Chlor-alkali membrane electrolysis plant

Protects divisions; far below any physical value in the model.

Market range Not applicable.

Neutral value used in selectors and the retrofit gap floor.

Market range Exact.

Unit multiplier used in the CRF, the load penalty and the deviation ratios.

Market range Exact.

Turns a percent input (0-100) into a fraction.

Market range Exact.

Turns a ratio into a percent for display.

Market range Exact.

Converts the kt/yr capacity input into tonnes.

Market range Exact.

Converts kg H2 per tonne of Cl2 into tonnes, and back to kg/h.

Market range Exact.

Converts kWh per tonne into MWh and EUR/MWh into EUR/kWh.

Market range Exact.

Converts the H2 lower heating value from MJ/kg to GJ/kg.

Market range Exact.

Expresses the plant CAPEX per kW of electrical load.

Market range Exact.

Hours in a non-leap year; converts annual tonnes into full-load hourly rates.

Market range Exact.

Selector code: caustic evaporated to 50 wt-% (BREF Table 3.13 energy boundary).

Market range Exact.

Selector code: cell-liquor caustic (about 32 wt-%) sold without evaporation.

Market range Exact.

Option 1 of technology_case: cell 2 573 kWh/t, auxiliaries 177, evaporation 0.703, brine heating 0.226, salt 1.700.

Market range Not applicable.

Option 2 of technology_case: cell 2 455 kWh/t (Table 4.17); auxiliaries, steam and salt at the medians since Table 4.17 does not give them. Consistent with the new-plant CAPEX.

Market range Not applicable.

Tolerance used to test whether an input sits exactly on the documented nominal value.

Market range Not applicable.

Lower guard of the specific CAPEX clamp. The Equation 2 curve only reaches 100 EUR per t/yr far above any real plant, so the guard never binds on the 50-200 kt/yr slider (812-1 231 EUR per t/yr).

Market range Not applicable.

Upper guard of the specific CAPEX clamp. The Equation 2 curve only reaches 5 000 EUR per t/yr below 0.5 kt/yr, so the guard never binds on the 50-200 kt/yr slider.

Market range Not applicable.

Lower end of the Customized CAPEX slider; below it invalid_input = 1 when Customized is selected.

Upper end of the Customized CAPEX slider; above it invalid_input = 1 when Customized is selected.

Market range No independent range cited.

Defines the ECU (1 t Cl2 + 1.128 t NaOH 100 %), the caustic output and the conversion of evaporation steam from a NaOH to a Cl2 basis.

Shows the caustic output a plant at the low end of practice would sell; the ECU itself keeps 1.128.

Co-produced hydrogen per tonne of chlorine; sets the H2 outlet and the fuel-substitution credit.

Market range Approximately 28 kg/t (single value in the source).

Reference for the salt-use ratio output.

Market range Exact stoichiometry.

Default salt use and reference for the deviation output.

Default cell electricity (AC, including rectifier and transformer losses) and part of the BREF median reference.

Market range 2 279-2 865 kWh/t for bipolar plants (Table 3.10).

Lower end of the cell-electricity slider.

Market range 2 279-3 000 kWh/t (Table 3.9).

Upper end of the cell-electricity slider.

Market range 2 279-3 000 kWh/t (Table 3.9).

Cell electricity of the reference case 'new bipolar electrolyser at 6 kA/m2', and benchmark for the electricity gap to a new electrolyser. Table 4.17 excludes auxiliaries, steam and salt, which stay at the medians in that case.

Market range 2 280-2 535 kWh/t across 4-7 kA/m2 (Table 4.17).

Default auxiliary electricity and part of the BREF median reference.

Default evaporation steam and part of the BREF median steam reference.

Default brine-heating steam and part of the BREF median steam reference.

Product concentration when the 32 % cell liquor is sold without evaporation.

Market range Median of the membrane sample (Table 3.11).

Product concentration when the caustic is evaporated.

Market range Fixed by the BREF boundary definition.

Specific CAPEX of a complete new plant at the reference capacity.

Market range No independent range cited.

Anchor capacity of the specific-CAPEX scaling.

Market range Fixed by Equation 2.

