Density Straight vegetable oil Diesel engine Combustion a b s t r a c tThe straight use of vegetable oils as fuel in diesel engines entails adjusting several physical properties such as density and viscosity. By adequately heating the vegetable oil before entering the injection system, its physical parameters can reach values very close to that of diesel fuel. Consequently, by properly adjusting the temperature of vegetable oils used as fuel, it is possible to improve their combustion performance, thus avoiding premature engine aging due to incomplete burning. In this study the density and viscosity of several vegetable oils are studied within a wide variety of temperatures. The optimal range of temperatures at which each vegetable oil should operate in order to adjust its properties to those of automotive diesel and biodiesel is then found. Additionally an empirical relationship between the dependence of viscosity with density is presented. Thus, by means of the above-described relationship, through measuring the density of a given oil, its viscosity can be directly deduced.ª 2012 Elsevier Ltd. All rights reserved. IntroductionDiesel engines are being extensively utilized worldwide due to their high economic advantage and durability [1,2]. They have appealing features including robustness, high torque, and lower fuel consumption under certain conditions. According to Moron et al. [3] they are prevalent in sectors such as road and train transport, agriculture, military, construction, mining, maritime propulsion and stationary electricity production. Diesel engines can use several fuel types, including diesel fuel, straight vegetable oils (SVO), biodiesel e transesterified vegetable oil e and short chain alcohols. Diesel engines may also function with hybrid fuels, including SVO mixtures in different proportions with diesel or diesel/ ethanol. At the present time there is an increasing demand for energy, concerns about global warming and a growing interest in renewable energy sources; particularly in biofuels [4,5]. This is due to diminishing reserves and price instability of the world's petroleum fuel. These challenges are in part due to the diesel engines themselves. Consequently, it is an urgent matter to reduce hazardous pollutants that diesel engines emit such as NO x , CO, CO 2 and particulate matter (PM). According to Lee at al.[1] this can be achieved by using new combustion technology, by improving fuel characteristics and or by applying after-treatment technology. It is well known that utilizing biofuels with internal combustion engines may contribute to reduce greenhouse gas emissions [6]. Smallscale produced SVOs are considered attractive options for renewable fuel because of environmental benefits [7]. Smallscale use of vegetable oils is also considered an interesting option because they can be obtained from agricultural or industrial sources with very simple processing. This processing includes cold pressing and refining stages that avoid * Corresponding author. Tel.: þ34 938035300; fax: þ34 938031...

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Summary Life cycle assessment (LCA) is a widely accepted methodology to support decision‐making processes in which one compares alternatives, and that helps prevent shifting of environmental burdens along the value chain or among impact categories. According to regulation in the European Union (EU), the movement of waste needs to be reduced and, if unavoidable, the environmental gain from a specific waste treatment option requiring transport must be larger than the losses arising from transport. The EU explicitly recommends the use of LCA or life cycle thinking for the formulation of new waste management plans. In the last two revisions of the Industrial Waste Management Programme of Catalonia (PROGRIC), the use of a life cycle thinking approach to waste policy was mandated. In this article we explain the process developed to arrive at practical life cycle management (LCM) from what started as an LCA project. LCM principles we have labeled the “3/3” principle or the “good enough is best” principle were found to be essential to obtain simplified models that are easy to understand for legislators and industries, useful in waste management regulation, and, ultimately, feasible. In this article, we present the four models of options for the management of waste solvent to be addressed under Catalan industrial waste management regulation. All involved actors concluded that the models are sufficiently robust, are easy to apply, and accomplish the aim of limiting the transport of waste outside Catalonia, according to the principles of proximity and sufficiency.

The aim of the present work is to evaluate a new sustainable continuous system for processing bovine leather. By means of a prototype described in the international patent WO, 2010/070571 (A2) of the technological centre AIICA, a dehydration process for bovine hides is carried out. What is obtained through this new process is a dehydrated leather with the optimal physical and chemical characteristics that will allow its subsequent tanning by immersion processes in aqueous solutions of chemical products. When compared to existing traditional processes, there are economic and environmental advantages resulting from the use of this new system. More specifically, the new process results in reductions of 30.6% in water use, 50.2% in chemical use and 16.4% in process time. In addition, a reduction of 27.3% in wastewater and a reduction of 47.5% of thermal energy consumption are obtained. However, this new system presents an increase in electricity consumption of 63.03% and an increase in gaseous emissions of 75% due to the use of acetone in the dehydration process and the 0.5% losses of acetone during the process.; In order to better assess the environmental impact of this new tanning system, life cycle analysis methodology has been chosen to perform calculations on the Global Warming Potential (CO2 equivalent emissions) and the energy consumption comparing both traditional and new tanning processesPostprint (published version

The use of straight vegetable oil (SVO) as biofuel has been recognized as a valid substitute of diesel fuel in the agricultural sector under specific circumstances. Its direct use reduces most of the chemical processes involved when converting it into biodiesel, thus lowering harmful emissions. This study presents the economic analysis of a selfsupply farming model that uses rapeseed as its fuel base. This model addresses agricultural environmental concerns and can even minimize dependence on the fluctuating costs of diesel fuel. The use of SVO in agriculture can help reduce farmers' vulnerability to fossil fuel prices. The economic evaluation of the model proposed in this study shows clear economic benefits of introducing rapeseed to the traditional crop rotation of wheat and barley. The key factors analyzed in this model are diesel fuel price, diesel fuel grants and crop aids. The current situation in Spain favors the use of diesel fuel in agriculture rather than rapeseed SVO due to an 8% profit difference. However, results show that changes in key factors slightly affect the profit margin, calculating a difference of only 3.7% for particular factor combinations. Combined environmentalfriendly agriculture supporting policies are necessary to cover this slight profit difference to promote this biofuel.