CO2-to-methanol synthesis unit (H2 + CO2 to Grade AA methanol, modular to world-scale)

Prevents division by zero and NaN propagation in every guarded denominator.

Market range Not applicable (numerical parameter).

The DSL forbids inline magic numbers; complements and unit sums are written with this constant.

Market range Exact.

Used by the make-up compression on/off branch and by guard expressions.

Market range Exact.

All percent inputs are carried 0-100 (OJ convention) and converted here, never relabelled.

Market range Exact.

Converts a computed fraction back to the percent unit used by the reported efficiencies.

Market range Exact.

Capacity-factor annualisation basis. The calculator carries NO days-per-year constant: the apparent 365 of the #244 bug is 8760/24 and is written as such.

Market range 8760 (non-leap year); 8784 (leap year).

Turns the MTPD capacity into an hourly rate. This single constant replaces the x365 kta->kg/day slip that #244 carried.

Market range Exact.

Mass unit conversion used across the mass balance.

Market range Exact.

Reports annual production in kt/year, the unit the market and calculator #244 used.

Market range Exact.

Capital costs are carried in MEUR and reported in EUR.

Market range Exact.

Specific electricity is carried in kWh/t and annualised in MWh/year.

Market range Exact.

Converts the methanol LHV and the reaction enthalpy to MWh for the energy efficiency.

Market range Exact (1/3600).

Used for the catalyst bed geometry.

Market range Exact.

Drives the adiabatic compression work of the make-up and recycle compressors.

Market range Exact by definition since 2019.

Denominator of every specific quantity of the calculator.

Market range Exact for the natural isotopic mix.

Stoichiometric CO2 demand and the CO2 volumetric conversion.

Market range Exact for the natural isotopic mix.

Stoichiometric H2 demand and the H2 volumetric conversion.

Market range Exact for the natural isotopic mix.

Water is the stoichiometric by-product of CO2 hydrogenation; it is reported, not priced.

Market range Exact for the natural isotopic mix.

Converts the mass balance into the Nm3/h that vendor datasheets print. This is the unit guard of the whole calculator: at 15 degC (23.645 Nm3/kmol) Topsoe's printed H2 consumption would fall BELOW stoichiometry, which is impossible.

Market range 22.414 at 0 degC / 1 atm; 23.645 at 15 degC; 24.055 at 20 degC.

Three moles of hydrogen per mole of methanol; the whole hydrogen balance rests on it.

Market range Exact.

Exothermic heat removed by the boiling-water reactor, and the steam it raises.

Market range -49.2 to -49.8 kJ/mol across handbooks.

Numerator of the LHV energy efficiency.

Dominant energy input of the loop: the hydrogen carries about 97 % of the energy entering this battery limit.

Market range 33.3 MWh/t (119.96 MJ/kg).

Single calibration point of the electricity model: the on-site power recovery fraction is set so that the compression model reproduces this figure at the JRC flowsheet's own feed rates.

Market range 0.177 MWh/t (JRC) to 0.182 MWh/t (Mucci et al. 2023, 1.8 MW for 9.9 t/h).

Reported for utility sizing; it is not priced inside the levelised cost.

Market range 0.862 MWh/t (JRC) to 1.39 MWh/t (Mucci, 13.8 MW for 9.9 t/h).

Published recycle ratio of the reference loop. It feeds only the reference overall conversion (93.4 % with JRC's 22 % per pass); the recycle flow the calculator compresses uses the recycle ratio implied by the selected case, which closes on that case's CO2 utilisation (98.1 % for JRC, 99.2 % for Topsoe).

Divides the ideal adiabatic work of every compressor in the loop.

Sets the specific work of each compression stage through R.T/M.

Number of intercooled stages on the CO2 make-up train.

Suction pressure of the CO2 make-up compressor.

Market range 1 bar from a capture unit; 15-30 bar if the CO2 arrives from a pipeline.

Suction pressure of the H2 make-up compressor - the typical delivery pressure of a pressurised electrolyser.

Discharge pressure of both make-up trains and of the recycle compressor.

Loop pressure. With the 78 bar discharge it sets the pressure the recycle compressor has to restore.

Ratio of specific heats in the adiabatic work of the CO2 make-up compressor.

Ratio of specific heats for the H2 make-up compressor and for the hydrogen-rich recycle gas (75 mol % H2).

Scale of the reference flowsheet, and the scale at which its ISBL is priced.

Market range World-scale methanol trains run 1 500-5 000 t/day.

