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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Aging studies of Dual functional materials for CO 2 direct air capture with in situ methanation under simulated ambient conditions: Ru thrifting for cost reduction

Dual function materials (DFMs) comprised of 0.25 %Ru, 6.1 %Na 2 O/γ-Al 2 O 3 //monolith were evaluated for about 250 hours time-on-stream (TOS) at various simulated ambient climate capture conditions followed by temperature swing methanation to 280 °C. Herein this paper focuses on the impact of thrifting Ru to low levels and the impact on performance. Results showed both stable CO 2 capture capacity and CH 4 production with 0.25 % Ru DFM deposited on a ceramic monolith. The CO 2 conversion to CH 4 production was decreased slightly by the Ru decrease from 1 % to 0.25 %. The capture capacity decreased since a lower Ru content reduces the complete decomposition of the Na 2 CO 3 precursor producing fewer active adsorption sites (“Na 2 O”). The deployment of a low Ru DFM monolith would significantly decrease the overall capital cost and give more potential for a large-scale direct air capture and methanation (DACM) application.

03 NATURAL GAS↗
DOE OSTI2024

Effective direct steam regeneration of bis-iminoguanidine solid sorbent used for carbon dioxide capture

A cost-effective, energy-efficient sorbent regeneration process for phase-changing guanidines used for CO 2 capture was developed based on direct-steam stripping. This approach enhances the regeneration rate, simplifies the overall CO 2 capture process, and reduces the energy cost compared to conventional conductive thermal regeneration. A direct-steam sorbent regeneration reactor was developed, demonstrating that aqueous bis(iminoguanidines) (BIG) sorbents, e.g., methylglyoxal-bis(iminoguanidine) (MGBIG) and glyoxal-bis(iminoguanidine) (GBIG), could be efficiently regenerated with up to ~ 99 % CO 2 recovery through direct-steam stripping. Using low-temperature steam at 100 °C, a 4.5 times faster regeneration rate for GBIG carbonate sorbent (e.g., 30 min for 10 g) was demonstrated compared to conductive-heating (e.g., 135 min for 10 g) at 130 °C. Additionally, fully regenerated MGBIG converts into an aqueous MGBIG solution when the steam condenses onto the sorbent surface. Condensed steam with the guanidine can be easily recycled as an aqueous solution into the gas–liquid contactor to achieve a continuous-flow CO 2 -capture process. Molecular dynamics simulation was employed to provide a better understanding of the process. Higher heat transfer rates from steam to guanidine carbonate, compared to air heating, were attributed to the vibration resonance of water molecules within MGBIG with that of vapor molecules and the effective transfer of kinetic energy from vapor to solid. Technoeconomic analysis demonstrated that direct-steam stripping significantly decreases the CO 2 capture cost by 50 % compared to traditional conductive heating methods. Further, enhanced mass transfer facilitated by low-temperature steam and subsequent condensation effectively heats up the H 2 O-containing BIG-carbonate crystals, facilitating the desorption of CO 2 from the solid crystals, thereby leading to fast, effective, and energy-efficient sorbent regeneration.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Energy-efficient carbon capture from industrial point sources via commercially available green solvent and hollow fiber membrane contactors

Solvent-based absorption systems have emerged in the carbon capture space due to their high absorption capacities, reusability, and favorable energy requirements. Using diethyl sebacate as a solvent for pre- and post-combustion carbon capture has advantages over other solvents, including high hydrophobicity, low viscosity, low vapor pressure, high CO 2 solubility, high CO 2 selectivity, and being commercially available in large quantities. Despite these advantageous properties, the use of diethyl sebacate as a solvent for post-combustion carbon capture has not been studied in detail. To examine the capability of diethyl sebacate, a scalable, energy-efficient, hollow fiber membrane (microporous polypropylene and polyvinylidene fluoride) contactor (HFMC)-based process with low-cost and high surface area is investigated. A purity of 95.3 % CO 2 with 46 % recovery in one absorption stage was achieved, with a permeate flux over one magnitude greater than using a deep eutectic solvent in the same system. Technoeconomic analysis determined a ∼ 0.8 GJ per ton of CO 2 at a processing cost of ∼$93 per ton of CO 2 . Results from this work underscore the potential for utilizing green solvents in HFMC-based separation processes for effective carbon capture and provide a pathway towards practical deployment.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

