THE IMPACT OF CO2 ON SURFACE AND GROUNDWATER CHEMISTRY: A FEASIBILITY STUDY OF EMPLOYING GEOLOGIC CARBON SEQUESTRATION IN ERIE COUNTY, PA USA.

Open Access
Author:
Frye, Evan James
Graduate Program:
Energy and Mineral Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
July 26, 2011
Committee Members:
  • Li Li, Thesis Advisor
  • Seth Adam Blumsack, Thesis Advisor
Keywords:
  • Lake Erie
  • wastewater treatment
  • heavy metal
  • geologic carbon sequestration
Abstract:
The Rose Run formation located in Kentucky, Ohio, West Virginia, New York and Pennsylvania has suitable reservoir properties to undergo CO2 injection, which include a high porosity (2.8%), high permeability (>10 mD), is at sufficient depth (>2,355 meters) and is laterally continuous. Additionally, the Rose Run formation is overlain by a thick Huron shale cap rock (>300 m) that has low porosity (<0.10%) and low permeability (<10 mD), which is also laterally continuous. Considering storage potential through mineral trapping and immobilization of CO2 in the pore space, our target reservoir can hold between 10.42 and 20.21 million tons of CO2. Over the course of 35 years, 1.58 million tons of CO2 will be produced at the Samuel Carlson Generating Station (SCGS) [located in Jamestown, NY] and emitted to the atmosphere if the power output continues at present day rates. Viewed from the reservoir capacity perspective, the Rose Run target reservoir could hold 6.65 times the mass (Mt CO2) of emissions produced at the SCGS during the 35-year period. From our stated formation properties, it is determined that our reservoir has a total mass of 9.3 x 1012 kilograms, with sandstone mass > mixed mass > carbonate mass. In considering the potential leakage rate of carbon dioxide out of our injection reservoir, we assume that 0.01% of the total CO2 that is injected into the reservoir is available for migration out of the injection reservoir or 1.58 kilotons could potentially leak out of the target reservoir. To generate CO2 partial pressures high enough to impact water quality, flux rates between 5 and 25 m2 y-1 suggest that total leakage of mobile carbon dioxide could occur between 316 and 63 years, respectively. Twelve column experiments suggest that even moderate reductions in system pH as related to CO2 saturated water can impact cadmium desorption rates. It further appears that there is a linear relationship associated with cadmium removal from which we can use to infer leaching rates as analogues for the Lake Erie system. An average desorption rate of 25.1% is observed. The influence of calcite and its natural abundance in Lake Erie sediments suggest that desorption rates in the field may be lower than those observed in the laboratory. Experimental results suggest that somewhere between 0.00008 and 0.004 ppm per minute of cadmium is removed from the illite mineral surface after the introduction of an acidic solution to the system From relationship of pCO2 and pH, we can determine carbon dioxide partial pressures that need to be achieved in the laboratory to create CO2 saturated at specific pH values. Levels of risk from aforementioned heavy metal concentrations are produced through the assumption that 20-25% of the available heavy metals desorbs from clay materials as a result of an influx of CO2 at a pCO2 between 0.01 and 2.5 atm. From these desorption rates, impacts to human health and increases in wastewater treatment costs have been determined. This risk occurs when water consumption exceeds 3.0 liters per day and fish consumption exceeds 0.2 kilograms per week. Because sorption rates suggest only minor increases in aqueous heavy metal concentrations (20-25%), risks associated from Lake Erie water consumption are low. It is determined that Cleveland Water currently treats influent Lake Erie water with a heavy metal concentration of 0.211 mg/L. Cleveland Water annually produces over 64,095 kilograms of heavy metal sludge. It is revealed that if 25% of the heavy metals in Lake Erie sediments are mobilized into lake water, annual treatment costs for low, medium, and high concentrations will increase by 135, 355, and 62,500 percent at the municipal level, respectively. In considering the volume of information presented, the Rose Run formation can hold sufficient quantities of carbon dioxide produced at the nearby Samuel Carlson Generating Station for 35 years. The selected site of injection lacks any vectors of migration for mobile CO2 and as a result, impacts to water quality do no exceed levels that are harmful to humans or the environment and there is no merit in wastewater treatment retrofitting. Therefore, employing geologic carbon sequestration within the Rose Run formation at our injection is feasible and poses little or no economic or heath threat to humans or the environment.