Direct air capture Process Flowsheets & Simulations
Explore 2 validated, solved Direct air capture simulation flowsheets in MaximaLabs — real components: n2, oxygen, co2, water, calcium_carbonate, calcium_oxide. Open any one directly in your browser.
Solved via: COOLPROP.
Direct air capture with solid-sorbent calcination + CO2 liquefaction
A Carbon Engineering-style DAC train: a fan draws ambient air (400 ppm CO2) through a liquid-KOH contactor (a fixed-recovery separator — the same simplification the existing carbon-capture example uses for chemical absorption, since no CO2-KOH electrolyte package exists) capturing ~75% of the CO2. The captured CO2 is causticized and precipitated into CaCO3 pellets by the real (unmodeled-in-detail) KOH/Ca(OH)2 loop — represented here as a matched pellet feed sized to the captured CO2 rate, since the generic reactor unit op can't itself produce a solid product (only a rotary kiln's decomposition path can, which is exactly what's used next). Those pellets calcine at ~977 degC in an indirectly-heated rotary kiln (real Arrhenius decomposition kinetics, Sullivan-Maynard-Valentine residence time), releasing pure CO2 that's compressed to ~20 atm and chilled to 250 K — above the real Span-Wagner CO2 saturation pressure at that temperature, so the solved outlet stream is genuine subcooled LIQUID CO2 (not just dense-phase pipeline gas) — while the CaO leaves for slaking and reuse (the lime side of the closed loop, out of scope for the same reason as the causticization step). Run the Carbon Footprint report on this example for the real Scope 1/2/3 CO2e + carbon-tax liability breakdown already built into this codebase's report generator.
12 unit ops • COOLPROP
20 1
View & openSolid-sorbent fluidized-bed DAC with compression heat recovery
A second, lower-temperature DAC pathway alongside the liquid-KOH + rotary-kiln example: the captured CO2 loads onto a solid sorbent, which regenerates in an indirectly-heated fluidized bed (real Wen-Yu minimum-fluidization sizing + Arrhenius desorption kinetics, unitops/solids.py's FluidizedBed) at 120 degC -- the real low-temperature regime solid amine/physisorbent DAC sorbents actually use, versus the other example's ~977 degC calcination. The bed is fluidized by a recycled CO2 sweep (self-sweep with product gas, a real design choice that sidesteps needing a steam-condensate knockout step). The desorbed CO2 is compressed toward liquefaction pressure in one adiabatic stage -- hot enough (~780 K discharge) that routing it through a heat exchanger against process utility water genuinely converts that water from subcooled liquid to a boiling mixed-phase stream before the CO2 continues on to the same real liquefaction physics as the other DAC example. Honesty note: this recovers real compression waste heat into a genuinely useful utility stream (the actual mechanical-vapor-recompression principle -- reusing a compressor's own heat instead of rejecting it to cooling water) but does NOT feed that heat back into the fluidized bed's own desorption duty, which this unit op takes as a fixed wall-temperature parameter, not a second heating-utility stream -- a literal closed MVR loop onto the desorber itself isn't wireable with this unit op as built.
14 unit ops • COOLPROP
19 0
View & open