A simulation-based model studying monoethanolamine and aprotic heterocyclic anion ionic liquid (AHA-IL) mixtures for carbon capture

Capturing of waste CO 2 , particularly from large industrial point sources, is necessary for either permanent storage or CO 2 utilization. Amine solvents used for carbon capture have certain drawbacks, particularly the high energy required by the reboiler for solvent regeneration and degradation of the amine with absorption/regeneration cycling. These challenges may be overcome using ionic liquids (ILs) that can be tailored for operating under typical flue gas stream conditions (8–10% CO 2 , 18–20% H 2 O, 2–3% O 2 , and 67–72% N 2 ). ILs, however, oftentimes suffer from high viscosities, leading to diffusion limitations when compared to amine solvents. This work models the combinations of aprotic heterocyclic anion ILs (AHA-IL) with monoethanolamine (MEA) and studies the carbon capture effectiveness of these mixtures. Furthermore, this study found that all AHA-IL/MEA mixtures exhibited 32 % lower enthalpy of reaction (compared to MEA) and 64 % lower viscosity (compared to AHA-IL), which are desirable characteristics for CO 2 capture solvents.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Life cycle assessment of co-firing biomass at coal-fired power plants with carbon capture and storage toward net-zero emissions

Co-firing biomass with carbon capture and storage (BECCS) offers a technological option to decarbonize coal-fired power plants toward net-zero emissions. This study estimates the life cycle emissions of co-firing biomass at coal-fired power plants with CCS and quantifies its variability and uncertainty. Deployment of co-firing BECCS at coal-fired power plants can significantly reduce the life cycle emissions toward the net-zero target but lower the power plant performance, which vary with numerous factors, including coal type, biomass type, co-firing level, and CO 2 capture rate. The breakeven co-firing levels required for biomass at coal-fired power plants with 90 % CO 2 capture to reach net-zero emissions fall with a range roughly from 15 % to 25 % on an energy basis, depending on coal and biomass types. Increasing the CO 2 capture rate from 90 % to 95 % can lower the breakeven co-firing levels by about 5 to 8 percentage points for the biomass resources of interest, which can lower reliance on biomass resources and facilitate large-scale deployment of co-firing BECCS in fossil-rich regions but with limited biomass resources. Furthermore, findings improve the understanding of the techno-environmental performance of co-firing BECCS and inform strategic planning decisions on net-zero emissions in the coal-fired power sector.

Breakeven co-firing level↗
DOE OSTI2020

The current status of high temperature electrochemistry-based CO 2 transport membranes and reactors for direct CO 2 capture and conversion

The concept of direct CO 2 capture and conversion has attracted significant interest from industries and academia in recent decades due to its potential to address the current grand challenge of global warming/climate change, rapid depletion of fossil fuels and realization of a future carbon neutral ecosystem. The incumbent benchmark technology for CO 2 capture is the post-combustion flue-gas “amine washing”, which is energy intensive and costly for large-scale commercial implementation. The CO 2 conversion technologies, on the other hand, are still at their infancy with many technical challenges to overcome, but primarily being explored in laboratory-scale, low-temperature, solution-based and high-temperature, solid-oxide-based electrochemical cells with renewable electricity perceived as the energy input. In this article, we provide a comprehensive overview on an emergent class of high-temperature electrochemical CO 2 transport membranes that can capture and convert CO 2 into valuable chemicals in single catalytic reactor fashion. The review starts with the chemistry and transport theory of three basic types of membranes purposely designed for different CO 2 feedstocks and downstream conversions. A range of key functional materials used in these membranes and their microstructural/electrochemical properties important to the CO 2 transport are then thoroughly discussed in conjunction with the effects of surface modifications and operating conditions. Several types of combined CO 2 capture and conversion catalytic reactors based on these membranes are also assessed with a focus on their working principles, system configurations and performance demonstrations. Finally, challenges and prospective of these electrochemical CO 2 transport membranes and their associated conversion reactors are candidly discussed for future development.