Independent reference feed rate, used to calibrate the on-site power recovery at the JRC flowsheet's own conditions.

Market range 93.2 Nm3/h per MTPD, against Topsoe's printed 88.7.

Independent reference feed rate on the carbon side.

Market range 31.1 Nm3/h per MTPD, against Topsoe's printed 30.0.

Largest modular train on the market; above it the calculator counts trains rather than pretending one vessel exists.

Sizes the catalyst inventory and its annual replacement cost.

Turns the catalyst inventory into a bed volume, then into reactor bed dimensions.

Market range 1 000-1 300 kg/m3 for Cu/ZnO/Al2O3 pellets.

Only dated, printed price found for this catalyst; kept even though it is high for a bulk Cu/ZnO/Al2O3.

Market range Bulk quotes are often cited at 20-50 EUR/kg, but none of them is dated and printed.

Annualises the catalyst charge.

Turns the catalyst bed volume into a reported diameter and height.

Reference scale of the power-law CAPEX.

Market range 1 320 t/day = 482 kt/year at full load.

Largest section of the synthesis island, and the only one the make-up compression toggle touches.

Market range 38.3 % of the 122.3 MEUR island ISBL.

Second largest section; the loop is heat-integrated, so exchanger area dominates alongside compression.

Market range 38.8 % of the island ISBL.

Guard bed and drying on the CO2 make-up, retained because captured CO2 is never synthesis-grade as delivered.

Market range 11.0 % of the island ISBL.

The reactor itself is a small part of a synthesis island; the money is in compression and heat transfer.

Market range 1.9 % of the island ISBL.

Purification to Grade AA methanol and its reboiler duty.

Market range 7.2 % of the island ISBL.

Power recovery machinery and pumps. These turbines are the hardware behind the on-site power recovery this calculator calibrates.

Market range 2.9 % of the island ISBL.

First layer above the battery limit of the synthesis island.

Design and project management layer.

Contingency layer.

Working capital layer, annualised with the rest of the capital.

Independent factorial convention, reported as a check ratio against this calculator's own layer cascade rather than substituted for it.

First term of the detailed fixed-O&M route used as a cross-check on the flat percentage.

Second term of the detailed fixed-O&M route.

Operating labour of the detailed fixed-O&M route. Held constant with capacity: a synthesis loop is manned per shift, not per tonne.

Fully loaded cost of one operator, EUR2014.

Market range 60 000-95 000 EUR/year across western European sites.

Third term of the detailed fixed-O&M route.

Fourth term of the detailed fixed-O&M route.

Lower clamp of the part-load multiplier.

Market range Not applicable.

Upper clamp of the part-load multiplier.

Market range Not applicable.

Turns the specific compression work of each machine into the kWh per tonne the energy balance reports.

Market range Exact (1000/3600).

Single-pass conversion of the REFERENCE flowsheet, held fixed so that the power-recovery calibration is anchored on JRC's own operating point and does not move with the user's inputs. It is also the per-pass conversion of BOTH reference cases: Topsoe does not print a per-pass conversion for ModuLite eMeOH, so the Topsoe Tier 1 case reuses JRC's 22 %.

Cube root exponent of the catalyst bed diameter.

Market range Exact.

Geometry coefficient of the catalyst bed diameter.

Market range Exact.

Exponent of the power law on the TOTAL installed ISBL: ISBL = ISBL_ref x (S/1 320)^0.6, so the SPECIFIC cost varies as S^-0.4. Held as a model constant, not an input: a scale law is defended or not written. Evidence medium because the source applies the textbook rule rather than regressing it on plant costs.

Market range Two cost points only: JRC at 1 320 t/day and Mucci at about 238 t/day (80 kt/year), the latter about 0.6x the JRC law at that size on a different costing basis.

Integer identifier of a reference case: the DSL carries no strings.

Market range Not applicable.

Integer identifier of a reference case: the DSL carries no strings.

Market range Not applicable.

Hydrogen utilisation of the Topsoe Tier 1 case. Topsoe prints a feed rate, not a utilisation; the value is derived against stoichiometry.

Market range 93.8 % (JRC) to 98.6 % (Topsoe) across the two reference cases.

Carbon utilisation of the Topsoe Tier 1 case, derived against stoichiometry from the printed CO2 feed rate.

Market range 93.8 % (JRC) to 97.2 % (Topsoe); Mucci Table A.3 implies 88.3 % but prints no per-pass conversion, so it is not offered as a case.

