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Multi-region multi-sector energy-economic models are often used to analyze long-term scenarios of energy development, however, these models usually rely on a simplified representation of technological details in power generation. To strengthen this representation, we develop a method for modeling the economic competition between different advanced technologies in multi-region multi-sector dynamic energy-economic models based on a markup approach, which represents the measure of the cost of a technology relative to the price received for electricity generation. The markup includes capital costs, fixed and variable operating and maintenance (O&M) costs, fuel costs, and transmission and distribution (T&D) costs. For intermittent technologies, it also includes a backup requirement to make these technologies effectively dispatchable. For carbon capture and storage (CCS) technologies, it also includes the costs of CO2 capture, transportation and storage. We provide a standardized markup calculation for generation technologies for different regions of the world, including USA, China, India, EU, Japan and others. Then we analyze the sensitivity of the calculation to critical inputs, including capital costs, fuel costs, carbon prices and capacity factors. We provide a detailed calculation of the relative costs of the following technologies: new pulverized coal, new pulverized coal with CCS, natural gas combined cycle, natural gas with CCS, biomass-fueled plant, biomass with CCS, advanced nuclear, wind (for small and medium penetration levels), solar, wind with backup (for large penetration levels), co-firing of coal and biomass combined with CCS, and advanced CCS on natural gas. For illustration, we incorporate the markups into the MIT Economic Projection and Policy Analysis (EPPA) model, a global multi-sector multi-sector dynamic energy-economic model with a detailed representation of power generation technologies, and run several scenarios. Our analysis and results provide insight on the deployment of different low-carbon power generation technologies depending on assumptions about carbon policy stringency.

Mobile nuclear magnetic resonance (NMR) operating in Earth's magnetic field is adapted to detect leaked or spilled oil trapped in or under sea ice without the need to place any personnel on the ice. A helicopter placed a 6-meter diameter NMR coil system weighing approximately 1000 kg on 92 cm-thick ice surrogate and detected the equivalent of 1 cm thick oil under the ice surrogate in 3–1/2 min.

Assessments of the geologic storage capacity of carbon dioxide in the current literature are incomplete and inconsistent, complicating efforts to assess the worldwide potential for carbon dioxide capture and storage (CCS). We developed a method for generating first-order estimates of storage capacity requiring minimal data to characterize a geologic formation. We show this simplified method accounts for the majority of the variance in storage capacity found in more detailed studies conducted in the United States. We apply our method to create a worldwide database of storage capacity, disaggregated into 18 regions, and compare this storage capacity to CCS deployment in the MIT Economic Prediction and Policy Analysis (EPPA) model. Globally, we estimate there are between 8,000 and 55,000 gigatonnes (Gt) of practically accessible geologic storage capacity for carbon dioxide. For most of the regions, our results indicate storage capacity is not a limiting factor for CCS deployment through the rest of this century even if stringent emissions reductions are required.

Carbon capture and storage (CCS) technology is an important option in the portfolio of emission mitigation technologies in scenarios that lead to deep reductions in greenhouse gas (GHG) emissions consistent with limiting increases in global average surface air temperature to 2 degrees Celsius (2C). Industrial CCS applications are more challenging to analyze than CCS in the power sector -- mainly due to the vast heterogeneity in industrial and fuel processes. Our study focuses on the cement industry and provides the estimated costs associated with several CCS options: coal-fired post-combustion capture (PCC), natural gas-fired PCC, and Cryogenic Carbon Capture (CCC). We explore regional cost estimates with variations in costs of capital and fuels to provide a basis for regional and global projections of industrial CCS deployment. We offer a methodology for incorporating the CCS cost information into energy-economic and integrated assessment models. Our methodology can be applied to other applications of CCS in the industrial sector. We illustrate our method by introducing the industrial CCS options into the MIT EPPA model, a global energy-economic model that provides a basis for the analysis of long-term energy deployment, and we discuss different scenarios for industrial CCS deployment in different parts of the world. We tested in the EPPA model the potential for industrial CCS under the assumptions that CCS is the only mitigation option for deep GHG emission reduction in industry and that negative emission options are not available for other sectors of the economy. Overall, industrial CCS enables the continued use of energy-intensive goods with large reductions in global and sectoral emissions. We find that in scenarios with stringent climate policy, CCS in the industry sector is a key mitigation option, and our approach provides a path to projecting the deployment of industrial CCS across industries and regions.

