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WHY ARE WE IGNORING THE PROMISE OF THE ‘NON-UTILIZATION OF CARBON ROUTE’ ? - CHOA eJournal 20 07 2023

WHY ARE WE IGNORING THE PROMISE OF THE ‘NON-UTILIZATION OF CARBON ROUTE’ IF CARBON SEQUESTRATION IS VITAL FOR THE ENERGY TRANSITION?

CHOA Synopsis by CHOA Editorial Committee

SPE Paper “Carbon Sequestration: The Ignored Promise of the ‘Non-Utilization of Carbon Route.’

by Dr Subodh Gupta, SPE

The full published paper can be accessed at this link.

Subodh’s SPE paper begins by noting certain limitations of carbon capture, hydrogen production, direct air capture, and renewables as viable pathways for the transition to a low-GHG emissions energy future. He explores why these pathways haven’t seen more uptake: high input energy costs, fundamental limitations to scale, and so on.

For example, when it comes to mature carbon capture and storage (CCS) technology, “The extent of its global application has been less than 0.1% in addressing the emissions challenge". “The reason is the high cost of CCS compared to the prevailing price on carbon in most jurisdictions.” Subodh goes on to examine why the other alternatives like hydrogen or renewable fuels also have not achieved sufficient market share.

The paper states “two approaches discussed here promise to be more costeffective than the alternatives.” Subodh proposes development of alternatives to CCS that instead turn waste byproducts of combusting carbon-based fuels into solids or liquids, as opposed to gaseous CO₂:

- L-Ox processes - lower-state oxidation of fuel to avoid production of CO₂

- L-Red processes - low-energy reduction of combustion byproduct CO₂, to reduce costs of CO₂ disposal.

1. L-Ox Processes (Lower-State Oxidation of Fuel to Avoid Production of CO)

In L-Ox processes, the fuel is oxidized only to the degree of becoming a liquid waste byproduct (not a gas). These liquid waste products do not interact with the atmosphere and can more easily be disposed of In the example given below, the L-Ox reaction of methane yields approximately 70% of the energy of full combustion.

Fig. 1 - Combustion Oxidation (left) vs. L-Ox (right)

2. L-Red Processes (Low-Energy Reduction of Combustion Byproduct - CO)

The L-Red process still uses combustion, but in the example given, turns the resulting CO₂ back into a liquid that can be much more economically disposed of downhole.

Fig. 2 - An L-Red Process Example

3. We Must Pursue Least-Cost Options

Finally, Subodh posits that we should be avoiding the many ineffective decarbonization technologies that are

1. proven, but high cost, or

2. unproven, with little or no chance to sufficiently reduce cost.

Instead, we should pursue options that will be more effective based on their high-level physical architecture.

Although this may appear an obvious conclusion, there are real-world examples today of non-promising technologies receiving substantial private and public investment [CHOA Editorial Committee comment: The Canada-Germany green hydrogen project could be one such example – so much energy is lost between energy conversions and trans-Atlantic transportation that there might never be a business case for this announced green hydrogen project.]

Fig. 3 - Charting Various Technology Options for Decarbonization According to Their Cost

Dr Subodh Gupta, Technology Advisor, Founder, HERETECH ENERGY

Dr Subodh Gupta is the founder of Heretech Energy, where he provides value through advising on workable solutions to decarbonizing the energy and finance industry, ranging from practical emissions-reduced subsurface recovery methods to low-carbon surface processing and carbon-abatement alternatives. He worked for over 25 years at Cenovus, most recently as the Chief of R&D. Subodh is also a member of the CHOA Journal Editorial Committee In March 2023, Subodh presented a full paper on this subject to the SPE Canadian Energy Technology Conference and Exhibition, entitled “Carbon Sequestration: The Ignored Promise of the ‘Non-Utilization of Carbon’ Route.”

Dr Subodh Gupta

CHOA eJournal 20 07 2023

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