Optimizing hydrogen purification performance by membrane from industrial waste of methanol production
Irfan Ali Qazi, Ammar Ali, Masad Mezher Hasan, Mohd Roslee Othman
Abstract
• Possibility of recovering and purifying hydrogen from methanol purge gas is explored. • Research applies and validates complete mixing model for membrane separation using actual data from literature. • Results from the study suggest that the complete mixing model was suitable for enriching hydrogen from methanol purge gas using membrane. • Maximum H2 purity from this model achieved 99.99% and 53.89% H 2 purity and recovery in permeate stream respectively. There is an increasing interest to migrate from fossil fuel energy dependency to a greener hydrogen economy. In order to meet this challenge, hydrogen should be made cheap and readily available for both industrial and public consumption. In this research, polyetherimide membrane was used to achieve highly purified hydrogen from methanol purge gas (MPG) containing hydrogen, carbon dioxide, nitrogen, carbon monoxide and methane gas. The novelty of this research stems from the development of semi-empirical models for correlating the membrane's characteristics and operating condition with purity and recovery of hydrogen from penta-nary MPG components and optimizing the membrane's purification process to achieve maximum hydrogen purity and recovery. Results from the study suggest that membrane area was one of the important factors affecting the hydrogen purity in the permeate. Keeping stage cut and membrane thickness constant at 0.340 and 0.25 µm, respectively, hydrogen purity was increased from 86.00% to 99.00% by increasing membrane area from 55.4 to 80.0 cm 2 . Membrane thickness was found to affect the hydrogen recovery in permeate significantly. By reducing the thickness from 25.00 to 1.00 µm, the hydrogen recovery was increased from merely 3.00% to 43.00% at a constant stage cut of 0.3400 and membrane area of 55.4 cm 2 . When the membrane parameters were optimized at 80.0 cm membrane area, 0.25 um membrane thickness and 0.3395 stage cut, the maximum hydrogen purity and recovery from this model achieved 99.99% and 53.89%, respectively.