Wobbe

Wobbe is the complete working system of a biomethane plant that digests farm and food waste and injects the finished gas into the national gas grid - the operation that weighs in the feedstock, feeds the digesters, holds the biology stable, upgrades raw biogas to grid specification, proves the Wobbe index and the calorific value at the grid entry unit, odorises the stream, flares what it cannot sell, spreads the digestate back to land and answers to the environmental permit for every cubic metre.

Thirteen real modules, each a browsable page with real seeded plant data. FEEDSTOCK INTAKE AND WEIGHBRIDGE carries every delivery weighed in - supplier, feedstock type, gross, tare and net tonnage, measured dry matter, expected biomethane yield per tonne, gate fee and the acceptance decision with its rejection reason. DIGESTER PERFORMANCE is the daily record per digester: operating temperature, pH, the volatile fatty acid to alkalinity ratio, ammonia in milligrams per litre, organic loading rate, hydraulic retention time and biogas output in normal cubic metres an hour. GAS QUALITY AND WOBBE INDEX holds the specification every batch must meet - methane and carbon dioxide, oxygen, hydrogen sulphide in parts per million, water dewpoint, calorific value, relative density and the calculated Wobbe index against its permitted band. UPGRADING PLANT LOG follows the membrane train with its stage pressures, methane slip to tail gas, recovery efficiency and carbon vessel changeouts. GRID ENTRY UNIT records the connection itself: entry pressure and flow, odorant injection rate, chromatograph calibration against its certified reference gas, and every network rejection with its duration and cause.

FLARE AND VENT LOG accounts for the gas that never reached the grid, with the running flare percentage against the permit limit. DIGESTATE AND LAND SPREADING carries the nitrogen, phosphorus and potassium analysis, lagoon freeboard, the field spread with its rate per hectare, closed-period compliance and PAS 110 conformity. ODOUR AND EMISSIONS, PLANT MAINTENANCE REGISTER, METERING AND RECONCILIATION, PERMIT AND COMPLIANCE REGISTER and PARASITIC LOAD AND POWER complete the plant's view. A FEEDSTOCK SUPPLIER PORTAL gives a supplier their own deliveries, dry matter against contract, yield performance and payments due, and a PLANT DASHBOARD closes the loop.

The signature drawing is the process flow plate: the whole works drawn left to right as a true engineering schematic on a keyline plate with a corner title block - reception pit, two digesters as stroked cylinders, gas holder, membrane upgrader, grid entry unit, flare stack, CHP and digestate lagoon - with nine numbered streams ruled between them and stream eight to flare drawn heavier in flare orange. Designed in mid-century industrial gas-board technical plate crossed with Dutch functionalist engineering diagram: a pale plate grey-green ground, deep pipe green ink, technical teal rules, and a single flare orange reserved strictly for an off-spec Wobbe index, a grid rejection, a souring digester or a rejected delivery.