A biomethane upgrading package cannot be specified from flow rate alone. The correct basis combines the raw-biogas envelope, the required product standard, available utilities and the operating conditions of the complete plant.
Define inlet and outlet boundaries
Raw gas data should include expected ranges for methane, carbon dioxide, hydrogen sulphide, water, oxygen and relevant trace compounds. The product basis should state quality limits, delivery pressure, turndown, metering and any grid or transport-fuel interface requirements.
Compare technologies on a common basis
Membranes, pressure swing adsorption, water scrubbing and chemical absorption have different pretreatment, pressure, heat, water, chemical and off-gas requirements. Vendor offers should be normalised to the same boundary conditions and operating profile.
Include balance of plant
Cooling, dewatering, compression, activated carbon, analysers, flare interfaces, odorisation, electrical distribution, controls and building requirements can sit outside a package quotation. These interfaces must be assigned clearly to avoid gaps during construction.
The best upgrading system is the one that meets the product specification inside the complete plant operating model.
Performance guarantees also need defined test conditions, measurement methods and allowed operating ranges. Without that common basis, headline recovery or energy figures are difficult to compare and harder to verify at commissioning.