The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost
Not Available
54 ENVIRONMENTAL SCIENCES↗
SEARCH · Engineering Papers
Results for “Gas Separation”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Techno-economic analysis of carbon dioxide capture from low concentration sources using membranes
Rising carbon dioxide (CO 2 ) levels in the atmosphere lead to global warming, causing climate change. As such, carbon capture has become necessary to slow the increase and reduce CO 2 levels in the atmosphere. Point source emissions have a wide range of CO 2 concentrations, but emissions below 3% CO 2 have mostly been ignored because Carbon capture from these sources has been viewed as costly and economically unsustainable. Membrane technologies are considered the most viable solution by virtue of more energy-efficient operation. Our group at Idaho National Laboratory (INL) has developed poly[bis((2-methoxyethoxy)ethoxy)phosphazene] (MEEP)-based carbon dioxide selective membranes with CO 2 /N 2 selectivity greater than 40 and CO 2 permeability greater than 450 Barrer. To understand the economics of carbon capture, a spreadsheet-based techno-economic analysis (TEA) model was developed to consider multiple parameters, including selectivity and permeability of the membranes, performance conditions such as the number of stages, module material, electricity price, membrane price, and capital financing. The cost of carbon capture in US $\$$/metric ton was calculated at various purities and compared with other membrane processes, cryogenic capture, solvent-based capture, and pressure swing adsorption-based capture. It was determined that a MEEP-based three-stage process had a capture cost of US $\$$ 50.1/metric ton for 99.8% purity CO 2 from a 1% CO 2 feed source in nitrogen (N 2 ). In conclusion, the capture cost using the best performing Pebax-based membrane was 464% higher, cryogenic capture was 60%–140% higher, pressure swing adsorption was 55%–165% higher, and chemical absorption was -10%–110% higher than MEEP-based membrane capture, respectively.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Evaluation of adsorption and mechanical strength of 13X zeolite mixtures with phyllosilicate binders using molecular dynamics simulation and positron annihilation spectroscopy
There is growing interest in developing zeolites with novel internal structures that have optimal adsorptive capacity and high mechanical strength, while offering advantages, such as being light weight. We integrate computational and experimental methods to explore the effect of binder/zeolite types, and weight percentages on the mechanical strength of 13X zeolite and adsorption capacities of N 2 , H 2 O, and CO 2 for additive manufacturing (AM) applications with the goal of maximizing both adsorption and strength. Zeolite 13X mixtures and phyllosilicate binders (either bentonite or kaolin) are combined using molecular dynamics (MD) simulations to create structures with various binder/zeolite weight percentages. Further, adsorption capabilities and mechanical strength are assessed using the grand canonical Monte Carlo (GCMC) and ReaxFF modules, respectively. Our modeling shows that an optimized zeolite/binder ratio for N 2 adsorption is around 15 wt% for kaolin and roughly 10 wt% for bentonite. The resulting parameters can be applied to facilitate macro-scale computational fluid dynamics (CFD) and finite element method (FEM) simulations of an AM zeolite structure. We also performed Positron Annihilation Lifetime Spectroscopy (PALS) measurements on zeolite samples to explore the effect of changes in the internal volume. The results show an inverse relationship between the free volume and the solid loading and adding a binder changes the morphology of the zeolite-binder compound and decreases open-volume area significantly.
