Metal organic frameworks appended with cyclic diamines for carbon dioxide capture

Abstract

Achieving the selective and reversible adsorption of CO2 from humid, low partial pressures streams such as the flue gas resulting from the combustion of natural gas in combined cycle power plants (4%CO2) is challenging due to the need for high thermal, oxidative, and hydrolytic stability as well as moderate regeneration conditions to reduce the energy of adsorption / desorption cycling. Appending cyclic primary, secondary diamines, exemplified by 2-(aminomethyl)piperidine (2-ampd), to the metal-organic frameworks Mg2(dobpdc) (dobpdc4- = 4,4-dioxidobiphenyl-3,3-dicarboxylate), Mg2(dotpdc) (dotpdc4- = 4,4''-dioxido-[1,1':4',1''-terphenyl]-3,3''-dicarboxylate) or Mg2(pc-dobpdc) (pc-dobpdc4- = dioxidobiphenyl-4,4'-dicarboxylate) produces adsorbents of the classes EMM-44, EMM-45, and EMM-46, respectively, that display step-shaped adsorption of CO2 at the partial pressures required for 90% capture from natural gas flue gas at temperatures up to or exceeding 60 DEG C. Using a cyclic diamine inplace of a diamine functionalized with bulky alkyl groups enables fast adsorption / desorption kinetics with sharp CO2 adsorption and desorption steps.

Description

[0001] Cross References to Related Applications [0002] This application calls for an application filed on August 4, 2017 titled "For CO 2 Trapped Metal-Organic Frameworks Appended with Cyclic Diamines for CO 2 Capture), which is incorporated herein by reference. technical field [0003] This application relates to the ability to efficiently capture CO at low partial pressure 2 And at the same time, an adsorbent regenerated at moderate temperature with low regeneration energy for carbon capture applications. Background technique [0004] Carbon dioxide (CO2) from burning fossil fuels in thermal power plants 2 ) may be the main contributor to global climate change. See Pachauri and Meyer, Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, International Government Panel on Climate Change, Geneva, Switzerland, 2014. To address the increasing CO in the atmosph...

AI Technical Summary

Problems solved by technology

However, one problem associated with materials functionalized after synthesis is that Mg 2+ loss of diamine at the center, which will lead to gradual degradation of the adsorbent

Attaching higher molecular weight diamines is a potential means to overcome this problem, but large alkyl groups on diamines may interfere with adsorption / desorption kinetics and CO 2 Adsorption mechanism

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