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Abstract: The quest for renewable energy has intensified since the escalating price of crude petroleum in the recent years. Renewable energy such as biodiesel has the potential to replace petroleum-derived transportation fuel in the future. Biodiesel is defined as the mono-alkyl esters of long-chain fatty acids derived from vegetable oils such palm oil, rapeseed and soybean. Currently, more than 80% of the world biodiesel productions are from rapeseed oil. However, the cost of palm oil which is at least US$ 200 per tonne cheaper than rapeseed oil indicates that palm oil could be a more suitable and attractive candidate as the source of biodiesel compared to other vegetable oils. Although palm oil is known to be a multi-purpose vegetable oil with products ranging from food to biodiesel, there are a lot of issues surrounding palm oil production. Nevertheless, some of these issues reported in the literature were found to be misleading and are thus confusing the public perception on palm oil. Thus, the aim of this paper is to highlight and clarify the negative issues reported in the literature surrounding palm oil production. Apart from that, various policies or/and strategies that will lead to a more sustainable production and development of palm oil industries will also be proposed. Hence, palm oil will be able to become the leading vegetable oil in terms of food and non-food production, especially as the main source of renewable energy, biodiesel. [Copyright &y& Elsevier]

Abstract: Biodiesel is one kind of biodegradable fuel. Substituting fossil diesel with biodiesel can reduce air emissions, increase the domestic energy supply, and create new markets for farmers. Further, generating biodiesel from energy crops cultivated on polluted farmlands can provide a solution for re-using polluted farmlands. This paper investigates the characteristics and benefits of biodiesel and its current status and development potential in Taiwan, identifies barriers to the adoption of biodiesel, and formulates key policy measures to achieve the target (i.e., 100 million liters per year by 2010 and 150 million liters by 2020) of the 2nd National Energy Conference. The results of this study show that the potential annual output of biodiesel can amount to 233–285 million liters, meaning that the goal of the second National Energy Conference could be achieved. However, there are many barriers to the practical adoption of biodiesel. Many issues (such as acquiring material sources, establishing a recycling system, defining economic and legal measures, and improving public acceptance and inter-ministry coordination mechanisms) must still be addressed to actively promote biodiesel utilization. [Copyright &y& Elsevier]

Abstract: Biodiesel is gaining more and more importance as an attractive fuel due to the depleting fossil fuel resources. Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feed stock like vegetable oils and animal fats. It is produced by transesterification in which, oil or fat is reacted with a monohydric alcohol in presence of a catalyst. The process of transesterification is affected by the mode of reaction condition, molar ratio of alcohol to oil, type of alcohol, type and amount of catalysts, reaction time and temperature and purity of reactants. In the present paper various methods of preparation of biodiesel with different combination of oil and catalysts have been described. The technical tools and processes for monitoring the transesterification reactions like TLC, GC, HPLC, GPC, 1H NMR and NIR have also been summarized. In addition, fuel properties and specifications provided by different countries are discussed. [Copyright &y& Elsevier]

Abstract: The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Alternative fuels, energy conservation and management, energy efficiency and environmental protection have become important in recent years. The increasing import bill has necessitated the search for liquid fuels as an alternative to diesel, which is being used in large quantities in transport, agriculture, industrial, commercial and domestic sectors. Biodiesel obtained from vegetable oils has been considered a promising option. In this paper, an attempt has been made to review the work done on biodiesel production and utilization, resources available, process(es) developed/being developed, performance in existing engines, environmental considerations, the economic aspect, and advantages in and barriers to the use of biodiesel. [Copyright &y& Elsevier]

