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Polyhydroxybutyrate Production In A Photobioreactor Using Spirulina Platensis, Adrianna Mika

Electronic Thesis and Dissertation Repository

Biopolymers and other naturally derived chemicals continue to gain attention over petrochemical based products due to the price volatility of crude oil, increasing need to reduce greenhouse gas emissions and public awareness of environmental issues. Cyanobacterium Spirulina (Arthrospira) platensis, a commercially feasible blue-green alga, is able to synthesize poly(3-hydroxybutyrate) (PHB), a biodegradable and biocompatible polymer, as an energy storage product of photosynthesis directly from CO₂. A flat plate photobioreactor (PBR) with LED illumination was designed for the cultivation of S. platensis. Computational fluid dynamics (CFD) software was used to improve airflow uniformity and mixing in the …

Pyrolysis Based Biorefineries For The Production Of Fermentable Substrates, Luis Carlos Luque-Moreno

Electronic Thesis and Dissertation Repository

Fast pyrolysis is rapid thermal conversion process capable of transforming multiple feedstocks into various energy carriers, specifically pyrolysis oil, bio gas, and bio char. The oil phase is of high value due to its complex mixtures of organic molecules, along with large number of anhydrous carbohydrates, which can be easily transformed into glucose via acid hydrolysis. These carbohydrates can be either biocatalyzed into fuels and chemicals by microorganisms or converted after further treatment steps. However quantities of these carbohydrates in the oil are a function of feedstock composition and process parameters. The research presented in this thesis focuses on producing …

The Effects Of Volatile Fatty Acids On The Performance Of Microbial Electrolysis Cells, Nan Yang

Electronic Thesis and Dissertation Repository

This study investigated the performance of microbial electrolysis cells (MECs) fed with three common fermentation products: acetate, butyrate, and propionate. Each substrate was fed to the reactor for three consecutive-batch cycles. The results showed high current densities for acetate, but low current densities for butyrate and propionate (maximum values were 6.0 ± 0.28, 2.5 ± 0.06, 1.6 ± 0.14 A/m², respectively). Acetate also showed a higher coulombic efficiency of 87 ± 5.7 % compared to 72 ± 2.0 and 51 ± 6.4 % for butyrate and propionate, respectively. This paper also revealed that acetate could be easily oxidized …

Production Of Activated Carbons From Pyrolytic Char For Environmental Applications, Anastasia Colomba

Electronic Thesis and Dissertation Repository

Biomass pyrolysis has the potential to become a major component of future biorefineries, since biomass is cracked to produce gases, liquid products (bio-oil) and solid products (bio-char). In order for the process to be economically feasible, it is necessary to obtain the maximum value from each stream, thus no by-product can be regarded as a waste.

Bio-char is normally regarded as a by-product of fast pyrolysis, which is optimized to target bio-oil production. However, there are many potentially attractive applications for it: for example, it can be used for the production of activated carbons, which are the most commonly used …