Synthesis, Selection, And Optimization Of Doped Zeolite Catalyst For The Nonbiological Production Of Lactic Acid Derivatives From Biomass Derived Carbohydrates
Date of Award
Doctor of Philosophy (PhD)
The objective of the overall project is to chemically synthesize fatty acids, hydrocarbons, other fuel constituents, or high value chemicals directly from biomass-derived carbohydrates (e.g. sugars generated using processes developed for the cellulosic ethanol industry). This work will look specifically at synthesizing lactic acid and its derivatives for later use to build chemically identical fuel components or high value chemicals.
We have built upon recent advancements in the literature using Sn-doped beta zeolite catalysts. Previous work has demonstrated that glucose can be chemically transformed into fructose then reduced to methyl lactate in a methanol solution. Since these reactions are not biochemical, increased reaction rates can be realized by increasing temperatures above those tolerated by biological entities. This should result in substantial savings in time and resources required to achieve the final end product. These savings can translate into more cost effective pathways to renewable fuels and chemicals.
The literature's reported best results focused on sucrose substrate with a methanol solvent and achieved overall methyl lactate yields of 64%, with >99% conversion of the feedstock. The challenge this research undertook was to maximize selective conversion of glucose substrate, the main product from the breakdown of biomass, in a water solvent as an economical and "green" universal solvent. An important part of this work was to carefully characterize side reaction constituents so that we can identify ways to transform these constituents into valuable co-products in the future.
When operating conditions were optimized roughly 80% of all products were determined utilizing GC-MS analysis technique, greatly increasing the known product yields reported in the literature. Lactic acid was maximized at 47% using Sn+4-doped beta zeolite in pure water. Levulinic acid was maximized at 53% recovered using Sn+2-doped beta zeolite in pure water. Methyl lactate, 22%, and methyl levulinate, 49%, were produced using Sn+4-doped beta zeolite in methanol. These results are a key step in the overall project to produce fuel components and value chemicals from cellulosic biomass.
Kadrmas, Clancy Raymond Rick, "Synthesis, Selection, And Optimization Of Doped Zeolite Catalyst For The Nonbiological Production Of Lactic Acid Derivatives From Biomass Derived Carbohydrates" (2014). Theses and Dissertations. 1552.