Curt M. White

Separation and capture of CO2 from large stationary sources and sequestration in geological formations--coalbeds and deep saline aquifers.

Abstract The topic of global warming as a result of increased atmospheric CO2 concentration is arguably the most important environmental issue that the world faces today. It is a global problem that will need to be solved on a global level. The link between anthropogenic emissions of CO2 with increased atmospheric CO2 levels and, in turn, with increased global temperatures has been well established and accepted by the world. International organizations such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC) have been formed to address this issue. Three options are being explored to stabilize atmospheric levels of greenhouse gases (GHGs) and global temperatures without severely and negatively impacting standard of living: (1) increasing energy efficiency, (2) switching to less carbon-intensive sources of energy, and (3) carbon sequestration. To be successful, all three options must be used in concert. The third option is the subject of this review. Specifically, this review will cover the capture and geologic sequestration of CO2 generated from large point sources, namely fossil-fuel-fired power gasification plants. Sequestration of CO2 in geological formations is necessary to meet the President’s Global Climate Change Initiative target of an 18% reduction in GHG intensity by 2012. Further, the best strategy to stabilize the atmospheric concentration of CO2 results from a multifaceted approach where sequestration of CO2 into geological formations is combined with increased efficiency in electric power generation and utilization, increased conservation, increased use of lower carbonintensity fuels, and increased use of nuclear energy and renewables. This review covers the separation and capture of CO2 from both flue gas and fuel gas using wet scrubbing technologies, dry regenerable sorbents, membranes, cryogenics, pressure and temperature swing adsorption, and other advanced concepts. Existing commercial CO2 capture facilities at electric power-generating stations based on the use of monoethanolamine are described, as is the Rectisol process used by Dakota Gasification to separate and capture CO2 from a coal gasifier. Two technologies for storage of the captured CO2 are reviewed—sequestration in deep unmineable coalbeds with concomitant recovery of CH4 and sequestration in deep saline aquifers. Key issues for both of these techniques include estimating the potential storage capacity, the storage integrity, and the physical and chemical processes that are initiated by injecting CO2 underground. Recent studies using computer modeling as well as laboratory and field experimentation are presented here. In addition, several projects have been initiated in which CO2 is injected into a deep coal seam or saline aquifer. The current status of several such projects is discussed. Included is a commercial-scale project in which a million tons of CO2 are injected annually into an aquifer under the North Sea in Norway. The review makes the case that this can all be accomplished safely with off-the-shelf technologies. However, substantial research and development must be performed to reduce the cost, decrease the risks, and increase the safety of sequestration technologies. This review also includes discussion of possible problems related to deep injection of CO2 . There are safety concerns that need to be addressed because of the possibilities of leakage to the surface and induced seismic activity. These issues are presented along with a case study of a similar incident in the past. It is clear that monitoring and verification of storage will be a crucial part of all geological sequestration practices so that such problems may be avoided. Available techniques include direct measurement of CO2 and CH4 surface soil fluxes, the use of chemical tracers, and underground 4-D seismic monitoring. Ten new hypotheses were formulated to describe what happens when CO2 is pumped into a coal seam. These hypotheses provide significant insight into the fundamental chemical, physical, and thermodynamic phenomena that occur during coal seam sequestration of CO2 .

Identification and geochemical significance of some aromatic components of coal

Abstract The aromatic fraction of a Homestead, Kentucky, coal extract was analyzed by combined gas chromatography-mass spectrometry using glass capillary columns. The aromatic fraction was further analyzed by gas chromatography using sulfur specific flame photometric detection. Seventy-eight compounds were identified, some of which have been traced to their possible biological origins. Sulfur-containing aromatic compounds are thought to originate from reaction of elemental sulfur or pyrite with hydrocarbons.

The regional nature of PM2.5 episodes in the upper Ohio River Valley

Abstract From October 1999 through September 2000, particulate matter (PM) with aerodynamic diameter ≥2.5 μm (PM2.5) mass and composition were measured at the National Energy Technology Laboratory Pittsburgh site, with a particle concentrator Brigham Young University-organic sampling system and a tapered element oscillating microbalance (TEOM) monitor. PM2.5 measurements had also been obtained with TEOM monitors located in the Pittsburgh, PA, area, and at sites in Ohio, including Steub-enville, Columbus, and Athens. The PM data from all these sites were analyzed on high PM days; PM2.5 TEOM particulate mass at all sites was generally associated with transitions from locally high barometric pressure to lower pressure. Elevated concentrations occurred with transport of PM from outside the local region in advance of frontal passages as the local pressure decreased. During high-pressure periods, concentrations at the study sites were generally low throughout the study region. Further details related to this transport were obtained from surface weather maps and estimated back-trajectories using the hybrid single-particle Lagrangian integrated trajectory model associated with these time periods. These analyses indicated that transport of pollutants to the Pittsburgh site was generally from the west to the southwest. These results suggest that the Ohio River Valley and possible regions beyond act as a significant source of PM and its precursors in the Pittsburgh area and at the other regional sites included in this study.

