Algebraic Approach for the Integration of the Hydrogen Network with a Single Impurity

Fresh hydrogen is an expensive utility in refineries. The integration of hydrogen networks can make full use of hydrogen and reduce the fresh hydrogen consumption. In this work, a rigorous algebraic approach is proposed on the basis of the pinch conception to identify the minimum fresh hydrogen consumptions and pinch locations of hydrogen networks. This algebraic approach is derived from an existing graphical method by transforming the moving procedure of the source composite curve into an algebraic calculation according to the geometrical transformations. The conception of relative flow rate is introduced to describe each hydrogen source and sink. On this basis, a noniterative algebraic procedure is developed to figure out the surplus fresh hydrogen in each interval. Finally, the minimum fresh hydrogen consumption and pinch location can be identified. Furthermore, the proposed approach can be enlarged by considering the hydrogen purification process, and the purification process can be further analyzed to minimize its feed flow rate. This approach has a clear conception and an easy procedure and is valid for the hydrogen network with fresh hydrogen of any hydrogen concentration. A conventional hydrogen network is analyzed to test the applicability of the proposed approach