Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Division of Forestry and Natural Resources
A multi-stage spatial analysis was first conducted to select locations for lignocellulosic biomass-based bioproduct facility, using Geographical Information System (GIS) spatial analysis, multi-criteria analysis ranking algorithm, and social-economic assessment. A case study was developed to determine locations for lignocellulosic biorefineries using feedstocks including forest residue biomass and three energy crops for 13 states in the northeastern United States. In the entire study area, 11.1% of the counties are high-suitable, 48.8% are medium-suitable for biorefinery siting locations. A non-parametric analysis of cross-group surveys showed that preferences on biorefinery siting are homogeneous for experts in academia and industry groups, but people in government agencies presented different opinions. With the Maximum Likelihood test, parameters of distributions and mean values were estimated for nine weighted criteria. Social asset evaluation focusing on degree of rurality and social capital index further sorted counties with higher community acceptance and economic viability. A total of 15 counties were selected with the highest potential for biorefinery sites in the region.
A mixed-integer linear programming model was then developed to optimize the multiple biomass feedstock supply chains, including feedstock establishment, harvest, storage, transportation, and preprocessing. The model was applied for analyses of multiple biomass feedstocks at county level for 13 states in the northeastern United States. In the base case with a demand of 180,000 dry Mg/year of biomass, the delivered costs ranged from $67.90 to $86.97 per dry Mg with an average of $79.58 /dry Mg. The biomass delivered costs by county were from $67.90 to 150.81 per dry Mg across the northeastern U.S. Considered the entire study area, the delivered cost averaged $85.30 /dry Mg for forest residues, $84.47 /dry Mg for hybrid willow, $99.68 for switchgrass and $97.87 per dry Mg for Miscanthus. Seventy seven out of 387 counties could be able to deliver biomass at $84 per dry Mg or less a target set by US DOE by 2022. A sensitivity analysis was also conducted to evaluate the effects of feedstock availability, feedstock price, moisture content, procurement radius, and facility demand on the delivered cost. Our results showed that procurement radius, facility capacity, and forest residue availability are the most sensitive factors affecting the biomass delivered costs.
An integrated life cycle and techno-economic assessment was carried out for three bioenergy products derived from multiple lignocellulosic biomass. Three cases were studied for production of pellets, biomass-based electricity, and pyrolysis bio-oil. The LCA was conducted for estimating environmental impacts on cradle-to-gate basis with functional unit of 1000 MJ for bioenergy production. Pellet production had the lowest GHG emissions, water and fossil fuels consumption, for 8.29 kg CO2 eq, 0.46 kg, and 105.42 MJ, respectively. Conversion process presented a greater environmental impact for all three bioenergy products. With producing 46,926 tons of pellets, 260,000 MWh of electricity, and 78,000 barrels of pyrolysis oil, the net present values (NPV) for all three cases indicated only pellet and biopower production cases were profitable with NPVs $1.20 million for pellet, and $81.60 million for biopower. The pellet plant and biopower plant were profitable only when discount rates are less than or equal to 10%, while it will not be profitable for a pyrolysis oil plant. The uncertainty analysis indicated that pellet production showed the highest uncertainty in GHG emission, bio-oil production had the least uncertainty in GHG emission but had risks producing greater-than-normal amount of GHG. For biopower production, it had the highest probability to be a profitable investment with 95.38%.
A study evaluated the environmental and economic impacts of activated carbon (AC) produced from lignocellulosic biomass was evaluated for energy storage purpose. Results indicate that overall “in-plant production” process presented the highest environmental impacts. Normalized results of life cycle impact assessment showed that the AC production had environmental impacts mainly on carcinogenics, ecotoxicity, and non-carcinogenics categories. We then further focused on life cycle analysis from raw biomass delivery to plant gate, the results showed “feedstock establishment” has the most significant environmental impact, ranging from 50.3% to 85.2%. For an activated carbon plant of producing 3000 kg AC per day in the base case, the capital cost would be $6.66 million, and annual operation cost was $15.46 million. The AC required selling price (RSP) was $16.79 per kg, with the discounted payback period (DPB) of 9.98 years. Alternative cases of KOH-reuse and steam processes had GHG emission of 15.4 kg CO2 eq, and 10.2 kg CO2 eq for every 1 kg activated carbon, respectively. Monte Carlo simulation showed 49.96% of the probability for an investment to be profitable in activated carbon production for supercapacitor electrodes.
Wang, Yuxi, "Integrated Techno-Economic and Life Cycle Analyses of Biomass Utilization for Value-Added Bioproducts in the Northeastern United States" (2020). Graduate Theses, Dissertations, and Problem Reports. 7765.
Available for download on Monday, July 05, 2021