energy_mass_balanceequipment_sizingcostingother
Screening-level direct methanol synthesis calculator: input methanol output, compute H2/CO2 needs, water co-product, key equipment sizing, and CAPEX/OPEX via a power-law cost curve (compression excluded).
Net saleable methanol production target at battery limit on a nameplate annual basis (kta = 1000 t/year). The model converts to daily, hourly, and annual production. Minimum is 100 kta for cost curve validity.
min 100 · max 500 · step 1 · kta
Fraction of the year the plant operates at nameplate equivalent. Used to compute load hours and annualized production/consumption.
min 10 · max 100 · step 1 · %
Used only to annualize CAPEX via the capital recovery factor (CRF).
Amortization period for annualizing CAPEX via CRF (not a detailed depreciation/tax model).
Delivered H2 price to the synthesis block battery limit (compression excluded from this calculator’s scope).
CO2 supply price. Can be negative to represent a credit (e.g., paid to take CO2), depending on contract/accounting.
Cost of supplied heat/steam (e.g., natural gas boiler steam or imported steam).
Electricity price for pumps, controls, and auxiliaries. Gas compression electricity is excluded by scope.
Methanol (net product)
User-defined net saleable output at battery limit (nameplate day basis).
Methanol (net product)
Hourly equivalent of the net nameplate output.
Methanol (net product)
Annual net production accounting for capacity factor.
Hydrogen feed required
Daily H2 requirement at nameplate.
Hydrogen feed required
Hourly H2 requirement (gross synthesis basis, incl. utilization losses).
Hydrogen feed required
Annual H2 requirement accounting for capacity factor via load hours.
CO2 feed required
Daily CO2 requirement at nameplate.
CO2 feed required
Hourly CO2 requirement (gross synthesis basis, incl. utilization losses).
CO2 feed required
Annual CO2 requirement accounting for capacity factor.
Water co-product
Annual water produced accounting for capacity factor.
Water co-product
Stoichiometric water produced (co-product stream), hourly basis.
Electricity demand (excl. compression)
Annual electricity use for synthesis block utilities, excluding gas compression.
Heat demand (excl. compression)
Annual process heat/steam demand for synthesis + separation, excluding gas compression.
Methanol losses
Difference between gross synthesis output and net saleable product (modeled yield/handling losses).
Hydrogen not converted (proxy)
Indicative annual H2 lost to purge/inefficiencies implied by hydrogen utilization factor.
CO2 not converted (proxy)
Indicative annual CO2 lost to purge/inefficiencies implied by CO2 utilization factor.
Equipment purchase cost (EPC)
Purchased equipment only; excludes installation, indirects, owner’s costs.
Installed plant cost (installed)
Equipment purchase plus installation-related direct costs (bulk materials, labor).
Total project CAPEX (TPC)
Installed plant cost plus indirects/owner’s costs via a multiplier.
Annual feedstock cost
Annual cost of H2 and CO2 (CO2 price may be negative for credit).
Annual utilities cost
Electricity + heat cost, excluding compression power.
Annual fixed O&M
Fixed O&M estimated as a fraction of installed plant cost, scaled with size.
Annual catalyst replacement (average)
Average annualized cost of catalyst replacement based on interval.
Total annual cost
Sum of annualized CAPEX, O&M, replacement, feedstocks, and utilities.
Indicative unit cost of methanol
Screening unit cost = total annual cost divided by annual net methanol.
Number of process trains
Estimated parallel trains based on a maximum single-train capacity heuristic.
Reactor diameter (per train)
Indicative cylindrical reactor internal diameter derived from catalyst volume and L/D ratio.
Reactor height (per train)
Indicative internal height using fixed L/D ratio.
Plot space requirement
Indicative plot area including an integration margin.
Calculator context
This calculator provides a pre-feasibility (screening) estimate for a direct methanol synthesis (DMS) block converting CO2 + H2 → CH3OH + H2O, where the user specifies the methanol production rate and the model returns feedstock needs (H2, CO2), co-product water, selected equipment sizing indicators, and CAPEX/OPEX based on a power-law costing curve. The scope follows common techno-economic screening practice (IEA/IRENA/NREL-style approaches) and explicitly excludes gas compression energy and compression equipment per the operating constraint.
The model is organized as (i) availability/part-load effects, (ii) stoichiometric mass balance with utilization losses, (iii) simplified sizing relationships, and (iv) cost curve + annualization.
Key calculations (variables defined in-line; all costs in EUR):
Cost-curve structure and scaling practice are consistent with standard chemical engineering cost scaling references (e.g., Towler & Sinnott; Peters & Timmerhaus) and are commonly used in IEA/IRENA/NREL-style screening TEAs.
46 assumptions used in the calculations
Prevents division-by-zero and improves robustness for edge cases during screening.
