Redox-responsive polymers for the reversible extraction of butanol from water

[摘要] (cont.) The electrochemical activity and reversibility of the RPEs prepared using the different techniques were ascertained by cyclic voltammetry. The impregnated electrodes were used to demonstrate the successful use of the polymer gel to extract butanol from its aqueous solution, and release it into water upon oxidation. Conceptual scheme of a continuous separation system that can be built using these RPEs was proposed and the separation that can be achieved using such a system was determined by simulating the continuous separation process using finite element modeling. It was determined that the separation system integrated with a fermentation reactor can help maintain the concentration of butanol at a value 20% lower than the critical value beyond which fermentation is completely inhibited. The mechanism of electron transport in the polymer coated RPEs was investigated. Diffusion of electrons was found to be the rate controlling step. Further, it was found that diffusion of electrons due to the ;;hopping;; of electrons from one redox site to the next, and the electronic motion due to the motion of the polymer chains themselves played important roles in determining the apparent diffusivity of electrons. As part of the PhDCEP Capstone project, the potential of butanol produced through fermentation, commonly known as bio-butanol, was analyzed as a blend for gasoline was analyzed. It was found that although the market for gasoline blend is huge and growing, butanol suffers from higher cost of production with respect to its primary competitor, bio-ethanol. Chances of bio-butanol;;s potential success can be enhanced through a combination of technological breakthroughs including development of strains of high yield bacteria, use of inexpensive lignocellulosic biomass, and process design improvements.

[发布机构] Massachusetts Institute of Technology