The Effects of Synthesis Conditions on the Carbon Capture Capacity of Polyethylenimine Impregnated Protonated Titanate Nanotubes

Abstract

Capture and storage of carbon dioxide emitted from power plants, which burn fossil fuels, is one of the best ways to mitigate climate change. Polyethylenimine (PEI) impregnated protonated titanate nanotubes (PEI-PTNTs) are efficient amine-modified solid adsorbents for post combustion carbon capture. This study is to investigate the effects of synthesis conditions of titanate nanotubes on the carbon capture capacity of PEI-PTNTs. PTNTs are synthesized using hydrothermal treatment of TiO2 anatase powder at different temperatures and in different days, followed by washing with dilute HCl solution and deionized water. PEI-PTNTs are prepared by loading PEI (M.W. = 10,000) onto PTNTs at a weight ratio of 1:1 using a wet impregnation process. PTNTs and PEI-PTNTs are characterized using transmission electron microscopy, porosity and surface area analysis, powder X-ray diffraction, and Fourier transform infrared spectroscopy. CO2 adsorption is conducted at 75 °C using simulated flue gas, and CO2 desorption is performed at 110 °C by purging the adsorbent with dry nitrogen gas. CO2 adsorption experiments demonstrate that the PEI-PTNTs synthesized at 130 °C within 3 or 5 days, have the highest CO2 capture capacity. These optimized PEI-PTNTs have a significant potential to capture CO2 from power plants.