Hydrothermal liquefaction of wild-harvested cyanobacterial bloom from hypereutrophic Lake Tainter, Wisconsin

Swoboda, Megan

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https://hdl.handle.net/2142/102439 Copy

Description

Title

Hydrothermal liquefaction of wild-harvested cyanobacterial bloom from hypereutrophic Lake Tainter, Wisconsin

Author(s)

Swoboda, Megan

Issue Date

2018-12-07

Director of Research (if dissertation) or Advisor (if thesis)

Zhang, Yuanhui

Committee Member(s)

• Akdeniz, Neslihan
• Davidson, Paul

Department of Study

Engineering Administration

Discipline

Agricultural & Biological Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

algae blooms, cyanobacteria, eutrophication, biocrude oil, hydrothermal liquefaction, catalysis, nutrient recovery, Lake Tainter, Menomonie

Abstract

This study demonstrates the potential of Harmful Algae Blooms (HABs) as a feedstock for generating biofuels hydrothermal liquefaction (HTL) and asserts that HTL is a uniquely practical technology for use of this biohazardous material. Using a wild-harvested cyanobacteria HAB from Lake Tainter, Wisconsin as a low-cost feedstock for HTL, the projected Minimum Fuel Selling Price of reformed biocrude produced from the Lake Tainter HAB is 18-29% lower than biocrude produced from cultivated algae. The biocrude produced is of sufficient yield and quality to realize a net energy profit making HTL an important environmental remediation strategy for air and water quality. HTL reactions were conducted over a range of reaction temperatures (280-350°C), holding times (30-60 min), and feedstock total biomass solids content (10%-25%TS) using fresh and aged biomass. Bulk biocrude properties (e.g., yield, elemental analysis, high heating value (HHV)), energy balances, and nutrient recovery in the products were compared from each condition. Using HTL, at 340°C and 50 min retention time with 20%TS, 41.8±6.1% daf biocrude yield is possible with this feedstock. The biocrude produced has an HHV of 32.5 MJ/kg, recovering 73.9% of the energy in the biomass and 1:3.3 ratio for energy input for heating to energy recoverable in the crude. Promisingly, this biocrude has a low sulfur content (0.07% wt.) and 60% wt. of the crude is in the light and medium molecular weight fractions (volatile<350ºC). However, high nitrogen (5.93% wt.) and oxygen (16.74% wt. by calc.) contents, and probable acidic nature of the biocrude indicate upgrading is needed pre-refinery. At this temperature, 47% of the nitrogen in the feedstock is recoverable in the post-hydrothermal processing wastewater (HPW), with 55.8% of it as ammoniacal nitrogen.

Graduation Semester

2018-12

Type of Resource

text

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http://hdl.handle.net/2142/102439

Copyright and License Information

Copyright 2018 Megan Swoboda

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