Search

Worldwide pulp and paper industry is recognized as a serious threat due to the discharge of various toxic contents present in its effluent to the surrounding environment. To combat this challenge, the role of oleaginous yeast to utilize the pulp and paper industry effluent for the integrated toxic contents removal and sustainable biodiesel production were undertaken. Oleaginous yeast Rhodosporidium kratochvilovae HIMPA1 was used as a model organism for its unique ability to utilize pulp and paper industry effluent as a culture medium and accumulate high quantity of triacylglycerol or neutral lipids as large size lipid droplets of 4.56 ± 0.24 μm within its cellular compartment. The maximum cell dry weight (13.87 g/L) with total lipid yield of 8.56 g/L was obtained after 144 h of cultivation. Data showed significant reduction in effluent toxic components i.e. color, 89%; lignin, 94.27%; phenol, 99.60%; biochemical oxygen demand, 77.36%; total dissolved solids, 84.59%; and chemical oxygen demand, 94.22%. Fatty acid methyl esters profile revealed high quantity of long chain monounsaturated fatty acids (45.43%) and polyunsaturated fatty acids (15.91%) that improves biodiesel quality under low temperature condition in terms of low cold filter plugging point along with good oxidative stability and cetane number as per American Society for Testing and Materials D6751-02 and European Committee for Standardization - EN14214 guidelines. [ABSTRACT FROM AUTHOR]

With industrialization and development in modern science enzymes and their applications increased widely. There is always a hunt for new proficient enzymes with novel properties to meet specific needs of various industrial sectors. Along with the high efficiency, the green and eco-friendly side of enzymes attracts human attention, as they form a true answer to counter the hazardous and toxic conventional industrial catalyst. Lipases have always earned industrial attention due to the broad range of hydrolytic and synthetic reactions they catalyse. When these catalytic properties get accompanied by features like temperature stability, pH stability, and solvent stability lipases becomes an appropriate tool for use in many industrial processes. Extremophilic lipases offer the same, thermostable: hot and cold active thermophilic and psychrophilic lipases, acid and alkali resistant and active acidophilic and alkaliphilic lipases, and salt tolerant halophilic lipases form excellent biocatalyst for detergent formulations, biofuel synthesis, ester synthesis, food processing, pharmaceuticals, leather, and paper industry. An interesting application of these lipases is in the bioremediation of lipid waste in harsh environments. The review gives a brief account on various extremophilic lipases with emphasis on thermophilic, psychrophilic, halophilic, alkaliphilic, and acidophilic lipases, their sources, biochemical properties, and potential applications in recent decades. • Extremophilic lipases include hot and cold active thermophilic and psychrophilic lipases, acid and alkali resistant and active acidophilic and alkaliphilic lipases, and salt tolerant halophilic lipases. • Microorganisms as sources of extremophilic lipases and their adaptations. • Extremophilic lipases as catalyst for detergent formulations, biofuel synthesis, ester synthesis, food processing, pharmaceuticals, leather, and paper industry. • Scope of genetic manipulation and continuous production on cheap substrates point towards the biotechnological potency of extremophilic lipases. [ABSTRACT FROM AUTHOR]

Abstract The objective of this paper is to assess the impact on fuel saving and emission reduction of biodiesel for power generation, using a wide range of economic indicators. There are many benefits that countries, especially developing ones can gain from renewable fuels like biodiesel. Apart from the possibilities that opens for economic growth and development across the country, especially for rural communities; opportunities are available for independent power producers to generate power to off-grid users and local businesses. This is only achievable from engines and fuels with good economic performance. This paper analyse the impact of Callophyllum inophyllum (CI) biodiesel on the fuel saving and the carbon dioxide (CO 2) emission reduction, focusing on the application of CI biodiesel in two different systems, namely internal combustion engines in the transport sector and gas turbines in the power sector. The results showed that application of CI biodiesel in the power sector is able to have more significant savings in fuel and reduction in the CO 2 emissions. [ABSTRACT FROM AUTHOR]

Abstract This paper presented experimental results to evaluate the optimization of production parameters through response surface methodology. These parameters significantly affected the yield of cottonseed oil methyl ester (COME). The input variables for the production of methyl ester from cottonseed oil were methanol/oil molar ratio, concentration of catalyst, temperature, and stirring speed. The response or output variable was the yield of methyl ester. The fatty acid methyl ester composition of COME (biodiesel) was obtained using a gas chromatography (GC) analyzer. BS EN 14103:2011 was the standard used to analyze the fatty acid methyl ester. The derived mathematical model was statistically accurate to predict the optimum value of COME. The optimized values to obtain a 98.3% yield of methyl ester were as follows: methanol/oil molar ratio of 6:1, catalyst concentration of 0.97% (w/w), temperature of 63.8 °C, and speed of 797 rpm. The physicochemical properties of COME were measured in accordance with ASTM D6751. The friction and wear properties of COME and its blends with petroleum diesel were tested using a four-ball wear testing machine. The tribological characteristics of COME as a new biofuel were assessed. COME displayed good lubricity with a low coefficient of friction and wear scar diameter. The coefficient of friction of pure COME (COME100) was lower than that of pure petroleum diesel (DL100) and COME blends with petrol diesel (COME10, COME20, and COME50). The average coefficient of friction of COME 100 was lower than that of DL100, COME10, COME20, and COME50 by 28.06%, 19.49%, 7.49%, and 3.65%, respectively. The wear scar diameter of COME100 for the tested ball was lower than that of DL100, COME10, COME20, and COME50 by 47.6%, 33.3%, 32.1%, and 21.42%, respectively. The worn surfaces of the tested balls were examined by scanning electron microscopy, and the results were presented in this paper. Highlights • The response surface methodology was utilized to optimize the production process parameters. • The tribological characteristics of cottonseed oil methyl ester (COME) as a new biofuel were assessed. • Friction and wear were reduced with increased concentration of COME in the testing fuel. • The average coefficient of friction was reduced with increased concentration of COME in the testing fuel. • The wear scar diameter of worn surfaces was enhanced with the reduction of COME concentration in the testing fuel. [ABSTRACT FROM AUTHOR]

The past few decades had seen a rapid hike in the world's population, which has caused an excessive use of fossils and, consequently, the diminution of fossil resources and the advent of global pollution problems. In this regard, the renewable and eco-friendly properties of biodiesel fuel provide an alternative to petroleum fuel. Many countries are looking into the use of biodiesel, particularly countries that are more susceptible to environmental problems. Biodiesel could be synthesized from different origins, including organic oils from animal fats and vegetables. At the same time, the production of biodiesel from vegetable edible oils can create food security problems; hence, the selection of cheap sources, like animal fats, is a valuable feedstock, but its availability is limited. Thus, more preferable sources other than low-cost feedstocks with high free fatty acids content include unrefined crude oils, discarded cooking oil and inedible oils. This paper is aimed to highlight biodiesel and its availability from various feedstock for its preparation. It also discussed how the ionic liquids (ILs) can be the catalysts to produce biodiesel; these liquids are sourced by different feedstocks by transesterification method. Due to several limitations and problems associated with traditional homogeneous and heterogeneous catalysts in recent years, ILs are increasingly used as the catalysts or solvents for free fatty acids esterification, as well as the transesterification of vegetable oils. This paper is focused on the transesterification of fatty acid with ILs, cost and recycling of ILs, the effects of adding enzyme, Lewis acids and amines on ILs catalysed reaction, the use of Brønsted acidic, basic and dicationic basic ILs as the sole solvent which supported acid/base-catalysed IL for biodiesel synthesis. In addition, the proper research focuses and new developments in this regard would make the ILs as an ideal catalyst for biodiesel preparation from various feedstocks. [ABSTRACT FROM AUTHOR]