10 SYNTHETIC FUELS↗
DOE OSTI2021

Carbon dioxide capture with aqueous amino acids: Mechanistic study of amino acid regeneration by guanidine crystallization and process intensification

CO 2 capture from powerplant-generated flue gas via a phase-changing process involving absorption with aqueous amino acids (e.g., glycine or sarcosine) and bicarbonate crystallization with bis-iminoguanidines (e.g., glyoxal-bis-iminoguanidine or GBIG) is investigated in this paper. This process is of high interest due to its potential to decrease the energy penalty for CO 2 capture by significantly reducing the solvent regeneration energy typically associated with aqueous amine solvents. A critical step in the proposed CO 2 capture mechanism is the regeneration of the amino acid by removal of protons and bicarbonate ions from solution through crystallization of GBIGH 2 2+ bicarbonate salt. Here, we investigated the thermodynamics and kinetics of glycine regeneration by crystallization of GBIGH 2 2+ (HCO 3 – ) 2 (H 2 O) 2 . A theoretical model was developed and compared to experimental data to simulate and predict the glycine regeneration and determine its reaction mechanism. This combined experimental and theoretical study led to the conclusion that, while the GBIGH 2 2+ bicarbonate crystallization step provides most of the thermodynamic driving force for the glycine regeneration, the rate-limiting step is the protonation of GBIG prior to crystallization. The CO 2 loading and amino acid regeneration steps were combined into a single, intensified process using a bubble column reactor. The CO 2 loading capacity of GBIG was experimentally determined to be roughly 1.36 mol CO 2 per mol GBIG. These results provide the fundamental basis for developing an effective carbon capture technology with phase-changing amino acid/guanidine absorbents.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Breakthrough Zn(II) Catalyst for Direct Air Capture Employing CO 2 Hydration

Direct air capture (DAC) represents a vital technology for atmospheric CO₂ remediation, but few studies have tested catalysts at dilute atmospheric CO₂ concentrations. Inspired by the carbonic anhydrase metalloenzyme, we report a catalytic DAC strategy employing robust zinc(II) enzyme mimics that enable efficient CO₂ sequestration pathways. A catalyst-mediated CO₂ hydration cycle in aqueous sorbents facilitates accelerated capture from dilute atmospheric air, thereby addressing the kinetic limitations observed in carbonate-based systems. Our developed complexes [ZnC1] and [ZnC2] enhance capture rates up to two-fold at millimolar concentrations and improve CO₂ mass transfer by 40-60% in 1 M K₂CO₃ sorbent under ambient conditions. These bench-stable, earth-abundant zinc catalysts operate effectively under dilute CO₂ concentrations, overcoming the kinetic limitations of conventional carbonate-based sorbents. As a result, mechanistic studies support a biomimetic catalytic cycle that facilitates rapid CO₂ conversion, demonstrating that catalyst-assisted DAC can enable energy-efficient, scalable carbon capture technologies.

Atmospheric chemistry↗
DOE OSTI2024

Role of Intermolecular Interactions in Deep Eutectic Solvents for CO 2 Capture: Vibrational Spectroscopy and Quantum Chemical Studies

Recent research and reviews on CO 2 capture methods, along with advancements in industry, have highlighted high costs and energy-intensive nature as the primary limitations of conventional direct air capture and storage (DACS) methods. In response to these challenges, deep eutectic solvents (DESs) have emerged as promising absorbents due to their scalability, selectivity, and lower environmental impact compared to other absorbents. However, the molecular origins of their enhanced thermal stability and selectivity for DAC applications have not been explored before. Therefore, the current study focuses on a comprehensive investigation into the molecular interactions within an alkaline DES composed of potassium hydroxide (KOH) and ethylene glycol (EG). Combining Fourier transform infrared (FT-IR) and quantum chemical calculations, the study reports structural changes and intermolecular interactions induced in EG upon addition of KOH and its implications on CO 2 capture. Experimental and computational spectroscopic studies confirm the presence of noncovalent interactions (hydrogen bonds) within both EG and the KOH-EG system and point to the aggregation of ions at higher KOH concentrations. Additionally, molecular electrostatic potential (MESP) surface analysis, natural bond orbital (NBO) analysis, quantum theory of atoms-in-molecules (QTAIM) analysis, and reduced density gradient-noncovalent interaction (RDG-NCI) plot analysis elucidate changes in polarizability, charge distribution, hydrogen bond types, noncovalent interactions, and interaction strengths, respectively. Evaluation of explicit and hybrid models assesses their effectiveness in representing intermolecular interactions. This research enhances our understanding of molecular interactions in the KOH-EG system, which are essential for both the absorption and desorption of CO 2 . The study also aids in predicting and selecting DES components, optimizing their ratios with salts, and fine-tuning the properties of similar solvents and salts for enhanced CO 2 capture efficiency.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Ionic Liquid-Enhanced Interfaces to Boost Reactive C O2 Capture

