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Evaluation of molecular spectroscopy for predicting oxidative degradation of biodiesel and vegetable oil: Correlation analysis between acid value and UV–Vis absorbance and fluorescence
摘要： The present study evaluated the applicability of UV–Vis absorption and fluorescence spectroscopy for monitoring oxidation level of oil extracted from white sesame seeds (Sesamum indicum L.) and its respective biodiesel degraded at 110 °C for various times. Correlations between spectroscopic data and acid value of the samples demonstrated that both optical techniques could be used to monitor the oxidative degradation. Additionally, a quantitative model to predict the acid value of oil and biodiesel using the UV–Vis absorption data was proposed. The prediction model was tested using a cross-validation (leave-one-out) analysis and demonstrated, for the first time, that the acid value of both biodiesel and vegetable oil can be predicted by applying the same protocol for UV–Vis spectra analysis. An average error of about 3 and 8% was achieved for the predicted acid value of the oil and biodiesel samples with respect to the measured acid values, respectively. Therefore, UV–Vis absorption technique could be applied to quantitatively monitor the oxidative degradation of vegetable oil and biodiesel in a rapid and practical way.
关键词： Oxidative stability,Optical spectroscopy,Biodiesel,Acid value,Vegetable oil
更新于2025-09-23 15:21:01
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Coherent TiO <sub/>2</sub> /BaTiO <sub/>3</sub> heterostructure as a functional reservoir and promoter for polysulfide intermediates
摘要： Promoting biodiesel industrialization is not only an important measure in addressing the energy crisis and global warming but is also a driver for industrial restructuring and rural development. To promote the development of the biofuel industry, the Chinese central government has set a target that biofuel will account for 15% of transport energy consumption by 2020. The macroeconomic impacts of this policy, however, are unknown. This paper estimates the economic and environmental impacts on Yunnan of meeting this target using a demand-driven input–output model for Jatropha curcas L. biodiesel. The study combines life-cycle analysis and input–output analysis to establish the industrial relationship of the biodiesel sector with other sectors. The results show that meeting the biofuel policy target in 2020 will generate 296,780 thousand job opportunities annually (man-year) and increase household income. Meeting this target will also lower carbon emission by 11.39 million tonnes of CO2 equivalent, valued at 2.41 billion Yuan. However, meeting the target will decrease tax revenue by 1.8 billion Yuan and reduce the provincial gross domestic product by 754.95 million Yuan. Thus, the industrialization of J. curcas L. biodiesel can contribute to the development of a green economy and is a positive response to the policies of energy conservation and emission reduction. The promotion of biodiesel production, however, requires a trade-off between economic and environmental targets.
关键词： carbon emission reduction,economic impact,input–output analysis,Jatropha biodiesel,life-cycle analysis
更新于2025-09-19 17:15:36
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Application of infrared spectroscopy as Process Analytics Technology (PAT) approach in biodiesel production process utilizing Multivariate Curve Resolution Alternative Least Square (MCR-ALS)
摘要： Process Analytical Technology means at-line collection of analytical information from the process when the reaction is in progress. Obtained information enables process engineers to better control the Critical Process Parameters and direct the reaction to desirable routs. Near-infrared spectroscopy due to its analytical features, as well as the high capability of automation, versatile sampling and spectral acquisition methods is a useful tool in process monitoring when coupled to chemometrics. The Multiple Scatter Correction preprocessing technique and Alternative Least Square method can extract spectral and concentration information of a reaction mixture simultaneously, were employed pairing with fiber optic Near-Infrared spectroscopy in 1000-2250 nm spectral region was employed to extract the analytical information from the biodiesel production process. The obtained output demonstrated appropriate results about the concentration and type of components during the process. The kinetics of the reaction was also studied using the obtained results and showed a three-stage kinetics with different rates.
