Patent ID: 8541121

Claim:
A quench system, comprising: a quench solution including FeCl 2 in a dilute HCl solution; a container holding the quench solution, the container including an input that directs a gaseous emission into the quench solution; and a quench sensor including: a double walled tubing having an open-ended inner volume and a sealed outer volume, a first light source and a corresponding first detector, and a second light source and a corresponding second detector, wherein: the quench sensor is positioned in the container such that before any quenching has begun, the first light source and the corresponding first detector are positioned in the sealed outer volume below a quench solution level, and the second light source and the corresponding second detector are positioned in the sealed outer volume and at a predetermined threshold level above the quench solution level, and Cl 2 gas is removed from the gaseous emission by a reaction with the quench solution.