The addition of ionic liquids (ILs) to a mixture containing a molecular solvent and other ionic species can induce the heterogeneous redistribution of cations and anions at the gas–liquid interface. This nonuniform redistribution of cations and anions driven by the differences in the solvophilicity of ions can improve the thermophysical and interfacial properties of such mixtures, creating a local chemical environment that is conducive to some reactions. In this work, ILs are added to a mixture of potassium hydroxide (KOH) and ethylene glycol (EG), used as a reactive absorbent and electrolyte in the migration-assisted moisture-gradient (MAMG) process for CO 2 capture. Molecular dynamics (MD) simulations are employed to probe into the effects of complex ion–ion and ion–solvent interactions and to examine the chemical composition at the gas–liquid interface. A total of 12 systems are investigated using molecular simulations to identify trends in the performance of IL additives based on the choice of cation, anion, and IL concentration. The cation effects are studied using IL additives based on 1-ethyl-3-methylimidazolium ([EMIM] + ) and 1-butyl-3-methylimidazolium ([BMIM] + ), while the impact of anions is examined using additives based on dicyanamide [DCA] − , triflate [TfO] − , bistriflimide [NTf 2 ] − , and hexafluorophosphate [PF 6 ] − anions, respectively. The influence of the IL concentration is also evaluated at molar concentrations between 1% and 4%. The simulation results indicate that the use of IL additives can affect the physical CO 2 solubility, surface tension, and the localization of CO 2 around the [OH] − ions at the gas–liquid interface. It is also evident that the choice of cations, anions, and IL concentration determines the extent to which the IL additives impact the local physicochemical properties. Physical dissolution, diffusive transport, and interaction with [OH] − are critical intermediate steps toward reactive CO 2 capture using a liquid absorbent. Hence, the improvement in one or more of these properties, aided by IL additives, is expected to improve the overall CO 2 capture performance. Experiments reaffirmed the impact of IL additives on CO 2 capture performance and the sensitivity to the choice of the cation, anion, and concentration of the IL additive.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

In Situ Investigation on the Nanoscale Capture and Evolution of Aerosols on Nanofibers

Aerosol-induced haze problem has become a serious environmental concern. Filtration is widely applied to remove aerosols from gas streams. Despite classical filtration theories, the nanoscale capture and evolution of aerosols is not yet clearly understood. In this paper, we report an in situ investigation on the nanoscale capture and evolution of aerosols on polyimide nanofibers. We discovered different capture and evolution behaviors among three types of aerosols: wetting liquid droplets, nonwetting liquid droplets, and solid particles. The wetting droplets had small contact angles and could move, coalesce, and form axisymmetric conformations on polyimide nanofibers. In contrast, the nonwetting droplets had a large contact angle on polyimide nanofibers and formed nonaxisymmetric conformations. Different from the liquid droplets, the solid particles could not move along the nanofibers and formed dendritic structures. Finally, this study provides an important insight for obtaining a deep understanding of the nanoscale capture and evolution of aerosols and benefits future design and development of advanced filters.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Photoreactive Capture and Conversion of Dilute Carbon Dioxide into Synthetic Natural Gas

This study introduces a photoreactive system that integrates the capture of dilute CO 2 streams with their catalytic conversion to synthetic natural gas (CH 4 ), utilizing a Ru nanoparticle (NP)-doped TiO 2 composite loaded with linear polyethylenimine (L-PEI) and enhanced with plasmonic titanium nitride (TiN). This light-driven approach mitigates challenges that have plagued traditional thermal reactive carbon capture (RCC) methods, such as CO 2 slip and amine degradation. We demonstrate that L-PEI enables stable CO 2 capture and conversion, achieving ~70% conversion of captured CO 2 to CH 4 across multiple reaction cycles using nonflammable forming gas (~5% H 2 ) as the reductant. In contrast, branched PEI (B-PEI)-loaded composites exhibited significant catalyst deactivation after several RCC cycles. Scanning transmission electron microscopy (STEM) imaging confirms that significant sintering of the Ru NPs occur in the B-PEI sample under RCC conditions, whereas their size remains stable in more rigid L-PEI composites. Technoeconomic analysis (TEA) estimates that CH 4 production using this system could cost less than $\$$5/kg based on current electrocatalytic H 2 prices. These results represent one of the most promising demonstrations of amine-based RCC employing dilute CO 2 sources to date.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Tuning the Functionalities of Porous Liquids for Emergent Gas-Capture Properties

