Introduction

In this week we'll look critically at the energy considerations for CSS and DAC, and how that impacts the economics of each process. Energy is the primary operational cost, and in turn impacts the overall carbon intensity of these processes.

Learning Outcomes/Goals

Energy balance considerations

1. Thermodynamics of carbon capture
2. Absorption (amine based) chemistry
3. Adsorption and desorption
4. Heat recycling
5. Membrane separation

Energy requirements are the Achilles's heal of carbon capture. From chemical and physical principles we know that the reverse direction of a reaction requires (at least) equal and opposite enthalpy. Given that absorption and adsorption are always exothermic, regeneration of solvent/sorbent will require at least an equal amount of energy (kJ/mol). In many cases, this can require heat from fossil fuel thermal sources, and/or electricity with significant carbon intensity. Life Cycle Analysis (LCA) needs to be performed to ensure that the "carbon cost" doesn't exceed the "climate benefit", and that energy directly invested into carbon capture makes more sense than an equal investment in Renewable Energy (RE), which has both energy and carbon (climate) benefits.

Articles:

Direct air capture's hidden energy cost

'The amount of energy required by direct air carbon capture proves it is an exercise in futility'

Assignments and Due Dates

Watch the YouTube videos, answer the weekly questions, and reflect on the critical impact of energy on CSS and DAC, and try out some of the calculations we went over in class.

Thermodynamic and energy considerations of carbon capture