36 MATERIALS SCIENCE↗
Source characterization of a detector for heavy and superheavy nuclei
A new focal plane detector system for the Berkeley Gas-filled Separator (BGS) was designed, constructed, and tested offline with various α-decay and conversion-electron sources. The SuperHeavy RECoils (SHREC) detector comprises sets of double-sided silicon strip detectors arranged in an open-faced cuboid geometry. Alongside the detector upgrade new digital data acquisition electronics have been commissioned offline. This setup aims to detect separated recoiling heavy and superheavy nuclei as well as their correlated radioactive decay paths with improved energy resolution and overall sensitivity.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Nitrogen evolution, NO X formation and reduction in pressurized oxy coal combustion
Oxy-combustion is one of the most prominent solutions for reducing CO 2 emissions from coal-fired power plants using carbon-capture-and-utilization technology. However, when compared to air combustion at atmospheric pressure, oxy-combustion is very expensive, owing to the significant efficiency penalties associated with air separation, flue gas recirculation (FGR), treatment, compression, and storage or transit of CO 2 . In comparison, pressurized oxy-combustion (POC) is more efficient as it recovers a significant amount of heat energy from the flue gas moistures. Nevertheless, CO 2 derived from pressurized oxy coal combustion has impurities, e.g., acid gases (NO X and SO X ) that can corrode the plant equipment, transport lines as well as deteriorating effect on the environment. Fortunately, in pressurized combustion systems, both NO X and SO X can be scrubbed by a single-column direct contact cooler (DCC), but this requires a minimum ratio of NO X to SO X at the inlet to be efficiently removed. Therefore, NOx is one of the important hindering parameters in commercializing the pressurized oxy-combustion. Although NOx evolution during oxy-coal combustion has been explored extensively at 1 atm, higher pressure studies are rare. Much still needs to be done to better understand the NO X mechanism and the effects of different parameters on NO X emissions under these conditions. Here, this paper reviews the published literature on nitrogen evolution, NO X formation and reduction in pressurized oxy-coal combustion. At higher pressures, the NO X from fuel-bound nitrogen is generated through volatiles, tar and char, all of which are discussed. Where literature is not available, the effect of pressure on NOx evolution in different stages of coal combustion is predicted through CHEMKIN simulation. Homogeneous and heterogeneous pathways of NO X formation and their destruction in pressurized oxy-coal combustion are evaluated. Additionally, the effect of pressure on a few mature and commercialized NOx abatement methods is explored. In the last, the future perspective and recommendation are given. This review will aid in the provision of basic knowledge about NOx evolution and control in pressurized fuel combustion, as well as the identification of new research areas to pursue.
01 COAL, LIGNITE, AND PEAT↗
Simplifying computational workflows with the Multiscale Atomic Zeolite Simulation Environment (MAZE)
Zeolites, an important class of 3-dimensional nanoporous materials, have been widely explored for a variety of applications including gas storage, separations, and catalysis. As the properties of these aluminosilicate materials depend on a number of factors (e.g., framework topology, Si/Al ratio, extra-framework cations etc.), detailed experiments (e.g., catalytic properties, adsorption capacities etc.) are often limited to only a handful of materials. Computational methods have played an important role in (1) providing molecular level insights to rationalize experimental observations, and (2) screening large libraries of zeolites to identify promising candidates for experimental synthesis and validation. Different levels of theory and computational chemistry codes are necessary to describe the range of relevant phenomena such as adsorption (e.g., grand canonical Monte Carlo), diffusion (e.g., molecular dynamics), and chemical reactions (e.g., density functional theory). Manipulation of atomic structures, handling of input files, and developing robust workflows becomes quite cumbersome. To mitigate these challenges, we describe the development of the Multiscale Atomic Zeolite Simulation Environment (MAZE) – a Python package that simplifies zeolite-specific calculation workflows by providing a user-friendly interface for systematically manipulating zeolite structures
97 MATHEMATICS AND COMPUTING↗
Atom-at-a-Time Radioactive Molecule Identification: Looking toward Studies of Superheavy Elements
The chemical behavior of superheavy elements (SHEs, Z > 103) remains poorly understood. Their chemical properties are expected to deviate from established trends, challenging the predictive power of the periodic table. To investigate these elements experimentally, they must first be synthesized through nuclear reactions and then quickly subjected to chemical studies before they decay. Given the low production rates of these reactions and the need for measurements on an atom-at-a-time basis, innovative techniques are needed. Here, to address these challenges, a novel gas-phase chemistry method has been developed at Lawrence Berkeley National Laboratory, utilizing the Berkeley Gas-filled Separator and FIONA. This technique enables the production, identification, and study of molecular species formed by SHEs. As a proof of concept, we present measurements on the formation and identification of 151,152 HoO + molecules, demonstrating the capability to study the production of radioactive molecules under controlled conditions and directly identify them via their mass-to-charge ratio. These measurements validate the effectiveness of this technique for low-statistics SHE studies, highlighting the potential of this approach to ignite the next generation of experimental SHE chemistry research, offering a path to re-evaluate SHE placement on the periodic table.