This paper is an investigation and study of how combustion characteristics appear in constant volume combustion chamber(CVCC) when biodiesel is mixed with pure gasoline. Experimental data for this study included four gasoline biodiesel fuel mixtures with concentrations of biodiesel of 5 and 20 designated GB05 and GB20 respectively. The study involves studying the positive aspects of combustion efficiency because biodiesel contains an oxygenated fraction. Through this study, we can find the most effective and efficient substitute fuel by comparing the total fuel mixture. Through these paper, you can improve your knowledge of gasoline biodiesel blended fuels and then utilize alternative fuels in high combustion efficiency and environmentally friendly modern gasoline compression ignition engines. [ABSTRACT FROM AUTHOR]

Rapeseed is currently cultivated as an industrial crop in Latvia as a source of oil rich biomass to contribute to renewable energy goals of the European Union. However, rapeseed oil can also be used as a feedstock biobased polyurethane production. Latvian State Institute of Wood Chemistry have developed polyols based on rapeseed oil and have developed biobased and volatile organic compounds-free polyurethane coatings. The main aim of this study was to present a Life Cycle Inventory of spring and winter rapeseed produced in Northern European country Latvia based on primary data of agricultural practices used in this region. The study was carried in accordance with ISO 14040 and ISO 14044. Data were collected from a large crop company in Latvia to ensure a specific and accurate data collection for the definition of the complete supply chain. The reference unit of this study was defined as 1 ha, time horizon 2008–2016, stages from the raw materials production to the seed harvesting were considered. The data presented will add to and expand the existing knowledge of rapeseed production in other European countries. Lastly, this paper is the first in a series of papers that will result in a complete Life Cycle Assessment for these develop polyurethane coatings based on rapeseed oil polyols to avoid black box unit process and provide transparent results. [ABSTRACT FROM AUTHOR]

Biodiesel is one of the ideal options, considering it is a renewable, biodegradable, non-toxic, environmentally friendly fuel with low pollutant emission. However, biodiesel encounters challenges, mostly connected to its high manufacturing costs, that hinder its continued development and advancement. Focusing on more affordable and environmentally friendly inputs, such as suitable and abundant feedstock and efficient catalysts, is crucial. This paper aims to summarize the literature on biodiesel production and life cycle assessment (LCA) studies, critically review the catalyst and oil feedstock employed, and the findings of the LCAs, focusing on spotting prospective low-cost feedstock sources. Furthermore, an overview of recent LCA-related works applied in various biodiesel processes incorporating various catalysts and oil feedstock was evaluated. The application of LCA and its environmental impacts in biodiesel production was discussed and summarised in table form. The importance of using a sustainable and favorable approach could result in cost-efficient biodiesel production. Additionally, the advantages and limitations of the LCA in biodiesel production have been discussed. Last, the status and challenges of LCA in biodiesel production are covered. The findings of using cheaper feedstock are expected to inspire future studies and help industry professionals develop sustainable biodiesel production. • A comprehensive review of LCA framework and biodiesel process technologies were covered. • LCA of biodiesel production using various catalysts and oil feedstock was reviewed. • Challenges and status were discussed for sustainable biodiesel production. [ABSTRACT FROM AUTHOR]

The current environmental scenario has encouraged the study of renewable and competitive alternative feedstocks for biodiesel production. Microalgae present a significant opportunity as a feedstock that does not require arable land and can be cultivated using wastewater. The paper investigates the optimization of biodiesel production from microalgae Nannochloropsis gaditana bio-oil using response surface methodology and also analyzes the main physicochemical properties of the bio-oil. It was confirmed that this methodology is suitable for materials with low homogeneity. The model is also adequate for determining optimal experimental conditions, resulting in a FAME content of 87.25 %. The biodiesel's physicochemical properties were analyzed. It was discovered that the high degree of unsaturation in the microalgae bio-oil's chemical structure resulted in a narrower temperature range for its application compared to other vegetable sources. [Display omitted] • RSM is also applicable to transesterification reactions of low homogeneity oils. • Higher FAME content was achieved by optimizing transesterification with RSM. • The high unsaturation in microalgae oil reduces the thermal stability of biodiesel. • Higher PP/lower FP in microalgae-derived biodiesel is due to the high unsaturation. [ABSTRACT FROM AUTHOR]

The world is facing critical energy concern, in view of depleting fossil fuel reserves and increasing environment pollution. Biodiesel can potentially substitute fossil fuel, and is produced through the transesterification of vegetable oils. This paper will emphasize on the transition from first generation derived from waste cooking oil, to second generation biodiesel derived from calophyllum inophyllum, which is a non-edible plant. The objective of this paper is to optimize the performance of biodiesel blends with diesel in a 30 kW microturbine. The characterization of chemical fuel properties of distillate and biodiesel blends will be conducted to determine if it meets international standards for power generation. Temperature profiles, pressure, and flame imaging will be closely monitored to detect possible problems in operability of the combustor caused by the differences in fuel characteristics. The findings may provide useful information towards optimization of microturbine performance, considering the wide range of biodiesel feedstock that exist. The paper outcome will show the potential of non-edible biodiesel blends to be used as alternative fuel in microturbines for power generation. [ABSTRACT FROM AUTHOR]

The transesterification of vegetable oils with alcohols is the most widely used method in biodiesel synthesis, generally taking place in batch processes. However, this production is currently being explored in microdevices, due to its short residence times and high conversions. This paper presents an experimental and numerical study of biodiesel synthesis in a microdevice from sunflower oil and ethanol using sodium hydroxide as catalyst. The influence of three operating variables were studied (temperature, ethanol/oil ratio and catalyst concentration). This paper also compares the reaction performance of a batch reactor with a microdevice reactor. The highest percentages of biodiesel found for the batch process and for the microdevice were 94.1% and 95.8%, respectively. These results proved the efficiency of microdevice in the biodiesel synthesis over conventional reactors. The superior results predicted for oil conversion, production yield and esters selectivity in numerical simulations were 99.90%, 2.10 and 0.42, respectively. The transesterification process simulation and intensification can be performed numerically evaluating reaction yield and selectivity parameters. [ABSTRACT FROM AUTHOR]

For remote areas, small-scale local biodiesel production is particularly attractive if producers and consumers are the same. Such supply chains are labeled as bidirectional. However, little is known on how raw material supply, transportation, logistics, production and operations uncertainties impact the operational performance of such Bidirectional Biodiesel Supply Chains. This paper contributes by exploring these uncertainties in a multiple case study, directed at mobile processing of rubber seeds, in a remote area. Scientifically, the paper contributes by identifying several novel sources of uncertainty: a short-term perspective, lack of knowledge and the previously unrecognized influence of the local government. Additionally, based on these findings, an extended theoretical framework is proposed which links sources of uncertainty to operational performance. The study provides also insights for stakeholders aiming to increase local biofuel production and provides a stepping-stone to investigate adequate measures to manage the identified uncertainties. [ABSTRACT FROM AUTHOR]

