ASSESSMENT OF SUBSURFACE FATE OF MONOETHANOLAMINE AT SOUR GAS PROCESSING PLANT SITES-PHASE III

Abstract

Alkanolamines are commonly used by the natural gas industry to remove hydrogen sulfide, carbon dioxide, and other acid gases from the natural gas in which they occur (''sour'' gas if hydrogen sulfide is present). At sour gas-processing plants, as at all plants that use alkanolamines for acid gas removal (AGR), spills and on-site management of wastes containing alkanolamines and associated reaction products have occasionally resulted in subsurface contamination that is presently the focus of some environmental concern. In 1994, the Energy and Environmental Research Center (EERC) initiated a three-phase program to investigate the natural attenuation processes that control the subsurface transport and fate of the most commonly used alkanolamine in Canada, monoethanolamine (MEA). Funding for the MEA research program was provided by the U.S. Department of Energy (DOE), Canadian Association of Petroleum Producers (CAPP), Canadian Occidental Petroleum Ltd. (CanOxy), Gas Research Institute (GRI), Environment Canada, and the National Energy Board of Canada. The MEA research program focused primarily on examining the biodegradability of MEA and MEA-related waste materials in soils and soil-slurries under a variety of environmentally relevant conditions, evaluating the mobility of MEA in soil and groundwater and the effectiveness of bioremediation techniques for removing contaminants and toxicity from MEA-contaminated soil. The presently inactive Okotoks sour gas-processing plant, owned by CanOxy in Alberta, Canada, was the source of samples and field data for much of the laboratory-based experimental work and was selected to be the location for the field-based efforts to evaluate remediation techniques. The objective of the research program is to provide the natural gas industry with ''real world'' data and insights developed under laboratory and field conditions regarding the effective and environmentally sound use of biological methods for the remediation of soil contaminated with amine-related wastes.