Production of biodiesel from animal fat using supercritical ethanol

Biodiesel is currently produced from a catalytic transesterification reaction of various types of edible and non-edible oil with methanol. The use of waste animal tallow instead of edible oils opens a route to recycle this waste. This material has the advantage of lower costs but the problem of high content of free fatty acids, becoming necessary a pre-esterification reaction that increases the cost of the catalytic process. The production of biodiesel using supercritical alcohols is appropriate for materials with high acidity and water content, therefore the use of this process with animal fat is a promising alternative. Ethanol has been used because it can be produced from biomass via fermentation resulting in a complete renewable biodiesel, instead of methanol that derives from fossil feedstocks. Two different processes have been studied: first, the direct transesterification of animal fat using supercritical ethanol and second a two-step process where the first step is a hydrolysis of the animal fat and the second step is the esterification of the resulting fatty acids. The temperature, the molar ratio ethanol:fat and the time have been modified in the different reactions to study the effect in the final conversion and the degradation of the unsaturated fatty acid esters, main inconvenient of these high temperature and pressure processes

Fuel / A novel gas chromatographic method for high-resolution analysis of gasoline fuels that enables the calculation of CHO ratio, higher and lower heating value, density and energy density

As the share of renewable gasoline fuels is likely to increase in the next decades to reduce greenhouse gas emissions, efforts to better understand the relationship between fuel composition and fuel properties need to be intensified to ensure the compatibility of alternative fuels with the existing engine fleet. Therefore, a gas chromatographic method with high resolution is presented here, with which it is possible to determine the chemical composition of renewable and conventional gasoline fuels with high accuracy and to calculate the properties CHO ratio, higher heating value (HHV), lower heating value (LHV), density, and energy density. Using a flame ionization detector and a very simple data evaluation algorithm, quantification is carried out via normalization, which avoids the need for complex calibration series. Identification is carried out using a mass spectrometer. The accuracy of the method was checked both internally using standard solutions and a certified reference material and externally by comparison with a measurement of a renewable gasoline sample consisting of 10 % [v/v] EtOH, 22 % [v/v] EtBE, 30 % [v/v] isooctane, and 38 % [v/v] renewable synthetic gasoline (e-fuel) in accordance with EN ISO 22854. All components of the certified reference material could be correctly determined within the mean value \ub1 uncertainty stated in the certificate of analysis. The comparison of the sum parameters with an external analysis according to ISO 22854 and the comparison with external measurements of the CHO ratio and the density were also within the deviations from the mean value of the respective methods given by the reproducibility. However, the HHV and LHV were no longer within the range of the value measured externally using DIN 51900 \ub1 the reproducibility of the method, but were slightly overestimated. The novelty of this method is that it can quickly provide both the chemical composition and some very relevant fuel properties with high accuracy, reliability, and precision, using equipment that is available in almost every chemistry laboratory. This method can therefore be particularly useful for the development of future sustainable gasoline fuels.Version of recor

Angular Stability Margins for the Remote Fusion Cutting Process

AbstractThe set of incident angles, that yields stable cuts when conducting remote fusion cutting (RFC), is of great importance when scheduling multiple cuts on a work piece. This is due to their ability to determine how much the laser beam can be moved by angling the cutting head instead of translating it. This paper investigates how the stability of the RFC process is affected by changing the incident angle when processing stainless steel sheets. This investigation was conducted as an experimental study in which the angle of incidence was decomposed into a work angle and a travel angle. The stability was evaluated by an automatic procedure based on images acquired by a programmable microscope and a computer vision algorithm developed in MATLAB. The results showed that the stability of the RFC process was dependent on the work and the travel angle. It was also seen that a coherent region of stable incident angles could be found. All experiments were conducted with a 3kW single mode fiber laser at the laser processing laboratory at Aalborg University

Influence of Ethanol Organosolv Pulping Conditions on Physicochemical Lignin Properties of European Larch

