Characteristics of evolution of tar from wood pyrolysis in a fixed-bed reactor

The thermally induced interrelation between total tar, chemical distribution of principal tar constituents and the three C-2 compounds (ethane, ethene, ethyne) obtained from wood pyrolysis at atmospheric pressure in a continuous bench-scale fixed bed reactor was investigated. Total tar and certain tar constituents exhibit a close correlation with the C-2 compounds over the temperature range 700-900 degrees C. Some characteristic compound ratios, namely indene to naphthalene (I/N), phenols to aromatics (P/A) and saturated to unsaturated C-2 compounds, were identified. These reactor-specific correlations have obvious potential application for on line continuous monitoring of non-gaseous products that so far are determined off-line. The analysis methods used were designed for quantification of aromatics, phenols, N-organics, asphaltenes and preasphaltenes.