Completed Projects

USDOE – Carbon Capture

Post-Combustion Carbon Capture

The Civil & Environmental Engineering research group along with the Mechanical Engineering research group at Prairie View A&M University performs research on the evaluation of post-combustion carbon capture methods using Polyethylenimine (PEI) functionalized titanate (TiO₂) nanotubes.

Objectives

• Establish a knowledge base on the synthesis of TiO₂ nanotubes, adsorption characteristics of PEI, and protocols available for the impregnation of PEI.
• Develop optimized protocols for synthesis of TiO₂ nanotubes impregnated with PEI.
• Characterize the PEI impregnated TiO₂ nanotubes and use it for refining the parameters for synthesis such as temperature, concentration and time.

Methodology (Proposed)

• Review literature to study the state of carbon capture technologies, nonmaterial synthesis protocols, reactor designs, and experimental protocols.
• Develop PEI impregnated TiO₂ nanotubes.
• Evaluate thermal stability and morphological study of the PEI impregnated TiO₂ nanotubes.
• Develop a fully functionalized CFD model that can be used for various reactor parameters and materials properties.
• Change the experimental testing of carbon capture under different conditions of temperature, concentrations, and time periods to determine optimal conditions for carbon capture.
• Identify a fully optimized and validated CFD model along with a standard operating procedure for bench scale carbon capture reactor

Findings, To Date (Based on Review of Literature)

• The current major CO₂ capture technologies are oxy-combustion capture, pre-combustion capture, and post-combustion capture.
• Post-combustion carbon capture was found to be especially desirable due to its potential to retrofit existing power plants with reasonable cost.
• A simplified schematic of post-combustion carbon capture for a coal-fired power plant is shown in Figure 1. CO₂ is captured after the flue gases are cleaned up by Electro Static Precipitator (ESP) and Flue Gas Desulfurization (FGD).

Figure 1: Schematic of post-combustion carbon capture in power plants.

• The current major post-combustion carbon capture technologies are absorption, adsorption, membrane, and cryogenics.
• Current technologies for post-combustion CO₂ capture focus mainly on solvent-based absorption. However, the low pressure of the power plant flue gas would result in additional cost for CO₂ compression, transportation and storage.
• Other disadvantages of absorption include degradation in an oxidizing atmosphere, higher energy intensity during regeneration, limited CO₂ loading capacity, and corrosion with foaming and fouling characteristics.
• There are limited studies that used PEI impregnated TiO₂ nanotubes in post-combustion carbon capture. The high surface areas and specific adsorption sites of porous materials make porous solid adsorbents good candidates for application in CO₂ capture.
• Synthesizing highly efficient amines-functionalized nanoporous materials is still a big challenge; more efforts need to be put on the investigation of optimal parameters for synthesizing economic and effective nanomaterial for CO2 capture.