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Graphical abstract Flowchart of the developed model. Highlights • A mathematical model to verified the inside cylinder performance was conducted. • Influence of the fraction of diesel and biodiesel in the mixture was investigated. • The combustion start crankshafts angle and the equivalence ratio were investigated. • The peaks of pressure and temperature were increased by raising the equiv. ratio. • The start of burning the fuel causes an increase in the pressure and temperature. Abstract This paper conducted a numerical simulation of the thermodynamic cycle of a diesel engine, which runs on diesel/biodiesel mixtures, and takes the processes of compression, combustion and expansion into account. The zero-dimensional mathematical model was adopted in order to build the numerical modeling based on the First Law of Thermodynamics and also of the state equation in order to obtain the pressure and temperature profiles of gases inside the cylinder which vary depending on the angle of the crankshaft. The mathematical modeling included taking account of the transfer of heat through the walls, the energy released during combustion considering the Wiebe function, the thermophysical properties of the reagents and the products and the geometric parameters of the engine. The largest relative error found was the 2% in the pressure which showed a good agreement between the simulated and experimental results from previous studies. A parametric analysis was performed considering the fraction of diesel and biodiesel in the mixture, the start angle of the combustion and the equivalence ratio with a view to assessing their effect on the performance of the engine. The results show that a reduction in temperature and in pressure values was achieved when the biodiesel share in the mixture is increased. This led to altering the values of the performance parameters values. In addition, the peaks of pressure and temperature were increased by raising the equivalence ratio which brings forward the point at which the fuel starts to burn due to the increases in the pressure and maximum temperature. It was verified that Wiebe function parameters have a direct influence not only on the pressure and temperature values but also on the performance data of the engine. [ABSTRACT FROM AUTHOR]

In this paper, we develop a decisional framework and a mathematical model for the sustainable design of biodiesel supply chain networks (BSCND). We consider a broad group of sustainable aims, i.e. standard economic goals (revenue and logistics costs of BSCND), environmental issues based on a biodiesel production life cycle assessment (LCA), and the social incidental aspects (e.g. crime control, political stability, and community attitude, among others). The framework begins with a simulation of the biodiesel production system, feeding later, with suitable input parameters and suitable solutions, and a macro-location model designed to establish the regional positioning of biofuel conversion plants. Optimal regions are used as initial feasible solution space for the proposed micro-location model. In this part of the framework, we introduce an adaptation of Extended Goal Programming to rank the best municipalities (definitive locations) emphasizing the social aspects under consideration. The framework application is set up in the following Colombian context: first generation biodiesel production from palm oil feedstock. Our computational results indicate that the Colombian city of Rionegro (in the Santader region) is the most sustainable location for a new biodiesel plant. [ABSTRACT FROM AUTHOR]

Combustion of fossil fuels in the transport sector represents the second largest source of greenhouse gas emissions. For this reason, governments are fostering diversification of energy sources by creating a set of governmental environmental policies and initiatives. In this context, biofuels are expected to represent a substantial part of source diversification, but it is necessary to assess the sustainability of their market to explore its effect on economical, technological, social, political and environmental dimensions. This research presents a dynamic simulation modelling of the Colombian biodiesel market and analyzes the policy support instruments for creating and managing it. A system dynamics based model is proposed to enable decision-makers to understand the influences between the different variables that describe the system and the impact of the biodiesel government policy in Colombia. The primary focus of this paper is to establish the characteristics of each sustainability dimension for the case of study and apply the system dynamics methodology with different types of validation. Finally, the Colombian market status and a sensitivity analysis are developed. The results show that in order to support the development of this sector, it is necessary to diversify the raw materials for the production of biodiesel in the medium term, which means raw materials without competence for the primary rainforest or competition with food productive lands. [ABSTRACT FROM AUTHOR]

This paper addresses the strategic planning of an IBSC (integrated biofuel supply chain) using total annualized cost and total life cycle GHG (green house gas) emissions as economic and environmental criteria respectively. The IBSC for an extended planning horizon H (e.g. 10 years) is considered and horizon H is further subdivided into a set of discrete time intervals. For each of these subintervals the diesel and the biodiesel fuel consumption can be varied according to a predetermined value. A mixed-integer linear programming model of biodiesel production that takes into account infrastructure compatibility, demand distribution, size and location of biorefineries using the available biomass and carbon tax data is proposed. An important aspect of the proposed model is the inclusion of crop rotation conditions to assure the supply of biological feedstock. The price of biodiesel and any byproducts produced are included in the model. Inputs to the model are the quantity of biological feedstock, the cost of biomass transportation, as well as inventory and processing costs. The proposed model is illustrated in Part 2 of this work with an example of Bulgarian economy for planning period 2010 to 2020 when the objectives of the Renewable Energy Directive 28/2009/EC will be achieved. [ABSTRACT FROM AUTHOR]

The growing demand for green world serves as one of the most significant challenges of modernization. Requirements like largest usage of energy for modern society as well as demand for friendly milieu create a deep concern in field of research. Biofuels are placed at the peak of the research arena for their underlying benefits as mentioned by multiple researches. Out of a number of vegetable oils, only a few are used commercially for biodiesel production. Due to various limitations of edible oil, non-edible oils are becoming a profitable choice. Till today, very little percentage of biodiesel is used successfully in engine. The research is still continuing for improving the biodiesel usage level. Recently, it is found that the blended biodiesel from more than one feedstock provides better performance in engine. This paper reviews the physicochemical properties of different biodiesel blends obtained from various feedstocks with a view to properly understand the fuel quality. Moreover, a short description of each feedstock is given along with graphical presentation of important properties for various blend percentages from B0 to B100. Finally, mathematical model is formed for predicting various properties of biodiesel blend with the help of different research data by using polynomial curve fitting method. The results obtained from a number of literature based on this work shows that the heating value of biodiesel is about 11% lower than diesel except coconut (14.5% lower) whereas kinematic viscosity is in the range of 4–5.4 mm 2 /s. Flash point of all biodiesels are more than 150 °C, except neem and coconut. Cold flow properties of calophyllum, palm, jatropha, moringa are inferior to others. This would help to determine important properties of biodiesel blend for any percentage of biodiesel and to select the proper feedstock for better performance. [ABSTRACT FROM AUTHOR]

Sustainability is an important and difficult consideration for the stakeholders/decision-makers when planning a biofuel supply network. In this paper, a Mixed-Integer Non-linear Programming (MINLP) model was developed with the aim to help the stakeholders/decision-maker to select the most sustainable design. In the proposed model, the emergy sustainability index of the whole biodiesel supply networks in a life cycle perspective is employed as the measure of the sustainability, and multiple feedstocks, multiple transport modes, multiple regions for biodiesel production and multiple distribution centers can be considered. After describing the process and mathematic framework of the model, an illustrative case was studied and demonstrated that the proposed methodology is feasible for finding the most sustainable design and planning of biodiesel supply chains. [ABSTRACT FROM AUTHOR]