Environmental Engineering Commons^™

Ozonation In Water Reuse: Formation And Mitigation Of N-~Nitrosodimethylamine, Erica J. Marti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Formation of N-nitrosodimethylamine (NDMA) is a substantial concern for drinking water and water reuse. NDMA, a probable human carcinogen, is formed when water is disinfected with chloramines and ozone. This research focused on three issues regarding NDMA formation and mitigation. The first issue involved understanding the compounds (i.e., precursors) present in water and wastewater that react with ozone to form NDMA. Model precursors were identified and molar yields for NDMA formation were determined. The model precursors form high amounts of NDMA with ozone, but form very little NDMA with chloramines, which means there are two distinct groups of NDMA precursors: …

Hydrogeological Conceptual Model Of La Villa River Watershed, Republic Of Panama, Maria G. Castrellon Romero

Honors Scholar Theses

Groundwater in Panama is a valuable and poorly understood resource. Its exploitation has increased 75% in the past decade, reaching a total value of 700,000 m³/day or 185 million gallons per day (MGD). Climate change has caused a lengthening of the dry season, which has reduced precipitation and streamflow, resulting in surface water scarcity during this period. Nevertheless, it has not been possible to determine the extent to which groundwater sources have been affected by these factors since systematic monitoring of groundwater levels has not been implemented in Panama. With support from National Institution of Drinking Water Supply …

Design And Testing Of Sorbents For Co2 Separation Of Post-Combustion And Natural Gas Sweetening Applications, Jiajun He, John To, Peter Psarras, Jianguo Mei, Jen Wilcox

CO2 Summit II: Technologies and Opportunities

In post-combustion processes, sorbents with both high capacity and selectivity are required for reducing the cost of carbon capture. Although physisorbents have the advantage of low energy consumption for regeneration, it remains a challenge to obtain both high capacity and sufficient CO₂/N₂ selectivity at the same time. A novel N-doped hierarchical carbon has been developed, which exhibits record-high Henry’s law CO₂/N₂ selectivity among physisorptive carbons while having a high CO₂ adsorption capacity. Specifically, the synthesis involves the rational design of a modified pyrrole molecule that can co-assemble with the soft Pluronic template via …

Techno-Economic Challenges Associated With Biomass Energy Utilization And Ccs, Carl Bozzuto

CO2 Summit II: Technologies and Opportunities

Despite the recent agreement by world leaders regarding the need for reductions in CO2 emissions from the global energy system, there will still be substantial amounts of fossil fuels utilized for the next few decades. According to IEA estimates, there will likely be an “overshoot” of the CO₂ concentration that is estimated to be needed to restrain average global temperatures increases in the range of 1.5–2˚C. As a result, biomass energy has been proposed as one means to reduce net CO₂ emissions and, perhaps, even reduce the level of CO₂ in the atmosphere. One approach has been …

Evaluation Of Physical Adsorbents For Post-Combustion Co2 Capture, Youssef Belmabkhout

CO2 Summit II: Technologies and Opportunities

CO₂ capture using physical adsorbents such as activated carbon, zeolites, and metal-organic frameworks (MOFs) have attracted a lot of attention because of the technical capability of adsorption technology using such separation agents to retrofit the energy demanding liquid amine scrubbing process. Nevertheless, this will be conceivable only if the separation agents (adsorbents) in question fulfil many unambiguous attributes in terms of porosity, CO₂ affinity, kinetics, energetics, stability, throughout the right capture mechanism, in addition to the adsorbents cost.

In this paper we report recent study about the evaluation of physical adsorbents for CO₂ capture from simulated flue …

Metallic Membranes For N2 Separation & Post-Combustion Co2 Capture Improvement, Simona Liguori, Kyoungjin Lee, Jennifer Wilcox

CO2 Summit II: Technologies and Opportunities

Carbon (CO₂) capture represents an important role in the reduction greenhouse gas emissions. Among various CO₂ capture technologies currently investigated, post-combustion capture allows for the retrofitting of existing plants and industrial units. Today, the amine scrubbing is considered the most competitive method for CO₂ removal in the flue gases from power plants in comparison to other technologies. Nevertheless, recent work has shown that the energy requirement for solvent recovery can decrease the overall efficiency of the power plants up to 16%¹. Moreover, additional costs may occur in the solvent absorption technology because of solvent …

Co2 Capture Using Nanoporous Tio(Oh)2/Tetraethylpentamine, Maryam Irani, Maohong Fan, Khaled Gasema

CO2 Summit II: Technologies and Opportunities

In this work, an inorganic-organic CO2 sorbent was prepared by immobilizing tetraethylenepentamine (TEPA) onto nanoporous titanium oxyhydrate (TiO(OH)2). The prepared sorbents were characterized using X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) analysis. At the optimal TEPA loading of 60 wt.% on TiO(OH)2, its CO2 sorption capacity reached 3.1 mmol CO2/g-sorbent for 1 vol.% CO2 in N2 along with ~1 vol.% H2O at 60°C. Studies of adsorption kinetics and thermodynamics showed that the activation energies for CO2 adsorption and desorption of TiO(OH)2/TEPA are 38.31 kJ/mol and 44.51 kJ/mol, respectively. Its low …

