UCLA

Increasing global energy demand serve as the impetus for the development of alternative sources of fuels and chemical intermediates. Toward this goal, many biologically based processes have been recently invented to convert biomass into short chain oxygenated molecules that can be subsequently converted to fuels and chemicals. The primary advantage of these biological processes is their high selectivity and mild operating conditions. However, the major drawback is that the final product is typically produced as a very dilute aqueous solution. The primary purpose of this work is to examine the major factors that affect the performance of solid adsorbent materials for the extraction of small chain alcohols, aldehydes, and ketones from dilute aqueous solutions that contain a wide range of molecules and ions, similar to those derived from fermentation processes. To understand the fundamentals of adsorption using microporous, aluminosilicate materials, and adsorption isotherms were collected for alcohols and aldehydes on proton forms of BEA, MOR, FER, FAU and MFI zeolites. The Langmuir adsorption model was used to develop a quantitative understanding of the relationship between adsorbent structure and performance by determining the effect of solution composition and adsorbent structure on the parameters of each model (equilibria constants, saturation capacities, and interaction parameters). The effects of different zeolite structure on the parameters for the Langmuir model were initially probed using butanol as the adsorbate. Maximum adsorption capacities were similar for all zeolites tested. The adsorption equilibrium coefficient parameter was lower for FAU and MOR compared to BEA and MFI.