Isomerization of long-chain saturated fatty acids (LCSFAs) by catalytic conversion through zeolites is of great interest in cosmetics and biofuel production. This conversion pathway has received attention in the last two decades due to the increasing interest in renewable feedstock. A favorable policy framework and a larger availability of lipid wastes from industry promote new valorization practices like this one and open new opportunities for the near future. Moreover, the next decade is likely to witness a considerable rise in the research for improvement of isomerization yield by testing various bifunctional zeolites. Although this approach has enormous potential in terms of applicability, it currently suffers from low yields that stems from focus on only one type of zeolite. Despite limited number of studies in this field, there is a considerable amount of literature about isomerization of similar compounds, i.e., long-chain unsaturated fatty acids (LCUFAs) and long-chain linear alkanes (LCAs); where, past research has focused on increasing the isomerization yield by using different catalysts, co-catalysts and optimizing operating conditions. Among all types of isomerization catalysts, bifunctional metal loaded microporous solid acids catalysts, known as zeolites, have attracted extensive attention due to their sustainable, environmentally friendly nature, as well as recoverable features. The current challenges of isomerization of LCSFAs are about enhancing the yields towards isomerized products and lowering the long reaction times to scale-up towards industrialization. The innovative aspect of this work is about the identification of the most promising catalysts and co-catalysts for isomerization of LCSFAs and the comparison of isomerization of two similar compounds, LCUFAs and LCAs. It also provides a comprehensive overview of the current state of the art. Results show that the best yields for isomerization of LCUFAs and LCAs have been obtained by 1-dimensional and 2-dimensional zeolites; while, 3-dimensional zeolites have shown the lowest isomerization yields. It also indicates that, for isomerization of LCSFAs, 3-dimensioanl zeolites are the only category that have been tested. Thus, the present paper, highlights shortcomings and provides a blueprint for future research on isomerization of LCSFAs. • A literature review on isomerization of LCUFAs and LCAs was carried out to address LCSFA. • The most promising catalysts and co-catalysts for isomerization of LCSFAs were identified. • Best isomerization yields of LCUFAs and LCAs obtained by 1-D and 2-D zeolites. • Isomerization yields for LCSFAs can be improved significantly using continuous systems. • Isomerization of LCSFAs, LCUFAs, and LCAs can be done by similar catalysts. [ABSTRACT FROM AUTHOR]

Investigations and applications of renewable and sustainable energy have become central for addressing the issue of emissions of greenhouse gases from the use of fossil transportation fuels. Triglyceride-based liquid fuels have great potential as substitutes for petroleum and its derivatives. To date, the proven technologies for converting triglycerides into biofuels include transesterification, thermal cracking conversion, and hydrogenation. This paper presents an overview of recent research on these conversion technologies, employing homogeneous, heterogeneous, enzymatic, and photocatalytic catalysts. We focus on technical aspects critical to triglyceride conversion, including feedstock analysis, mechanism research, analysis of technological advantages and disadvantages, and catalyst development and selection. Biodiesel produced by the transesterification process must be blended with diesel before use due to its higher oxide content. The resultant "green diesel" has a broader range of applications, especially when its structure has been upgraded. Life cycle assessment (LCA) and greenhouse gas (GHG) emissions are reviewed to assess the renewability and sustainability of biofuels. We discuss the typical biodiesel production technologies with their development status, as well as the relevant policies and prospects for biofuels, mainly concerning biodiesel and aviation biofuel. It is hoped that our work will be of guiding significance for future biofuel research. [Display omitted] • Overview of triglycerides biomass resources and their composition characteristics. • Overview of various possibilities conversion technologies for biofuel production are provided. • Overview of the composition characteristics of biodiesel and aviation biofuel and further upgraded for improving quality. • LCA and GHG emissions are reviewed to assess the renewability and sustainability of biofuels. [ABSTRACT FROM AUTHOR]

In recent years, furyl methanes are considered as important precursors in the biodiesel and jet fuel synthesis. Different catalysts such as mineral acid, solid acid, carbonaceous solid acid, ionic liquid, supported mixed metal or metal oxide and Lewis acid have been tested for cost-effective production of furyl methanes directly from commercially available or in situ generated aldehydes from biomass. Moreover, broad ranges of feedstock from carbohydrates have been used to generate FF (Furfural) and their performances have been investigated. Most of the reported methods have shown promising selectivity of the furyl methanes with the higher conversion rate of HAA (Hydroxyalkylation/alkylation) reactions under different catalysts. Production and upgrading methods for furyl methane based diesel precursors have not been surveyed in any review paper to date. This comprehensive review provides insight into the state-of-the-art accomplishments in the catalytic techniques to generate biodiesel precursors via hydroxyalkylation/alkylation reaction of furan derivatives with aryl and aliphatic or heteroaryl aldehydes. • Furyl alkanes are recognized as an essential precursor to the synthesis of biofuels. • Recent advances in catalytic production of furyl alkanes from biomass are outlined. • Typical condensation routes of bio-based molecules to furylmethanes are described. • The condensation routes are mainly based on the hydroxyalkylation/alkylation (HAA) reaction. • Policies, challenges, and future perspective on the state-of-the art are highlighted. [ABSTRACT FROM AUTHOR]