Carbon capture and sequestration is known to be energy intensive and will result in 20–30 % reduction in net output of a power plant. However, a simple thermodynamic tool is currently unavailable for assessing the work of CO2 separation using a given solid or liquid sorbent. This paper provides rigorous yet simple framework of equivalent work to assess the energy requirement for CO2 capture using liquid amines or solid adsorbents. First, the theoretical minimum work is determined by assuming that each step in the sorption - desorption cycle is thermodynamically reversible. Then, irreversible heat transfer losses are added to calculate total work for the actual process. The model provides useful insights into the sorbent and process selection. The minimum work for reversible separation can be calculated merely from CO2 sorption equilibria at ambient temperature without requiring laborious data or complex models. A sorbent with low ab/adsorption heat does require less thermal energy, but this thermal energy is required at a higher temperature. Thus, contrary to conventional thinking, the equivalent work is not reduced. The irreversible heat transfer losses for the amines are mostly dictated by the amine’s circulation rate which will be minimized by using amines with the highest CO2 capacity. On an energy requirement basis, the solid adsorbent based processes cannot compete with amines because practical methods of heat recuperation from the hot regenerated adsorbent are unavailable. Without heat recuperation, the solid adsorbent processes will be attractive only if their capital advantage outweighs their higher energy use.

A simple technique is presented for NMR of chemically reacting systems at conditions of high temperature and pressure. The method can follow reactions that are typical of refinery operations – hydrogenation, transfer dehydrogenation, methanol synthesis, and isomerization. All of the reacting materials are flame-sealed into a glass capillary. Gaseous agents such as O2 and CO are loaded into the capillary by condensation at liquid N2 temperature. H2 is provided by loading LiAlH4. The capillary holds the high pressure, up to 7 MPa, so the NMR probe can be a simple design with hot air flowing over the sample tube, up to 350 °C. Example reaction results are presented, including hydrogenation of benzene, hydrogenation/dehydrogenation of cyclohexene to benzene and cyclohexane (a disproportionation), and synthesis of methane, methanol and dimethyl ether from CO and H2. In this work we present a simple, inexpensive method with rapid temperature response for tracking chemical reactions in real-time at high temperature and high pressure.

To meet the world’s growing energy needs, the oil industry is pursuing oil resources in ice-prone regions. These activities will require robust oil spill contingency plans. One area of need is a method to remotely detect oil that is trapped beneath or within ice. The current operational method for oil detection within or under ice requires placing personnel on the ice to take measurements. A primary challenge with these measurements is the speed at which they can be collected. Presented here is a scaled-down prototype of an Earth’s field nuclear magnetic resonance device that can be moved from one spot to another on the ice by a helicopter to quickly survey large areas. This smallscale version has been built and tested. It successfully differentiates an oil surrogate from the bulk water signal by using an adiabatic inversion, followed by a delay to suppress the otherwise overwhelming water signal before acquiring the signal after an adiabatic half passage. The device will be scaled up, and further testing will be conducted. Initial proof-of-principle results show great promise for the development of a remote oil detector.

Magnetic resonance (MR) imaging techniques have been used to study gas phase dynamics during co-current up-flow in a column of inner diameter 43 mm, packed with spherical non-porous elements of diameters of 1.8, 3 and 5 mm. MR measurements of gas hold-up, bubble-size distribution, and bubble-rise velocities were made as a function of flow rate and packing size. Gas and liquid flow rates were studied in the range of 20–250 cm3 s−1 and 0–200 cm3 min−1, respectively. The gas hold-up within the beds was found to increase with gas flow rate, while decreasing with increasing packing size and to a lesser extent with increasing liquid flow rate. The gas hold-up can be separated into a dynamic gas hold-up, only weakly dependent on packing size and associated with bubbles rising up the bed, and a ‘static’ hold-up which refers to locations within the bed associated with temporally-invariant gas hold-up, over the measurement times of 512 s, associated either with gas trapped within the void structure of the bed or with gas channels within the bed. This ‘static’ gas hold-up is strongly dependent on packing size, showing an increase with decreasing packing size. The dynamic gas hold-up is comprised of small bubbles – of order of the packing size – which have rise velocities of 10–40 mm s−1 and which move between the packing elements within the bed, along with much larger bubbles, or agglomerates of bubbles, which move with higher rise velocities (100–300 mm s−1). These ‘larger’ bubbles, which may exist as streams of smaller bubbles or ‘amoeboid’ bubbles, behave as a single large bubble in terms of the observed high rise velocity. Elongation of the bubbles in the direction of flow was observed for all packings.

