Model explorer
The variable register. Each entry carries its source, confidence and approval state — nothing in this model is an anonymous number.
Data source: Yorks Process Flow v1 (07/08/26, Merged Models)
Yorks_Process_Flow-v1-070826-Merged_Models.xlsx — 47 of 64 variables read from 2 sheets (118 cells captured). The two earlier workbooks are retired and are kept only for comparison on the Reconciliation screen.
Measured evidence
0%
Workbook / calculated
89%
Assumed
11%
Unvalidated
0%
Variable register
Search by name, canonical code, sheet or cell. Every workbook-sourced row shows the exact cell it was read from.
| Variable | Value | Unit | Source | Workbook cell | Confidence | Approval | Reference |
|---|---|---|---|---|---|---|---|
Operating days per year meta.operatingDaysPerYear | 365 | days/yr | workbook | Levers!B31 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B31 = 365 days/yr — Site operating days per year |
TMA solid processing rate reception.solidRateTph | 12.5 | t/hr | workbook | Levers!B28 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B28 = 12.5 t/hr — Solid throughput when TMA running (liquid matched 50/50) |
TMA liquid processing rate reception.liquidRateTph | 12.5 | t/h | calculated | — | medium | pending | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B28 note: liquid matched 50/50 to the solid rate |
Reception operating window reception.operatingHoursPerDay | 9.429 | h/day | calculated | — | medium | pending | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B46-B47, 5.5 days/wk x 12 h averaged to a day |
Soup production rate storage.soupProductionRateTph | 25 | t/h | calculated | — | medium | pending | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B28, TMA solid rate plus matched liquid |
Soup storage capacity storage.soupCapacityM3 | 425 | m3 | workbook | — | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B30 + Levers!B33 (125 m3 soup tanks + 300 m3 shared pool) |
Solid feedstock storage storage.solidCapacityTonnes | 175 | tonnes | workbook | Levers!B29 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B29 = 175 tonnes — Reception hall buffer |
Dedicated liquid waste storage storage.liquidCapacityM3 | 200 | m3 | workbook | Levers!B32 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B32 = 200 m3 — Liquid-waste-only portion of the 500 m3 tank farm |
Tanker fleet size transport.tankerCount | 2 | tankers | workbook | Levers!B37 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B37 = 2 tankers — 1 driver, 2 tankers |
Tanker payload transport.payloadTonnes | 27 | tonnes | workbook | Levers!B38 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B38 = 27 tonnes — Per load |
Shunting time per load transport.shuntingMinutes | 5 | minutes | workbook | Levers!B43 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B43 = 5 minutes — Shunting time per load |
Driver shift length transport.driverShiftHours | 12 | hrs | workbook | Levers!B39 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B39 = 12 hrs — Driver shift length |
Driver breaks per shift transport.breakMinutesPerShift | 60 | minutes | workbook | Levers!B40 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B40 = 60 minutes — Breaks and downtime per shift |
Transport operating days transport.operatingDaysPerWeek | 5.5 | days/wk | workbook | Levers!B46 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B46 = 5.5 days/wk — 5.5 days per week |
Travel time one way transport.travelMinutesOneWay | 3.5 | min | calculated | — | medium | pending | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B42, 7 min both directions halved |
Parallel load/unload mode transport.parallelLoadUnload | false | boolean | assumed | — | medium | draft | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!D45 raises the question but the sheet models it sequentially |
Hydrolysis working volume hydrolysis.workingVolumeM3 | 2,200 | m3 | workbook | Levers!B55 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B55 = 2200 m3 — Single hydrolysis tank |
Hydrolysis feed pump capacity hydrolysis.feedPumpCapacityM3PerHour | 30 | m3/hr | workbook | Levers!B53 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B53 = 30 m3/hr — Pumps handle max 18% DS |
Hydrolysis pump hours hydrolysis.operatingHoursPerDay | 24 | hr/day | workbook | Levers!B54 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B54 = 24 hr/day — Daily pumping window |
Hydrolysis temperature hydrolysis.temperatureC | 30 | degC | workbook | Bio Levers!C12 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C12 = 30 degC — Mesophilic hydrolysis — drives kh kinetics |
Hydrolysis rate constant at reference temperature hydrolysis.khRefPerDay | 0.3 | day^-1 | workbook | Bio Levers!C28 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C28 = 0.3 day^-1 — First-order kh for food waste (ADM1) |