Nitrogen-Functionalized Porous Carbons For Enhanced Co2 Capture, Peter Psarras, Jennifer Wilcox

CO2 Summit II: Technologies and Opportunities

The global consequences of increased anthropogenic carbon dioxide emissions are well documented. To avoid the catastrophic long-term damages associated with climate change, much attention has been devoted to the development of CO₂ emission mitigation strategies. A present challenge in the mitigation of anthropogenic CO₂ emissions involves the design of less energy- and water-intensive capture technologies. Traditional capture methods, e.g. MEA solvent scrubbing, have prohibitive regeneration costs, and recent concerns in drought-ridden states like California have brought these water-intensive processes under increased scrutiny. Sorbent-based capture represents a promising solution to the aforementioned hurdles, as they do not incur the …

Direct Air Capture Versus Post Combustion Capture For Coal Fired Power Plants: Energy Balance And Life Cycle Environmental Assessment, Christoph Meinrenken

CO2 Summit II: Technologies and Opportunities

Direct air capture (DAC) has been suggested as a possible alternative to post combustion capture (PCC), as a way to lower the climate impact of fossil-based electricity generation. However, various literature suggests that the much lower concentration of CO2 in ambient air (compared to flue gas) will cause DAC to require ~3x higher energy consumption than PCC per ton CO2 captured, in turn leading to impractically high parasitic loads, costs, and potentially other adverse environmental impacts of DAC for purposes of mitigating emissions from e.g. coal-fired power plants. Here we present a comparative techno-economic and life cycle assessment (LCA) of …

Optimal Molecular Design Of Poly (Ionic Liquids) For Co2 Capture From The Atmosphere, Kun Ge, Tao Wang

CO2 Summit II: Technologies and Opportunities

Polymeric ionic liquids (PILs) are promising CO₂ adsorption materials for that they combine the unique properties of ionic liquids with the flexibility and properties of macromolecular architectures. Previous studies have demonstrated that a carbonated-functionalized quaternary ammonium based PIL could adsorb CO₂ from atmosphere when dry and release CO2 when wet, which constituted a moisture swing cycle, which provides an economical approach for air capture. Moreover, the performance of the PIL (such as CO₂ affinity, reaction kinetics, swing size and hydrophobicity), could be improved owing to its fine tunability. To find out its optimal structure, molecular simulation was …

Pathway To Achieve Negative Co2 Emissions - Combining Biomass With Ccs, Antti Arasto, Janne Karki, Kristin Onarheim

CO2 Summit II: Technologies and Opportunities

The urgency to stabilize the global temperature rise at 1.5°C as highlighted in Paris COP21 and the IPCC Fifth Assessment Report calls for solutions that can remove CO2 from the atmosphere. The ability of carbon negative processes to offset historic emissions and emissions across different sectors is also highlighted in recent scenarios by IEA and WEC. Achieving negative CO₂ emissions by removing CO₂ from the atmosphere is possible by applying carbon capture in processes utilizing biomass (bio-CCS). Biomass has the capability of withdrawing and storing atmospheric CO₂. As a result, CO₂ released during biomass thermo-chemical …

Co2 Mitigation Opportunities In China, Wayne Xu

CO2 Summit II: Technologies and Opportunities

Over the past thirty years China has focused on urbanization and economic growth through rapid development and modernization of its manufacturing capability. Much of this growth was achieved though massive adoption of coal based power generation with industry and manufacturing accounting for over 70% of all electricity consumption. Although the use of coal and other hydrocarbons have successfully fueled China into an era of prosperity and global recognition, it has come at a cost to the environment and quality of life. Significant efforts to reduce coal based generation emissions have recently been achieved through the development and adoption of world …

Carboncycle And Other Profitable Strategies For Air Capture Of Co2, Deane Little

CO2 Summit II: Technologies and Opportunities

Development of an effective and economically viable strategy for air capture of CO2 would be a game-changing development in the fight against global warming. If widely adopted such a process would allow “chemostatting” the atmosphere at sustainable CO2 levels and might not require widespread social change in how we use fossil fuels. Unfortunately the concept that air capture of CO2 “doesn’t work” has taken hold in academic and policy circles, based on the assumption that such a process is inherently expensive and results in no useful products. In fact, air capture of CO2 can be profitable and offers fundamental advantages …

Metal Oxides With Ionic-Electronic Conductivity For Thermochemical Energy Storage, Eric Coker, Sean Babiniec, Andrea Ambrosini, James Miller