The mechanisms of the reaction of CO2 with hindered alkanolamines are described based on direct reaction monitoring with in situ 13C NMR spectroscopy. Four amines of increasing steric hindrance were studied and compared with unhindered primary, secondary, and tertiary alkanolamines. The number and location of additional methyl (or other) groups on the nitrogen or adjacent carbon atoms create different degrees of steric hindrance. As steric hindrance increases, the Lewis basicity (nucleophilicity), as an affinity of the amine nitrogen to directly attack the electrophilic carbon of CO2 and form a carbamate, decreases. At the same time, methyl (or other) groups present on nitrogen or adjacent carbon atoms do not change the Bronsted basicity of hindered amines. Coupled with lower Lewis basicity, the CO2–amine–water reaction equilibrium favors formation of bicarbonate, with higher CO2 loading capacity and lower thermal stability, both of which are favorable properties for cyclic CO2 capture. Due to lower stabi...

We describe here the CO 2 sorption and desorption properties of hollow fiber sorbents—a polymer/zeolite hybrid sorbent that possesses a coated bore that allows for exceedingly fast heat transfer between the heat transfer fluid and the sorbent. The fiber sorbents are intended for use in post-combustion CO 2 . The fiber sorption properties are tested chromatographically with simulated flue gas in the absence of a heat transfer fluid and are found via in situ thermal measurements to be highly non-isothermal, which results in up to 40% losses in CO 2 breakthrough capacities. The thermal front moving through the fiber wall was found to progress approximately 30% faster than the propagating speed of the CO 2 sorption front. Upon the addition of a heat transfer fluid (water) in the bores of the fibers, breakthrough CO 2 capacities were maintained at all flue gas superficial velocities studied (up to 50 cm/s). The propagation speed of the CO 2 front was reduced by 38% by the addition of cooling water in the bores, and the in situ thermal measurements revealed that the fiber sorbents were nearly isothermal during the CO 2 sorption step. One of the main conceptual advantages of a fiber sorbent CO 2 capture platform is the ability to transfer the released sorption enthalpy to the bore-side cooling water, which can then be later used in a beneficial way. By varying the cooling water velocity, in situ thermal measurements showed that 22,000 J per mol of flowing CO 2 could be transferred to the cooling water out of a possible 36,000 J per mol. Finally, plug flow-mode desorption experiments were performed, and a 40.5 mol% CO 2 product was obtained. The small scales of the system prohibit sharper thermal fronts, which likely causes unwanted product CO 2 and interstitial N 2 mixing.

The aggregation of ammonium borate salts in hydrocarbon was investigated by 1H, 19F, and 11B pulsed field gradient (PFG) NMR. The molecular self-diffusion coefficients of the borate salts, [C(C6H5)3][B(C6F5)4], [N(CH3)2(n-C18H37)2][B(C6F5)4], [N(n-C18H37)4][B(C6F5)4], a neutral borane compound, and a siloxane model compound were measured in toluene, cyclohexane, hexane, and a solvent of mixed alkanes. Diffusion coefficients were determined from the echo attenuation of the stimulated echo pulsed field gradient NMR signal as described by Stejskal and Tanner. In all of the samples studied, the echo decay was observed to be a pure exponential decay, corresponding to a single diffusion coefficient within the resolution of the NMR experiment. The hydrodynamic radius of an equivalent diffusing sphere was calculated from the experimental diffusion coefficients using the Stokes−Einstein relation. We found that the neutral borane and siloxane model compounds are monomeric (nonaggregated) in both the aliphatic and a...

In porous materials, susceptibility contrasts between the matrix and the pore fluid generate pore-scale inhomogeneities in the magnetic field that are referred to as internal gradients. Internal gradients impact NMR measurements, and can cause large errors in the calculated diffusion coefficient if they are not accounted for. The magnitude of the internal gradients is determined by the susceptibility contrast, the strength of the background magnetic field, and the pore geometry. We use statistical analysis to look for correlation between measured internal gradients and properties of sediment samples. The primary goal of this analysis was to identify parameters that could be used as predictors of internal gradient magnitudes. We measured internal gradients using two different NMR methods: Method 1 estimates an average effective gradient, and Method 2 calculates a distribution of effective gradients. The sediment properties that we consider are magnetic susceptibility, iron content, specific surface area, grain size, and measured NMR parameters including the mean log T2 and the T1/T2 ratio. In our preliminary analysis, conducted with data from 20 sediment samples, we observe linear trends between iron content and measured gradients, and between magnetic susceptibility and measured gradients. We also see that the mineral form of iron appears to impact the relationships between iron content, magnetic susceptibility, and internal gradients. The correlation observed between gradients measured with Method 1 and both the specific surface area and T2 could indicate that this method is biased by relaxation time; this relationship was not observed for the gradients measured with Method 2. We plan to collect data on more sediment samples to better understand these relationships and develop a model for the estimation of internal gradients. Such a model will enable us to include internal gradient values in diffusion coefficient calculations for a range of nearsurface applications.

