Full-Scale Implementation of a Novel Digester Gas Conditioning System Using Biological Scrubbing and Molecular Sponge Siloxane Removal

摘要

The City of Calgary (the City) recently commissioned a project to upgrade an existingrncogeneration facility to maximize onsite electrical power generation and waste heat recoveryrnusing digester gas as the principal fuel source at the Bonnybrook Wastewater Treatment Plantrn(BBWWTP). The purpose of this system is better utilization of digester gas for generation ofrnelectricity and heat. The power generation and heating (PGH) facility upgrade replaced fourrnobsolete combined heat and power (CHP) that were installed in 1984. A significant componentrnof this project is the digester gas conditioning equipment. Digester gas typically requires somernform of pre-treatment prior to cogeneration to remove siloxanes and hydrogen sulphides (H_2S).rnTwo new processes to North America were pioneered for the removal of H_2S using an allrnbiological scrubbing system and a molecular sponge siloxane removal system. The purpose ofrnthe systems is to reduce the corrosive and abrasive effects of digester gas used for generation ofrnelectricity and heat. This paper presents the results of the full scale implementation of these twornnovel digester gas conditioning systems including process design considerations, performancerndata, and recommendations for future installations.