Biodiesel is a promising alternative energy source as it is renewable, biodegradable, and environmental friendly. This study deals with oils production from wastewater sludge. Primary, secondary, and mixed municipal sludge and pulp and paper secondary sludge collected in Québec City, Canada has 5–11% oil content (based on weight) in initial sludge. The oil content is in the order of pulp and paper secondary sludge > municipal primary sludge > municipal mixed sludge > municipal secondary sludge. Different types of sludge were also used for lipid production by Pichia amethionina sp ., Galactomyces sp ., and Trichosporon oleaginosus . The results showed that maximum lipid content was obtained in municipal secondary sludge among all types. Further, the effect of initial sludge suspended solids concentration (10–30 g/L) on lipid accumulation was investigated. The maximum lipid content of 30.17% and 32.42% w/w dry weight, was reached by P . amethionina sp. and Galactomyces sp., respectively, at 25 g/L suspended solids concentration, and that of 37.69% w/w dry weight by T . oleaginosus at 30 g/L suspended solids concentration all with municipal secondary sludge. The results showed that carbon to nitrogen ratio had more obvious effect on lower suspended solids concentration (10 g/L) than on the higher one (30 g/L) in lipid accumulation of the three strains. [ABSTRACT FROM AUTHOR]

In a previous paper we investigated the influence of sorbed biodiesel or diesel on mechanical properties of a typical polyethylene grade for tank applications. Besides the basic sorption and desorption behavior of these two fuels, the study addressed the concentration-dependent mechanical properties as revealed by a non-instrumented Charpy impact test and dynamic mechanical analysis (DMA). In the present paper we extend this investigation focusing on the temperature-dependent impact fracture behavior. Therefore, an instrumented Charpy impact test was employed, allowing a more detailed analysis of the fracture behavior. Furthermore, from the load-time-diagrams obtained from the instrumented impact test, corresponding fracture times can be calculated, allowing a clear correlation of the fuel sorption induced changes in fracture toughness with the enhanced β-relaxation observed by DMA. As in the previous study, the fracture surfaces of the impact tested specimens were analyzed in order to confirm the brittle or ductile character of the fracture indicated by impact strength and the corresponding load-deflection diagrams. [ABSTRACT FROM AUTHOR]

The present paper investigates about the production of biodiesel from neat Mahua oil via base catalyzed transesterification and mixing of the biodiesel with a suitable additive (Dimethyl carbonate) in varying volume proportions in order to prepare a number of test fuels for engine application. The prepared test fuels are used in single cylinder water cooled diesel engine at various load conditions to evaluate the performance and emission parameters of the engine. The results of investigation show increase in brake power and brake thermal efficiency with load for all prepared test fuels. It is also noticed that brake thermal efficiency increases with the percentage of additive in all the test fuels. The brake specific fuel consumption decreases with increase in additive percentage. Exhaust gas temperature increases almost linearly with load for all test fuels and decreases with increase in additive percentage. It is also seen from the results that both CO and HC emissions tend to decrease with increase in additive percentage in biodiesel. The smoke and NOx emissions also decrease with increase in additive percentage in the biodiesel fuel. During the course of this experimental investigation it was found that the overall performance and emission characteristics of the engine was satisfactory with all the test fuels and improved with repeated experiments. All the test results significantly improved with increase in the additive percentage in biodiesel. Therefore the present paper provides a strong platform to continue further investigation on using biodiesel fuel in a diesel engine with variety of fuel additives under varying engine operating parameters. [ABSTRACT FROM AUTHOR]

This review emphasizes the crucial role of enzyme immobilization technology in advancing the production of two main biofuels, ethanol and biodiesel, with a specific focus on the Cross-linked Enzyme Aggregates (CLEAs) strategy. This method of immobilization has gained attention due to its simplicity and affordability, as it does not initially require a solid support. CLEAs synthesis protocol includes two steps: enzyme precipitation and cross-linking of aggregates using bifunctional agents. We conducted a thorough search for papers detailing the synthesis of CLEAs utilizing amylases, cellulases, and hemicellulases. These key enzymes are involved in breaking down starch or lignocellulosic materials to produce ethanol, both in first and second-generation processes. CLEAs of lipases were included as these enzymes play a crucial role in the enzymatic process of biodiesel production. However, when dealing with large or diverse substrates such as lignocellulosic materials for ethanol production and oils/fats for biodiesel production, the use of individual enzymes may not be the most efficient method. Instead, a system that utilizes a blend of enzymes may prove to be more effective. To innovate in the production of biofuels (ethanol and biodiesel), enzyme co-immobilization using different enzyme species to produce Combi-CLEAs is a promising trend. • The review deals the use immobilized enzymes in the ethanol and biodiesel production. • Due to the nature of substrates, the CLEAs strategy received a special focus. • The CLEAs as biocatalysts have high potential for the ethanol and biodiesel production. • The Combined-CLEAs technology can be a new tendency to innovate in this field. [ABSTRACT FROM AUTHOR]

Abstract: This special volume of the Journal of Cleaner Production was developed primarily based on materials presented at the 2nd International Workshop Advances in Cleaner Production held in São Paulo, Brazil, in 2009. The content reflects the growing awareness of the urgent and unavoidable need for making changes to help transform unsustainable to sustainable societies. The eleven papers provide different viewpoints to help society make progress on the journey towards sustainability. Key elements of this urgent journey are addressed in this collection of papers; some challenge society to address the problems in a systematic manner and some underscore the essentiality of proper planning by using green teams, or a Sustainable Environmental Management System. Other authors explored the role of proactive regulation and economic instruments to promote environmental performance improvements. Innovation through learning and promotion of multidisciplinary thinking as well as transference of information and knowledge between academy and industry are key aspects explored. Their inputs enabled this editorial team to propose alternatives uses for ‘wastes’, for substituting one raw material for another, which is environmentally and economically advantageous, for changing industrial process to decrease Greenhouse Gas emissions, or for optimizing diverse processes. The role of the Clean Development Mechanism as a promoter of implementation of innovative cleaner technologies in host countries is discussed. A systemic assessment tool, emergy synthesis, was employed to evaluate a reverse logistic enterprise from an environmental perspective. [Copyright &y& Elsevier]

Abstract: The depleting fossil fuels with their ever increasing prices have paved ways for alternative fuels. Biodiesel is one of those alternative fuels which have picked up keen interest of the people due to its similar properties to diesel. However due to biodiesel being costlier than diesel in the present scenario, it has not been preferred to diesel. However if the cost of biodiesel is reduced then its effective usage can be made, either by blending with conventional diesel or by utilizing its byproduct (glycerol) effectively. One way is to use glycerol to produce hydrogen. Hydrogen, being another source of renewable energy, is also seen as a clean fuel for transportation purpose. Hydrogen can be prepared through glycerol via various routes namely steam reforming, auto-thermal reforming, partial oxidation, etc. The paper here focuses on the steam reforming process. This process is used widely used in the industries and it would not require much change in the system if the feedstock is changed to glycerol from naphtha or natural gas. However like every process this process also has some limitations which hinder the effective production of hydrogen. The paper throws light on these challenges, along with few possible solutions which can be used in order to avoid or eliminate these challenges and help in efficient production of hydrogen. [Copyright &y& Elsevier]

