According to the International Energy Agency, the contribution of international shipping to carbon footprint is as large as some major countries. To curb emissions, containerized shipping lines have implemented some technical and operational.
The latest port study of PortEconomics member Pierre Cariou co-authored with Ali Cheaitou and Rim Larbi (University of Sharjah, United Arab Emirates), considers this element in the context of the strategic and tactical aspects of liner services design. The objective is to determine the optimal sequence of ports to be visited as well as the number and operating speed of vessels to be deployed in a liner service when considering the joint objectives of cost and CO2 emissions minimization.
The authors analyse the problem using a non-linear bi-objective optimization framework for which an approximation scheme for the sailing speed and a reformulation are required to solve the problem using a bi-objective integer linear program based on the travelling salesman problem. Using data from a service operating between Europe and Asia with seven ports of call, we apply the proposed new scheme that can be solved using any commercial solver for real life instances. The results show that the cost and CO2 minimization objectives are easier to reconcile when bunker prices are high and tax on CO2 emissions is therefore more efficient at such a time.
The port study of Pierre, Ali and Rim titled “Green Liner Shipping Network Design: A Bi-Objective Non-Linear TSP Based Model” was presented in the IAME 2017 Conference held 27-30 June in Kyoto, Japan. The paper and presentation of the study is available and can be freely downloaded @PortEconomics.