Activated Carbon Fiber Felt Composites for the Direct Air Capture of Carbon Dioxide.

Negative emissions technologies to mitigate climate change require innovative solutions for the direct air capture (DAC) of CO from the atmosphere. KCO readily reacts with CO to form KHCO; however, bulk KCO suffers from very slow sorption kinetics. By incorporating KCO into activated carbon (AC) fiber felts, the sorption kinetics were significantly improved by increasing the surface area of KCO in contact with air.

A general binary isotherm model for amines interacting with CO and HO.

CO capture by primary or secondary amines has been a topic of great research interests for a century because of its industrial importance. Interest has grown even more, because of the need to eliminate CO emissions that lead to global warming. Experimental evidence shows that CO sorption by primary or secondary amines is accompanied by co-absorption of HO.

Confronting the Carbon-Footprint Challenge of Blockchain.

The distributed consensus mechanism is the backbone of the rapidly developing blockchain network. Blockchain platforms consume vast amounts of electricity based on the current consensus mechanism of Proof-of-Work (PoW). Here, we point out a different consensus mechanism named Proof-of-Stake (PoS) that can eliminate the extensive energy consumption of the current PoW-based blockchain.

Kinetic model for moisture-controlled CO sorption.

The understanding of the sorption/desorption kinetics is essential for practical applications of moisture-controlled CO sorption. We introduce an analytic model of the kinetics of moisture-controlled CO sorption and its interpretation in two limiting cases. In one case, chemical reaction kinetics on pore surfaces dominates, in the other case, diffusive transport through the sorbent defines the kinetics.

Isotherm model for moisture-controlled CO sorption.

Moisture-controlled sorption of CO, the basis for moisture-swing CO capture from air, is a novel phenomenon observed in strong-base anion exchange materials. Prior research has shown that Langmuir isotherms provide an approximate fit to moisture-controlled CO sorption isotherm data. However, this fit still lacks a governing equation derived from an analytic model.

Postcombustion Capture or Direct Air Capture in Decarbonizing US Natural Gas Power?

This analysis investigates the cost of carbon capture from the US natural gas-fired electricity generating fleet comparing two technologies: postcombustion capture and direct air capture (DAC). Many of the existing natural gas combined cycle (NGCC) units are suitable for postcombustion capture. We estimated the cost of postcombustion retrofits and investigated the most important unit characteristics contributing to this cost.

Sorbents for the Direct Capture of CO from Ambient Air.

The urgency to address global climate change induced by greenhouse gas emissions is increasing. In particular, the rise in atmospheric CO levels is generating alarm. Technologies to remove CO from ambient air, or "direct air capture" (DAC), have recently demonstrated that they can contribute to "negative carbon emission.

Humidity effect on ion behaviors of moisture-driven CO sorbents.

Ion hydration is a fundamental process in many natural phenomena. This paper presents a quantitative analysis, based on atomistic modeling, of the behavior of ions and the impact of hydration in a novel CO sorbent. We explore moisture-driven CO sorbents focusing on diffusion of ions and the structure of ion hydration complexes forming inside water-laden resin structures.

Net-zero emissions energy systems.

Some energy services and industrial processes-such as long-distance freight transport, air travel, highly reliable electricity, and steel and cement manufacturing-are particularly difficult to provide without adding carbon dioxide (CO) to the atmosphere. Rapidly growing demand for these services, combined with long lead times for technology development and long lifetimes of energy infrastructure, make decarbonization of these services both essential and urgent. We examine barriers and opportunities associated with these difficult-to-decarbonize services and processes, including possible technological solutions and research and development priorities.

The catalytic effect of HO on the hydrolysis of CO in hydrated clusters and its implication in the humidity driven CO air capture.

The hydration of ions in nanoscale hydrated clusters is ubiquitous and essential in many physical and chemical processes. Here we show that the hydrolysis reaction is strongly affected by relative humidity. The hydrolysis of CO with n = 1-8 water molecules is investigated using an ab initio method.

Spontaneous Cooling Absorption of CO by a Polymeric Ionic Liquid for Direct Air Capture.

A polymeric ionic liquid (PIL), with quaternary ammonium ions attached to the polymer matrix, displays CO affinity controlled by moisture. This finding led to the development of moisture swing absorption (MSA) for direct air capture of CO. This work aims to elucidate the role of water in MSA.

Kinetic analysis of an anion exchange absorbent for CO2 capture from ambient air.

This study reports a preparation method of a new moisture swing sorbent for CO2 capture from air. The new sorbent components include ion exchange resin (IER) and polyvinyl chloride (PVC) as a binder. The IER can absorb CO2 when surrounding is dry and release CO2 when surrounding is wet.

