Scholarship & Research
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Item Investigation of field relevant parameters for microbially enhanced coalbed methane scale up(Montana State University - Bozeman, College of Engineering, 2019) Platt, George Addison; Chairperson, Graduate Committee: Robin Gerlach; K. J. Davis, E. P. Barnhart, M. W. Fields and R. Gerlach were co-authors of the article, 'Optimization of 13C-algae amendment concentration for enhanced coal dependent methanogenesis' submitted to the journal 'International journal of coal geology' which is contained within this thesis.; K. J. Davis, H. D. Schweitzer, H. J. Smith, E. P. Barnhart, M. W. Fields, R. Gerlach were co-authors of the article, 'Algal amendment enhances biogenic methane production from coals of different thermal maturity' submitted to the journal 'International journal of coal geology' which is contained within this thesis.Energy production from coal is projected to decline significantly over the next 30 years, due to concerns over anthropogenic carbon emissions, climate change, and cost. As coal-based energy production decreases, the demand for natural gas is expected to increase. Coalbed methane (CBM), a biogenic natural gas resource found in subsurface coal beds, may aid in meeting the projected increase in demand. However, costs associated with traditional CBM extraction currently make utilizing this resource economically prohibitive due to slow coal-to-methane conversion rates and the necessity to treat co-produced water. Algae can be cultivated in co-produced formation water and the addition of very small amounts of this algal biomass can increase coal-to-methane conversion rates. The goal of this work was to determine the optimal algae amendment concentration for the enhancement of microbial coal-to-methane conversion to maximize return on investment. Concentrations of 13C-labeled algae amendment ranging from 0.01-0.50 g/L (equivalent to 0.0001-0.005 g per g of coal) were tested in coal-containing batch microcosms. Enhanced methane production was observed in all amended microcosms and maximum methane production occurred between 169-203 days earlier than in unamended microcosms. When as little as 0.01 g/L algae amendment was added, 13CH 4 and 12CH 4 tracking revealed that the improvement in coal-to-methane conversion kinetics was due to enhanced coal degradation. Increasing amendment concentrations to 0.05-0.50 g/L improved coal-to-methane conversion rates further, but improvements from amendment concentrations above 0.05 g/L were insignificant. The geologic scope of this CBM enhancement strategy was investigated by studying methane production from five coals ranging in thermal maturity. Biogenic methane was produced from all coals, with subbituminous coals generally producing more methane than thermally mature bituminous coals. The addition of algae amendment to thermally mature coal microcosms resulted in methane production that was comparable to production from unamended, thermally immature coals. This improvement was associated with an increased relative abundance of coal degrading microorganisms. Collectively, this work demonstrates that algae amendment concentrations can be reduced further (to 0.01-0.05 g/L) relative to the previously investigated concentrations (ranging from 0.1-0.5 g/L) and still improve coal-to-methane conversion rates for a range of coal sources.Item Price relationships in the U.S. nitrogen fertilizer industry(Montana State University - Bozeman, College of Agriculture, 2018) Gumbley, Thomas J.; Chairperson, Graduate Committee: Anton BekkermanThis study estimates the price dynamics in the U.S. nitrogen fertilizer industry, measures information flow efficiency in spatially separated fertilizer markets, and measures to what extent structural changes in corn and natural gas markets may have altered these price dynamics and information flow relationships. A vector error correction model is used to measure the short-run and long-run relationships between nitrogen fertilizer markets, natural gas markets, and corn markets. The results show that price information flows from the central market of New Orleans to inland regional markets. The efficiency of this information flow increased in the period after the Renewable Fuel Standards increased the demand for corn.Item North Dakota natural gas : the decision to flare(Montana State University - Bozeman, College of Agriculture, 2015) Stiglbauer, Gordon Case; Chairperson, Graduate Committee: Timothy FitzgeraldUnconventional oil and natural gas production in North Dakota's Bakken shale formation has caused a boom in the state's production. As production in the Bakken grows, wells are one-third of their produced gas, valued at roughly $1 billion per year. Using a well-level panel of monthly production, I explore potential determinants of flaring and provide insight into the decision to produce oil from wells that