GUARD, not a clamp. A Customized vendor quote that implies a specific CAPEX below this floor is REFUSED through invalid_input - the output is never squashed back into range. Calculator #244 clamped instead, and that clamp is what hid the wrong sign on its scaling exponent.

Market range The JRC anchor scaled over 150-1000 MTPD with the 0.6 exponent spans about 103 500-221 100 EUR/(t/day) in EUR2014, up to about 309 600 at 150 MTPD with the x1.40 escalation cap; the Mucci family sits about 0.6x as high.

GUARD on user-entered CAPEX: a quote above this ceiling is refused rather than clamped. It is the highest specific CAPEX the sourced cost law reaches in current-year euros at the smallest size of the domain; it also rejects a x365 unit slip on the capacity. The Customized slider stops at the same value.

Market range About 103 500-309 600 EUR/(t/day) for the JRC family over the declared capacity domain and escalation range.

SCOPE. This calculator models the SYNTHESIS LOOP ONLY: make-up and recycle compression, boiling-water reactor, purge, raw-methanol flash and distillation to Grade AA (99.85 wt %). Neither electrolysis nor CO2 capture is inside it - hydrogen and CO2 are PURCHASED inputs, declared as inlet flows so that project mode prices them or chains them to an upstream asset.

Market range Not applicable (scope statement).

CAPEX BOUNDARY. costs.capex.isbl exports the INSTALLED ISBL of the synthesis island, and costs.capex.battery_limit is declared 'installed'. Project mode therefore adds working capital plus contingency (about x1.17 at default settings) and nothing else. The all-in figure this calculator computes for its own levelised cost is exported separately as isbl_plus_osbl, which project mode never consumes. The user-specific CAPEX input is documented as an ISBL figure for exactly this reason: entering an all-in EPC price there would over-count the project CAPEX by roughly 17 %.

Market range Not applicable (contract statement).

SINGLE-POINT CALIBRATION, declared as such. The adiabatic compression model returns 261.8 kWh/t of GROSS shaft work at the JRC flowsheet's own feed rates, against the 177 kWh/t of NET electricity JRC reports. The difference is on-site power recovery - the JRC flowsheet carries turbines, 2.7 % of its island ISBL, and a steam-raising reactor. This calculator models it as a fixed 32.4 % recovery on gross compression work, fitted on that ONE point. It is not validated on two independent designs, and it is not a measured efficiency.

Market range No published split between gross shaft work and recovered power was found for this process.

NO STEAM CREDIT. The boiling-water reactor raises 0.430 MWh of steam per tonne of methanol and the distillation reboiler consumes essentially all of it. Net steam export is therefore zero by default and no steam revenue enters the levelised cost. Selling the steam while still paying for distillation would count the same energy twice.

Market range A genuine surplus exists only with a different heat integration, which is outside this screening model.

FLOW VERSUS OPEX. Hydrogen, CO2 and electricity are declared as INLET FLOWS, so project mode prices them. They are therefore absent from costs.opex: the meta exports only fixed O&M and the catalyst charge as OPEX. The hydrogen, CO2 and electricity costs this calculator reports are for ITS OWN levelised cost, which project mode does not read.

Market range Not applicable (contract statement).

DECLARED DOMAIN. The bounds shipped with this calculator describe the PUBLISHED market envelope for flows and efficiency, and the sourced CAPEX envelope: 87-96 Nm3/h of H2 and 29-34 Nm3/h of CO2 per MTPD, 76-88 % LHV efficiency, 60 000-310 000 EUR/(t/day) of specific CAPEX (the JRC anchor at 150 MTPD brought to 2023 with CEPCI) and 450-2 300 EUR/t of levelised cost. Executed over the 16 384 corners of the input box (capacity 150-1000 MTPD, both reference cases, both CAPEX sources, escalation 1.00-1.40), every bound holds: 88.7-93.2 and 30.0-31.1 Nm3/h per MTPD, 80.1-86.6 % LHV, 60 000-310 000 EUR/(t/day) and 463-2 251 EUR/t. The highest levelised cost sits at 1 000 MTPD, 50 % capacity factor, the JRC case, a 310 000 EUR/(t/day) Customized quote (taken flat at every size, so it carries no scale benefit), 6 EUR/kg hydrogen, 150 EUR/t CO2, 12 % over 15 years and 6 % fixed O&M; it lies above the published 720-1 440 EUR/t because every cost input sits at its worst at once. A Customized cost outside the CAPEX envelope is refused, not clamped.

