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<p></p><p>Supercritical water gasification
is a promising waste-to-energy technology with the ability to convert aqueous
and/or heterogeneous organic feedstocks to high-value gaseous products.
Reaction behavior of complex molecules in supercritical water can be inferred
through knowledge of the reaction pathways of model compounds in supercritical
water. In this study methanol, ethanol, and isopropyl alcohol are gasified in a
continuous supercritical water reactor at temperatures between 500 and 560 °C,
and for residence times between 3 and 8 s. <i>In situ</i> Raman spectroscopy is
used to rapidly identify and quantify reaction products. The results suggest
the dominance of chain-branching, free radical reaction mechanisms that are
responsible for decomposing primary alcohols in the supercritical water
environment. The presence of a catalytic surface is proposed to be highly
significant for initiating radical reactions. Global reaction pathways are
proposed, and mechanisms for free radical reaction initiation, propagation, and
termination are discussed in light of these and previously published
experimental results.</p><br><p></p></div>