Reference temperature for kh hydrolysis.referenceTemperatureC | 35 | degC | workbook | Bio Levers!C29 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C29 = 35 degC — Temperature at which kh_ref is defined |
Temperature coefficient (theta) hydrolysis.temperatureCoefficient | 1.06 | - | workbook | Bio Levers!C30 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C30 = 1.06 - — kh(T) = kh_ref x theta^(T - Tref) |
Target degradation hydrolysis.targetDegradationFraction | 0.75 | fraction | workbook | Bio Levers!C31 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C31 = 75 % — Fraction of substrate converted to VFAs |
Pasteuriser tank count pasteurisation.tankCount | 3 | count | workbook | Levers!B98 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B98 = 3 count — 1 filling / 1 holding / 1 emptying |
Usable volume per pasteuriser tank pasteurisation.usableVolumePerTankM3 | 26 | m3 | workbook | Levers!B99 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B99 = 26 m3 — Batch = 26 m3 tanker load |
Hold time pasteurisation.holdMinutes | 60 | min | workbook | Levers!B100 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B100 = 60 min — >=60 min at 70 degC (PAS110) |
Pasteuriser operating hours pasteurisation.operatingHoursPerDay | 24 | hr/day | workbook | Levers!B57 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B57 = 24 hr/day — Near-continuous batch process |
Treatment temperature pasteurisation.treatmentTemperatureC | 71 | degC | workbook | Bio Levers!C13 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C13 = 71 degC — ABPR/PAS110: >=70 degC (pathogen kill) |
Heat recovery pasteurisation.heatRecoveryFraction | 0.944 | fraction | workbook | Levers!B113 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B113 = 94.4 % — Recovery-HX effectiveness (feed side) |
Boiler efficiency pasteurisation.boilerEfficiency | 0.95 | fraction | workbook | Levers!B118 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B118 = 95 % — Boiler efficiency |
Approved treatment temperature pasteurisation.approvedTemperatureC | 70 | degC | literature | — | high | pending | UK ABP / PAS110 food-waste regime (70degC / 60 min) — confirm against the site's own approval |
Approved hold time pasteurisation.approvedHoldMinutes | 60 | min | literature | — | high | pending | UK ABP / PAS110 food-waste regime — confirm against the site's own approval |
Digester count digestion.digesterCount | 2 | count | workbook | Levers!B61 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B61 = 2 count — Digesters per site |
Digester working volume digestion.workingVolumePerDigesterM3 | 4,000 | m3 | workbook | Levers!B62 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B62 = 4000 m3 — 2 digesters per site |
Minimum safe HRT digestion.minSafeHrtDays | 30 | days | workbook | Bio Levers!C19 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C19 = 30 days — Must exceed methanogen doubling time or washout |
DS loading limit digestion.maxDsLoadKgPerM3PerDay | 5 | kg DS/m3 | workbook | Bio Levers!C17 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C17 = 5 kg DS/m3 — Max kg DS per m3 digester per day |
Volumetric push rate digestion.volumetricPushRateM3PerDay | 200 | m3/day | workbook | Levers!B63 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B63 = 100 m3/day — Max 125 @16% DS; historic 100 |
Digester temperature digestion.temperatureC | 42 | degC | workbook | Bio Levers!C14 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C14 = 42 degC — Mesophilic 40-42 degC — REL methanogen activity |
Methane content of biogas digestion.methaneFraction | 0.603 | fraction | calculated | Bio Levers!C20 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C20 = 60.273972602739725 % — Buswell-consistent: CH4% = 50 + (BOD/COD) x 20, bounded 50-70% |
Maximum organic loading rate (VS) digestion.maxOlrKgVsPerM3PerDay | 3.5 | kg VS/m3/day | literature | — | medium | draft | Not stated in the merged workbook — internal engine assumption, requires site validation |
Maximum organic loading rate (COD) digestion.maxOlrKgCodPerM3PerDay | 6 | kg COD/m3/day | literature | — | medium | draft | Not stated in the merged workbook — internal engine assumption, requires site validation |
Methane per kg COD destroyed gas.ch4PerKgCodDestroyed | 0.35 | m3 CH4/kgCOD | workbook | Bio Levers!C34 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C34 = 0.35 m3 CH4/kgCOD — 0.35 m3 CH4 per kg COD at STP |
Volumetric biogas yield (COD chemistry) gas.fixedYieldNm3PerM3Feed | 144.125 | Nm3/m3 | workbook | Bio Levers!C42 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C42 = 144.12522727272727 Nm3/m3 — COD chemistry yield per m3 of feed |
BUU proven operating capacity gas.buuProvenNm3PerHour | 1,350 | Nm3/hr | workbook | Levers!B12 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B12 = 1350 Nm3/hr — Nameplate 1500; actual 1350 (2023 flow test) |
