Browsing by Author "Waldon, Jefferson L."
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- Maximizing wildlife benefits through hardwood timber harvest schedulingWaldon, Jefferson L. (Virginia Polytechnic Institute and State University, 1987)A computerized system for planning timber harvest to maximize habitat quality over time for a specified group of wildlife species was developed for upland oak forests of the Eastern United States. This system, called WILDWOOD for WILDiife/WOOD optimization system, is designed to run on a microcomputer. It utilizes a widely available database management system called PCFile III, Version 4, a forest growth and yield simulator adapted from work by Dale (1972), and a program developed by the author. The system utilizes 43 species-specific habitat value models developed by the author and others. Timber harvests in approximately one ha blocks (patch clearcut) are specified for each year to result in a maximum yearly average wildlife benefit figure. Wildlife benefits are defined as the product of a wildlife species value provided by the user, a forest-size-classspecific habitat value index, and the area of the cutting unit. WILDWOOD was demonstrated on a 106 ha tract of upland oak forest on Havens Wildlife Management Area of the Virginia Commission of Game and Inland Fisheries. Six different objective functions were investigated and several model tests were conducted. Implications for the application of the WILDWOOD system were discussed, and it was concluded that, although the objectives of the study were met, the current WILDWOOD system should be modified to include smooth wildlife habitat succession models, at least a 150-year planning horizon, and capabilities for addressing cutting unit size, shape, and juxtaposition. Other possibilities for future revisions inclu~e modifying HEP (U.S. Fish and Wildlife Service) for use with WILDWOOD, and linking ageographic information system to WILDWOOD.
- Technoeconomic Analysis of Negative Emissions Bioenergy with Carbon Capture and Storage through Pyrolysis and Bioenergy District Heating InfrastructureLim, Theodore C.; Cuellar, Amanda; Langseth, Kyle; Waldon, Jefferson L. (American Chemical Society, 2022-01-11)Bioenergy with carbon capture and storage (BECCS) has been identified as a cost-effective negative emission technology that will be necessary to limit global warming to 1.5 °C targets. However, the study of BECCS deployment has mainly focused on large-scale, centralized facilities and geologic sequestration. In this study, we perform technoeconomic analysis of BECCS through pyrolysis technology within a district heating system using locally grown switchgrass. The analysis is based on a unique case study of an existing switchgrass-fueled district heating system in the rural southeastern United States and combines empirical daily energy data with a retrospective analysis of add-on pyrolysis technology with biochar storage. We show that at current heating oil and switchgrass prices, pyrolysis-bioenergy (PyBE) and pyrolysis BECCS (PyBECCS) can each reach economic parity with a fossil fuel-based system when the prices of carbon is $116/Mg CO2-eq and $51/Mg CO2-eq, respectively. In addition, each can reach parity with a direct combustion bioenergy (BE) system when the prices of carbon is $264/Mg CO2-eq and $212/Mg CO2-eq, respectively. However, PyBECCS cannot reach economic parity with BE without revenue from carbon sequestration, while PyBE can, and in some cases, PyBECCS could counterintuitively require more reliance on fossil fuels than both the PyBE case and BE.