International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This study proposes a mathematical model for design and optimization of a hydrogen supply chain, covering all stages of the life cycle – feedstocks, production, storage, distribution, end-use in the transport sector. The developed methodology integrates different hydrogen production technologies and takes into account environmental, economic and social impacts in order to identify the most efficient and sustainable configuration. The focus in this work falls on hydrogen production by steam reforming of methane and hydrogen production by electrolysis of water in hydrogen refueling stations. The mathematical model is formulated in terms of MILP programming and can be solved using the GAMS software product. The aim is to find an optimal balance between economic efficiency, environmental sustainability and social impact by using weighted coefficients (weights). The proposed concept provides a decision-making tool for planning hydrogen infrastructure in line with European decarbonization and sustainable transport goals.

This study proposes a mathematical pathway to achieve sustainable design and resource-friendly management of a biodiesel supply chain produced from dairy waste scum. In the work, the features of a combined biodiesel/dairy supply chain are outlined and a set of design and management tools is developed, which is formulated in MILP terms. The optimization criterion is defined in terms of economic sustainability and environmental assessment data is applied as part of it. The purpose of the defined mathematical model is to obtain optimal operating conditions of the considered combined supply chain. A test example based on a case study from Bulgaria was considered. The results of the toolbox implementation can be used as a decision-making tool.

In this paper a model for optimal hydro-thermal coordination of a power system is proposed when contracts for power import and export power are available. The power flows outside the localized area of the local power system are divided into planned and planned quantities in order to assign different penalties for them in the cost criterion. The model also introduces the work of thermal and hydro power plants by separating each unit with a linear approximation. The resulting model is a mixed-integer linear programming problem.