Environmental assessment of HYGAS Pilot Plant streams

The US Department of Energy has commissioned an environmental assessment program to obtain experimental data from the HYGAS Pilot Plant. An important objective of this program is the development of predictive methods to extend the environmental data base to larger-scale demonstration and commercial HYGAS coal gasification plants. This report discusses the systems which have been specifically established for sampling, analysis, and data evaluation to define the fate of compounds of environmental interest generated during pilot plant operation. The pilot plant units of interest include the pretreater and gasifier reactors which are considered scalable to larger plants. Sampling methods used in the program include scheduled, routine grab samples, composited grab samples, on-line composited liquids and solid samples, and on-line gas analysis for selected sulfur species. This paper also discusses the development and use of a high-pressure, high-temperature, sampling system to collect organic and inorganic species from the HYGAS gasifier. Even though the reactor sampling system adopted is very man-power intensive, it greatly reduces the number of samples required and results in a higher overall sampling efficiency. In addition, the on-line sampling train provides immediate capture and stabilization of reactive and volatile species, eliminates process unit lag times, avoids quench tower inefficienciesmore » for many species, and allows rapid monitoring of differences in pollutant production with changing process conditions.« less