Furans : the potential atmospheric impact of a next-generation bio fuel

Abstract: There has been a worldwide debate about “the climate change” over the past years, accompanied with the efforts in finding a more environmental friendly way to live. One area of research is to find replacements for the fossil fuels, which is the major energy source today. The aim of this project is to investigate the atmospheric properties of a new potential group of biofuels, i.e. the group of compounds called furans, and especially the two molecules 2-Methyltetrahydrofuran and 2,2-Dimethyltetrahydrofuran. The reason for this is that the environmental impact of a large scale use must be well known before any production can be considered. Therefore the reaction between these molecules and the atmospheric chlorine atoms will be investigated with respect to reaction speed and what products that will be formed. The project is based on experimental work performed at the Copenhagen Centre for Atmospheric Research. A smog chamber which can be filled with a desired mixture of atmospheric gases, can be exposed to UV-light for a specific time and a detector can register the infrared light from a laser that goes through the gas mixture. This was used to test how the reactions proceeded between chlorine atoms and 2-Methyltetrahydrofuran and 2,2-Dimethyltetrahydrofuran respectively. The speed of the reaction, which is represented by a rate constant, was determined by analysing data and using the relative rate method. The products were studied by comparing infrared spectra from different molecules. The results from the experiments were that the rate constants for the two compounds have the values k2-MTHF+Cl = 1.3∙10-10 cm3molecule-1s-1 and k2,2-DMTHF+Cl = 1∙10-10 cm3molecule-1s-1. The products that are known to be formed are hydrogen chloride, HCl, carbon dioxide, CO2, carbon monoxide, CO, water, H2O and formic acid, HCOOH. This project resulted in the conclusion that the reaction with chlorine is fast and can be very important in some urban areas. This work has been one of the first of its kind, and even if it does not absolutely describe the atmospheric implications of these two potential fuels, it has laid a foundation for future research in the area.