were not very effective when used independently. However, a strong synergistic effect was noted in the catalytic activity of the hybrid catalyst which reduced the FFA value from 45.64 to 0.903% with a conversion efficiency of 98%. Reusability of the catalyst was also tested and the results were promising in up to three cycles of use when used with lower amounts of FFA (6.64%) in the oil. Under the influence of the catalyst, the reaction was found to follow first order kinetics. Activation energy was calculated to be 45.42 KJ·mol−1 for 2 wt.% of hybrid catalyst. The products were analyzed by FT-IR and NMR spectroscopic techniques and the results are reported.
[es]Se aborda la síntesis mediante el uso de un catalizador híbrido en la esterificación de ácidos grasos libres (AGL) de aceites de Jatrofa. Se investigaron tres catalizadores: ácido sulfúrico sobre sílica, trifluoruro de boro sobre sílice y un catalizador híbrido, combinación de los dos anteriores en una relación 1:1en peso. Muestras de aceites de Jatrofa con una amplia gama de valores de FFA: desde 6,64 a 45,64% se prepararon y se utilizaron en la parte experimental de este trabajo. Este estudio mostró que los soportes de ácido sulfúrico sobre sílica y el de trifluoruro de boro sobre sílice no eran muy eficaces cuando se utilizan de forma independiente. Sin embargo, un fuerte efecto sinérgico se observó en la actividad catalítica del catalizador híbrido que reduce el valor de FFA de 45,64 a 903% con una eficiencia de conversión del 98%. La reutilización de catalizador también fue probado y los resultados fueron prometedores hasta tres ciclos de uso cuando se utiliza un aceite con menor cantidad de FFA (6,64%). Bajo la acción del catalizador, se encontró que la reacción sigue una cinética de primer orden. La energía de activación se calculó y fue de 45,42 kJ·mol−1 para el catalizador híbrido al 2% en peso. Se reportan los resultados de los productos analizados por técnicas espectroscópicas FT-IR y RMN.
[en] Highlights: • Biodiesel can be produced via catalytic and non-catalytic processes. • Mass production of biodiesel with continuous-flow reactors is reviewed. • Continuous process assisted with ultrasound, microwave, supercritical method. • New techniques developed to improve mass transfer and biodiesel conversion. • Continuous-flow conversion of microalgal oil is intensively reviewed. - Abstract: Biodiesel has been receiving considerable attention as an alternative energy source over the last decade. Conventionally, biodiesel is produced by transesterification of lipid and alcohol, with or without the aid of catalysts. Due to the presence of multiple phases during the catalytic reaction, the mass transfer between reactants and catalysts, as well as the type of catalyst used are the two major factors that should be considered during the design of the reactor applied for the targeted conversion. Most efforts in this area focused on the selection of effective catalysts (e.g., homogeneous catalysts, heterogeneous catalysts, enzymes) for biodiesel conversion via transesterification. The tests are regularly conducted on batch mode and the optimization of the operating conditions was done. However, to scale up the biodiesel production, many researchers utilized continuous-flow regime to continuously convert lipids to biodiesel with preferable process design to solve the problems encountered during continuous operation. This review is aimed at providing the knowledge and updated information on recent advances of the continuous-flow biodiesel production technology. This article presents and critically discusses the advantages and limitations of using catalyzed and non-catalyzed transesterification in conventional continuous-flow reactors and those assisted by supercritical conditions, membrane reactors, ultrasound, microwave, and other special techniques. Several newly developed processes, such as oscillatory flow reactor (OFR), microchannel reactors, laminar flow reactor-separator, liquid-liquid film reactor, which could minimize mass transfer resistance and improve biodiesel conversion are also presented. Finally, updates on conversion technologies for lipids from oleaginous microalgae (potential third-generation oil feedstock) to biodiesel and reviews on commercial continuous-flow biodiesel conversion technologies are provided.