Type 3 Porous Liquids (PLs) are a class of materials with the potential to revolutionize gas capture, storage, and utilization. These PLs are formed by suspending sorbent nanoparticles (e.g., metal−organic frameworks) in sterically excluded solvents, creating permanent porosity for gas capture in a processable, low-viscosity phase. Herein, a computational study revealed sorbent surface functionalization strategies to enhance CO 2 sorption, and the molecular structural signatures underpinning the enhancements in gas uptake. PLs composed of a ZIF-8 surface functionalized with 3-amino-1,2,4-triazole (Atz) in glyceryl triacetate were targeted for emergent CO 2 capture, exceeding that of the unfunctionalized ZIF-8 PL. ZIF-8 was surface functionalized with Atz at various surface coverage fractions (f), and classical molecular dynamics simulations predicted an increase in CO 2 sorption capacity with increasing f, up to f = 0.75. Additionally, detailed structural analyses revealed that solvent orientational order, derived from the solvent triplet-angle distribution, can identify the gas-capture potential of a PL without requiring computationally expensive direct modeling of the CO 2 sorption. Combined with experimental validation, initial computational screening of PL compositions promises to accelerate the discovery of PL compositions for novel gas separation materials platforms.

gas capture↗
DOE OSTI2019

Steam-Stable Basic Immobilized Amine Sorbent Pellets for CO 2 Capture Under Practical Conditions

Pelletization of basic immobilized amine sorbent (BIAS) particles is required to improve their mechanical strength and facilitate their practical CO 2 capture application under fixed or dynamic reactor conditions. Herein, we utilized two methods to prepare amine-functionalized BIAS pellets. Method (ii-a) involved combining latex polychloroprene (PC)/polyamine solutions with fly ash (FA)/BIAS powder to form sorbent pellets. Alternatively, method (ii-b) entailed shaping and drying wet pastes of binder solution plus FA/SiO 2 powder into pellet supports. These supports were then functionalized with leach-resistant polyethylenimine MW = 800 (PEI 800 )/N-N-diglycidyl-4-glycidyloxyaniline (tri-epoxide cross-linker, E3) or ethylenamine E100/E3 mixtures. All pellets were screened for CO 2 capture by thermogravimetric analysis (dry 14% CO 2 /N 2 , 55–75 °C), H 2 O stability by accelerated water washing, and mechanical strength by crush and ball-mill attrition testing. The mechanism of superior method (ii-b) pellet formation was uncovered by N 2 physisorption measurements, diffuse reflectance infrared Fourier transform spectroscopy, and scanning electron microscopy. Extended fixed bed testing of optimum E3/PEI 800 -0.13/1 pellets under practical conditions revealed complete CO 2 capture stability of 1.5 mmol CO 2 /g after 48 h of continuous steam exposure (7.2% H 2 O/He, 105 °C) and minimal 14.6% loss in capacity after 75 hours of combined CO 2 capture cycling and steam treating (48 h). This slight oxidative degradation could be alleviated by incorporating a K 2 CO 3 antioxidant into the pellet formulation. Overall, the robust physiochemical properties of the polyamine/cross-linker method (ii-b) pellets confirm their suitability for pilot-scale testing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Polydiallylammonium-Polysulfone Multiblock Copolymers for Moisture-Swing Direct Air Capture of Carbon Dioxide

Polysulfones are an important class of materials for a variety of applications due to their excellent strength and thermal stability. Quaternary ammonium polymers are also useful materials due to their ion exchange properties, and such materials with alkaline counterions have been used to capture carbon dioxide (CO 2 ) from ambient air through a moisture-driven mechanism. Herein, we design sulfone-based multiblock copolymers containing ammonium functionalities and demonstrate their potential for CO 2 capture. Specifically, a series of multiblock copolymers containing both polydiallyldimethylammonium (PDADMA) and polysulfone (PSf) blocks were synthesized. PSf blocks provide mechanical integrity, while the PDADMA blocks enable the direct air capture of CO 2 . Multiblock copolymers were synthesized at high yield, and PDADMA(OH)-PSf copolymer films with good flexibility and strength were formed with IECs of 424 μmol/g (17 mol % PDADMA(OH)), 1407 μmol/g (44 mol % PDADMA(OH)), and 1726 μmol/g (50 mol % PDADMA(OH)). Thermogravimetric analysis was used to determine that all films are thermally stable up to 345 °C. Differential scanning calorimetry revealed that the 17 and 44 mol % functionalized PDADMA(OH)-PSf multiblock copolymers showed one T g at 185 °C and 50 mol % PDADMA(OH)-PSf polymer showed a T g at 183 °C and a second T g at 16 °C. Atomic force microscopy showed that the multiblock polymers exhibit disordered phase separation. Furthermore, the copolymer materials displayed moisture-swing direct air capture of CO 2 , opening up pathways to utilize polymer architecture and chemistry to tailor the properties of promising sorbents.

