Keywords

biodiesel, mechanochemistry, transesterification, mechanocatalyst, lignin, adsorption

Abstract

Biodiesel production is currently energy-demanding and produces large volumes of waste despite being marketed as a greener approach to fuel. Here, we report the development and analysis of a more environmentally friendly way of producing biodiesel via mechanochemistry. In as little as one hour, biodiesel can be produced by ball milling intact oilseeds with methanol and no added catalyst. The catalyst for transesterification of oilseeds and methanol via mechanical milling comes from within the seed shells, rather than needing to be added from a separate source. The metals found in the milling media interact with lignin in the seed shells, complexing it temporarily and imparting catalytic activity. Additionally, using intact seeds eliminates all seed pretreatments required in industry, thus reducing time necessary, waste production, and energy consumption. In the transesterification reaction, the large excesses of methanol typically used are significantly reduced during mechanical milling. Furthermore, soapy byproducts are not created in the mechanochemistry method, so the need for water to clean the product is eliminated. As the catalytic component of the reaction remains within the solid seed shells, it is also unnecessary to extract the catalyst from solution, such as in acid or base catalyzed transesterification. This makes synthesis of biodiesel via mechanochemistry greener and less cost-, time-, and energy intensive than industrial methods. In just one step, clean biodiesel is generated from untreated seeds. The solid waste, consisting of ground seed shells generated from ball milling, can also be used as an adsorbent for heavy metals including mercury, lead, and zinc. These metals can later be desorbed, providing both cleanup of metals- contaminated water and the potential to reuse these metals in products or in other chemical reactions.

Completion Date

2025

Semester

Spring

Committee Chair

Hampton, Michael

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Chemistry

Identifier

DP0029404

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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