Abstract: In recent years, environmental problems caused by the use of fossil fuels and the depletion of petroleum reserves have driven the world to adopt biodiesel as an alternative energy source to replace conventional petroleum-derived fuels because of biodiesel''s clean and renewable nature. Biodiesel is conventionally produced in homogeneous, heterogeneous, and enzymatic catalysed processes, as well as by supercritical technology. All of these processes have their own limitations, such as wastewater generation and high energy consumption. In this context, the membrane reactor appears to be the perfect candidate to produce biodiesel because of its ability to overcome the limitations encountered by conventional production methods. Thus, the aim of this paper is to review the production of biodiesel with a membrane reactor by examining the fundamental concepts of the membrane reactor, its operating principles and the combination of membrane and catalyst in the catalytic membrane. In addition, the potential of functionalised carbon nanotubes to serve as catalysts while being incorporated into the membrane for transesterification is discussed. Furthermore, this paper will also discuss the effects of process parameters for transesterification in a membrane reactor and the advantages offered by membrane reactors for biodiesel production. This discussion is followed by some limitations faced in membrane technology. Nevertheless, based on the findings presented in this review, it is clear that the membrane reactor has the potential to be a breakthrough technology for the biodiesel industry. [Copyright &y& Elsevier]

• Glycerol is reformed into syngas by boiling it in the film boiling regime. • Product yields show 95% combustible gases with 70% being synthesis gas. • An optimal operating temperature based on a thermodynamic conversion efficiency is identified. • The most probable reactions are identified to explain the stable species formed. In this paper, a simple method is presented to transform saturated liquid glycerol into a gaseous fuel mixture containing hydrogen (H 2), carbon monoxide (CO), methane (CH 4), ethylene (C 2 H 4), and ethane (C 2 H 6). It is based on glycerol decomposition within the vapor film of the film boiling regime of multiphase heat transfer on a horizontal tube. In film boiling, a thin gas layer of predominantly glycerol vapor surrounds the tube and decomposes as the gases flow in the film under the influence of buoyancy. The decomposition products are removed in the form of bubbles percolating through the liquid pool and their contents are chemically analyzed to determine the decomposition products and their fractional amounts. The glycerol boiling curve and critical heat flux were measured to determine the operational domain for decomposition which is between glycerol's minimum film boiling temperature and an upper value dictated by material considerations of the tube that supports the vapor film. The results show that 95% of the gases produced by decomposition of glycerol are themselves viable as a fuel. Decomposition of glycerol is a multistep process initiated by radical species in the product stream. Key reactions are identified by a sensitivity and pathway analysis. An optimal thermal efficiency and corresponding temperature for conversion corresponding to the experimental design is suggested for conversion by film boiling at atmospheric pressure. [ABSTRACT FROM AUTHOR]

Though microalgae and macroalgae are considered as a potential feedstock for biofuel and industrially important co-products extraction, still there are several research barriers on the commercialization of algae-based fuels and products. Based on these bottlenecks, this review underpins the biochemical composition of micro- and macroalgae regarding biofuel production and bioactive compounds extraction. Further, the second chapter summarizes the various cultivation systems for rapid generation of macroalgal biomass. Micro- and macroalgae are untapped for bioenergy production to assess the feasibility of future green fuel sustainability. In general, algae were considered as a potential source for various applications worldwide owing to their rich and enormous bioactive potential. Therefore, a separate section devoted to recognize the crucial role and biological activities of primary and secondary metabolites in micro- and macroalgal species, their significant contribution as functional foods or therapeutic agents in nutraceutical and pharmaceutical industries. The extensive discussion on the phenolics, flavonoids and pharmacological properties of other bioactive compounds extracted from microalgae has been provided. Further, carbohydrates, proteins (phycobiliproteins and phycoerythrin) and their organic extraction from macroalgal strains (seaweeds) were well described. This review paper describes the importance of bioactive compounds and their value in the various other markets besides biofuel production. Image 1071 • Insights on biochemical composition of micro- and macroalgae were given. • Flaws in bioenergy production from microalgae and macroalgae were addressed. • Bioactive compounds from microalgae and their applications were presented. • Algal co-products in pharmacology and nutraceutical were critically discussed. • High-value products of macroalgae and their extraction were reviewed and described. [ABSTRACT FROM AUTHOR]

Abstract Evaluating the impacts on biodiversity by means of the life cycle assessment (LCA) is a task researchers are currently facing. One impact assessment method that aims to do so is the recently developed biodiversity impact assessment BIA+. The aim of the present paper is to test this method and to show its applicability and feasibility. Additionally opportunities and challenges of this method shall be revealed. For this purpose, a case study for assessing the impacts of biodiesel production on freshwater biodiversity is introduced. Two substances, namely phosphorus and 1,4-dichlorobenzene (DCB), which are used for the biodiesel production for fertilization and the usage of pesticides, are being considered. The inventory data needed for the case study is gathered through the grey water footprint of the crop production that forms the basis of the European biodiesel consumption. Further, the BIA+ method is applied in order to assess the impacts of the biodiesel consumption in Europe for the year 2010 on freshwater biodiversity. The results reveal that even though assumptions have to be made and the results are highly uncertain, this method helps to identify hotspots within production processes. By including the BIA+ as an impact assessment method into LCA, impacts of products can be assessed with regard to biodiversity including genetic, species and ecosystem diversity. The main impact hotspot occurs in France with a potential loss of the biodiversity of 0.5 points. The lowest loss of the biodiversity occurs in Brazil (loss of 8.05*10–06 points). The results are mainly influenced by the impact of the toxic substance 1,4-DCB. By means of the case study, it is shown that the BIA+ method is applicable. [ABSTRACT FROM AUTHOR]

Biodiesel production depends to a great extent on the use of cheap raw materials, since biodiesel itself is a mass product, not a high-value product. New processing methods, such as micro-flow continuous processing combined with enzymatic catalysis, open doors to the latter. As reported here, the window of opportunity in enzyme-catalyzed biodiesel production is the conversion of waste cooking oil. The main technological challenge for this is to obtain efficient immobilization of the lipase catalyst on beads. The beads can be filled into tubular reactors where designed packed-bed provide porous channels, forming micro-flow. It turns out, that in this way, the immobilization costs become the decisive economic factor. This paper reports a solution to that issue. The use of oil cake enables economic viability, which is not given by any of the commercial polymeric substrates used so far for enzyme immobilization. The costs of immobilization are mirrored in the earnings and cash flow of the new biotechnological process. • Adding value and minimizing waste from the vegetable oil production. • Use of waste/by-product from oil industry in biodiesel production. • Economic feasibility of biodiesel production with immobilized lipase onto oil cake. • Biodiesel production in packed-bed micro-flow reactors with enzymes at industrial level. [ABSTRACT FROM AUTHOR]