We report on the magnetic-field-dependent optically detected magnetic resonance (ODMR) spectra for polycrystalline samples of the bridged Zr(IV) metallocenes, Me2Si

Internal magnetic field gradients in water saturated glass bead packs were studied by numerical simulations and a constant time spin echo (CTSE) experiment. The CTSE is comprised of two spin echo refocusing periods where each of the two evolution periods, τ 1 and τ 2 , is varied so that the total evolution, 2(τ 1 + τ 2 ), is held constant. The experiment is similar to that introduced by Norwood and Quilter and allows the effects of dephasing due to diffusion in a magnetic field gradient to be separated from other relaxation mechanisms. In our experiments, the magnetic susceptibility difference between the pore fluid and glass beads creates the internal field gradient. CTSE measurements were performed at 7 T (300 MHz 1 H) for water saturated in 50 μm diameter glass bead pack. We find that the internal gradients in the center of the pore bodies, where free diffusion applies, is in the range of 10 to 100 G/cm. This fluid volume accounts for ≤ 10% of the total pore volume. From direct numerical simulations of the internal magnetic field based on a first principles calculation, we find that the major fraction, >90%, of the pore volume has internal gradients of order 500 to 5,000 G/cm. Signals from water in these large gradients is not observed in our CTSE measurements.

The distribution of fluids in the pore space of a series of sandstones is calculated as a function of capillary pressure using a two phase flow simulation model. The pore space is represented by a system of channels and nodes which are derived from x-ray micro-tomography images of sandstones. The sandstones studied varied in permeability from approximately 40 to 3,000 mD. The simulation results illustrate the significance of the pore level by-pass phenomena in controlling the location of fluids within the pore structure. The implications of these results on the interpretation of NMR T(2) distributions to determine the irreducible water saturation are discussed.

The incorporation of Fe(III), during the synthesis, into aluminosilicate sodalite (FeSOD) and aluminophosphate sodalite, AlPO4-20 (FAPO), was investigated by continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) techniques at X- and W-band. Specifically, the effect of the framework composition and the presence of occluded template molecules (tetramethyl ammonium hydroxide, TMAOH) in the β cages on the distribution of the Fe(III) species was explored. The X-band CW EPR spectrum of FAPO shows the existence of two types of species, one with a large (g ≈ 6.3,4) and the other with a small (g ≈ 2) zero field splitting (ZFS) interaction. These species were also found in FeSOD synthesized with TMAOH. The X-band field-sweep echo-detected (FS-ED) EPR spectrum shows contributions only from the Fe(III) species in the more symmetric environment (g ≈ 2). The other was not detected due to fast relaxation. This spectrum is very broad and suffers from distortions due to the nuclear modulation effect. In contrast, the W-band FS-ED EPR spectrum of the same species was significantly narrower and free from distortions. Analysis of the temperature dependence of the width and relative intensity of the peak corresponding to the |−½ 〉 | +½ 〉 EPR transition shows that the g ≈ 2 signal arises from a number of Fe(III) species with a distribution of ZFS parameters. Calcination significantly reduces the ZFS parameter, D, suggesting that the distortions of the T sites are due to specific interactions with the template. Electron spin echo envelope modulation (ESEEM) experiments shows the presence of weak dipolar interaction between Fe(III) and template 14N and 1H template nuclei, as well as framework 27Al and 31P nuclei. This indicates that the species characterized by small ZFS are well dispersed and are located within the inner structure of the zeolite. These g≈ 2 species are most probably Fe(III) in framework sites. A small fraction that occupies highly asymmetric sites (g ≈ 6.3,4), situated at ‘defect’ framework or extraframework sites, and some Fe(II) produced due to the reduction of Fe(III) by the organic template (detected by Mossbauer spectroscopy), were found as well. The possible presence of some extraframework Fe(III) with a g ≈ 2 signal cannot be excluded. Copyright © 1999 John Wiley & Sons, Ltd.

In calculating low Mach number flows one faces the stiffness problem in two different facets:?the applicable time steps become very small?the constants of the cancellation errors become very large (1/?).Usually the first point receives attention. Here we want toconcentrate on the cancellation problem only.To our knowledge there is no detailed investigation of this problem in the related literature. In primitive variable formulations the problem can be solved by using the pressure coefficient instead of the pressure and a similar variable for the temperature or the internal energy. In conservative variable formulations this is thought not to be possible and therefore is sacrificed. We are able to show that a local reference state can also be introduced into a conservative scheme, if carefully applied to all quantities and applied to all constituent parts of the program. A detailed error analysis is given for all these parts. Finally, we show that we can perform a very low Mach number calculation atM=10?11with a seven digits arithmetic only and still maintain the set of conservative variables. The governing equations are unaltered and the method depends neither on the time integration scheme nor the specific discretization. The method should be used in connection with the standard strategies like preconditioning, multigrid, or an (semi-)implicit method if acceleration is desired.