are not connected to the gas gathering system. Through initial linear regressions, I show that North Dakota Bakken wells are twice as much, on average, than Montana Bakken wells. Further, I find that unconnected wells are nearly four times as much as connected wells. I model the decision to connect wells through duration analysis to show that connection timing varies between operators of different sizes and that the threat of flaring penalties increases the hazard rate of connection. Lastly, I exploit variation between field oil production rules in North Dakota to find that the rate of rule compliance varies both by rule stringency and the size of the operator.Item Combustion studies of natural gas with special reference to the Bozeman supply(Montana State University - Bozeman, College of Engineering, 1938) Ford, Albert D.Item Pipeline constraints in wholesale natural gas markets : effects on regional pricing and market integration(Montana State University - Bozeman, College of Agriculture, 2012) Avalos, Roger George; Chairperson, Graduate Committee: Randal R. Rucker.Natural gas markets in the United States depend on an extensive network of pipelines to transport gas from production fields to end users. While these pipelines are essential for the operation of natural gas markets, their capacity sets a physical limit on the quantity of gas that can be moved between regions. Taking advantage of a rich data set of daily pipeline capacities and flows, this thesis tests the effects of binding pipeline constraints directly. It is found that these constraints affect the citygate prices for the Florida and Southern California markets. The Law of One Price is tested using cointegration techniques and found to hold when pipeline flows are not constrained, and break down during constrained periods. It is also shown that cointegration techniques may not identify bottlenecks between regions when bottlenecks are not severe, or when they only occur for limited periods of time. Contrary to earlier results, Southern California markets are found to be integrated with the national market. Cointegration tests using data from 14 market points suggest that regional wholesale natural gas markets in the United States are generally integrated into a national market.Item Reclamation potential of experimental oak mat and conventional natural gas drill pad construction techniques in a sagebrush steppe community(Montana State University - Bozeman, College of Agriculture, 2008) McWilliams, Colin Shamus; Chairperson, Graduate Committee: Douglas J. Dollhopf; Jon M. Wraith (co-chair)Conventional cut-and-fill drill pad construction associated with natural gas production displaces existing plant communities and results in surface disturbances requiring extensive soil remediation and revegetation. At the Jonah natural gas field, Wyoming, use of an oak mat drilling platform placed atop the intact landscape was evaluated to facilitate drilling while minimizing disturbances to soil and plant resources. Concerns inherent to both techniques include adverse, long-term impacts to vegetation communities, soil compaction and soil physical and chemical characteristics. The percent change (%Δ) in grass density at oak mat removal areas (OMRA) (+37 %) was significantly greater than at cut-and-fill locations reclaimed pre-2005 (RCAF<05) (+16 %). Forb density %Δ at OMRA (+24 %) was significantly higher than at RCAF<05 locations (-86 %). At RCAF<05 locations 99 % of forb density was contributed by weedy forb species. This indicates that OMRA were more successful in promoting high grass density, maintaining forb populations and minimizing weedy forb components than RCAF<05 locations. RCAF<05 locations indicate an -84 %Δ in shrub density whereas OMRA indicate a -33 %Δ. Wyoming big sagebrush seedling density was highest at OMRA indicating that shrub density had a greater potential to recover there relative to RCAF<05 locations. Mean soil bulk density (ρb) at OMRA had -3.0, +1.8 and +3.9 %Δ in depth increments between 0-30.5 cm. The mean ρb at cut-and-fill locations reclaimed in 2005 or later (RCAF > or equal to 05) had +7.0, +10.9 and +11.7 %Δ in different depth increments between 0-45.7 cm. Using a ρb range of 1.45-1.70 g/cm 3 as an indicator of potential plant growth problems, ρb exceeding 1.45 g/cm 3 occured infrequently at OMRA compared to RCAF > or equal to 05 locations. RCAF > or equal to 05 locations had significant increases in %Δ soil saturated-paste extract ECe (+209 %), CaCO 3 percentage (+48 %) and sand percentage (+16 %) compared to OMRA, presumably due to mixing of soil horizons. It is counterintuitive to expect that oak mats should alter physicochemical soil properties. Although limited to construction on slopes < or equal to 3 %, measured vegetation and soil characteristics indicated that the reclamation success of oak mat drill pads was greater than that obtained at reclaimed cut-and-fill locations.