Market range 1e-9 to 1e-6 (typical numerical guard values)
Avoids inline magic numbers in validation logic.
Market range 0
Avoids inline magic numbers in formulas (except CRF pattern).
Market range 1
Used to derive reactor diameter from volume and L/D ratio.
Market range 0.333333
Used in cylinder volume rearrangement (4V/(pi*L/D)).
Market range 4
Ensures the part-load penalty cannot improve performance below nameplate.
Market range 1
Used to convert capacity factor to load hours.
Market range 8760
Converts daily nameplate to hourly rate.
Market range 24
Converts kWh to MWh for annual electricity outputs and costs.
Market range 1000
Converts MJ to GJ for annual heat outputs and costs.
Market range 1000
Converts kg to tonnes for CO2 and capacity representation.
Market range 1000
Captures higher specific auxiliary consumption at lower capacity factors (controls, recycles, thermal losses).
Market range 0.05 to 0.3 (dimensionless)
Prevents extreme part-load penalty inflation for very low CF in a screening model.
Market range 1.1 to 1.5
Represents net-vs-gross losses from purge, off-spec, storage/handling, or incomplete recovery in separation.
Market range 0.0 to 0.03
Accounts for H2 not converted due to purge or recycle inefficiency without explicit recycle simulation.
Market range 0.9 to 0.99
Accounts for CO2 not converted due to purge or recycle inefficiency without explicit recycle simulation.
Market range 0.9 to 0.995
3 mol H2 per 1 mol MeOH; converted using molar masses.
Market range Fixed by chemistry
1 mol CO2 per 1 mol MeOH; converted using molar masses.
Market range Fixed by chemistry
1 mol H2O per 1 mol MeOH; converted using molar masses.
Market range Fixed by chemistry
Represents pumps, instrumentation, recycles, and general auxiliaries for synthesis + separation; compression excluded by scope.
Market range 0.05 to 0.3 kWh/kg (excluding compression; highly site/process dependent)
Represents net useful heat duty for separation/purification and process heating.
Market range 1.0 to 5.0 MJ/kg (process-dependent)
Captures distribution losses and imperfect heat integration at screening stage.
Market range 0.05 to 0.25
Anchor point for the power-law cost curve at screening stage.
Market range 10 to 2000 t/day (varies by reference study)
Represents purchased equipment only for the DMS block (excluding compression); used to build a scalable curve for large assets.
Market range 60000 to 220000 EUR/(t/day) for large chemical processing blocks
Typical exponent for chemical process equipment scaling in early estimates.
Market range 0.5 to 0.8
Avoids overly optimistic extrapolation to very large scales.
Market range 50000 to 150000
Avoids unrealistic cost escalation when extrapolating to very small scales.
Market range 200000 to 800000
Converts purchased equipment cost to installed plant cost including bulk materials and installation labor.
Market range 1.8 to 3.0
Adds indirects and owner’s costs as a screening multiplier.
Market range 1.15 to 1.3
Represents staffing, maintenance, insurance, and overhead in a simplified manner.
Market range 0.012 to 0.045
Allows modest economies of scale in fixed O&M fraction.
Market range -0.2 to 0.0
Avoids unrealistic fixed O&M fractions at large scale in screening.
Market range 0.01 to 0.03
Avoids unrealistic fixed O&M fractions at small scale in screening.
Market range 0.04 to 0.08
Covers minor consumables, waste disposal, and routine variable costs not captured elsewhere.
Market range 0.0 to 0.02 EUR/kg
Used to estimate number of parallel trains and per-train equipment sizing.
Market range 50 to 500 t/day per train (project dependent)
Used only for indicative catalyst inventory and reactor sizing; not a kinetic model.
Market range 0.2 to 1.5
Converts catalyst mass to catalyst bed volume for reactor sizing.
Market range 900 to 1400
Converts catalyst bed volume to reactor internal volume allowance.
Market range 0.35 to 0.5
Used to derive reactor diameter and height from internal volume.
Market range 2 to 6
Used for cylinder geometry calculations.
Market range 3.141593
Provides order-of-magnitude site footprint for the DMS block including access and integration allowances.
Market range 3000 to 50000 m2 at ~100 t/day (varies widely)
Captures economies of scale for plot space with increasing throughput.
Market range 0.5 to 0.9
Adds allowance for pipe racks, electrical rooms, access roads, and laydown areas.
Market range 1.1 to 1.6
Used to estimate replacement cost magnitude; actual depends on catalyst formulation and vendor contract.
Market range 10 to 60 EUR/kg
Represents periodic catalyst change-out; used to annualize replacement cost.
Market range 2 to 6 years
Converts kta (1000 t/year) to kg/day for internal calculations.
Market range 1000000