Chemistry↗
Fine Tuning the Pore Surface in Zirconium Metal–Organic Frameworks for Selective Ethane/Ethylene Separation
Not Available
36 MATERIALS SCIENCE↗
In Silico Discovery of Covalent Organic Frameworks for Carbon Capture
We screen a database of more than 69 000 hypothetical covalent organic frameworks (COFs) for carbon capture using parasitic energy as a metric. To compute CO 2 –framework interactions in molecular simulations, we develop a genetic algorithm to tune the charge equilibration method and derive accurate framework partial charges. Nearly 400 COFs are identified with parasitic energy lower than that of an amine scrubbing process using monoethanolamine; more than 70 are better performers than the best experimental COFs and several perform similarly to Mg-MOF-74. We analyze the effect of pore topology on carbon capture performance to guide the development of improved carbon capture materials.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Active site identification and CO oxidation in UiO-66-XX thin films
Metal-organic frameworks (MOFs) offer an intrinsically porous and chemically tunable platform for gas adsorption, separation, and catalysis. Herein we investigate thin film derivatives of the well-studied Zr–O based MOF powders to understand their adsorption properties and reactivity with their adaption to thin films, involving diverse functionality with the incorporation of different linker groups and the inclusion of embedded metal nanoparticles: UiO-66, UiO-66-NH 2 , and Pt@UiO-66-NH 2 . Using transflectance IR spectroscopy, we determine the active sites in each film upon consideration of the acid-base properties of the adsorption sites and guest species, and perform metal-based catalysis with CO oxidation of a Pt@UiO-66-NH 2 film. Our study shows how surface science characterization techniques can be used to characterize the reactivity and the chemical and electronic structure of MOFs.
36 MATERIALS SCIENCE↗
Investigation of the 244 Pu ( 48 Ca,𝑥𝑛) 292−𝑥 Fl reaction with the LBNL SHREC detector: Investigation of decay chains of isotopes of flerovium (𝑍=114)
The 244 Pu ( 48 Ca,𝑥𝑛) 292−𝑥 Fl reaction was investigated at Lawrence Berkeley National Laboratory’s 88 Inch Cyclotron using the Berkeley Gas-filled Separator (BGS), the newly installed Superheavy Recoil detector, along with an upgraded digital electronics and data acquisition system. Seven decay chains were observed starting with an evaporation residue, followed by a single 𝛼 decay and a spontaneous fission. The decay characteristics of these seven decay chains led to an assignment to 288 Fl , the product of the 4𝑛 reaction channel. Two additional chains were (tentatively) assigned to the decay of the 3𝑛 exit channel, 289 Fl . Cross sections for the 4𝑛 and 3𝑛 exit channels were 𝜎 prod =6.7($^{36}_{25}$) pb and 𝜎 prod =1.6($^{22}_{11}$) pb, respectively. Another decay chain, tentatively assigned to the 5𝑛 exit channel through the 48 Ca + 244 Pu reaction or the 3𝑛 exit channel of the 48 Ca + 242 Pu reaction, was also detected. Detailed information regarding the observed decay chains and their nuclear structure aspects is discussed, along with the performance of the BGS and the new detection system.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Investigation of 48 Ca-induced reactions with 242 Pu and 238 U targets at the JINR Superheavy Element Factory
Experiments using a 48 Ca beam on 238 U and 242 Pu targets to produce superheavy nuclei were performed at the gas-filled separator DGFRS-2 online to the new cyclotron DC280 at the SHE Factory at JINR. The decay properties of 286 Fl and 287 Fl, as well as their α-decay products, were refined after the detection of 25 and 69 new decay chains, respectively. In addition, 16 decay chains of 283 Cn were observed in the 238 U+ 48 Ca reaction. The possibility of existing of isomeric states in the 287 Fl consecutive α decays is discussed. A new α line with an energy of 100–200 keV lower than the main one at 10.19 MeV was observed for the first time for even-even 286 Fl decay. A maximum cross section of $10.4^{+3.5}_{-2.1}$pb was measured for the 242 Pu( 48 Ca,3n) 287 Fl reaction.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