A Life Cycle Assessment Case Study of Coal-Fired Electricity Generation with Humidity Swing Direct Air Capture of CO versus MEA-Based Postcombustion Capture.

Most carbon capture and storage (CCS) envisions capturing CO from flue gas. Direct air capture (DAC) of CO has hitherto been deemed unviable because of the higher energy associated with capture at low atmospheric concentrations. We present a Life Cycle Assessment of coal-fired electricity generation that compares monoethanolamine (MEA)-based postcombustion capture (PCC) of CO with distributed, humidity-swing-based direct air capture (HS-DAC).

The Effect of Moisture on the Hydrolysis of Basic Salts.

A great deal of information exists concerning the hydration of ions in bulk water. Much less noticeable, but equally ubiquitous is the hydration of ions holding on to several water molecules in nanoscopic pores or in natural air at low relative humidity. Such hydration of ions with a high ratio of ions to water molecules (up to 1:1) are essential in determining the energetics of many physical and chemical systems.

Capture CO2 from Ambient Air Using Nanoconfined Ion Hydration.

Water confined in nanoscopic pores is essential in determining the energetics of many physical and chemical systems. Herein, we report a recently discovered unconventional, reversible chemical reaction driven by water quantities in nanopores. The reduction of the number of water molecules present in the pore space promotes the hydrolysis of CO3(2-) to HCO3(-) and OH(-).

Relative permeability experiments of carbon dioxide displacing brine and their implications for carbon sequestration.

To mitigate anthropogenically induced climate change and ocean acidification, net carbon dioxide emissions to the atmosphere must be reduced. One proposed option is underground CO2 disposal. Large-scale injection of CO2 into the Earth's crust requires an understanding of the multiphase flow properties of high-pressure CO2 displacing brine.

Co-location of air capture, subseafloor CO2 sequestration, and energy production on the Kerguelen plateau.

Reducing atmospheric CO2 using a combination of air capture and offshore geological storage can address technical and policy concerns with climate mitigation. Because CO2 mixes rapidly in the atmosphere, air capture could operate anywhere and in principle reduce CO2 to preindustrial levels. We investigate the Kerguelen plateau in the Indian Ocean, which offers steady wind resources, vast subseafloor storage capacities, and minimal risk of economic damages or human inconvenience and harm.

Moisture-swing sorption for carbon dioxide capture from ambient air: a thermodynamic analysis.

An ideal chemical sorbent for carbon dioxide capture from ambient air (air capture) must have a number of favourable properties, such as environmentally benign behaviour, a high affinity for CO(2) at very low concentration (400 ppm), and a low energy cost for regeneration. The last two properties seem contradictory, especially for sorbents employing thermal swing adsorption. On the other hand, thermodynamic analysis shows that the energy cost of an air capture device need only be slightly larger than that of a flue gas scrubber.

The urgency of the development of CO2 capture from ambient air.

CO(2) capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society's present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology--which by necessity has to operate on a large scale--it may need to be complemented with air capture, removing CO(2) directly from the atmosphere.

Image quality of digital direct flat-panel mammography versus an indirect small-field CCD technique using a high-contrast phantom.

Objective: To compare the detection of microcalcifications on mammograms of an anthropomorphic breast phantom acquired by a direct digital flat-panel detector mammography system (FPM) versus a stereotactic breast biopsy system utilizing CCD (charge-coupled device) technology with either a 1024 or 512 acquisition matrix (1024 CCD and 512 CCD).

Materials And Methods: Randomly distributed silica beads (diameter 100-1400 μm) and anthropomorphic scatter bodies were applied to 48 transparent films. The test specimens were radiographed on a direct digital FPM and by the indirect 1024 CCD and 512 CCD techniques.

Moisture swing sorbent for carbon dioxide capture from ambient air.

An amine-based anion exchange resin dispersed in a flat sheet of polypropylene was prepared in alkaline forms so that it would capture carbon dioxide from air. The resin, with quaternary ammonium cations attached to the polymer structure and hydroxide or carbonate groups as mobile counterions, absorbs carbon dioxide when dry and releases it when wet. In ambient air, the moist resin dries spontaneously and subsequently absorbs carbon dioxide.

Cortical representation sites of mimic movements after facial nerve reconstruction: a functional magnetic resonance imaging study.

Objectives/hypothesis: To describe cortical reorganization after classic hypoglossal-facial nerve anastomosis (HFA) (four patients), hypoglossal-facial nerve jump anastomosis (HFJA) (three patients), and facial nerve interpositional graft (FNIG) (three patients).

Study Design: Prospective case series.

Methods: Functional magnetic resonance imaging (fMRI) was performed during lip and tongue movement using a block or an event-related design.