BUU methane recovery gas.buuMethaneRecovery | 0.98 | fraction | workbook | Levers!B14 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B14 = 0.98 fraction — Fraction of REL BUU biomethane available for grid entry |
BUU nameplate capacity gas.buuNameplateNm3PerHour | 1,500 | Nm3/h | workbook | — | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!D12 note: nameplate 1500, actual 1350 |
Biogas yield basis gas.yieldMode | cod_kinetic | - | workbook | — | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C34-C42, COD-chemistry yield (the merged sheet drops the fixed 140 Nm3/m3 rule) |
Grid entry / NEA limit grid.neaLimitNm3PerHour | 853 | Nm3/hr | workbook | Levers!B6 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B6 = 853 Nm3/hr — Max biomethane+propane to grid at REL (revenue ceiling) |
Biomethane GCV grid.biomethaneGcvMjPerM3 | 37.791 | MJ/Sm3 | workbook | Levers!B80 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B80 = 37.791105882352944 MJ/Sm3 — Calorific value of pipeline biomethane |
Grid target GCV grid.targetGcvMjPerM3 | 40.5 | MJ/Sm3 | workbook | Levers!B78 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B78 = 40.5 MJ/Sm3 — NGN grid entry specification (GCV target) |
Propane GCV grid.propaneGcvMjPerM3 | 95.826 | MJ/Sm3 | workbook | Levers!B79 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B79 = 95.82593527808434 MJ/Sm3 — Calorific value of propane enrichment gas |
Annual grid injection target grid.annualTargetNm3 | 7,472,280 | Nm3/yr | calculated | — | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B6 x 24 x Levers!B31 |
CW soup delivered feedstock.cw.tonnesPerDay | — | t/day | workbook | — | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B21 = 76,480 t/yr, divided by Levers!B31 operating days |
External feedstock delivered feedstock.ext.tonnesPerDay | — | t/day | workbook | — | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Levers!B22 + Levers!B23 = 41,000 t/yr, divided by Levers!B31 |
Feedstock dry solids feedstock.dsFraction | — | fraction | workbook | Bio Levers!C5 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C5 = 16 % — Feedstock DS analysed daily |
Volatile solids of DS feedstock.vsOfDsFraction | — | fraction | workbook | Bio Levers!C6 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C6 = 85 % — Typical for food waste (lit. 80-90%) |
Feedstock COD feedstock.codKgPerTonne | — | kg/t | workbook | Bio Levers!C7 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C7 = 292000 mg/L — Chemical Oxygen Demand |
Feedstock BOD feedstock.bodKgPerTonne | — | kg/t | workbook | Bio Levers!C8 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C8 = 150000 mg/L — Biological Oxygen Demand |
Feedstock pH into hydrolysis feedstock.ph | — | pH | workbook | Bio Levers!C9 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C9 = 5.5 pH — Target 5.5-6.5 |
COD biodegradability feedstock.biodegradableCodFraction | — | - | workbook | Bio Levers!C35 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C35 = 0.85 - — Fraction of COD degraded |
Feedstock soup density feedstock.density | — | tonne/m3 | workbook | Bio Levers!C36 | high | approved | Yorks Process Flow v1 (07/08/26, Merged Models) — Bio Levers!C36 = 1 tonne/m3 — Converts mg/L to kg/tonne |
Gas price commercial.gasPricePerMwh | 78 | GBP/MWh | assumed | — | low | requires site validation | Not stated in the merged workbook — internal engine assumption, requires site validation |
Propane cost commercial.propaneCostPerNm3 | 0.62 | GBP/Nm3 | assumed | — | low | requires site validation | Not stated in the merged workbook — internal engine assumption, requires site validation |
Calculation basis
The equations the engine runs, stated plainly so they can be challenged.
Hydrolysis kinetics
kh_eff = kh_ref x theta^(T - T_ref) x solids factor x pH factor; required retention = -ln(1 - target degradation) / kh_eff.
Hydrolysis capacity
min(feed pump m3/h x operating hours, working volume / required retention), then derated for measured downtime.
Pasteurisation
Compliant batches/day = (operating hours x 60 / cycle minutes) x tanks, gated on the approved temperature, hold time and particle size.
Digestion
min(hydraulic HRT limit, VS loading, COD loading, DS loading, volumetric push rate), derated for mixing availability.
Biogas yield
COD destroyed = COD load x biodegradable fraction x degradation; CH4 = COD destroyed x 0.35 Nm3/kg; biogas = CH4 / CH4 fraction.
Biological derate
Yield x methanogenic temperature factor x digester pH factor x solids factor x hydrolysis achievement.
Upgrading
Biomethane = min(biogas offered, proven BUU capacity) x CH4 fraction x methane recovery.
Propane enrichment
Propane = biomethane x (target GCV - biomethane GCV) / (propane GCV - target GCV).
Downtime
Events are expanded onto an hourly timeline and unioned per stage, so overlapping outages are never double-counted.
Confidence band
The low/base/high band widens as the data quality score falls; it is an evidence band, not a statistical interval.