Autothermal reforming (ATR) hydrogen plant with CO2 capture

Prevents division by zero in every guarded denominator.

Market range Not applicable (numerical parameter).

Used for complements, the r = 0 branch of the CRF and the scaling exponent offset.

Market range Exact.

Used by the input guard.

Market range Exact.

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

Market range Exact.

Upper limit of the capacity factor and capture-rate guards, and fraction-to-percent conversion of reported shares.

Market range Exact.

Annualises the hourly production through the capacity factor.

Market range Exact.

Converts the nameplate t/day into kg/h; annual output is then built from 8760 h, so no days-per-year constant exists in the model.

Market range Exact.

Tonne to kilogram.

Market range Exact.

kWh to MWh.

Market range Exact.

Converts the gas intensity to GJ/kg, the unit NETL and IEAGHG use for fuel.

Market range Exact.

Restates the gas price in EUR/GJ, as the brief's method writes it.

Market range Exact.

MW to kW.

Market range Exact.

Reports the overnight cost in MEUR.

Market range Exact.

Converts the carbon balance into CO2 mass.

Market range Exact to 0.01 %.

Converts the carbon balance into CO2 mass.

Market range Exact to 0.01 %.

Used only for the cold-gas-efficiency output, which compares the model with the 75.7 % NETL prints.

Keeps the power law away from extrapolation should the slider range ever be widened.

Market range Not applicable.

Upper twin of capex_scale_ratio_min.

Market range Not applicable.

Denominator of every per-kg intensity derived from the NETL flows.

Market range Design point of the anchor plant.

Reference capacity of the scaling law: at 660 t/d the scale factor is exactly 1 and every cost equals NETL's.

Market range World-scale ATR: 200-1500 t/d across announced projects.

Gives the gas mass flow, reported for logistics alongside the energy flow.

Numerator of the gas intensity: 1,408,040 / 27,500 = 51.20 kWh_HHV/kg = 0.1843 GJ_HHV/kg (derived ratio).

Kept as an independent second print of the gas intensity; not used in a node because the two prints agree.

Market range Not applicable.

Reference for the hhv_cold_gas_efficiency_model_pct output; the model does not force itself onto it.

Oxidant demand of the ATR; drives the reported oxygen flow.

Defines the oxidant basis of oxygen_kg_per_kg_h2 (stream mass, not pure O2).

Denominator of asu_power_reference_ratio, a consistency indicator between NETL's ASU section and its power table, not a validation.

Market range ~200-450 kWh/t O2 depending on purity, pressure and basis.

One line of the electricity build-up; ASU lines scale with oxidant, capture lines with captured CO2, the H2 compressor with H2.

Market range Design point of the anchor plant.

One line of the electricity build-up; ASU lines scale with oxidant, capture lines with captured CO2, the H2 compressor with H2.

Market range Design point of the anchor plant.

One line of the electricity build-up; ASU lines scale with oxidant, capture lines with captured CO2, the H2 compressor with H2.

Market range Design point of the anchor plant.

One line of the electricity build-up; ASU lines scale with oxidant, capture lines with captured CO2, the H2 compressor with H2.

Market range Design point of the anchor plant.

One line of the electricity build-up; ASU lines scale with oxidant, capture lines with captured CO2, the H2 compressor with H2.

Market range Design point of the anchor plant.

One line of the electricity build-up; ASU lines scale with oxidant, capture lines with captured CO2, the H2 compressor with H2.

Market range Design point of the anchor plant.

Closes the electricity balance at 4.0 kWh/kg H2.

Default of the capture-rate input.

Market range ATR projects 94.2-98.7 % (NETL Exhibit 2-14).

Reference flow of the capture island: its CAPEX and its compression power are scaled on captured CO2 relative to this stream.

Market range Design point of the anchor plant.

Carbon content of the gas per unit of HHV energy: CO2 generated follows the gas actually burnt.

Cross-check of the emitted-CO2 output; not used in a node.

Market range Not applicable.

Total plant cost; the reforming-island share is derived as 1,092 - 408 - 54 - 124 = 506 $/(kg/d) (ATR, prereformer, syngas coolers, WGS 22, recycle compressor, PSA 47, H2 compressor, fired heater, cooling water, BOP).

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

Total overnight cost. TOC/TPC = 1.256 is applied as the owner's-cost rung (owner's costs, start-up, first catalyst fill, financing costs).

