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 C2 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 C2 compounds over the temperature range 700–900°C. Some characteristic compound ratios, namely indene to naphthalene (IN), phenols to aromatics (PA) and saturated to unsaturated C2 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.