X-band (∼9.3 GHz) pulsed ENDOR measurements were carried out on 57 Fe-substituted sodalite (FeSOD) which contains only one type of Fe(III) ( S = 5 2 ) located at a framework site. The ENDOR spectrum recorded at g = 2 shows three doublets corresponding to the six M S manifolds. The assignment of these signals was confirmed by hyperfine-selective and triple ENDOR experiments. The components of each of the doublets had different intensities, reflecting the different populations of the EPR energy levels at the measurement temperature, 1.8 K. ENDOR spectra were recorded at magnetic fields within the EPR powder pattern, and the field dependence observed showed an anisotropic behavior, unexpected from the isotropic character of the 57 Fe(III) hyperfine coupling. This dependence was attributed to the high-order effects of the zero-field splitting (ZFS) interaction on the ENDOR frequencies. Three different theoretical approaches were used to account for the dependence of the ENDOR spectrum on the ZFS interaction. The first involves the exact diagonalization of the total spin Hamiltonian, the second uses third-order perturbation approximations, and the third employs an effective nuclear Hamiltonian for each of the M S manifolds. The simulations showed that the ENDOR signals of the M S = ±5/2 (ν ±5/2 ) manifold are the least sensitive to the magnitude of the ZFS parameter D and are therefore the most appropriate for the determination of a iso . It is shown that at X band and a iso values of about 30 MHz, the perturbation approach is valid up to D values of 500 MHz if all three doublets are concerned. However, if only the ν ±5/2 doublet is considered, then this approach is valid for D a iso values of ∼30 MHz. Using the method of exact diagonalization together with orientation selectivity, the trends observed in the experimental spectra could be reproduced. The ENDOR spectra of the 57 Fe-substituted zeolites ZSM5, L, and mazzite showed broad and ill-defined peaks since the ZFS of Fe(III) in these zeolites is significantly larger than that of FeSOD. Because this broadening is a high-order effect, it can be significantly reduced at higher spectrometer frequencies.

Orientation selective and multiple frequency ESEEM experiments on substrate free cyctochrome P450cam (CP450cam) with {sup 17}O-enriched water are reported. The {sup 17}O ESEEM frequencies were obtained from Fourier transformation of the ratio of ESEEM waveforms of CP450cam with enriched water and CP450cam with non-enriched water. Numerical simulations were carried out to determine the isotropic and the anisotropic hyperfine interactions and the quadrupole interaction of the {sup 17}O. From the magnitude (e{sup 2}qQ/h = 6.6 MHz) and asymmetry ({eta} = 0.95) of the {sup 17}O quadrupole interaction, we conclude that the distal axial ligand of Fe{sup 3+} in the CP450 heme is a water molecule. Moreover, from the orientation of the {sup 17}O quadrupole tensor, the orientation of the water molecule was found to be confined (within {+-}10{degree}) with respect to the Fe-N directions within the heme plane. Two possible sets of isotropic and anisotropic components of the {sup 17}O hyperfine interaction, ({+-}2.6, {+-}10.3 MHz) and ({+-}0.4, {+-}1.8 MHz), were found to satisfactorily reproduce the experimental results. Both sets indicate very small {sup 17}O hyperfine couplings which is consistent with the unpaired electron residing predominately in the d{sub yz} orbital of the Fe{sup 3+}. Ligand field models for each set are more » presented. 50 refs., 11 figs., 1 tab. « less

The magnetic couplings of 17O in H217O coordinated to high spin Mn2+ in a frozen aqueous solution were determined using the complementary magnetic resonance techniques of pulsed and continuous wave (cw) ENDOR (electron nuclear double resonance), ESEEM (electron spin echo envelope modulation), and PFSEPR [pulse field sweep electron paramagnetic resonance (EPR)]. Several complications arise from the high electron spin multiplicity of the d5, Mn2+ ion and the high nuclear spin multiplicity, I=5/2, of the 17O nucleus. At the applied magnetic field strengths in 9 GHz EPR studies, the zero‐field splitting of the S=5/2 Mn2+ ion in aqueous frozen solution is small relative to the electron spin Zeeman interaction so that the MS=±1/2,±3/2,±5/2 electron spin states all contribute to the ENDOR spectrum.This results in a complex spectrum in which the 17O ENDOR powder pattern arising from the MS=±1/2 manifolds are separately resolved but the powder patterns from the MS=±3/2,±5/2 manifolds overlap the multiple 1H ENDOR ...