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

ASU section of the plant cost - 37 % of TPC, the largest single item.

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

Capture island, solvent part; scaled with captured CO2.

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

Capture island, compression part; scaled with captured CO2.

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

Part of the 506 $/(kg/d) reforming-island remainder; carried for traceability of that remainder, not used separately.

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

Part of the 506 $/(kg/d) reforming-island remainder; carried for traceability, not used separately.

Market range Real-2024 costs are materially higher; use the Customized CAPEX option.

Labour, maintenance, administration, property taxes and insurance.

NETL variable O&M INCLUDING electricity; the electricity line is subtracted so that power is priced at the user's tariff.

Market range Not applicable.

Removed from NETL variable O&M: the other variable O&M (catalysts, MDEA, TEG, water, maintenance material) is (0.35760 - 0.28727)/1.142 = 0.0616 EUR/kg.

Market range Not applicable.

NETL's own US price; reference only - the calculator uses the IEAGHG NL basis.

Market range Reference value.

About 13.2 EUR/MWh_HHV at 1.142 $/EUR: the lower end of the gas-price slider.

Market range Reference value.

US Gulf Coast saline storage; far below European T&S, which is why the IEAGHG NL fee is used.

Market range Reference value.

Same 90 % default as here.

Market range Reference value.

NETL levelises over 30 years; this calculator uses IEAGHG's 25, and the slider spans 20-30.

Market range Reference value.

Low-price reference (~1.39 EUR/kg). Not reproduced and not re-attributed: NETL uses its own capital charge factor and US prices.

Market range Reference value.

Reference only.

Market range Reference value.

Default of the discount_rate input (0.08 as a ratio).

Converts every NETL dollar figure to euro. No 2018-to-2020 escalation is applied on top (see cost_year_and_escalation).

Default of the gas price input.

Default of the electricity price input.

Bounds and default of the CO2 T&S fee.

Bounds and default of the CO2 T&S fee.

Bounds and default of the CO2 T&S fee.

Bounds and default of the CO2 T&S fee.

Default of the carbon price input; applies to the residual (uncaptured) CO2 only.

Plausibility anchor for the nominal LCOH.

Upper-regime reference for the LCOH bound.

Market range 4.41 EUR/kg (2023), 6.38 (2022).

Low end of announced ATR capture rates.

High end of announced ATR capture rates.

Default economic lifetime of the CRF.

Whole-plant capacity-scaling exponent on total overnight cost, held as a constant (no longer an input). One exponent for all islands, so specific CAPEX scales as (capacity/660 t/d)^-0.30.

Market range QGESS account exponents for this plant's equipment span 0.41-0.88 depending on account and configuration; no whole-plant ATR range is cited.

SCOPE. Oxygen-blown ATR with prereformer, elevated-pressure ASU (95 vol% O2), water-gas shift, MDEA pre-combustion capture, PSA, CO2 compression and drying, H2 compression, and a fired heater burning the PSA off-gas. The ASU is INSIDE the battery limit, so oxygen is not an inlet flow: its cost is in the CAPEX and its power in the electricity import.

Market range Not applicable (statement).

Per-kg intensities are ratios of printed NETL flows (derived, not printed): they hold at the design point and are held constant with scale, which is the usual screening assumption for a plant built from parallel trains.

Market range Not applicable (statement).

CO2 generated is computed from the carbon content of the gas burnt (Exhibit 3-41) and split by the capture rate. The captured stream is then compared with the CO2 product stream of a different exhibit (3-36): the two agree, which is an independent closure of the balance, not an identity.

Market range Not applicable (statement).

Capture-island CAPEX (MDEA AGR + CO2 compression, 178 $/(kg/d)) and capture power (113.4 kWh per t CO2 captured) are scaled LINEARLY with captured CO2 relative to NETL's 242,411 kg/h. Raising capture from 94.5 % to 97 % therefore raises them by 2.6 %; the real cost of the last percent of capture is steeper, which is why the slider stops at 97 %.

Market range Not applicable (statement).