CO2 Summit II: Technologies and Opportunities

One of the key approaches to developing a supply of renewable energy is Concentrating Solar Power (CSP). However, the diurnal and intermittent nature of the solar resource necessitates efficient energy storage solutions if a reliable energy supply is to be expected. By increasing the temperature and energy density of thermal storage, improvements in power cycle efficiency and energy storage cost are possible and can result in increased economic competitiveness. Thermochemical energy storage (TCES) holds promise for enabling this goal. Metal oxides (MOs), with their elegantly simple reduction/re-oxidation (redox) chemistry, approach an ideal medium for TCES in many respects. For instance, …

Kinetic Enhancement Of Adsorbent For Co2 Capture From Atmosphere By Porous Material, Tao Wang, Jun Liu, Kun Ge, Zhongyang Luo

CO2 Summit II: Technologies and Opportunities

Strategies for stabilizing atmospheric greenhouse gas concentrations will need to consider future CO2 emissions from an enormous resource of worldwide fossil fuel supplies and a diverse range of mitigation technologies. In 2013, global CO2 emissions due to fossil fuel use (and cement production) were 36 gigatonnes (Gt CO2), and are projected to increase by an additional 2.5% in 2014. Even if all emissions from large fixed sources could be captured, the roughly 30-50% of global emissions due to transportation and mobile sources would still be released into the atmosphere. To ensure the concentration of atmospheric CO2 in the scope of …

Factors That Impact The Co2 Mitigation Potential Of Cogeneration, Carl Bozzuto

CO2 Summit II: Technologies and Opportunities

Cogeneration systems that produce both heat and power are being promoted as a means of improving the overall energy efficiency around the world, especially in the industrial and power sectors. Claims are often made regarding dramatic improvements in efficiency for such systems. For example, a cogeneration system is advertised as being 85% efficient, while, for example, the U.S. grid is only 31% efficient. However, comparing such efficiency figures directly can be misleading. An 85% efficient cogeneration system is being evaluated at full load and on a first law of thermodynamics basis (i.e., input = output at steady state). The average …

Zerronox Corporation: Using Pulsed Electron Beams For The Removal Of Carbon Dioxide, Nitrogen Oxides And Other Emissions From Power Plants, Stephen Kennedy

CO2 Summit II: Technologies and Opportunities

Zerronox Corporation is a technology company addressing the market for emission abatement from fossil fuel power plants, specifically coal, natural gas, oil and diesel. Our mission is to commercialize the patented pulsed electron beam (PEB) technology for the cost effective removal of carbon dioxide, nitrogen oxides (NOx), and other exhaust stream pollutants such as sulfur oxides and mercury. The core technology was developed by the Naval Research Laboratory over the past fifteen years with a total investment from the DOE of more than $150M. Consequently, the developed technology is industrial scale in scope and has been tested for durability.

The …

Baysian Uncertainty Quantification And Calibration Of A Clean-Coal Design Code, Troy Holland, Sham Bhat, Peter Marcy, James Gattiker, Joel Kress, Thomas Fletcher

CO2 Summit II: Technologies and Opportunities

Current concerns about atmospheric carbon levels have sparked demands for massively reduced carbon emissions. These demands, both environmental and regulatory, exceed the capacity for near-term deployment of emission free technologies. Therefore, to simultaneously meet carbon emission targets and supply the vast global energy demands in the foreseeable future, energy generation must incorporate carbon-capture and sequestration technologies on point source CO­₂ emitters such as coal-fired power plants.

Coal-fired power plants have long been the primary energy pillar of industrialized nations, and while reduced utilization is an important target for CO₂ reduction, coal combustion remains the most intensive and prevalent …

Fulfilling The Promise Of The Paris Agreement: The Role Of Efficiency And Renewable Energy, Chuck Kutscher

CO2 Summit II: Technologies and Opportunities

Renewable energy, energy policy, energy efficiency, buildings

The rapid large-scale deployment of efficiency and renewable energy technologies is crucial to meeting the goals of the COP21 agreement. Key to achieving this is transitioning to zero-carbon cities comprised of highly efficient buildings powered by renewable electricity. This presentation will survey the current efficiency and renewable energy research underway at the National Renewable Energy Laboratory with special attention paid to zero-carbon buildings and the challenges of developing a renewable energy electric grid.

Using Geologic Co2 Storage For Enhanced Geothermal Energy And Water Recovery And Energy Storage, Thomas Buscheck, Jeffrey Bielicki, Jimmy Randolph

CO2 Summit II: Technologies and Opportunities

Reductions in CO₂ emissions at a scale consistent with limiting the increase in the global average temperature to below 2oC above pre-industrial levels requires a range of measures, including increased use of renewable and low-carbon energy and reduced CO₂ intensity of fossil energy use, with each of these measures having major deployment barriers. The variability of the predominant renewable resources (wind and solar) requires major advances in utility-scale diurnal-to-seasonal energy storage. Base-load energy, such as nuclear, that cannot be cycled during periods of over-generation will have difficulty co-existing on electric grids with a large presence of variable renewables. …