Abstract Due to the European favorable policy, the process to convert Used Cooking Oil (UCO) into biodiesel has resulted in a rapid increase over the last years. However, the manufacture of biodiesel can be hazardous if suitable precautions are not taken, as it involves the storage, handling and use of several hazardous substances. Although the rise in the number of biodiesel process plants and new operators has resulted in a number of incidents resulting in loss of life and property, publications concern the risks regarding the production of UCO based biodiesel are limited. By taking into account the high rise of the biodiesel industry and UCO collection it is essential to develop an operational risk management tool. The scope of this paper is: (i) the clarification of the importance of safety during the production (life cycle) of UCO based biodiesel; (ii) the identification of probable hazards incorporated to the overall production process of UCO based biodiesel; and (iii) the assessment of these hazards by stakeholders. In this way, there will be available data which allow to check the performance and to avoid mishap recurrence, by identifying the converse incidents which are more likely to occur. Highlights • Hazards in the UCO-to-biodiesel industry were categorized and assessed. • The highest identified hazards were related to the storage and use of methanol in the biodiesel plant. • The major type of accidents at biodiesel facilities recognized to be fires and explosions. [ABSTRACT FROM AUTHOR]

Abstract Now-a-days biodiesel is gaining attention for its positive impact on the environment. The vegetable oils are major sources of biodiesel. For biodiesel programme in India, jatropha (Jatropha curas) has been identified as one of the most suitable tree borne non-edible oil seed. But its major drawback is its poor oxidation stability. The mahua (Madhuca indica) is another tree borne non-edible oil seed found in India and its production potential is about 60 MT per annum. Its oil content is around 35–40% and its calorific value is close to that of mineral diesel. In this paper, an attempt has been made to study and compare the oxidation and storage stability of mahua biodiesel with that of jatropha biodiesel and mineral diesel. To improve the oxidation stability, the biodiesels have been blended with mineral diesel and it has been found that 20% blended jatropha biodiesel (JB20) and 30% blended mahua biodiesel (MB30) satisfy the EN-590 limit of 20 hrs. When both the biodiesels are blended in different proportions, the 50:50 mixtures by volume satisfy the EN-14214 limit of 6 hrs. For the storage stability study, the different biodiesel samples have been stored in a specified conditions for 8 fortnights (120 days) period and the different properties like density, kinematic viscosity, flash point and acid number of the samples have been measured. It has been found that the rate of change in values of the properties is higher in case of jatropha biodiesel and its blends than that of mahua biodiesel and its blends. [ABSTRACT FROM AUTHOR]

Abstract This paper concerns about bio fuel production from renewable biomass resource and its characteristics in diesel engines. In this research work, Free Fatty Acid Oils (FFAO) from oil refineries was considered as biomass renewable resource for the production of biodiesel. These free fatty acid oil are one of the waste by product in edible oil extraction refineries and its potential energy can be easily converted into useful biodiesel in bio fuel sector by the process of transesterification. Due to ethanol catalyst used in transesterification process, Ethyl esters of free fatty acid oils (EEFFAO) were extracted from FFAO. These EEFFAO were blended with diesel in different proportions (20, 40, 60, 80 and pure EEFFAO) to indentify the maximum possibility to use an biodiesel in diesel engines. From the results, possibilities of biofuel from free fatty acid oil can be replaced at 20 percentage in existing fossil fuel depletion. [ABSTRACT FROM AUTHOR]

Abstract This paper studied the production of waste cooking biodiesel as an alternative fuel for diesel engine. The biodiesel was produced through conventional transesterification process using the base catalyst (KOH). A multi-cylinder diesel engine was used to evaluate the emission of 20% (B20) waste cooking biodiesel fuel at different engine speeds and full load condition. It was found that the characteristics of biodiesel are within the limit of specified standards (American Society for Testing and Materials, ASTM D6751) and comparable to diesel fuel. Engine emission results indicated that waste cooking biodiesel fuel sample reduces the average carbon monoxide (CO) and particulate matter (PM) emissions except nitrogen oxides (NO x) than diesel fuel. Finally, it can be concluded that 20% of waste cooking biodiesel can significantly contribute to lower the harmful emission of an unmodified stationary diesel engine to the environment. [ABSTRACT FROM AUTHOR]

Abstract Renewable energy is free, abundant, clean and could contribute towards a significant reduction of the global warming emissions. It is massively introduced as a source of electricity production across the globe and is expected to become the primary source of energy within the following decades. However, despite the naturally replenished energy, the supply is not always available. For this reason, it is necessary at times of excess energy, any surplus quantity to be sufficiently captured, stored and later used when a deficit occurs. In this paper, an overview of a backup power system operating with a hydrogen-biodiesel dual-fuel internal combustion engine is provided. The system is utilizing the organic chemical hydride method for safe hydrogen storage and transportation. The high energy content of hydrogen stored in the form of an organic hydride under ambient conditions makes it an ideal energy backup medium for large-scale and long-term applications. The research work focusses on the operation and emissions output of the dual-fuel internal combustion engine running on fully renewable fuels and the results are compared with the conventional petroleum-derived diesel engine. Biodiesel-hydrogen operation shows significant benefits in the reduction of carbon and soot emissions but deteriorates the NOx formation compared to the conventional diesel-powered engines. The operation of the engine at high loads can provide high exhaust thermal energy while alternative combustion strategies are necessary to be implemented at low load conditions for the optimum operation of the backup power system. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study is to identify, through motivating, inhibiting and facilitating factors, responses to institutional pressures on the relationship between biodiesel plants and family farming cooperatives via the Social Fuel Seal (SFS) in the South region of Brazil. This region is characterized by well-endowed family farming cooperatives. This paper adopts as theoretical lens the institutional theory. It is based on case studies involving qualitative research drawing results from four biodiesel plants with SFS certification and eight family farming cooperatives. The results indicate that the institutional biodiesel framework influenced the SFS-based relationships. This coercion mechanism led the plants to comply with the promotion of family farming via cooperatives. The plants seek legal legitimacy and opt to accept institutional pressures, primarily due to the guaranteed sale of all biodiesel produced via government sponsored auctions. Cooperatives are attracted by the receipt of the social bonus, seen as a prime motivating factor, which can be interpreted as an informal coercive pressure. Considering the context in which the plants and cooperatives are inserted, the SFS promoted changes in the sale of raw materials. It was also found that cooperatives facilitating factors are inversely related with plants inhibiting factors. Highlights • The government acts as an inducer and regulator of the biodiesel supply chain. • SFS based institutional interventions curb market dynamics. • In environments controlled by coercive pressures, companies adapt through specific incentives. [ABSTRACT FROM AUTHOR]

Highlights • Glycerine emulsions of diesel-biodiesel blends are tested in a modern diesel engine. • Glycerine from biodiesel production is purified and used in making glycerine emulsions. • Lower temperatures and emissions of oxides of nitrogen were observed with glycerine emulsions. • Lower smoke with glycerine emulsions was also obtained. Abstract The extensive use of biodiesel as an alternate fuel has resulted in the oversupply of glycerine, leading to an increased demand to look for the use of glycerine as an alternate fuel. In this paper, multiple blends of diesel-biodiesel and their glycerine emulsions were compared to investigate the performance and emissions in a modern small diesel engine. A direct injection diesel engine was tested at different loads and speed conditions. Biodiesel was produced onsite and crude glycerine obtained as a by-product was purified using an orthogonal test method. Hydrophilic-lipophilic balance was formulated using two surfactants: Polyoxyethylene Sorbitan Monooleate and Sorbitan Monooleate, which were used in the emulsification process to attain desired stability of glycerin emulsion. Emulsion stability, mean particle droplet size, fuel properties, engine performance, and emissions were examined. Test results show that with the increase in glycerine concentration, brake-specific fuel consumption and brake-thermal efficiency increased. In terms of emissions, it was seen that carbon monoxide and unburned hydrocarbon increased, and reductions in exhaust gas temperature and oxides of nitrogen were observed. In addition, there was a significant decrease in smoke (approximately 80%) with an increased concentration of glycerine at 3000 rpm, at high load. [ABSTRACT FROM AUTHOR]