Diffusion dynamics for water in a series of sandstone core plugs with a broad range of permeabilities was studied using both the Carr-Purcell-Meiboom-Gill (CPMG) and inversion recovery experiments. Both the transverse and longitudinal magnetization curves were found to fit well to stretched exponential relaxation kinetics. At short times, the transverse magnetization is well described by an expression for free diffusion averaged over a distribution of pore sizes. The stretch exponents for the transverse and longitudinal magnetization are shown to be simply related to the width of the pore size distribution. A cross over from free to restricted diffusion is evident in the dependence of T2 with increasing diffusion time set by the interpulse spacing τ in the CPMG experiment. The T2(τ) data is fit to a model which interpolates between the limits of free and restricted diffusion. A length derived from this model is shown to provide a simple estimate of the absolute fluid flow permeability.

To solve the ID Euler equations for compressible low Mach number flow, we investigated two flux-vector splittings. Both splittings are applied to a quasi one-dimensional nozzle flow, using the explicit as well as a semi-implicit Euler scheme with a finite volume upwind formulation. Results at low and very low Mach numbers are compared with calculations using the Roe scheme. A von Neumann stability analysis was carried out for the more promising scheme based on a convection-pressure splitting.

For the water protons that coordinate to Mn2+, the frozen solution ENDOR (electron nuclear double resonance) spectra are made complex by the anisotropic electron–proton hyperfine interaction and by multiple contributions of the electron spin 5/2 manifold. A spin 5/2 Mn2+ ion having magnetic quantum numbers Ms=±1/2, ±3/2, ±5/2 and small zero‐field splittings has overlapping electron spin EPR transitions. Proton hyperfine couplings to each of these electron spin states have yielded overlapping ENDOR patterns whose interpretation is nontrivial, even in so simple a system as Mn2+ ion having hexaaquo coordination. We have experimentally obtained and theoretically explained these proton ENDOR patterns and in so doing have laid the foundation for interpreting and sorting out frozen solution ENDOR patterns in more complex (enzyme) environments. Pulsed and cw ENDOR experiments showed features of metal‐coordinated water protons occurring not only within a few MHz of the free proton frequency (as will happen for an ...

Focus on Carbon Capture and Storage (CCS) has grown over the past decade with recognition of CCS’s potential to make deep CO2 emission reductions and that fossil fuels will continue to be needed to supply much of the world's energy demands for decades to come. How CCS will compare to other options in the future depends critically on the cost of CCS (the focus of this paper) and resolution of barriers to CCS deployment, as well as costs and barriers for other emission reduction options. This paper provides a comparison of the cost of electricity of five power generation options – coal and gas Combined Cycle Gas Turbine (CCGT,) with and without CCS and nuclear – and shows regions of carbon price and fuel prices where each can be economically viable. Current cost estimates for coal CCS for Nth-of-a-kind power generation plant are in the 60-100 $/ton of CO2 avoided – higher than some of the earlier CCS estimates, and higher than the generally accepted range of expected carbon prices in the next two decades. The high cost of coal CCS suggests that:Gas based power generation is much more economical than coal CCS at carbon prices below 60-100 $/ton CO2.Even after carbon prices reach 60-100 $/ton CO2, gas CCS produces lower cost electricity than coal CCS as long as natural gas prices remain below 9 $/MBTU.Nuclear has a lower cost of electricity than coal CCS. Although Coal or Gas CCS is unlikely to be economical in power generation over the next two decades, subsidized demonstrations of CCS are likely to occur. In addition, components of CCS technologies will continue to be economically practiced in early use segments such as natural gas processing and Enhanced Oil Recovery (EOR) operations. In this paper, we share ExxonMobil’s experience at LaBarge in using CO2 from a natural gas facility for EOR use – the single largest CO2 capture site for sub-surface injection in the world today. In the natural gas processing industry, CO2 separation cost is a fraction of the cost of CO2 capture in power generation due to its higher gas pressure, and the CO2 separation is typically necessary to monetize the natural gas resource. In contrast, CCS for most refinery and industrial emissions is expected to be significantly more costly than power generation because the CO2 streams are typically smaller scale and more distributed than those from large power plants. Realistic estimates of cost for CCS, as well as for other greenhouse gas (GHG) mitigation options, are an important input for focusing research, development and demonstration (RD&D) addressing barriers to applications that show the greatest promise, and development of sound policy.

