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Biodiesel can be produced from vegetable oils, animal fats, and waste cooking oils by transesterification with ethanol (also called ethanolysis) in order to substitute fossil fuels. In this work, the batch ethanolysis of high oleic sunflower oil was transferred into a continuous microstructured device, which induces a better control of heat and mass transfers. Various parameters were studied, notably the initial ethanol to oil molar ratio. An innovative method using NIR spectroscopy was also developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol in microreactors (circular PFA tube 1/1600 OD, 0.0200 ID). The reactions were monitored directly in the microreactors through sequential scans of the reaction medium by the means of an adequate probe. The asset of the method is that no sample collection or preparation is necessary. Partial Least Squares regression was used to develop calibration and prediction models between NIR spectral data and analytical data obtained by a reference method (gas chromatography with flame ionization detection, GC–FID). This method is fast, safe, reliable, nondestructive and inexpensive contrary to conventional procedures, such as gas chromatography and high performance liquid chromatography generally used to determine the composition of crude transesterification medium.

Biodiesel is a fuel generally consisting of a mixture of fatty acid methyl esters (FAMEs) which is used in alternative or in combination with petroleum diesel for its environmental benefits. Biodiesel is conveniently manufactured from vegetable oils by transesterification of triglycerides with methanol. However, the process brings about the concurrent formation of glycerol, which may become an oversupplied chemical if biodiesel production keeps growing. A novel biodiesel-like material (abbreviated as DMC-BioD) was developed by reacting soybean oil with dimethyl carbonate (DMC), which avoided the co-production of glycerol. The main difference between DMC-BioD and biodiesel produced from vegetable oil and methanol (MeOH-biodiesel) was the presence of fatty acid glycerol carbonate monoesters (FAGCs) in addition to FAMEs. In the following study, details regarding synthesis and composition of DMC-BioD are provided along with physical properties relevant for its use as a fuel. In addition, the production of potential pyrogenic contaminants was investigated by analytical pyrolysis and compared with those from MeOH-biodiesel, and the model compounds tristearin, triolein, trilinolein and oleic acid glycerol carbonate ester (OAGC). The presence of FAGCs influenced both fuel and flow properties, while the distribution of main pyrogenic compounds, including polycyclic aromatic hydrocarbons (PAHs), was little affected. Benefits and drawbacks of DMC as a candidate transmethylating reagent for producing biofuel from renewable resources and alternative co-products (glycerol carbonate and glycerol dicarbonate) are discussed.

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Abstract The present work focuses on finding the suitability of cotton seed oil as a fuel for diesel engines by comparing the different methods to improve the performance of neat cotton seed oil (CSO). Tests were conducted with neat CSO and diesel to obtain base data. Transesterification with alcohol, preheating of CSO and diesel–CSO blends; blending of orange oil, diesel, or diethyl ether (DEE) with CSO and the use of semi adiabatic engine concept are the methods which have been investigated. The brake thermal efficiency of diesel and neat CSO at peak power is 32.3% and 28% respectively. An increase in the brake thermal efficiency to 30.4% is noticed at peak output with ethyl ester of cotton seed oil (EECSO). Smoke, CO and HC levels are reduced with EECSO compared to neat CSO. A blend of 60% CSO and 40% of diesel results in good brake thermal efficiency and a significant reduction in smoke level. The preheated blend of 60% of CSO and 40% of diesel at 90 °C shows an increase in brake thermal efficiency, which is close to diesel. Engine performance improves with the addition of orange oil (OO) and DEE with CSO. The brake thermal efficiency increases with adiabatic engine at part loads compared to neat CSO operation. It is concluded that CSO and EECSO can be directly used in diesel engines without any modifications. However, preheating of CSO or its blend with diesel is a very effective way to lower its viscosity and improve its performance. Blending small quantities of orange oil and diethyl ether with CSO are also other effective methods to improve the performance of diesel engines.

Abstract Co-current combustion front propagation in a bed of crushed oil shale (OS) leads to the production of liquid oil, of a flue gas and of a solid residue. The objective of this paper was to provide a detailed chemical characterization of Timahdit oil shale and of its smoldering combustion products. The amount of fixed carbon (FC) formed during devolatilization is measured at 4.7% of the initial mass of oil shale whatever the heating rate in the range 50–900 K min −1 . The combustion of oil shale was operated using a mix of 75/25 wt. of OS/sand with an air supply of 1460 l min −1 m −2 . In these conditions, not all the FC is oxidized at the passage of the front, but 88% only, with a partitioning of 56.5% into CO and the rest into CO 2 . A calorific gas with a lower calorific value of 54 kJ mol −1 is produced. Approximately 52% of the organic matter from OS is recovered as liquid oil. The front decarbonates 83% of carbonates.

Abstract To identify the performance and mechanism of variant molten salts during biomass pyrolysis in molten salt, the thermogravimetric and differential scanning calorimetry (TG-DSC) analyzer, fixed-bed reactor and thermodynamic equilibrium simulation were applied to study the thermal melting characteristics and stability of molten salt as well as the selectivity for biomass pyrolysis products. The KCl-ZnCl2 is appropriate for the preparation of H2-rich gas and the carbon material with abundant mesoporous structure due to its activation effect. At 850 °C, the pyrolysis gas obtained from KCl-ZnCl2 contained 42.22 vol% H2 with the H2/CO ratio reaching 1.69. The carbonates demonstrated excellent improvement for the gas composition of biomass pyrolysis products, with 75.43 vol% and 70.52 vol% syngas (H2 + CO) collected from the Li2CO3-K2CO3 and Li2CO3-Na2CO3-K2CO3 pyrolysis systems at 850 °C respectively. With the presence of carbonates, the bio-oil and char prepared by biomass pyrolysis also achieved better quality. The thermodynamic simulation revealed the shifting (formation of Li2O) of molten salt composition during biomass pyrolysis. The interaction between Li2CO3 and char under high temperature explained the high yield of CO in pyrolysis gas products, also resulted in the consumption of salts and limited the sustainable use of the molten salt pyrolysis system.

Abstract Mixtures of peat with bark and peat with straw were burned in a large lab-scale entrained flow reactor under controlled conditions, and deposits were collected on an air-cooled probe controlled at four to six different probe surface temperatures between 475 and 625 °C. The results show that the probe surface temperature has no effect on the deposition rate when peat is burned. When burning bark, either alone or in mixtures with peat, the deposition rate decreases with increasing probe surface temperature. When burning straw, either alone or in mixtures with peat, the deposition rate increases with increasing probe surface temperature up to 550 °C and remains constant at higher temperatures. The Cl content in the deposits decreases with increasing probe surface temperature, regardless of the mixture composition. In deposits obtained from burning peat–bark mixtures, K appears as K 2 SO 4 when the deposition rate is low and as KCl when the deposition rate is high. In deposits obtained from burning peat–straw mixtures, no clear relationship is found between the deposition rate and the contents of Cl, S and K in the deposits.