Narrow-boiling distillates of coal liquefaction products: 2. Heat capacities

Abstract The liquid phase heat capacities of narrow-boiling-range distillates from coal liquefaction products were predicted using group contribution, corresponding states and curve-fitting procedures. These predictions were compared to experimentally determined values. The results indicate that the accuracy of the correlations can be ranked in the following order: groupcontribution >curvefits >correspondingstates. The success of the group contribution approach can be attributed to the structural information that is incorporated into the correlation. Using the group contribution method, one can estimate liquid heat capacities of the narrow-boiling range distillates with an overall accuracy of 8% using data from only 1H n.m.r. and elemental analysis.

Narrow-boiling distillates of coal liquefaction products. 1. Functional group distributions

Abstract Coal liquefaction products from the H-coal and the Wilsonville Integrated two-stage liquefaction processes were separated into narrow-boiling distillates. The Wilsonville product was from the first stage. Information resulting from elemental analysis, proton nuclear magnetic resonance ( 1 H n.m.r.), low-voltage, highresolution mass spectrometery (LVHRMS), infrared spectroscopy (i.r.) and open-column preparative liquid chromatography were obtained for each distillate. The analytical data were used to estimate the concentrations of the major functional groups in the distillates. The results indicated that the structure and functionality of the molecular constituents of the two sets of distillates boiling in the same temperature range were similar. Structural differences appear to be primarily related to the concentrations of alkylated aromatics and saturates.

Pollen and fungal spore sampling and analysis. Statistical evaluations

Statistical evaluations of samples obtained from a Burkard seven-day recording volumetric pollen/spore trap were performed to determine the precision of the sampling and analysis procedures. The reproducibility of co-located traps was also investigated. The results showed that pollen grain transect counting was not significantly different, while fungal spore counting produced statistically different results. There was no statistical difference in the number of pollen and fungal spores counted between the co-located samplers. Reasons for the differences in the fungal spore counts are presented.

Ground-penetrating radar survey and tracer observations at the West Pearl Queen carbon sequestration pilot site, New Mexico

The potential for leakage of injected CO2 at carbon sequestration sites is a significant concern in the design and deployment of long-term carbon sequestration efforts. Effective and reliable monitoring of near-surface environments in the vicinity of these sites is essential to ensure the viability of sequestration activities as well as long-term public and environmental safety. Identification of geologic features (such as faults, fracture zones, and solution enhanced joints that might facilitate release of injected CO2 back into the atmosphere) is a key step in this process. This study reports on near-surface geologic and geophysical characterization efforts conducted at the Department of Energy National Energy Technology Laboratory (NETL) West Pearl Queen carbon sequestration pilot site in southeastern New Mexico, USA, and their use for uncovering possible mechanisms associated with escape of small amounts of perfluorocarbon tracers injected with the CO2.

Polarizability of coal liquefaction product distillates: Insight into intermolecular forces☆

Abstract A purpose of this investigation is to gain insight into the intermolecular forces present in coal liquefaction products. The mid-boiling point of distillates from coal liquefaction products reflects the intermolecular forces present. The mid-boiling point of distillates from H-Coal and Wilsonville products is a linear function of their average molar volume and average molar polarizability, which are directly related to van der Waals forces. The results presented here support, but do not prove, the conclusion that van der Waals forces are the dominant intermolecular forces in the H-Coal and Wilsonville distillates.

Exploratory study of some potential environmental impacts of CO2 sequestration in unmineable coal seams

An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production, using a CO2 injection process (CO2-ECBM). A high volatile bituminous coal, Pittsburgh No. 8, was reacted with synthetic produced water and gaseous carbon dioxide at 40C and 50 bar to evaluate the potential for mobilisation of toxic metals during CO2-ECBM/sequestration. Microscopic and X-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction and chemical analysis of the synthetic produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilising toxic trace elements from coal beds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.

Identification of Polycyclic Hydrocarbons in Fossilized Latex From Brown Coal

Abstract Partially coalified, structurally intact latex fibers(“Affenhaar”) found in a low-rank coal have been characterized by various analytical methods. It has been proposed in previous studies, and it appears to be so here, that the latex was “naturally” vulcanized during the coalification period. The Affenhaar samples studied here are high in sulfur. However, the sulfur constituents were not extracted in the pyridine solvent used to exact the hydrocarbons. Two fossilized latex samples recovered from different locations within the brown coal deposit were characterized. Pyridine extracts of the samples were analyzed by capillary gas chromatography, combined capillary gas chromatography-mass spectrometry, and high-resolution mass spectrometry. Twelve compounds in the extract were tentatively identified as amyrin and hopane biomarker derivatives by comparing the Kovats retention indices, mass spectra, and order of elution with those in the literature. Three of these, identifications were verified by coch...