The influence of polyethyleneimine type and molecular weight on the CO2 capture performance of PEI-nano silica adsorbents

Kaimin Li, Jianguo Jiang*, Feng Yan, Sicong Tian, Xuejing Chen

*Corresponding author for this work

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

Amine-silica adsorbents are considered alternatives to aqueous solutions of amines, which have been traditionally used to capture carbon dioxide (CO2) from flue gas. Among amine-silica adsorbents, polyethyleneimine (PEI)-silica is particularly effective at capturing CO2 from flue gas due to its high thermal stability. In this study, we investigated the influence of PEI type (i.e. branched vs. linear) and molecular weight on the CO2 capture performance of PEI-silica adsorbents. PEI molecular weight influenced the thermal stability of PEI-silica adsorbents; however, when the molecular weight was >= 1200 Da the increase in stability was negligible in the temperature range of 25-160 degrees C. Branched PEIs (BPEIs) achieved higher CO2 saturated sorption capacities compared to linear PEIs (LPEIs); however, LPEIs were more stable than BPEIs during CO2 sorption-desorption cycling. PEI molecular weight also influenced the CO2 saturated sorption capacity; CO2 saturated sorption capacity decreased as PEI molecular weight increased, and among the adsorbents tested in this study BPEI/800-silica had the highest CO2 saturated sorption capacity (202 mg CO2/g adsorbent). Both PEI type and molecular weight exhibited influence on the sorption or desorption heat of PEI-silica adsorbents. The CO2 regeneration heat was much lower than that of MEA solution for all PEI-silica adsorbents tested in this study. (C) 2014 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)750-755
Number of pages6
JournalApplied Energy
Volume136
DOIs
Publication statusPublished - 31 Dec 2014
Externally publishedYes

Keywords

  • Carbon capture
  • Polyethyleneimine
  • CO2 adsorbent
  • Nano silica
  • CARBON-DIOXIDE
  • POSTCOMBUSTION CAPTURE
  • AMINE SORBENTS
  • HIGH-CAPACITY
  • ADSORPTION
  • SBA-15
  • DESORPTION
  • KINETICS
  • TEMPERATURES
  • ZEOLITES

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