tech details

Method for Regeneration of Immobilized Amine Sorbents for Use in CO2 Capture (the BIAS Process)

Opportunity

Research is currently active on the following patent-pending and patented technologies:

  • "Regenerable Immobilized Aminosilane Sorbents for Carbon Dioxide Capture", known as the Basic Immobilized Amine Sorbent (BIAS) process
  • "Regenerable Sorbent Technique for Capturing CO2 Using Immobilized Amine Sorbents"

These technologies are available for licensing and/or further collaborative research from the U.S. Department of Energy’s National Energy Technology Laboratory.


Overview

Carbon sequestration entails a multi-step process in which anthropogenic CO2 emissions are captured from CO2-laden process gas streams and permanently stored. Carbon capture is a critical step in the process and accounts for a considerable portion of the overall cost. Newly developed, high-capacity amine-based sorbents offer many advantages over existing technology including:

  1. Increased CO2 capture capacity
  2. Reduced corrosion, energy requirements, and costs
  3. Minimized water usage

Additionally, amine-based sorbents are scalable for use in industrial applications, including coal combustion and gasification power generating systems. Alternative applications include landfill gas cleanup, EOR natural gas sweetening, and life support systems.

The BIAS Method: This advanced technology is a steam regeneration process for amine-based solid sorbents used in CO2 capture. This method reduces the impact of water loading on sorbent regeneration by using a conditioner after the steam regeneration step. The conditioner utilizes a drying gas, which contacts the regenerated sorbent to remove free steam, and it reduces the water loading of the regenerated sorbent by removing part of the adsorbed water present. The adsorbed water removed by the conditioner is equivalent to the water uptake expected during the subsequent CO2 absorption process. This provides for water loadings on the sorbent exiting the absorber and entering the regenerator to be matched to the moisture loading of the sorbent exiting the regenerator under a sweep of steam, allowing the thermal energy transferred to the loaded sorbent to be utilized for CO2 desorption rather than desorption of adsorbed water. The method allows for optimal CO2 removal capacity for a given absorption and regeneration reactor size. Management of water loading in this manner allows optimal operation of the regeneration reactor with a significant reduction in energy losses incurred by the desorption of adsorbed water.

The Sorbent: Development of this second generation sorbent for the capture of carbon dioxide was based on the BIAS process steam requirements. This novel sorbent fabrication combines both chemical grafting and immobilization of the amine and the aminosilane into the high pore structure of the silica based substrate. In tests, the sorbent remained stable and resulted in significant carbon dioxide capture loadings.

Ultimately, the BIAS process method reduces the impact of water loading on sorbent regeneration by utilizing a conditioner following the steam regeneration step. The conditioner receives a flow of drying gas which contacts the regenerated sorbent to remove free steam, as well as reducing the water loading of the regenerated sorbent by removing part of the adsorbed water present. The adsorbed water removed by the conditioner is considerably equivalent to the water uptake expected to occur during the subsequent CO2 absorption process. This provides for water loadings on the sorbent equivalent to the moisture loading of the regeneration process, allowing the thermal energy transferred to the loaded sorbent to be utilized for CO2 desorption rather than desorption of adsorbed water. The method allows for optimization of the CO2 removal capacity for a given absorption and regeneration reactor size. Management of water loading in this manner allows optimal regeneration reactor operation with a significant reduction in energy losses incurred by the necessary desorption of adsorbed water.


Significance

  • Reduces energy loss during sorbent regeneration
  • Maximizes CO2 removal capacity
  • Accounts for and minimizes moisture in the overall sorbent process
  • Minimizes the overall cost of CO2 capture


Applications

  • Combustion or gasification power generation systems using amine-based solid sorbents for CO2 capture and natural gas, landfill gas, or biogas cleanup
  • Possible application for air purification in life support systems


Related Patents

U.S. Patent No. 8,500,854, issued August 6, 2013, titled "Regenerable Sorbent Technique for Capturing CO2 Using Immobilized Amine Sorbents.”

Inventors: Henry Pennline, James Hoffman, McMahan Gray, Daniel Fauth, Kevin Resnik

U.S. Patent No. 8,834,822 titled, "Regenerable Immobilized Aminosilane Sorbents for Carbon Dioxide Capture" was issued on September 16, 2014.

Inventors: McMahan Gray, Christopher Jones, Sunho Chai


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