Over the years, the organosolv pulping process has proven to be a valuable pretreatment method for various lignocellulosic feedstocks. The objective of this study was to characterize and assess the potential applicability of the organosolv lignin fraction from European larch sawdust, as no research has been conducted in this field so far. Eight different samples were prepared from the European larch sawdust under varied reaction conditions and one milled wood lignin sample as reference. The reaction temperature and sulfuric acid loading were varied between 420 and 460 K and 0.00 and 1.10% (w/w on dry wood basis) H2SO4, respectively. The antiradical potential (via DPPH• method), chemical structure (via ATR-FTIR, 1H NMR, 31P NMR, and thioacidolysis), as well as the molecular weight distribution of the isolated lignins were analyzed and compared. Results from thioacidolysis show a direct correlation between the amount of β-ether bonds broken and pulping process severity. Similarly, both antiradical potential and phenolic hydroxyl group content exhibit a direct relationship to reaction temperature and catalyst loading. On the contrary, the content of aliphatic hydroxyl groups and the average molecular weights both decreased with increasing process severity. The high content of phenolic hydroxyl groups and antioxidative potential of the larch organosolv fractions, especially for the sample isolated at 460 K and 1.10% H2SO4 loading, indicate good applicability as antioxidants as well as feedstocks for further downstream valorization and require additional research in this area

Influence of base-catalyzed organosolv fractionation of larch wood sawdust on fraction yields and lignin properties

Lignocellulose-based biorefineries are considered to play a crucial role in reducing fossil-fuel dependency. As of now, the fractionation is still the most difficult step of the whole process. The objective of this study is to investigate the potential of a base-catalyzed organosolv process as a fractionation technique for European larch sawdust. A solvent system comprising methanol, water, sodium hydroxide as catalyst, and anthraquinone as co-catalyst is tested. The influence of three independent process variables, temperature (443-446 K), catalyst loading (20-30% w/w), and alcohol-to-water ratio (30-70% v/v), is studied. The process conditions were determined using a fractional factorial experiment. One star point (443 K, 30% v/v MeOH, 30% w/w NaOH) resulted in the most promising results, with a cellulose recovery of 89%, delignification efficiency of 91%, pure lignin yield of 82%, residual carbohydrate content of 2.98% w/w, and an ash content of 1.24% w/w. The isolated lignin fractions show promising glass transition temperatures (>= 424 K) with high thermal stabilities and preferential O/C and H/C ratios. This, together with high contents of phenolic hydroxyl (>= 1.83 mmol/g) and carboxyl groups (>= 0.52 mmol/g), indicates a high valorization potential. Additionally, Bjorkman lignin was isolated, and two reference Kraft cooks and a comparison to three acid-catalyzed organosolv fractionations were conducted

Fatty acid ethyl esters from animal fat using supercritical ethanol process

Biodiesel is currently produced from a catalytic transesterification reaction of edible and nonedible oils with methanol. New policies are encouraging the development of advanced biofuels produced from lignocellulosic feedstocks or industrial waste as animal fat. This material is less expensive than current oils but usually has high content of free fatty acids and a pre-esterification reaction becomes necessary, increasing the cost of the catalytic process. The production of biodiesel using supercritical alcohols is appropriate for materials with high acidity and water content; therefore, the use of this method for animal fat is a promising alternative. Two different processes have been studied: a single-step direct transesterification using supercritical ethanol and a two-step process of hydrolysis and esterification. Ethanol, instead of methanol, has been used as the reagent because it can be produced from biomass via fermentation, resulting in a complete renewable biofuel. The final conversion and degradation of unsaturated fatty acid esters, which is the main drawback of these high temperature and pressure processes, have been studied through the change of several parameters such as temperature, ethanol:animal fat molar ratio, and reaction time

Fatty Acid Ethyl Esters from Animal Fat Using Supercritical Ethanol Process

Biodiesel is currently produced from a catalytic transesterification reaction of edible and nonedible oils with methanol. New policies are encouraging the development of advanced biofuels produced from lignocellulosic feedstocks or industrial waste as animal fat. This material is less expensive than current oils but usually has high content of free fatty acids and a pre-esterification reaction becomes necessary, increasing the cost of the catalytic process. The production of biodiesel using supercritical alcohols is appropriate for materials with high acidity and water content; therefore, the use of this method for animal fat is a promising alternative. Two different processes have been studied: a single-step direct transesterification using supercritical ethanol and a two-step process of hydrolysis and esterification. Ethanol, instead of methanol, has been used as the reagent because it can be produced from biomass via fermentation, resulting in a complete renewable biofuel. The final conversion and degradation of unsaturated fatty acid esters, which is the main drawback of these high temperature and pressure processes, have been studied through the change of several parameters such as temperature, ethanol:animal fat molar ratio, and reaction time