Every plant-cost block is scaled by (capacity/660 t/d)^(0.70 - 1) per kg/d. The capacity slider is limited to 500-820 t/d (anchor +/-25 %). That range is an OpenJack screening choice that keeps the extrapolation from NETL's single priced size short; it is NOT a domain printed by a source. QGESS's own +/-25 % applies to the median of the ranges printed in its exhibits, not to a user's reference plant, and under that definition the ATR ASU (about 3,068 t/d O2 = 127,850 kg/h x 24) is already below the 4,000-4,800 TPD range QGESS prints for account 4.3. The off-anchor CAPEX is therefore a screening estimate. The clamp on the capacity ratio (0.2-2) never binds inside the slider (ratio 0.76-1.24).

Market range Not applicable (statement).

Plant costs and NETL O&M are December-2018 US dollars converted to euros at IEAGHG's 2020 average rate, with an escalation factor of 1 from Dec-2018 to 2020. That factor of 1 is a modelling assumption, not a measured index ratio. There is no escalation input any more: the exported CAPEX is declared EUR 2020, and the project re-escalates from there. A user with a current quote enters it through the Customized CAPEX option, in EUR 2020. Equipment prices rose markedly after 2020, so a build priced today costs more than shown.

Market range Not applicable (statement).

All costs are in constant euros with no escalation of O&M, fuel or power over the life, so the discount rate is applied as a REAL rate. The annuity form CRF x CAPEX / annual H2 + annual costs / annual H2 equals NPV(expenditure)/NPV(H2) when annual flows are constant and construction time is ignored (overnight cost; interest during construction is excluded, see capex_battery_limit_declaration).

Market range Not applicable (statement).

The gas price is applied to the HHV gas intensity (51.20 kWh_HHV/kg). European hub prices are quoted on a gross calorific (HHV) basis, which is the convention retained; IEAGHG does not state the basis of its table, which is flagged here.

Market range Not applicable (statement).

In project mode: natural gas (MWh_HHV/year) and electricity (MW average) are inlets; hydrogen is the main outlet; captured CO2 is an outlet (manual alignment). costs.opex.variable_excluding_feedstocks carries only the other variable O&M, the CO2 T&S fee and the carbon cost. If you chain the CO2 outlet to an explicit transport & storage asset, set the T&S fee here to 0 to avoid paying for storage twice.

Market range Not applicable (statement).

The CAPEX exported to project mode is NETL's total overnight cost: TPC plus owner's costs (pre-production, inventory, land, financing fees, other owner's costs). It EXCLUDES escalation during construction and interest during construction: NETL's total as-spent cost is TOC x 1.070, so the capital component here is about 7 % (about 0.024 EUR/kg at nominal) below a TASC basis. battery_limit is declared fully_financed and project mode adds no further uplift. Installation is already inside NETL's TPC: no installation factor is applied on top. In Customized mode the value entered must be on the same TOC perimeter.

Market range Not applicable (statement).

Bounds were checked at every corner of the input box, not only along axes. At every corner the seven components sum to the LCOH and the CAPEX split sums to the TOC. With every other input at its worst corner, a gas price above about 58 EUR/MWh would take the LCOH past the 5 EUR/kg bound (about 71 EUR/MWh with the other inputs at nominal); the gas slider stops at 45 EUR/MWh, and 2022-type prices are outside the declared domain.

Market range Not applicable (statement).

The economic basis is the one shared with the SMR calculator of the same batch, so the two LCOH figures are comparable line by line; only the plant (NETL Case 3 ATR) differs.

Market range Not applicable (statement).

CUSTOMIZED CAPEX. capex_customized = 1 replaces the model's specific TOC by the value entered (EUR 2020 per kg/d, TOC perimeter) at every size, with no scaling law. The exported split (ASU, capture, reforming island, TPC, owner's costs) is the model's split prorated to the retained TOC, so it always sums to the TOC; the capture-chain view follows the same prorating. Fixed O&M follows the retained TOC at NETL's ratio 37.469/1,372 = 2.73 %/yr of TOC (identical to 3.43 %/yr of TPC in model mode).

Market range No independent range cited.

Heat and losses = gas HHV in + electricity in - H2 out x 39.41 kWh_HHV/kg, all on an HHV basis. It is an output, not an outlet: NETL does not export the heat.

Market range Not applicable (statement).

Reference size of the capacity-scaling law: the only plant size NETL prices.

Market range Not applicable (single design).

No part-load penalty is modelled: the unsourced part-load slider was removed. The capacity factor is read as full-load hours (on/off operation at the NETL design point), so gas, oxidant and power intensities are those of the design. load_penalty_factor is held at 1 and documented as such; it is not a lever.

Market range No independent range cited.