"The discussion of energy consumption for cryogenic & combined #DirectAirCapture systems is explored in the newly published thesis."ποΈ
Details are discussed in aπ§΅β¬οΈ
1/10
In this novel approach, "a thermodynamic model was constructed using psychometric theories to model the #desublimation of CO2 in a #DAC system. The system was modeled
to include a precooling heat exchanger & a deposition chamber where the desublimation
of CO2 occurs."
2/10
3οΈβ£ base systems studied:
πΈ NC (no precompression/turbine recovery)
πΈPC (precompression only)
πΈTR (precompression & turbine recovery)
at 3οΈβ£ different compression ratios, n=400, 800 & 2000.
Then, a combination #DAC system, PSA, was modeled."
3/10
"A dual-column, 4οΈβ£-step Skarstrom Cycle PSA (pressure swing adsorption & cryogenic distillation) unit was analyzed using Extended Langmuir Models & the
ideal gas law to simulate a CO2 conc. prior to the deposition chamber. The NC & PSA systems were assessed at Tamb= -50β¦C."
4/10
This study finds that "while increasing the compression ratio of the system, there is no net energy benefit when capturing CO2 given the current state-of-the-art in commercial compressor & #cryocooler capabilities."
5/10
"The assessment of the efficiency of a precooler versus TR finds that it is more advantageous to utilize a heat exchanger precooler than precompression with turbine recovery in a #DAC system. Combining DAC systems may yield a more efficient system."
6/10
"PSA combined with cryogenic capture is less energy intensive than cryogenic capture alone. In a combined #DAC system with PSA and cryogenic distillation,
the PSA unit has a significantly lower energy consumption than the #cryocooler."
7/10
"Increasing the concentration of CO2 entering the deposition chamber significantly decreases the required energy consumption of the #cryocooler."
8/10
Read the complete #Doctoral#Thesis entitled: "Atmospheric Carbon Capture: A Review on Current Technologies and Analysis of Energy Consumption for Various Direct Air Capture (DAC) Systems" here β¬οΈ commons.erau.edu/edt/728/
This episode dives into a radical proposal: using a buried nuclear explosion on the seafloor to break up basalt & speed up carbon removal via Enhanced Rock Weathering. The goal? Sequester 30 years of global CO2.
2/12
This episode unpacks a preprint by Hosea Olayiwola Patrick drawing lessons from COVID-19 for solar geoengineering.
π° Here's your round-up of top #CarbonDioxideRemoval News / Developments from this week (09 June - 15 June 2025):
π:
π§΅0/17
@InSoilClimate secured its largest funding to date through a β¬100 million agreement with Key Carbon, accelerating regenerative agriculture and carbon credit generation across Europe.
Canada Nickel partnered with NetCarb to scale mineral carbon sequestration at Crawford. NetCarb's tech could boost COβ uptake 10βfold to 10β15β―Mt/year, vs 1.5β―Mt via Canada Nickel's proprietary IPT Carbonation.
π¨A new study [preprint] shows that injecting sulfur at 50km could make #SolarGeoengineering much safer.
It cools the planet more effectively, speeds ozone recovery & avoids stratospheric disruptions. This could be done using a fleet of clean, reusable H2 rockets.
DETAILSπ§΅1/10
2/ SAI involves spraying SOβ into stratosphere, where it forms aerosols that reflect sunlightβcooling Earth. It mimics volcanic eruptions like Mt. Pinatubo (1991), which temporarily cooled the planet.
But current βSAI modelsβ inject SO2 at a rate of 10 Tg/yr at ~25km altitude.
3/ But Injecting at 25 km creates problems
Aerosols accumulate in the tropical lower stratosphere, causing up to 6Β°C warming in that layer.
This disturbs jet streams, increases stratospheric water vapor, and delays the ozone layerβs recoveryβby 25β55 years in Antarctica.
π¨A new study has revealed for the first time that ancient carbon, stored in landscapes for thousands of years or more, can find its way back to the atmosphere as COβ is released from the surfaces of rivers at a rate of 1.2 billion tonnes per year.
Detailsπ§΅1/8
2/ To understand the true source of river COβ, researchers compiled a global dataset of 1,195 radiocarbon measurements of dissolved inorganic carbon (DIC), COβ & CHβ from rivers & streams.
This let them determine whether the emitted carbon was modernβor much older.
3/ Using radiocarbon signatures (ΒΉβ΄C), they found that 59% of river COβ emissions come from "old" Cβmillennia-old soil carbon & even petrogenic carbon (rock-derived, >55,000 years old)
Only ~41% came from recent biological sources like plants & microbes (decadal carbon).