Heat integration in regeneration process of molecular sieves including heat storages.

Year 2016, , 137 - 144, 01.09.2016

Sahar Salame

https://doi.org/10.5541/ijot.5000153529

Abstract

Molecular sieves are materials often used in the petroleum industry, especially for the purification of gas streams and in the chemical industry for separating compounds and drying reaction starting materials. They are also used in the filtration of air supplies for breathing equipments. When saturated, the molecular sieve should be regenerated so that it can be used again. The objective of this paper is to study the heat integration possibilities in the process of regeneration and cooling of a molecular sieve using heat storages. We will be trying to find the optimum design of the heat integration network including heat storages and heat exchangers. This is done using a MILP (Mixed Integer Linear Programming) formulation of the multi period heat integration problem. The inputs of the algorithm are the temporal variation of the operational gas’ temperature and of its heat capacity over the whole cycle and the desired maximum number of heat storages to be used. The outputs of the algorithms are the heat storages temperatures, their capacities and the net heating and cooling energy demanded to satisfy all the energy needs of the process. The study will consider many simulations; in each the number of heat storages used is different. The results of each case will be shown and discussed and compared with the reference case, where all energy demands (heating and cooling) are satisfied using hot and cold utilities.

Keywords

Heat integration, multi-period; heat storage; MILP formulation; regeneration of molecular sieves.

References

• E. Maneses-Ruiz, G. Laredo, J. Castillo, J. Marroquin, "Comparison of different molecular sieves for the liquid phase seperation of linear and branched alkanes," Fuel Proces. Technol., 124, 258-266, 2014.
• P. Ho, S. Lee, J. Kim, D. Lee, H. Woo, "Properties of a manganese oxide octahedral molecular sieve (OMS-2) for adsorptive desulfurization of fuel gas for fuel cell applications," Fuel Proces.Technol., 131, 238-246, 2015.
• S. Cho, D. Lee, Y. Lee, "Separation of biomass using carbon molecular sieves treated with hydrogen peroxide," J. Industrial Eng. Chem., 21, 278-282, 2015.
• S. Salame, S. Zoughaib, "Conception d'un réseau chaleur d'échangeur fonctionnement multi-période," Société Française de Thermique, 2014. avec stockage en
• P. Krummenacher, D. Favrat, "Indirect and mixed direct-indirect heat integration of batch processes based analysis.," Thermodynamics, 4, 135-143, 2001. Int. J. Applied
• T. Majozi, X. Zhu, "A novel continuous-time MILP formulation for multi-purpose batch plants," Industrial Eng. Chem. Res., 40, 5935-49, 2001.
• I. C. Kemp, Pinch analysis and process integration: A user guide on process integration for the efficient use of energy, Oxford: Elsevier, 2007.
• R. Murr, H. Thieriot, A. Zoughaib, D. Clodic, "Multi- objective optimization of a multi water-to-water heat pump system using evolutionary algorithm," Applied Energy, 88, 3580-91, 2011.
• A. Christodoulos, L. Xiaoxia, "Continuous-time versus discrete-time approaches for scheduling of chemical processes: a review," Computer Chemical Eng., 28, 2109-2129, 2004.