关键词： MCR-ALS,Near-Infrared spectroscopy,Process Analytical Technology,Biodiesel
更新于2025-09-19 17:15:36
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Quantitative remote and on-site Hg2+ detection using the handheld smartphone based optical fiber fluorescence sensor (SOFFS)
摘要： Di-n-butyl ether (DBE) is one of the most promising alternative biofuels for vehicles due to its superior physicochemical properties and because it is a renewable resource. This study investigated the effects of DBE addition on the spray macroscopic characteristics of diesel-biodiesel blends under various injection and ambient conditions. Three kinds of ternary blended fuels were prepared—(1) 72% diesel, 18% biodiesel, 10% DBE by volume (D72B18DBE10); (2) 64% diesel, 16% biodiesel, 20% DBE by volume (D64B16DBE20); and (3) 56% diesel, 14% biodiesel, and 30% DBE by volume (D56B14DBE30)—in order to compare their spray characteristics with those of an 80% diesel–20% biodiesel mix (D80B20) and conventional diesel (D100). The experiments were conducted in a constant volume chamber with a high-pressure common rail injection system using a high-speed photography method. The results show that D80B20 gives the longest spray tip penetration and the smallest cone angle and projected area among the five test fuels. With increased DBE blending ratio, the spray penetration length decreases slightly, and spray cone angle and projected area increase. When the DBE volume fraction in the ternary blend is 20%, the spray tip penetration, cone angle, and projected area are comparable to those of diesel. In addition, air entrainment characteristics were analyzed with the quasi-steady jet theory. It was found that the addition of DBE can improve the air entrainment characteristics of diesel-biodiesel blends, and D64B16DBE20 results in fuel-air mixing similar to that of D100.
关键词： Biodiesel,Diesel,Di-n-butyl ether,Spray characteristics
更新于2025-09-19 17:13:59
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Optimal integration of microalgae production with photovoltaic panels: environmental impacts and energy balance
摘要： Background: Microalgae are 10 to 20 times more productive than the current agricultural biodiesel producing oleaginous crops. However, they require larger energy supplies, so that their environmental impacts remain uncertain, as illustrated by the contradictory results in the literature. Besides, solar radiation is often too high relative to the photosynthetic capacity of microalgae. This leads to photosaturation, photoinhibition, overheating and eventually induces mortality. Shadowing microalgae with solar panels would, therefore, be a promising solution for both increasing productivity during hotter periods and producing local electricity for the process. The main objective of this study is to measure, via LCA framework, the energy performance and environmental impact of microalgae biodiesel produced in a solar greenhouse, alternating optimal microalgae species and photovoltaic panel (PV) coverage. A mathematical model is simulated to investigate the microalgae productivity in raceways under meteorological conditions in Sophia Antipolis (south of France) at variable coverture percentages (0% to 90%) of CIGS solar panels on greenhouses constructed with low-emissivity (low-E) glass. Results: A trade-off must be met between electricity and biomass production, as a larger photovoltaic coverture would limit microalgae production. From an energetic point of view, the optimal configuration lies between 10 and 20% of PV coverage. Nevertheless, from an environmental point of view, the best option is 50% PV coverage. However, the difference between impact assessments obtained for 20% and 50% PV is negligible, while the NER is 48% higher for 20% PV than for 50% PV coverage. Hence, a 20% coverture of photovoltaic panels is the best scenario from an energetic and environmental point of view. Conclusions: In comparison with the cultivation of microalgae without PV, the use of photovoltaic panels triggers a synergetic effect, sourcing local electricity and reducing climate change impacts. Considering an economic approach, low photovoltaic panel coverage would probably be more attractive. However, even with a 10% area of photovoltaic panels, the environmental footprint would already significantly decrease. It is expected that significant improvements in microalgae productivity or more advanced production processes should rapidly enhance these performances.
关键词： Chlorococcum sp.,Renewable energy,Raceway,Desmodesmus sp.,Biodiesel,Life cycle assessment
更新于2025-09-16 10:30:52
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Design and construction of a new dual CHP-type renewable energy power plant based on an improved parabolic trough solar collector and a biofuel generator
摘要： A dual hybrid system, including an improved parabolic trough solar collector (CSP) and a biodiesel generator was designed and constructed in this study. The biodiesel was produced from 1st and 3rd generations of biofuel by means of the heat loss of CSP. In order to increase the efficiency of heat transfer of CSP with a working fluid, an optimization was performed with some nanoparticles in concentrate range of 1500 to 3500 ppm. The results showed that thermal conductivity coefficient of the fluid increased by enhancing the volume percentage. This led to an increase in the outlet temperature from the collector and caused better efficiency of CSP and therefore a better performance of the biodiesel transesterification reactor. However, the best working fluid was consisted of a water-based CuO nanofluid (efficiency of 66.42% and the rate of temperature of 1311.1 °C/min). Due to different outlet temperature, various experiments were conducted to produce fuel from rapeseed oil. The best efficiency results (74.54%) as well as the lowest finished costs (69 cents) occurred at temperature of 60 °C. Then, biodiesel was produced from chlorella oil at this temperature with an efficiency of 81.4% and total production cost of 143 ￠.