Experimental and theoretical aspects of multiple quantum (MQ) NMR coherence phenomena for paramagnetically coupled nuclei are presented. The spin interactions responsible for MQ NMR coherences observed in pulsed EPR and pulsed ENDOR (Electron Nuclear Double Resonance) are contrasted with those responsible for MQ coherences in pulsed NMR spectroscopy. MQ NMR coherences in pulsed ENDOR spectroscopy are demonstrated experimentally and described using an operator formalism approach. Detailed discussions of the phase incrementation technique for detecting MQ NMR coherences in ENDOR spectroscopy, different microwave excitation schemes for the preparation of nuclear spin order, off-resonance excitation, and the evolution of MQ coherences under free precession are presented. Experimental results on a single crystal of irradiated malonic acid and on the conjugated polyene polymer poly acetylene are presented.

A new experimental technique, pulsed electron-nuclear-electron triple resonance spectroscopy, is demonstrated. It is based on a modification of the pulse sequence for electron-nuclear double resonance (ENDOR) in which two EPR and one NMR transition are irradiated. The irradiation of one EPR transition is detected via a second EPR transition. The nuclear hyperfine coupling, which separates these EPR transition frequencies, is the irradiated NMR transition. The major advantages of triple resonance spectroscopy include the ability to resolve overlapping nuclear resonances in the ENDOR spectrum and a more direct quantitative assignment of nuclear hyperfine and quadrupole couplings. The triple resonance experiment is an alternative to the recently proposed method of employing rapid magnetic field jumps between microwave pulses for generating hyperfine selective ENDOR spectra.

We present a theoretical investigation of the origin of the unusual 3‐pulse electron spin echo envelope modulation (ESEEM) pattern obtained from 13C enriched polyacetylene, which exhibits modulation at multiple harmonics of the nuclear Larmor frequency ωn. ESEEM signals have been calculated for different models of the electron–nuclear spin coupling. It is shown that the local hyperfine tensors observed in electron nuclear double resonance (ENDOR) experiments on (13CH)x cannot account for the ESEEM results. These tensors have isotropic components which are too large to give narrow peaks at ωn, and there are too few nuclei to produce the large number of harmonics observed. Simulations for a point electron coupled to nuclei on a spherical shell, the spherical model, give insight into the conditions required to obtain narrow lines at multiple harmonics of ωn: The electron must be weakly coupled to a very large number of nuclei. Analytical results show that for the spherical model in the limit of small couplin...

The sections in this article are 1 Introduction 2 Basic Principles 3 Experimental Techniques with Selected Applications 4 Concluding Remarks 5 Biographical Sketches Related Articles

Electric fields were applied to fluid-saturated packed sand beds (0.23 ± 0.03 mm average pore diameter), and the effects on the mobility of the water molecules were monitored using stimulated echo (STE) and pulsed field gradient (PFG) experiments. The mean flow velocity, averaged over the entire sample, is expected to vanish in closed systems, but the PFG and time dependent signal decay was enhanced beyond the effects of thermal diffusion, due to velocity dispersion. The internal flow generated by the electric field was shown to be fully time-reversible upon inverting the electric field polarity (for total flow times of up to 0.4s), a strong indication that the NMR detected displacements were mainly due to electro-osmotic flow (EOF). However, a comparison of the velocity dispersion for different electrolyte concentrations showed that the measured effect scaled with the applied power VI (V = voltage, I = electric current), rather than with the voltage alone, contrary to the prediction of the basic model for EOF in a single capillary channel.

Experiments with converging and diverging turbulent boundary layers near a plane of symmetry are described by Pompeo et al. The test section used to generate the boundary layers on the plane y = 0 is shown. The experiments were compared with computations based on a finite-difference boundary-layer code by Bettelini. The prediction of the diverging flow agreed fairly well with the measurements and posed no special problems. The prediction of the converging flow, on the other hand, was very difficult. The results were very sensitive to the choice of parameters, and diverging solutions were observed for some combinations of parameters. It is the purpose of the present paper to investigate this tendency with different methods. Cases 1 and 2 are based on integral methods for laminar flow as described by Eichelbrenner. In case 1 the crossflow satisfies only the corresponding boundary condition at the wall which leads to a simple equation for the growth of the boundary-layer thickness. In case 2 the crossflow momentum equation is also taken into account, and case 3 uses Bettelini`s code. All three methods show that there exists a critical crossflow intensity beyond which the boundary-layer thickness delta(x) diverges at some x(sub s) in themore » test section, and the same holds true also for turbulent flow. The results of case 1 and case 2 show that the skin friction vanishes at x(sub s). This divergence can, therefore, be called separation. However, it is a very peculiar case as no pressure gradient exists that could decelerate the x component of the flow.« less

The class of compounds (RCp)2MX2, where M is a group IV metal, Cp is cyclopentadienyl, R is an alkyl, and X is a halide, has been of continuing interest as precursors for olefin coordination polymerization catalysts. In this communication, we demonstrate that the technique of optically detected magnetic resonance (ODMR) reveals subtle differences in the composition of the frontier molecular orbitals associated with the nature of the alkyl substituents on the Cp rings.

