Carbon Capture and Sequestration

Different Types of Carbon Capture

There are several different approaches to carbon capture and sequestration:

• Artificially converting CO₂ in effluent gasses from industrial processes where concentrations are as much as 20%.
• Artificially converting CO₂ from the air at 415ppm - Direct Air Capture
• Biochemically converting CO₂ in the air at 415 ppm with reforestation, afforestation, regenerative farming and soil management via photosynthesis

A positive report from Imperial College, London speaks to the growth of carbon capture and storage, and its contribution to meeting the necessary goals. Storage projections in Gt are less than previously estimated if we act soon:

"World can likely capture and store enough carbon dioxide to meet climate targets" phys.org - May 20, 2020

Problems with Capturing CO₂ from Air

Capturing carbon directly from the air is problematic because the concentration from a processing standpoint is so low, 415ppm. Natural biological processes, photosynthesis and trees may be a better way than trying to do it artificially.

Why carbon capture might be an illusion, see:

"The Carbon Capture (NETs) Big Lie, Carbon Capture Reduction Calculations Now Being Used to Set Global Fossil Fuel Reduction Targets Will Save Us From Extinction --- Just in Time" - JobOneForHumanity

"New carbon dioxide capture technology is not the magic bullet against climate change" - Phys.org - April 18, 2019

"Study Casts Doubt on Carbon Capture" - Phys.org - Taylor Kubota - October 25, 2019

Carbon Capture Technologies

Solar Thermal Electrochemical Photo Process

Perhaps there’s hope yet with the Solar Thermal Electrochemical Photo (STEP) carbon capture Process (George Washington University, 2010):

"Solar-powered process could decrease carbon dioxide to pre-industrial levels in 10 years" - Phys.org - Lisa Zyga - July 22, 2010

Similarly for CO₂ to Carbon Nanotubes emerging technology (George Washington University, 2015) see:

"Carbon Capture & Solar Research" - Licht Research Group

and see:

"‘Diamonds from the sky’ approach turns CO2 into valuable products" ACS - August 19, 2015

Metal Oxide Frameworks

Metal Oxide Frameworks (MOF) can reportedly capture CO₂ directly, see:

"Metal–Organic Framework-Based Materials for Energy Conversion and Storage" - ACS - Tianjie Qiu - January 8, 2020.

"New breakthrough in nanotechnology that uses atmospheric carbon to make useful chemicals" - Phys.org - Matt Cichowicz - October 3, 2018

The process requires a source of hydrogen gas. There remain lots of questions since this is still an area of research.

Cerium Catalyst Conversion to CO

An electrolysis process using a cerium oxide electrode selectively produces CO without the inconvenience of solid carbon. From phys.org, “New route to carbon-neutral fuels from carbon dioxide discovered”, Sept 16, 2019 at:

"New route to carbon-neutral fuels from carbon dioxide discovered" - Phys.org - Stanford University - September 16, 2019

Electrochemical Processes

The technique, based on passing air through a stack of charged electrochemical plates, is described in a new paper in the journal Energy and Environmental Science, by MIT postdoc Sahag Voskian, who developed the work during his PhD, and T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering and reported at:

"MIT engineers develop a new way to remove carbon dioxide from air" - MIT News - David Chandler - October 24, 2019

For a PBSNewshour discussion on the technology see:

"This new ‘battery’ aims to spark a carbon capture revolution" - PBS Newshour - Nsikan Akpan - November 15, 2019

While the process (still in the lab) removes CO₂ from the air and can provide a pure stream of CO₂, that CO₂ has to be stored and disposed of.

Zeolite Processes

A “new material is a bio-based hybrid foam infused with a high amount of CO₂-adsorbing 'zeolites," microporous aluminosilicates. This material has been shown to have very promising properties. The porous, open structure of the material gives it a great ability to adsorb the carbon dioxide” from:

"A sustainable new material for carbon dioxide capture" - Phys.org - Chalmers University of Technology - December 9, 2019

Polymer Membrane Processes

A polymer membrane that enhances the separation of CO₂ in effluent gases is described in:

"A Surprising Substance May Be Key in Capturing CO2 in the Atmosphere" - Norewegian University of Science and Technology - December 11, 2019

Natural Carbon Capture

(aka 'Negative Emissions)

Bioenergy with carbon capture and storage

Bioenergy with carbon capture and storage – better known by the acronym “BECCS” – may be one of the more viable and cost-effective negative emissions technologies. There are many attractive features, since this technology could provide energy – thus reducing our need for fossil fuels – and remove CO₂ from the atmosphere at the same time.

However, the full carbon-cycle impacts of large-scale deployment of BECCS are not well studied. No studies have looked at these impacts specifically for a scenario that could meet the 1.5°C target.

"Why BECCS might not produce ‘negative’ emissions after all" - Carbon Brief - Dr. Anna Harper - August 14, 2018

Reforestation and Afforestation

From Nature4Climate website...

Afforestation (growing new forests) and reforestation (restoring existing forests), combined with a variety of land management and conservation practices, could remove around 1-2bn tonnes of carbon from the atmosphere per year. There is a potential warming effect of forests as well, especially in high-latitude areas where adding trees can warm the climate since their albedo is lower than snowy ground or agricultural land.

Around the world, huge swaths of temperate and tropical forests have been cleared for human activity. Many of those lands are being used productively to grow food and raise livestock that we need and, with yet better practices, can sustainably yield even more food. Yet many other deforested lands are degraded, produce less than one cow per hectare, and are good candidates for reforestation.

"Reforestation" - Nature for Climate

Enhanced Rock Weathering

Still under development, some processes add minerals to the seas, others distribute dust on the land:

"Enhanced Weathering for Carbon Capture" - Earth.org - February 2020

"CO2 Removal With Enhanced Weathering and Ocean Alkalinity Enhancement: Potential Risks and Co-benefits for Marine Pelagic Ecosystems" - Frontiers in Climate - October 2019