Liquid phase ketonization of pentanoic acid into 5-nonanone -

Abstract

The world’s energy consumption is increasing at a high rate due to the expansion of the world’s population, especially in third world countries. The demand in energy is far exceeding the supply capability, and the available sources of energy are leaning towards depletion, which was the main cause for the development of alternative sources of energy such as wind energy, solar energy, hydro fuel cells and many others. However, the transportation sector remains highly dependent on liquid carbon fuels, which resulted in extensive researches to find an alternative way to produce them in a clean renewable process. The conversion of raw material, such as biomass, into high value chemicals is considered a promising trend in the field. Biomass can be cracked through a well designed process to produce pentanoic acid, which is further converted to 5-nonanone, hydrogenated to nonane, key precursor for biofuel. This process is called ketonization, and although vapor and organic phases ketonization are the most adopted, liquid phase ketonization shows higher advantages such as lower operating temperatures and enhanced conversion efficiency. In this work, liquid phase ketonization of pentanoic acid was tested in a batch reactor under a temperature of 350 °C and a pressure of 30 bar, using CeZrO2 and ZrO2 at different calcination temperatures as catalysts. The catalysts were characterized using XRD to study the crystallinity of the catalysts, BET to determine their surface area and pore sizes, SEM to familiarize with their structure, TGA to check their stability and XPS to depict any changes on the surface between the catalysts, and they were later tested for this experiment. The experiment turned out to be feasible using ZrO2 calcined at 400 °C, while the other catalysts were unsuccessful.