Market range Published e-methanol costs: USD 800-1 600/t (IRENA), about 920 EUR/t (Hy2Market base case), 0.90-2.02 EUR/kg (Mucci across scenarios).

CAPACITY DOMAIN. The catalogue sheet admits products down to 1 MTPD, but this calculator's slider starts at 150 MTPD, the Topsoe Tier 1 nominal and the only catalogue product - at most 8.8x under the 1 320 t/day JRC cost anchor. Below it the six-tenths law would extrapolate far under every cost point the bundle cites, which is not defensible in front of a financier; smaller units (including the 1 t/day MefCO2 demonstrator the catalogue sheet admits) do not bind to this calculator, by design. Should a source price a unit under 150 MTPD, the domain can be reopened. Above 600 MTPD the model counts two trains (n_trains) but keeps applying the 0.6 law continuously, as for a single plant, because the JRC anchor is a single-train plant. The domain is narrowed rather than the output clamped - clamping is what hid the sign error in calculator #244.

Market range Modular Power-to-X units run 150-600 MTPD; world-scale methanol trains run 1 500-5 000 t/day on syngas, a different technology.

WHAT THIS REPLACES. Calculator #244 carried two defects: a x365 conversion from kta to kg/day, and a POSITIVE exponent on the SPECIFIC CAPEX, so its cost per tonne per day rose with plant size. A floor clamp at 60 000 EUR/(t/day) then masked the sign error above about 400 t/day. This calculator changes the capacity unit to the MTPD the market prints, so that catalogue products bind; derives annual production from the capacity factor with no hidden days-per-year constant; puts the exponent where it belongs, on the total cost; refuses rather than clamps outside its validity envelope; and ships expected values on its nominal case and bounds on five outputs, which is what the gates needed in order to catch either defect.

Market range Not applicable (scope statement).

DEFAULTS ARE DERIVED, NOT PRINTED. Neither Topsoe nor anyone else prints a utilisation: the 98.6 % and 97.2 % defaults are BACK-CALCULATED from Topsoe's printed 13 300 and 4 500 Nm3/h at 150 MTPD against stoichiometry. Evidence level medium, not high. Real carbon utilisation across published flowsheets spans about 88 to 97 %, which is flowsheet dispersion rather than measurement noise - hence the reference-case selector (Topsoe Tier 1 or JRC) rather than a free slider.

Market range Carbon utilisation 93.8 % (JRC) and 97.2 % (Topsoe) in the two reference cases; 88.3 % (Mucci) reported, not offered.

COST YEAR. Capital costs are in EUR2014, the year of the JRC reference, and the meta declares currency_year 2014. No escalation is applied by default. The escalation slider lets the user apply one up to x1.40, which covers the CEPCI ratio 2023/2014 = 797.9/576.1 = 1.385, so a current-year model CAPEX is reachable: at 150 MTPD it is 221 129 x 1.385 = 306 300 EUR per MTPD. CEPCI is a US dollar plant index; applying it to euro costs is an approximation, stated here. The escalation factor multiplies the model value only; a Customized quote is taken as entered, in the user's own cost year, and the user sets the factor to that year's index ratio. Project mode reads currency_year 2014 and inflates to the project year itself, so the meta exports ISBL, all-in CAPEX and fixed O&M divided by the factor, back to EUR2014: no cost is escalated twice.

Market range CEPCI x1.385 from 2014 to 2023 (annual averages); the 2022 peak, 816.0, would give x1.42.

OPEN DIVERGENCE ON THE CAPITAL COST. IRENA writes that, once hydrogen and CO2 are provided, methanol synthesis and distillation represent only USD 30-50 per tonne of methanol. The Towler & Sinnott factorial estimate this calculator builds gives about 100 EUR/t at world scale and about 235 EUR/t at 150 MTPD - a factor of 2 to 5 above the consensus. Mucci's own anchor sits about half as high as the JRC one scaled to the same size, and Mucci writes that 'the capital cost is probably underestimated'. The user sees both: the levelised cost is built on the bottom-up route, the divergence is stated here, and the Customized option lets a vendor quote replace the estimate entirely.

Market range Specific CAPEX 200-700 USD per (t/year) for large methanol plants (ADI Analytics via Mucci); 350 EUR/(t/y) at 80 kt/year (Mucci); 664 EUR/(t/y) here at 150 MTPD.