Membrane-Based Processes: Optimization of Hydrogen Separation by Minimization of Power, Membrane Area, and Cost

Abstract

This work deals with the optimization of two-stage membrane systems for H2 separation from off-gases in hydrocarbons processing plants to simultaneously attain high values of both H2 recovery and H2 product purity. First, for a given H2 recovery level of 90%, optimizations of the total annual cost (TAC) are performed for desired H2 product purity values ranging between 0.90 and 0.95 mole fraction. One of the results showed that the contribution of the operating expenditures is more significant than the contribution of the annualized capital expenditures (approximately 62% and 38%, respectively). In addition, it was found that the optimal trade-offs existing between process variables (such as total membrane area and total electric power) depend on the specified H2 product purity level. Second, the minimization of the total power demand and the minimization of the total membrane area were performed for H2 recovery of 90% and H2 product purity of 0.90. The TAC values obtained in the first and second cases increased by 19.9% and 4.9%, respectively, with respect to that obtained by cost minimization. Finally, by analyzing and comparing the three optimal solutions, a strategy to systematically and rationally provide ‘good’ lower and upper bounds for model variables and initial guess values to solve the cost minimization problem by means of global optimization algorithms is proposed, which can be straightforward applied to other processes.

Efficiency Separation Process of H2/CO2/CH4 Mixtures by a Hollow Fiber Dual Membrane Separator

“…Gas membrane separation has great prospects in the petrochemical industry owing to extensibility and modularity, cost efficiency, and lower energy requirement [7][8][9]. The first industrial gas separation membrane is a polysulfone hollow fiber membrane for H 2 separation [10]. Nowadays, H 2 -selective membranes are widely used in the field of H 2 /N 2 and H 2 /hydrocarbon separation, which could reach 2 of 12 a selectivity of more than 100.…”

Recent Advances in Membrane-Based Electrochemical Hydrogen Separation: A Review

“…To take advantage of the capabilities of inorganic membranes combined with the low manufacturing costs of the organic membranes, mixed-matrix membranes have been developed (composite materials that consist of continuous polymeric matrix and imbedded, mainly inorganic, particles) [115]. According to their characteristics, membranes can be classified as either dense (non-porous) or porous [92,96]. Porous membranes can be divided into glasses, organic polymer, ceramic-and carbon-based membranes (carbon molecular sieves) [116].…”

Multi-scale membrane process optimization with high-fidelity ion transport models through machine learning

“…Thus, process optimization using this approach is currently not possible. On the other hand, heuristics or short-cut models can be embedded computational resource-efficiently in complex optimization superstructures [36][37][38][39][40][41][42]. However, these simplified heuristics or short-cut models do not sufficiently describe the influence of membrane parameters, such as the synthesis protocols or process environment, on the membrane performance.…”