Abstract: In this work the deactivation of an ionic exchange resin, used as catalyst for promoting the esterification of fatty acids for producing biodiesel, has been studied. At this purpose, a dynamic mathematical model, suitable to describe the performances of a continuous tubular reactor containing the catalysts mixed with stainless steel springs as inert diluent, and its evolution with time due to the catalyst deactivation, has been developed. Experimental runs, performed in a pilot plant tubular reactor on fatty acid mixtures (oleins), are reported in the paper. The catalyst deactivation has been shown to depend mainly on the poisoning effect of iron that was present as impurity in the fatty acids used as feedstock. Some information about catalyst regeneration is also given at the end of the paper. [Copyright &y& Elsevier]

Abstract: In the last few years, biodiesel has emerged as one of the most potential renewable energy to replace current petrol-derived diesel. It is a renewable, biodegradable and non-toxic fuel which can be easily produced through transesterification reaction. However, current commercial usage of refined vegetable oils for biodiesel production is impractical and uneconomical due to high feedstock cost and priority as food resources. Low-grade oil, typically waste cooking oil can be a better alternative; however, the high free fatty acids (FFA) content in waste cooking oil has become the main drawback for this potential feedstock. Therefore, this review paper is aimed to give an overview on the current status of biodiesel production and the potential of waste cooking oil as an alternative feedstock. Advantages and limitations of using homogeneous, heterogeneous and enzymatic transesterification on oil with high FFA (mostly waste cooking oil) are discussed in detail. It was found that using heterogeneous acid catalyst and enzyme are the best option to produce biodiesel from oil with high FFA as compared to the current commercial homogeneous base-catalyzed process. However, these heterogeneous acid and enzyme catalyze system still suffers from serious mass transfer limitation problems and therefore are not favorable for industrial application. Nevertheless, towards the end of this review paper, a few latest technological developments that have the potential to overcome the mass transfer limitation problem such as oscillatory flow reactor (OFR), ultrasonication, microwave reactor and co-solvent are reviewed. With proper research focus and development, waste cooking oil can indeed become the next ideal feedstock for biodiesel. [Copyright &y& Elsevier]

Abstract: Biodiesel is a low-emissions diesel substitute fuel made from renewable resources and waste lipid. The most common way to produce biodiesel is through transesterification, especially alkali-catalyzed transesterification. When the raw materials (oils or fats) have a high percentage of free fatty acids or water, the alkali catalyst will react with the free fatty acids to form soaps. The water can hydrolyze the triglycerides into diglycerides and form more free fatty acids. Both of the above reactions are undesirable and reduce the yield of the biodiesel product. In this situation, the acidic materials should be pre-treated to inhibit the saponification reaction. This paper reviews the different approaches of reducing free fatty acids in the raw oil and refinement of crude biodiesel that are adopted in the industry. The main factors affecting the yield of biodiesel, i.e. alcohol quantity, reaction time, reaction temperature and catalyst concentration, are discussed. This paper also described other new processes of biodiesel production. For instance, the Biox co-solvent process converts triglycerides to esters through the selection of inert co-solvents that generates a one-phase oil-rich system. The non-catalytic supercritical methanol process is advantageous in terms of shorter reaction time and lesser purification steps but requires high temperature and pressure. For the in situ biodiesel process, the oilseeds are treated directly with methanol in which the catalyst has been preciously dissolved at ambient temperatures and pressure to perform the transesterification of oils in the oilseeds. This process, however, cannot handle waste cooking oils and animal fats. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to understand and to model the environmental performance of biodiesel produced by various Greek raw materials under current conditions. Three energy crops (rapeseed, sunflower and soybean) have been studied, with regard to their levels of biodiesel productivity. Throughout the entire process, current Greek climatic conditions and cultivation parameters have been taken into account. At the stage of assessment, we conclude that the environmental impacts per crop area indicate that soybean has the lowest environmental impacts. However, by assessing the results per quantity of produced biodiesel, the crop with the minimum environmental impacts is sunflower. This paper shows that environmental benefits from biodiesel have better results, compared to conventional diesel, thus leading to the conclusion that it is feasible to succeed improved environmental performance. [Copyright &y& Elsevier]

Abstract: This issue of the Journal of Cleaner Production is based upon papers presented at the 1st International Workshop Advances in Cleaner Production (CP) held in São Paulo, Brazil, in 2007. The conference had the short-term purpose of deepening the Brazilian discussion on “The Roles of Cleaner Production in the Sustainable Development of Modern Societies”, and it had the long-term objective of providing an on-going interdisciplinary forum for knowledge development and exchange on Cleaner Production (CP) and Sustainable Development. This issue is devoted to papers covering a broad range of perspectives of CP practices and strategies. A special focus is placed upon methodological tools designed to support effective decision-making pertaining to quantitative benefits from CP. The ten papers provide insights from research designed to holistically integrate CP to help society make effective progress to sustainability. Papers cover the importance of informal knowledge, as complementary to formal knowledge, in performing effective ‘Environmental Impact Assessments.’ One paper explores the roles of radical and incremental innovation in the context of alternative automotive technologies. Benefits of Ecodesign are explored in two papers; one concerning its integration with remanufacturing to extend the life of used products and one focusing the adoption of ‘Emergy Environmental Accounting,’ as a complementary decision-making tool. The development of the Brazilian LCI database for ‘hydroelectric power generation’ and its contribution to support regionally relevant LCA studies is highlighted in one paper. The complete production chains of biodiesel and bioethanol are evaluated by using global methodologies, which help in the development of more objective and effective solutions. A “compensatory area”, calculated in terms of emergy, is proposed in order to work in a sustainable way for bamboo production. Finally, a paper about a novel approach for recycling used PET is also included. [Copyright &y& Elsevier]

Biodiesel and ethanol are fuels in clear growth and evidence, basically due to its relation with the greenhouse effect reduction. There are several works regarding regulated pollutants emissions, but there is a lack of reports in non-regulated emissions. In a previous paper (Corrêa and Arbilla, 2006) the emissions of aromatic hydrocarbons were reported and in 2007 another paper was published in 2008 focusing carbonyls emissions (Corrêa and Arbilla, 2008). In this work four mercaptans (methyl, ethyl, n-propyl and n-butyl mercaptans) were evaluated for a heavy-duty diesel engine, fueled with pure diesel (D) and biodiesel blends (v/v) of 2% (B2), 5% (B5), 10% (B10), and 20% (B20). The tests were carried using a six cylinder heavy-duty engine, typical of the Brazilian fleet of urban buses, during a real use across the city. The exhaust gases were diluted near 20 times and the mercaptans were sampled with glass fiber filters impregnated with mercuric acetate. The chemical analyses were performed by gas chromatography with mass spectrometry detection. The results indicated that the mercaptans emissions exhibit a reduction with the increase of biodiesel content, but this reduction is lower as the mercaptan molar mass increases. For B20 results the emission reduction was 18.4% for methyl mercaptan, 18.1% for ethyl mercaptan, 16.3% for n-propyl mercaptan, and 9.6% for n-butyl mercaptan. [Copyright &y& Elsevier]