关键词： Nanofluid,Temperature control,Transesterification,Parabolic trough solar collector,Biodiesel
更新于2025-09-10 09:29:36
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Cetane number prediction of waste cooking oil-derived biodiesel prior to transesterification reaction using near infrared spectroscopy
摘要： Fifty waste cooking oils (WCOs) were transesterified with methanol (1:8 WCO:methanol molar ratio) at 60 °C for 60 min using NaOH as catalyst (1% wt.). Fatty acid methyl ester (FAME) composition of the resulting biodiesels was analysed by gas chromatography, and near infrared (NIR) spectra of these biodiesels and those of the starting WCOs were acquired. Biodiesel cetane number was then calculated from both FAME composition and from biodiesel NIR spectra, this last technique using the former one as reference data. Because of transesterification does not modify fatty acid distribution of the starting WCO, and the similarity between biodiesel and WCO NIR spectra, biodiesel cetane number was successfully predicted from WCO NIR spectra, achieving RPD (ratio of performance to deviation) of 3.83. Therefore, biodiesel cetane number (and, as consequence, any other biodiesel property related to FAME composition) can be predicted by NIR spectroscopy before performing the transesterification reaction, which allows beforehand selecting the most suitable substrates for biodiesel production.
关键词： Waste cooking oil,NIRS,Biodiesel,Cetane number
更新于2025-09-09 09:28:46
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[ACS Symposium Series] Raman Spectroscopy in the Undergraduate Curriculum Volume 1305 || Integration of Raman Spectroscopy in Undergraduate Instruction and Research at Pace University
摘要： The integration of Raman spectroscopy into undergraduate instruction and research at Pace University is discussed in this chapter. This includes the introduction of the principle of Raman instrumentation, first by theory through the use of Gaussian calculations and interpretation of readily available spectra and then using the instrument after the acquisition of a B&W Tek Miniram in 2012. The availability of the instrument allows students to expand their research in sol-gel, ionic liquid, pharmaceuticals, and biodiesel. The development of simple experiments to incorporate into laboratory classes and side-by-side comparisons of experimental results and theoretical calculations are also presented. The challenges and successes of having this instrument in our teaching facility are also described.
关键词： undergraduate instruction,ionic liquid,research,Raman spectroscopy,pharmaceuticals,sol-gel,B&W Tek Miniram,biodiesel,Pace University
更新于2025-09-04 15:30:14
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Separation and Identification of Functional Groups of Molecules Responsible for Fluorescence of Biodiesel Using FTIR Spectroscopy and Principal Component Analysis
摘要： In order to separate and identify functional groups of molecules responsible for fluorescence compounds present in biodiesel, a column chromatography coupled with infrared spectroscopy and multivariate analysis was performed. A biodiesel sample was packed in a chromatographic column and the fractions obtained were used to perform the analyses. Before undergoing the separation process, the biodiesel sample was analyzed by light emitting diode (LED)-induced fluorescence and compared its spectrum with β-carotene and soybean oil patterns. The low cost and speed of analysis suggest that this technique can be used in the separation of biodiesel substances. The fluorescence emission spectra allowed identifying molecules such as β-carotene, in which the spectrum of its pattern exhibited fluorescence within a region ranging from 500 to 700 nm and chlorophyll molecules. When soybean oil is excited at around 405 nm, it features a fluorescent emission band within the region of 670 nm, which reveals the presence of chlorophyll. Infrared spectroscopy coupled with principal component analysis allowed to discriminate the fractions and to identify the functional groups of compounds present in the sample.
关键词： fluorescence,fluorophores,infrared spectroscopy,principal component analysis,biodiesel
更新于2025-09-04 15:30:14