A Petri nets approach for simulation and control of castor bean biodiesel supply chain

Abstract

Nowadays many countries present critical problems related to energy demand-supply equilibrium. Petroleumbased reserves are unable to face future demand for more than few decades. So, the search for alternative sources of energy has been strongly directed to biofuels. Several fruit oils can be used as a source for biodiesel production and the castor bean is an example. The castor bean agribusiness is based in a complex commodity chain, making necessary researches for the improvement of the performance of this chain. This paper put forward a new approach, based on the principles of Supervisory Control Theory and Petri nets, aiming the coordination of logistics flows in agribusiness chains and focusing the castor bean biodiesel supply chain. A new method for the supervisory control based on colored Petri nets was developed, called Constraints of Control on Decomposed Colors (CCDC). Also, it is proposed a framework for supervisory control in logistics systems which support agriculture chains. Most of the relevant activities in the castor bean biodiesel supply chain were surveyed to support the proposed modeling process. A mathematical model was developed using Petri nets and the control constraints of the model could be determined through computational simulation. Two scenarios could be conceived and the controlled system presented an acceptable performance. As conclusion, it seems clear that the proposed approach is a feasible and useful tool for the modeling, control and analysis of agribusiness chains.