This paper focused on the utilization of the waste insect shell for the development of a novel biochar-based heterogeneous catalyst (ZnO/PVP mediate -BC-S) with a highly acid-base bifunctional catalytic capacity for the conversion of the insect lipid into biodiesel. The introduction of polyvinyl pyrrolidone (PVP) as a support mediator was believed to improve the textural properties of support and catalytic activity of the catalyst for the conversion reaction. Meanwhile, the physicochemical properties of the synthesized composite catalyst were characterized with XRD, SEM, TEM, XPS, BET, and FT-IR analysis. The high biodiesel yield (94.36%) was obtained at the defined condition (carbonization temperature = 600 °C, Zn(Ac) 2 concentration = 0.3 mol/L, PVP amount = 35 wt%, reaction temperature = 65 °C, catalyst loading = 6 wt%, methanol/lipid molar ratio = 9:1). Moreover, the possible catalytic mechanism of the prepared catalyst was comprehensively described. In addition, the stability and reusability of the prepared catalyst during five reaction cycles were also demonstrated. Finally, the physicochemical properties of the biodiesel studied were well comparable with the ASTM standard as well as with the reported literature. [ABSTRACT FROM AUTHOR]

The voluminous nature of palm oil mill effluent (POME) is directly associated with environmental hazards and could be turned into biorefinery products. The POME, rich in BOD, COD, and oil and grease, with few hazardous materials such as siloxanes, fatty acid methyl ester, and phenolic compounds that may significantly increase the risk of violating the effluent quality standards. Recently, the application of chemical and biological risk assessment that can use electrochemical sensors and microalgae-like species has gained paramount attention towards its remediation. This review describes the existing risk assessment for POME and recommends a novel assessment approach using fish species including invasive ones as suitable for identifying the toxicants. Various physico-chemical and biological treatments such as adsorption, coagulation-flocculation, photo-oxidation, solar-assisted extraction, anaerobic digestion, integrated anaerobic-aerobic, and microalgae cultivation has been investigated. This paper offers an overview of anaerobic technologies, with particular emphasis on advanced bioreactors and their prospects for industrial-level applications. To illustrate, palmitic acid and oleic acid, the precursors of fatty acid methyl ester found in POME pave the way to produce biodiesel with 91.45%. Although there are some challenges in attaining production at an economic scale, this review offers some opportunities that could help in overcoming these challenges. [Display omitted] • This review emphases on POME biorefinery and its environmental hazards. • Various treatment options of POME treatment and biorefinery schemes were discussed. • Different pollution assessment methods were highlighted. • Biological risk assessment with possible remediations was elaborated. [ABSTRACT FROM AUTHOR]

An empirical approach proposed recently (Fluid Phase Equilibria, 434 (2017) 176–192) to distinguish different isomer molecules is extended in this paper aiming to apply for alkyl-esters. The vapor pressure, saturated liquid density of heavy unsaturated and branched alkyl-ester are predicted using the transferred parameters of groups from n-alkanes, branched alkane, cis-alkenes and alkyl-ester. For pressures up to 2100 bar, density data for esters, ranging from C8:0 to C18:0, with up to two unsaturated bonds, are predicted with deviations inferior to 3%. Different binary ester + ester systems were investigated. Furthermore, the VLE of methanol/ethanol + ester mixtures are predicted using a transferable cross-association parameters approach. The general agreement between mg-SAFT and experimental data is very good (within 2–3% deviation on pressure). Finally, in order to validate the predictive ability of the model to be applied in the biodiesel groundwork, the mg-SAFT was then applied to predict the liquid density of 74 biodiesel mixtures based on its fatty acid ester composition. Overall average prediction errors at atmospheric pressure data were 0.71% for 64 multi-component mixtures, and that of 1.36% compared to experimental data for 10 biodiesel systems at high pressure up to 1300 bar. [ABSTRACT FROM AUTHOR]

This paper focuses on the preparation and characterization of CaO, MgO and ZnO, both bulk and supported on γ-Al 2 O 3 and their catalytic activity in the transesterification of soybean oil and castor oil with methanol and butanol in order to produce biodiesel. XRD, SEM, CO 2 -adsorption followed by TGA and N 2 adsorption have been employed to characterize the prepared catalysts. In supported catalysts, the presence of γ-Al 2 O 3 improves alcohol dissociation on the superficial basic sites. The first step of the reaction mechanism is then favored (hydrogen abstraction). In the transesterification of castor oil with butanol, MgO/γ -Al 2 O 3 and ZnO/γ-Al 2 O 3 catalysts showed high yields to FABE (Fatty Acid Butyl Ester) (97% and 85%, respectively). These last catalysts constitute an efficient alternative for obtaining second-generation biodiesel, taking into account that castor oil is a nonedible source and butanol is an alcohol that can be obtained from biomass. [ABSTRACT FROM AUTHOR]

This paper compares the water footprint profiles of four feedstocks used for biodiesel production: palm, soya, rapeseed and waste cooking oil (WCO). The profiles include: (a) a water scarcity footprint related to freshwater consumption impacts and (b) a water quality degradation footprint related to freshwater degradation impacts. The water scarcity footprint was assessed using two impact assessment methods: one based on water stress indices (WSIs) and the other on the available water remaining (AWARE) indicator. The water degradation footprint was assessed considering the environmental mechanisms covered by the impact categories of eutrophication, aquatic acidification, human toxicity and freshwater ecotoxicity. The water scarcity profiles ranged from 0.002 to 2.11 world m 3 eq kg −1 oil (WSI method) and from 0.008 to 133.57 world m 3 eq kg −1 oil (AWARE method). Both methods showed that the cultivation stage assumes the primary role in the water scarcity footprint results and identified the same systems with higher water scarcity footprints. However, for the oil systems with closer results, the rank order given by each method is different due to the characterization factors of each method. Nevertheless, the results obtained with the AWARE method give more comprehensive water scarcity footprint results than those obtained when applying WSIs because AWARE considers the aquatic ecosystem water demand. The water degradation footprint of virgin oils is mainly caused by fertilizers and pesticides used in cultivation. WCO systems present lower impacts for all impact categories with the exception of human toxicity-cancer. The choice of locations with lower water scarcity to produce oil crops can be a determinant in the calculation of lower impacts. Moreover, optimizing fertilization schemes or choosing climatic conditions that require less fertilizers, pesticides and water consumption can reduce the impacts of the water footprint profile of vegetable oils. [ABSTRACT FROM AUTHOR]

This paper describes a new approach to transesterification stopping and separation improving by the addition of inorganic acid, hydrochloric and phosphoric, to the whole reaction mixture after the reaction. The transesterification of oil was carried out by methanol and potassium hydroxide as the catalyst. The inorganic acid neutralises methoxide ions (formed from methanol and potassium hydroxide) and transforms soaps (formed by oil saponification) to fatty acids, which increases the acid number. The principle of stopping is the neutralization of the methoxide ions only. Best results are achieved by concentrated phosphoric acid with a ratio of 0.25 wt% to oil. The advantage is that separation is relatively fast (5 h) and the biodiesel conforms to EN 14214 without any other purification processes such as centrifugation, wet and dry washing and drying of the ester phase. Moreover, the content of glycerol in the formed glycerol phase is approximately 75%. This method of biodiesel production, which uses neutralization of methoxide ions after the transesterification followed by separation, saves energy because no purification processes are needed and no waste is formed. The biodiesel is more environmentally friendly because less energy is consumed. [ABSTRACT FROM AUTHOR]

