Simultaneous detection of K, KOH, and KCl in flames and released from biomass using photofragmentation TDLAS

Gaseous potassium (K) species released from biomass during thermochemical conversion pose challenges to reactors and human health. Photofragmentation tunable diode laser absorption spectroscopy (PF-TDLAS) was used for simultaneous, high-dynamic range measurements of atomic K, hydroxide (KOH) chloride (KCl) in flat flames seeded with KCl salt. An expression the PF-TDLAS signal is presented experimentally verified. Axial K concentration profiles recorded at fuel-air equivalence ratios 0.8 1.3 are compared 2D axisymmetric reacting flow simulations. overall good agreement found, but KOH over-predicted simulations fuel-rich expense K. Quantification close softwood wheat straw particles converted demonstrated.