Continuous analysis of elemental emissions from a biofuel gasifier

Abstract

In recent years there has been significant and high-profile interest in the use of biofuels as possible alternatives to fossil fuels, as part of a move to reduce carbon dioxide emissions. Although combustion accounts for most biofuel use, there has also been significant research into biofuel gasification. However, the behaviour of trace elements during gasification can be problematic, with environmental concerns over toxic components, and process problems caused by alkali metal corrosion and fouling. Experiments have been conducted to continuously monitor the concentration of various trace elements in the raw gasification gas from an experimental reactor, in an effort to determine which elements are volatilised, using ICP-OES. Results of initial tests indicate that the concentration of some elements in the gas phase are extremely high, far higher than in combustion processes, and therefore are of significant concern. Owing to to problems with tar formation in the gasification process, the analysis proved extremely challenging, and further development of the sampling and pre-treatment procedure would be required to obtain more accurate, reliable, and long-term continuous monitoring results.