Impact of Trace Ammonia Impurities on the Utilization of Renewable Natural Gas

Abstract

Renewable natural gas (RNG), produced from biogas upgrading, is an important alternative to fossil fuels for power generation. Unfortunately, RNG contains several trace contaminants that may be harmful to the existing infrastructure for its transport and use. One such contaminant is ammonia (NH3), of particular concern for RNG produced from farming operations. The presence of NH3 in RNG, particularly if it is injected into the natural gas (NG) pipeline network, can have serious consequences. These can range from damage to components of the NG infrastructure to corrosion of analytical and end-user equipment and added pollutant formation during combustion. This research project addresses all these impacts. Its objectives were (i) to investigate the potential corrosion effects of NH3 on typical pipeline materials during their exposure to RNG derived from biogas and processed to meet pipeline NG quality specifications, (ii) to study the environmental impacts and other concerns during combustion of NH3-containing RNG for power and energy production, and (iii) to analyze the potential impact of NH3-containing RNG on the performance of analytical equipment commonly used during NG distribution and end-use. This paper describes the work performed and the key findings in each of these areas.