(318e) Measuring Trace Components in Syngas Using Gas Chromatography and Ion Chromatography

Patrick A Johnston¹, Patrick Woolcock¹, Karl Broer¹ and Robert C. Brown^1,2

¹Center for Sustainable Environmental Technologies

²Department of Mechanical Engineering

Iowa State University

Ames, Iowa, 50011

Specific nitrogen and sulfur containing compounds are unfavorable in upgrading syngas to hydrocarbon based fuels. These compounds are known to poison catalysts at concentrations of sub part-per-million levels in syngas.  It is critical to remove and quantify these compounds to provide an efficient and cost effective approach for Fischer-Tropsch synthesis.

The analytical techniques in this study will focus on off-line and on-line gas measurements that were analyzed from a 20kg/hr fluidized bed biomass gasifier with a unique gas cleaning system. Minor constituents of raw and clean biomass gasification syngas were analyzed on-line using a custom designed dual Gas Chromatography (GC) system before and after the cleaning stages.  Trace concentrations of hydrogen sulfide, carbonyl sulfide, carbon disulfide, and ammonia were determined with a limit of quantification (LOQ) level of parts-per-billion (ppb) with sulfur and nitrogen chemiluminescence detectors (SCD/NCD).

Hydrogen cyanide concentrations were determined using Ion Chromatography with pulsed amperometric detection (PAD) using a silver working electrode.  These samples will be captured in an impinger train using a basic aqueous solution and quantified off-line.