Robocast Zeolitic Lattices For Reversible CO2 Sorbent Monoliths

Date

7/10/2022

Journal Title

Journal ISSN

Volume Title

Publisher

51st International Conference on Environmental Systems

Abstract

There is room for improvement for NASA's current systems used to control CO2 levels in a cabin's atmosphere. Currently, packed beds of granules of zeolite are used as sorbents for CO2 in NASA CO2-removal assemblies. Problems and inefficiency associated with packed beds are related to random packing of granules and resulting poor thermal management and poor mechanical stability. An improved system is envisioned with the creation of a sorbent bed in the form of a 3D-printed monolithic lattice.

This presentation will show the potential of the extrusion-based additive manufacturing (AM) technique known as robocasting for fabricating prototype lattices of zeolite 13X that are robust and efficient for reversibly adsorbing and desorbing CO2. 13X by itself is difficult to sinter without inducing a tremendous loss of surface area. Therefore, the use of effective sintering aids (inorganic binders) was explored and assessed for the ability to suitably partially sinter zeolite particles together at temperatures of 725C.

Down-selected binder systems were successfully incorporated into zeolite paste feedstocks suitable for the robocasting process and were shown to have the ability to partially sinter into robust structures while simultaneously retaining relatively high surface area and microporosity. Strength data and adsorption data will be presented.

A further objective was to demonstrate the incorporation of heating elements into a robocast zeolite assembly and show the potential for in-situ desorption of CO2. A stack of 50mm lattice monoliths of zeolite 13X with adequate strength, adsorption capacity, and the ability to be heated to 250C will be demonstrated and the potential for up-scaling to systems capable of controlling CO2 levels in a cabin's atmosphere will be discussed.

Description

Joe Cesarano, Robocasting Enterprises LLC, US
Michael Niehaus, Robocasting Enterprises LLC, US
Tra-My Justine Richardson, NASA Ames Research Center, US
Eric Coker, Sandia National Laboratories, US
ICES302: Physio-chemical Life Support- Air Revitalization Systems -Technology and Process Development
The 51st International Conference on Environmental Systems was held in Saint Paul, Minnesota, US, on 10 July 2022 through 14 July 2022.

Keywords

zeolite, additive manufacturing, CO2, carbon dioxide, adsorption, sorbent, monolith, robocasting

Citation