CO₂ Capture by Means of an Enzyme‐Based Reactor

Abstract

We report a means for efficient and selective extraction of carbon dioxide (CO(2)) at low to medium concentration from mixed gas streams. CO(2) capture was accomplished by use of a novel enzyme-based, facilitated transport contained liquid membrane (EBCLM) reactor. The parametric studies we report explore both structural and operational parameters of this design. The structural parameters include carbonic anhydrase (CA) concentration, buffer concentration and pH, and liquid membrane thickness. The operational parameters are temperature, humidity of the inlet gas stream, and CO(2) concentration in the feed stream. The data show that this system effectively captures CO(2) over the range 400 ppm to at least 100,000 ppm, at or around ambient temperature and pressure. In a single pass across this homogeneous catalyst design, given a feed of 0.1% CO(2), the selectivity of CO(2) versus N(2) is 1,090 : 1 and CO(2) versus O(2) is 790 :1. CO(2) permeance is 4.71 x 10(-8) molm(-2) Pa(-1) sec(-1). The CLM design results in a system that is very stable even in the presence of dry feed and sweep gases.

Facilitated transport of CO2 across a liquid membrane: Comparing enzyme, amine, and alkaline

“…In one design the permeator is arranged much like a heat exchanger and consists of multiple sets of hollow fiber feed fibers and hollow fiber sweep fibers arranged orthogonally while a carrier fluid, the CLM, fills the space between the feed and sweep fiber bundles. We have also explored spiral wound hollow fiber designs that can operate in either co-current or counter-current mode [8].…”

Reactive absorption of CO2 into enzyme accelerated solvents: From laboratory to pilot scale

“…The application of alternative gas liquid contacting devices, such as e.g. membrane contactors could be considered [15,37]. They offer a higher flexibility in terms of decoupling the operating conditions of gas and liquid phase as well as modular design, which might benefit to the application of carbonic anhydrase in reactive absorption.…”

Hollow fiber contained hydrogel-CA membrane contactor for carbon dioxide removal from the enclosed spaces

“…Hydrophilic hollow fiber-based glycine-Na-glycerol CLM was experimentally studied by Chen et al for the separation of CO 2 from a humid mixture of CO 2 -N 2 [7,8]. Despite that all those membranes show remarkably high CO 2 permeance and selectivity of CO 2 versus O 2 and N 2 , their separation properties are degraded if the relative humidity of inlet feed and sweep gases or the core liquid level are not controlled [6][7][8]. The water extent in the CLM will decrease significantly with a decrease in feed relative humidity.…”

“…For instance, polysulfone humidifier was first used to control the feed and sweep gas humidity, and later a reservoir was adopted to continuously supply the core liquid to a CLM design [6]. Another alternative is to use low volatility and hygroscopic liquids, such as glycerol as the major component in the CLM fluid.…”