Plasma-Engineered Silica Acid Catalysts for Coffee Waste Conversion to Xylose

Abstract

s Recently, the need for next-generation energy sources to replace fossil energy is increasing rapidly due to various problems such as depletion of oil and generation of carbon dioxide. One alternative to this is coffee grounds, one of the substances being studied. Coffee is consumed a lot around the world, but the disposal of the grounds is a big problem. However, this coffee grounds can be used as a raw material for biodiesel because it is made of various organic compounds such as cellulose and hemicellulose. The most common process to make biodiesel is the process using concentrated sulfuric acid as homogeneous catalysts to break down coffee into monosaccharides. However, the corrosive nature and disposal problem create environmental concerns in this process. Recently, heterogeneous silica acid catalyst, attracts many attention due to its environmental friendly nature, low cost and recyclability. In this experiment, instead of the sol-gel method for preparing a conventional silica acid catalyst, we prepared silica acid catalyst using a plasma method that can improve the catalytic performance. In the case of using the plasma method, the specific surface area increased and the catalyst performance increased, which led to an increase in xylose conversion and selectivity of 6% and 4%, respectively.