This paper proposes a fast method to determine kinetic parameters in systems with nonlinear concentration dependencies in equilibrium reactions. Without the use of complicated software, the corresponding parameters can be obtained from linear relations, with a minimum number of experimental data, acquired by semi-batch operation. The underlying theory is given for a general equilibrium reaction A + B ↔ C + D and it is successfully applied for the real case of typical transesterification reactions. The proposed procedure opens the door for easy, i.e., linear, parameter estimation procedures using commercial software as Excel ® without the tedious and nerve-racking nonlinear parameter estimation procedures. The presented methodology gives an easy access to forward as well as backward transesterification rate coefficients, which can be used for simulation purpose for non-steady reactor operation and corresponding optimization. [ABSTRACT FROM AUTHOR]

This paper presents a novel and effective way for copper smelting with lower carbon emissions, where biodiesel is used as the fuel instead of diesel. In this study, we developed a two-phase numerical model to simulate the top-blown injection copper smelting process and we examined the dispersion characteristics of biodiesel spray droplets ejected from the lance nozzle tip immersed in water. The dispersion characteristics of the biodiesel spray droplets were examined at various air-fuel ratios and calculation model was verified by test. The results show that spray tip penetration distance of the biodiesel spray droplets increases while the mean diameter decreases with an increase in the atomized air velocity. The axial velocity of the atomized air is significantly reduced within the bubble generated at the nozzle tip and the axial velocity is 0 m/s when the distance between the nozzle tip and bottom of the bubble is 10–12 mm. The axial velocity of the biodiesel spray droplets slightly increases and then significantly decreases within the bubble generated at the nozzle tip. The axial velocity of the biodiesel spray droplets tends to stabilize when the spray droplets enter the water region of the two-phase model. [ABSTRACT FROM AUTHOR]

The booming of biodiesel production has led to the increase in biodiesel by-product or crude glycerol, which has been proven to be a potential raw material or feedstock to be adopted in green technologies for conversion into valuable products. Its versatility and sustainable nature make it a good candidate to replace petroleum based products. Efforts have been carried out to utilize crude glycerol into biohydrogen via glycerol fermentation. Biotransformation of crude glycerol is promising because the capital investment and operation is cheaper, and it can help in reducing waste thus making the process itself a clean process. This paper reviews on the latest development of biohydrogen production from biodiesel by-product with the main focus on glycerol fermentation. It also sheds light on the challenges, effects of operating parameters on biohydrogen yield, the microorganisms and their pathways, and the possible technologies that can be derived from this bioconversion of biodiesel waste. [ABSTRACT FROM AUTHOR]

The macroscopic characteristics of Hydrotreated vegetable oil (HVO), a renewable biodiesel, were investigated by both experimental and numerical approaches in this paper. The experiment on spray of 0.6ms injection duration was conducted in a constant volume vessel (CVV) at 1800 bar common rail pressure, 70 bar ambient pressure and 100℃ ambient temperature, and the numerical work with the Wave breakup model and RNG k-ε turbulence model was done on a corresponding 2D geometric model at the same condition. The results indicated that the spray tip penetration grew with a decreasing tip velocity and the cone angle increased gradually after a dramatic growth and slight drop. Moreover, the prediction of numerical method, when used in conjunction with experimental studies, was proven effective in elucidating the macroscopic characteristics of HVO spray. The error between the predicted spray tip penetration and the experimental one was no more than 4% except that within 0.2ms flow time after SOI. In addition, the predicted cone angle was in similar trend to the experimental one and the error was within 10% after 0.2 ms. [ABSTRACT FROM AUTHOR]

Biofuels include biodiesel and alcohols are considered sustainable replacements for fossilized fuels due to their higher oxygenated content with superior combustion characteristics. However, the combustion characteristics for biofuels are not fully understood and require more research works to investigate how the biofuels characterize. Therefore, the aim of this paper is to investigate the cyclic variations of the cylinder pressure in the single cylinder diesel engine operating with biodiesel-alcohol (BBu10 and BE10) blends with palm biodiesel (B100) and mineral diesel (B0) as the baseline fuels. These test fuels are tested at full engine load under a constant engine speed of 2300 rpm. The engine combustion characteristics were examined using cyclic variations of combustion pressure and indicated mean effective pressure (IMEP) at 200 cycles. Statistical analysis of combustion characteristics of diesel engine has been carried out over two different engine load and speed. The results of this study demonstrate that the cyclic variations of combustion characteristics of BE10 are very high. The results also showed that presented that the engine operating with B100 and BBu10 tend to be very stable as compared to mineral diesel using COVIMEP. It can be concluded from the study that alcohols contribute a significant effect on the higher engine cyclic variation that related to engine combustion characteristics. [ABSTRACT FROM AUTHOR]

This paper has investigated the mechanistic issues of ultrasound-assisted transesterification process using solid Cu 2 O catalyst and mixed feedstock of non-edible oils. The optimum conditions for transesterification have been determined using statistical experimental design in packed bed catalytic reactor. The kinetic constants of different steps of transesterification process have been determined using kinetic model based on Eley-Rideal mechanism coupled to time profiles of reactants and products of transesterification in batch slurry reactors. The batch experiments have been performed at optimum conditions predicted by statistical experimental design: alcohol/oil molar ratio = 10.6, temperature = 62.5 °C, catalyst concentration = 7.25 wt% oil. It is revealed that adsorption of methanol is the slowest and rate determining step of transesterification process. Sonication enhanced the kinetics of reaction steps of transesterification process, but its effect on methanol adsorption on Cu 2 O catalyst was adverse. The activation energy of overall transesterification process was 90.14 kJ/mol; while, the sum total of activation energies of the three reaction steps of triglyceride conversion was 40.98 kJ/mol. These results essentially point to strong mass transfer influence on Cu 2 O-catalyzed transesterification process, even in presence of sonication. The adsorptive mass transfer of methanol to catalyst sites is not enhanced by microturbulence generated by sonication. Two probable causes leading to this effect are: discrete and intermittent nature of acoustic (or shock) waves generated by the transient cavitation, and secondly, the high temperature of reaction that offsets the methanol adsorption on catalyst websites. [ABSTRACT FROM AUTHOR]

The paper is focused on the description of the activity/selectivity of mesoporous silica based materials loaded with various types of active species in the esterification of tall oil free fatty acids. The metals such as aluminium, molybdenum, gallium and zinc, including their combinations were impregnated on the mesoporous silica, which was tested in esterification reaction. All these catalysts preserved its tall oil free fatty conversion in the first and the second catalytic cycles. However, while only insignificant amount of gallium or molybdenum was lost from the solid catalyst into the liquid phases, zinc leached from every studied solid catalyst. In contrast to impregnated gallium on mesoporous silica, which exhibited higher acidity and higher tall oil free fatty acids conversion in the first catalytic cycle, but its value was not preserved in the second catalytic test. [ABSTRACT FROM AUTHOR]