New isotope 286 Mc produced in the 243 Am + 48 Ca reaction
In this paper, we present results of the second experiment on the synthesis of Mc isotopes in the 243 Am + 48 Ca reaction performed at the gas-filled separator DGFRS-2 of the SHE Factory at JINR. Here, the new isotope 286 Mc was synthesized, and its half-life of $20^{+98}_{–9}$ ms and α-particle energy of 10.71 ± 0.02 MeV were determined. A 286 Mc α–decay chain was recorded down to the spontaneous fission of 266 Db. The spontaneous fission of 279 Rg was observed for the first time in one of four new decay chains of 287 Mc. The excitation function of the reaction was measured at three 48 Ca energies of 242, 250, and 259 MeV; the latter resulted in the first observation of the 5$\textit{n}$–evaporation channel with a cross section of $0.5^{+1.3}_{–0.4}$ pb. The decay properties of 21 previously known odd–$\textit{Z}$ isotopes were improved. The potential for an electron-capture decay mode is discussed for 288 Mc and 284 Nh isotopes. The half-lives of spontaneously fissioning nuclei produced in the 48 Ca–induced reactions with actinide targets are compared with several theoretical predictions.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
First experiment at the Super Heavy Element Factory: High cross section of Mc 288 in the Am 243 + Ca 48 reaction and identification of the new isotope Lr 264
Here, we present results of the first experiment aimed at the synthesis of Mc isotopes in the 243 Am+ 48 Ca reaction performed at the new gas-filled separator DGFRS-2 online to the new cyclotron DC280 at the Super Heavy Element Factory at JINR. Fifty-five new decay chains of 288 Mc and six chains assigned to 289 Mc were detected. The α decay of 268 Db with an energy of 7.6–8.0 MeV, half-life of 16$^{+6}_{-4}$h, and a branch of 55$^{+20}_{-15}$% was registered for the first time, and a new spontaneously fissioning isotope 264 Lr with a half-life of 4.9$^{+2.1}_{-1.3}$h was identified. The cross section for the 243 Am( 48 Ca,3n) 288 Mc reaction was measured to be 17.1$^{+6.3}_{-4.7}$ pb, which is the largest value for the known superheavy nuclei at the island of stability.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Identification of the New Isotope 244 Md
In an experiment performed at Lawrence Berkeley National Laboratory’s 88-inch cyclotron, the isotope Md 244 was produced in the Bi 209 ( Ar 40 , 5 n ) reaction. Decay properties of Md 244 were measured at the focal plane of the Berkeley Gas-filled Separator, and the mass number assignment of A = 244 was confirmed with the apparatus for the identification of nuclide A . The isotope Md 244 is reported to have one, possibly two, α -decaying states with α energies of 8.66(2) and 8.31(2) MeV and half-lives of 0.4 – 0.1 + 0.4 and ~ 6 s , respectively. Furtermore, first evidence of the α decay of Bk 236 was observed and is reported.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Unusual High-Frequency Mechanical Properties of Polymer-Grafted Nanoparticle Melts
Not Available
03 NATURAL GAS↗
Molecular Recognition with Resolution Below 0.2 Angstroms Through Thermoregulatory Oscillations in Covalent Organic Frameworks
Crystalline materials with uniform molecular-sized pores are desirable for a broad range of applications, such as sensors, catalysis, and separations. However, it is challenging to tune the pore size of a single material continuously and to reversibly distinguish small molecules (below 4 angstroms). We synthesized a series of ionic covalent organic frameworks using a tetraphenoxyborate linkage that maintains meticulous synergy between structural rigidity and local flexibility to achieve continuous and reversible (100 thermal cycles) tunability of “dynamic pores” between 2.9 and 4.0 angstroms, with resolution below 0.2 angstroms. This results from temperature-regulated, gradual amplitude change of high-frequency linker oscillations. These thermoelastic apertures selectively block larger molecules over marginally smaller ones, demonstrating size-based molecular recognition and the potential for separating challenging gas mixtures such as oxygen/nitrogen and nitrogen/methane.
crystalline materials↗