42 ENGINEERING↗
DOE OSTI2025

Dual-Bed Radioiodine Capture from Complex Gas Streams with Zeolites: Regeneration and Reuse of Primary Sorbent Beds for Sustainable Waste Management

Dual-sorbent systems are proposed for radioiodine management with a regenerated primary bed for multiple cycles of use in complex conditions and a secondary bed for disposal with higher waste loadings. Sorbent approaches for the effective capture of gaseous radioiodine (isotopes 129 I and 131 I) produced from a range of nuclear processes have been studied for over half a century. (1−5) Whether or not a sorbent (e.g., molecular sieve) is required to physically screen/trap or chemically bind a radionuclide of interest through chemisorption, the complexity of the gas stream has a large impact on the performance (e.g., loading capacity, selectivity) and active life of a sorbent bed. (3) Silver mordenite (AgZ), the U.S. Department of Energy baseline sorbent for radioiodine capture from nuclear processes, performs well within acidic conditions and at elevated temperatures (6) and can be consolidated into a chemically durable waste form for long-term disposal. (7,8) However, new sorbents are being sought because optimal capture performance of AgZ significantly decreases in dynamic oxidizing environments with competing species, and it is expensive and it contains Ag (a toxic metal). (9) Until a new sorbent is found to replace AgZ, the regeneration and reuse of AgZ is an attractive alternative to a single-use primary sorbent bed. In this regard, a primary sorbent could be designed for enhanced capture in complex gas streams and the ability to be regenerated for reuse. Here, a secondary sorbent could then be tailored for maximum iodine loading in the gas stream and chemical durability within a disposal facility.

chemisorption↗
DOE OSTI2023

Electrochemical direct air capture of CO 2 using neutral red as reversible redox-active material

Direct air capture of carbon dioxide is a viable option for the mitigation of CO 2 emissions and their impact on global climate change. Conventional processes for carbon capture from ambient air require 230 to 800 kJ thermal per mole of CO 2 , which accounts for most of the total cost of capture. Here, we demonstrate electrochemical direct air capture using neutral red as a redox-active material in an aqueous solution enabled by the inclusion of nicotinamide as a hydrotropic solubilizing agent. The electrochemical system demonstrates a high electron utilization of 0.71 in a continuous flow cell with an estimated minimum work of 35 kJ e per mole of CO 2 from 15% CO 2 . Further exploration using ambient air (410 ppm CO 2 in the presence of 20% oxygen) as a feed gas shows electron utilization of 0.38 in a continuous flow cell to provide an estimated minimum work of 65 kJ e per mole of CO 2 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Phase-based design of CO 2 capture, transport, and storage infrastructure via SimCCS 3.0

The design of optimal infrastructure is essential for the deployment of commercial and large-scale carbon capture and storage (CCS) technology. During the design process, it is important to consider CO 2 capture and storage locations and CO 2 transportation pipelines to minimize the total project cost. SimCCS, first introduced in 2009, is an integrated open-source tool to optimize CCS infrastructure. The core CCS infrastructure design problem in SimCCS is structured as a mixed-integer linear programming problem by selecting the optimal pipeline routes, searching CO 2 source capture and storage locations, and determining the corresponding CO 2 amounts to meet desired capture targets. Multiple important and practical features have been developed to the latest version of SimCCS, SimCCS 3.0 . One of these features is phase-based modeling which enables users to dynamically design the CCS infrastructure. We demonstrate the phased-based modeling capability using two CCS infrastructure optimization case studies. The results from these case studies reveal that the phase-based modeling capability in SimCCS is particularly useful to optimize the dynamic deployment of CCS projects.

54 ENVIRONMENTAL SCIENCES↗