An atomizer had been designed that could create an aerosol of a liquid with high viscosity. The amount of additional driving gas that had to be used was very low. In a cooperation with the University Hospital in Zurich the atomizer was miniaturized and used for treating six patients.

EPR spectroscopy is a well-established method for characterizing the coordination structure of transition-metal ions and clusters of ions (Abragam and Bleaney, 1970; Pilbrow, 1991). In proteins, a metal site is often involved in an electron-transfer process. In enzymes, the metal sites are the active sites at which the substrate binds. EPR methods are a viable approach for probing the coordination structure of these active sites if the transition-metal sites are paramagnetic in one or more of the accessible oxidation states. An important advantage of EPR methods is that the signal emanates only from the specific site of interest in the macromolecule. Unlike many other spectroscopic methods, the EPR signals from the active site are not superimposed on a large background signal originating from other parts of the macromolecule.

We tested five explicit methods to solve the quasi 1D Euler equations for compressible low Mach number flow through a Laval nozzle. All of them converge similarly slowly to the steady state, although at least the preconditioning methods and the semi-implicit flux vector splitting were expected to perform better. The reason is probably due to the use of reflecting boundary conditions. For low Mach number flow, the error in pressure of the flux vector splitting methods is lower than that of Roe's scheme.

Publisher Summary The combination of the modern pulsed techniques in electron paramagnetic resonance (EPR) spectroscopy with modern pulse techniques in solid-state NMR spectroscopy has already created a variety of new experimental methodologies for metalloenzyme and metalloprotein studies. The impact that these new experimental methodologies will have in addressing problems in the biological sciences will certainly continue to expand as new laboratories enter the field. At the same time, new techniques and methodologies are currently under development that offer even greater and exciting potentials for structure and function elucidation. A potential limitation of both the crystallographic and spectroscopic methods discussed in this chapter is that the proteins must be in the solid state. For crystallographic studies, the protein must also obviously be in a crystalline form. For the spectroscopic studies frozen solutions can be studied and crystals are not necessary, but most experiments must be performed at low temperature. Structural data deduced from physical methods must be interpreted with the caveat that the data on the solid state must be related to the physiological state. Such a comparison can in fact provide insight into relevant physiological function.

Background Multiple locus sequence typing (MLST) has become a central genotyping strategy for analysis of bacterial populations. The scheme involves de novo sequencing of 6–8 housekeeping loci to assign unique sequence types. In this work we adapted MLST to a rapid microfluidics platform in order to enhance speed and reduce laboratory labor time. Methodology/Principal Findings Using two integrated microfluidic devices, DNA was purified from 100 Bacillus cereus soil isolates, used as a template for multiplex amplification of 7 loci and sequenced on forward and reverse strands. The time on instrument from loading genomic DNA to generation of electropherograms was only 1.5 hours. We obtained full-length sequence of all seven MLST alleles from 84 representing 46 different Sequence Types. At least one allele could be sequenced from a further 15 strains. The nucleotide diversity of B. cereus isolated in this study from one location in Rockville, Maryland (0.04 substitutions per site) was found to be as great as the global collection of isolates. Conclusions/Significance Biogeographical investigation of pathogens is only one of a panoply of possible applications of microfluidics based MLST; others include microbiologic forensics, biothreat identification, and rapid characterization of human clinical samples.

Diffusion dynamics for fluids in sandstone rocks were studied by CPMG and pulsed field gradient (PFG) NMR measurements. Stretched exponential decays of the transverse magnetization were observed while varying the interpulse spacing, τ, in the CPMG experiment which sets the time for diffusion. A crossover from free to restricted diffusion is evident in the dependence of both T2 and the stretch exponent, β2, on the diffusion time τ. The T2(τ) data is fit to a model which interpolates between free and restricted diffusion and has only one free adjustable length scale despite the fact that the sandstone rocks are characterized by a pore size distribution. This NMR derived length scale correlates with a characteristic length derived from Hg injection experiments at the percolation threshold. We compare these results from the CPMG experiment with stimulated echo PFG-NMR diffusion measurements. This provides a complementary method of probing the diffusion dynamics since the longitudinal magnetization is insensitive to the dephasing effects of diffusion in internal field gradients.