[en] In this study, the regulated and unregulated emissions profile and fuel consumption of an automotive diesel and biodiesel blends, prepared from two different biodiesels, were investigated. The biodiesels were a rapeseed methyl ester (RME) and a palm-based methyl ester (PME). The tests were performed on a chassis dynamometer with constant volume sampling (CVS) over the New European Driving Cycle (NEDC) and the non-legislated Athens Driving Cycle (ADC), using a Euro 2 compliant passenger vehicle. The objectives were to evaluate the impact of biodiesel chemical structure on the emissions, as well as the influence of the applied driving cycle on the formation of exhaust emissions and fuel consumption. The results showed that NOx emissions were influenced by certain biodiesel properties, such as those of cetane number and iodine number. NOx emissions followed a decreasing trend over both cycles, where the most beneficial reduction was obtained with the application of the more saturated biodiesel. PM emissions were decreased with the palm-based biodiesel blends over both cycles, with the exception of the 20% blend which was higher compared to diesel fuel. PME blends led to increases in PM emissions over the ADC. The majority of the biodiesel blends showed a tendency for lower CO and HC emissions. The differences in CO2 emissions were not statistically significant. Fuel consumption presented an increase with both biodiesels. Total PAH and nitro-PAH emission levels were decreased with the use of biodiesel independently of the source material. Lower molecular weight PAHs were predominant in both gaseous and particulate phases. Both biodiesels had a negative impact on certain carbonyl emissions. Formaldehyde and acetaldehyde were the dominant aldehydes emitted from both fuels.
[en] The rooting ability of hardwood cuttings from six selected non- edible oilferous plant species with potential for biodiesel production namely Telfairia pedata, Jatropha curcas, Excoecaria bussei, Croton macrostachyus, Croton megalocarpus and Ricinus communis was assessed on 4 different potting media i.e. forest top soil, sandy, clay and loamy soil. The proportion of cuttings that rooted were evaluated for the root numbers, root length, root dry weight, sprouting and callus formation. Complete randomized design (CRD) was adopted for the experiments and each of the species was replicated 4 times using 5 hardwood cuttings per plot (5 L capacity pots). An ANOVA was computed to test for the significance of variations between all treatments while Tukey-Kramer Multiple Comparisons test was used to test for the differences between treatment means. Jatropha curcas rooted well both in a non-mist propagator and open nursery pots, Telfairia pedata rooted only in the nursery pots, Excoecaria bussei sprouted in both non-mist propagator and open nursery pots but did not root throughout the entire experimental period of 3 months. Croton macrostachyus, Croton megalocarpus and Ricinus communis neither sprouted nor rooted calling for propagation methods other than using hardwood cuttings. Possibly all Excoecaria bussei cuttings which callused would have eventually differentiated into roots had the experiment been allowed to run for more than 3 months. (author)
[en] Highlights: • Oils/lipids from waste sources are the suitable candidates for transesterification. • Catalyst derived from waste materials proven its role in transesterification. • The use of materials from waste should be intensify for sustainability. - Abstract: For many years, the cost of production has been the main barrier in commercializing biodiesel, globally. It has been well researched and established in the literature that the cost of feedstock is the major contributor. Biodiesel producers are forced to choose between edible and non-edible feedstock. The use of edible feedstock sparks concern in terms of food security while the inedible feedstock needs additional pretreatment steps. On the other hand, the wide availability of edible feedstock guarantees the supply while the choice of non-edible results in a non-continuous or non-ready supply. With these complications in mind, this review attempts to identify possible solutions by exploring the potential of waste edible oils and waste catalysts in biodiesel preparation. Since edible oils are available and used abundantly, waste or used edible oils have the potential to provide plentiful feedstock for biodiesel. In addition, since traditional homogeneous catalysts are less competent in transesterifying waste/used oils, this review includes the possibility of heterogeneous catalysts from waste sources that are able to aid the transesterification reaction with success
[en] Nannochloropsis sp., one kind of green microalgae cultivated autotrophically and axenically in laboratory, is used as raw material to produce biodiesel by one-step method in an amended reactor. The effects of several reaction parameters on transesterification over Mg-Zr solid base catalyst were investigated through both conventional method and one-step method. One-step method could give a higher yield of methyl ester than conventional two-step method, which demonstrates that the present one-step method is suitable for biodiesel production from the microalgae Nannochloropsis sp. Moreover, the present one-step method realizes the convenient in situ separation of catalyst from microalgae residue which can be easily used consequently, reducing the procedure units as well as the overall costs.
