Multi-Stage Gas Upgrading Treatment Train
The plant is designed for an inlet flow of 3,000 SCFM of landfill gas entering near atmospheric pressure with a highly variable composition. The gas is upgraded through a sequential treatment train comprising free-liquid separation, a custom pre-treatment skid, a bulk hydrogen sulfide removal skid, a water-removal chiller and scrubber, and a pressure swing adsorption skid that removes nitrogen, carbon dioxide, and residual water to concentrate pipeline-quality methane.
High-Pressure Compression & Supporting Systems
The finished renewable natural gas is compressed to a 1,100-psig pipeline discharge pressure using an electric-driven compression skid. Supporting equipment includes a condensate storage and truck-out system, an instrument air skid, and a thermal oxidizer and flare for vapor and relief disposal, with power supplied through a 34.5-kilovolt utility feed to two pad-mounted transformers and an Allen-Bradley CompactLogix control system.
Engineering Challenges of Corrosive, Variable Feed Gas
ZAP’s engineering addressed a highly corrosive and contaminated feed gas that drove material selection, deep-vacuum inlet conditions requiring full-vacuum-rated equipment, a wide compression ratio from near-atmospheric inlet to 1,100-psig pipeline discharge, tight pipeline specifications requiring multi-stage treatment, and a cold northern climate requiring freeze protection and insulation, all coordinated across multiple vendor packages and the downstream pipeline interconnect.