[en] Energy demand is increasing day by day because of the rapid developments in the population, industrialization and urbanisation. Since, fossil fuels will be at the verge of getting extinct, researches are mostly focused on the renewable sources, such as biomass, in recent years. This paper provides an environmentally friendly process to convert waste biomass samples to bio-oil and bio-char by pyrolysis. For this purpose, pyrolysis characteristics of pomegranate peels under inert atmosphere were studied by using both TGA to analysis decomposition behaviour and a batch reactor to investigate product yields and properties. The properties of bio-oil and bio-char were investigated by different analytical techniques such as GC-MS, FT-IR, SEM, He pycnometry and elemental analysis. As a consequence, it is possible to obtain bio-oil, which has similar properties like petroleum hydrocarbons, and to obtain bio-char, which can be further used as a solid fuel or a carbonaceous adsorbent material via pyrolysis process. (full text)
[en] Highlights: • Marginal changes in ecosystem services were observed in small-scale biofuel project. • Documenting the creation of these (marginal) impacts has policy-relevance. • The ecosystem services framework could be improved using a process-based approach. - Abstract: Small-scale biodiesel production with a high level of community involvement has been associated with a number of benefits. These include relatively low environmental impacts, lack of competition with food production, strong poverty alleviation effects and enhanced access to energy. This Short Communication provides a qualitative analysis of the effects of the cultivation of biodiesel oilseed tree crops (mostly Millettia pinnata, along with Simarouba glauca, Azadirachta indica, Madhuca lungifolia and Jatropha curcas) in such a small-scale project, the Hassan Bio-Fuel Park in Karnataka, India. This extensive ethnographic research and using the ecosystem services approach to synthesize the findings suggests that the changes in both the flows of ecosystem services and different constituents of human wellbeing are marginal. While the ecosystem services approach can be useful to synthesize various forms of knowledge on biofuels to inform policy, this particular case study highlights the importance of being open about the different, often implicit, priorities and values of research projects and the various kinds of actors involved in biofuel production. Finally, it is crucial to understand not just which impacts are generated but especially how those impacts are generated.
[en] A lipid-producing microalga, Chlamydomonas sp. KNF0008, collected from the Arctic was capable of growing at temperatures ranging from 4 to 20 °C, and the highest cell density was measured at 15 °C and 100 μmol photons m−2 s−1 light intensity under continuous shaking and external aeration. KNF0008 showed the elevated accumulation of lipid bodies under nitrogen-deficient conditions, rather than under nitrogen-sufficient conditions. Fatty acid production of KNF0008 was 4.2-fold (104 mg L−1) higher than that of C. reinhardtii CC-125 at 15 °C in Bold’s Basal Medium. The dominant fatty acids were C16:0, C16:4, C18:1, and C18:3, and unsaturated fatty acids (65.69%) were higher than saturated fatty acids (13.65%) at 15 °C. These results suggested that Arctic Chlamydomonas sp. KNF0008 could possibly be utilized for production of biodiesel during periods of cold weather because of its psychrophilic characteristics.
[en] Bio diesel from green energy source is gaining tremendous attention for eco friendly and economically aspect. In this investigation, a two-step process was developed for the production of bio diesel from microalgae Spirulina maxima and determined best operating conditions for the steps. In the first stage, acid esterification was conducted to lessen acid value (AV) from 10.66 to 0.51 mg KOH/g of the feed stock and optimal conditions for maximum esterified oil yielding were found at molar ratio 12:1, temperature 60 degree C,1% (wt %) H2SO4, and mixing intensity 400 rpm for a reaction time of 90 min. The second stage alkali transesterification was carried out for maximum bio diesel yielding (86.1%) and optimal conditions were found at molar ratio 9:1, temperature 65 degree C, mixing intensity 600 rpm, catalyst concentration 0.75% (wt %) KOH for a reaction time of 20 min. Bio diesel were analyzed according to ASTM standards and results were within standards limit. Results will helpful to produce third generation algal bio diesel from microalgae Spirulina maxima in an efficient manner