Overall scale exponent on total CAPEX. The source writes the law on specific CAPEX with exponent 0.3 on (100/C): specific cost ~ C^-0.3, i.e. total cost ~ C^0.7. An exponent of 0.3 on the specific cost is equivalent to 0.7 on the total cost; the model writes base x (C/100)^(0.7 - 1).

Market range Single value in the source; applied there at 50 and 200 kt/yr only.

Lower end of the capacity slider and of the model domain: below it invalid_input = 1.

Upper end of the capacity slider and of the model domain: above it invalid_input = 1.

Evaluates the capital charge at the Table 4.18 plant size, for the depreciation comparison.

Market range Fixed by the source table.

Default electricity price; used by the nominal-point flag.

Market range EUR 30-130/MWh (Table 4.19 axis).

Low electricity price of the sensitivity outputs and of the slider.

Market range EUR 30-130/MWh (Table 4.19).

High electricity price of the sensitivity outputs and of the slider.

Market range EUR 30-130/MWh (Table 4.19).

Price of salt delivered to the brine plant.

Market range No independent range cited.

Table 4.18 steam price, kept as a benchmark for the fuel-indexed steam price.

Market range No independent range cited.

Heat delivered per tonne of process steam; with the boiler efficiency it sets the fuel burnt per tonne of steam.

Market range 2.40 GJ/t from steam tables at the same conditions against 2.5 GJ/t in the BREF.

Boiler efficiency: converts the steam heat into fuel burnt, so the steam price follows the fuel price that also values the H2 credit.

Market range No independent range cited.

Membrane replacement cost per tonne of chlorine.

Market range EUR 4.0-6.8/t with gaskets implied by BREF §4.3 (PDF p.201) against EUR 20/t in Table 4.18 (PDF p.197).

Brine-treatment chemicals and other consumables per tonne of chlorine.

Market range No independent range cited.

Cooling water, nitrogen and other utilities per tonne of chlorine.

Market range No independent range cited.

Operating labour per tonne of chlorine produced.

Market range No independent range cited.

Maintenance per tonne of chlorine produced at the Table 4.18 plant size.

Market range No independent range cited.

Plant overheads per tonne of chlorine produced.

Market range No independent range cited.

Taxes and insurance per tonne of chlorine produced at the Table 4.18 plant size.

Market range No independent range cited.

Corporate overhead allocated to the plant per tonne of chlorine.

Market range No independent range cited.

Converts the Table 4.18 fixed lines, printed per t produced, into an annual amount per t/yr of capacity (x 0.80), which the calculator then spreads over the chlorine actually produced.

Comparison point for the calculator cash cost.

Market range Single printed value.

Comparison point for the calculator cost before the H2 credit.

Market range Single printed value.

Comparison point for the capital charge at the 500 kt/yr reference size.

Market range Single printed value.

Comparison point that explains part of the gap to the Table 4.18 cash cost.

Market range Single printed value.

Comparison point that explains part of the gap to the Table 4.18 cash cost.

Market range Single printed value.

Economic life used in the capital recovery factor.

Default discount rate of the capital charge. Economic criterion transposed from the IEAGHG 2017-02 SMR hydrogen study; no chlor-alkali source prints it. Applied as a real rate to constant ~2010 EUR costs; also used by the nominal-point flag.

Low discount rate of the sensitivity outputs. Economic criterion transposed from the IEAGHG 2017-02 SMR hydrogen study; no chlor-alkali source prints it.

High discount rate of the sensitivity outputs. Economic criterion transposed from the IEAGHG 2017-02 SMR hydrogen study; no chlor-alkali source prints it.

Default utilisation and low end of the utilisation sensitivity.

High end of the utilisation sensitivity.

Energy content of the recovered H2 when it displaces fuel.

Market range Physical property.

Price of the fuel that the recovered H2 displaces; a natural-gas price transposed from the IEAGHG SMR study, not a chlor-alkali figure. Used by the nominal-point flag.

Low fuel price of the H2 credit sensitivity and of the slider; transposed from the IEAGHG SMR gas-price sensitivity.

High fuel price of the H2 credit sensitivity and of the slider; transposed from the IEAGHG SMR gas-price sensitivity.

Sets the number of membrane changes over plant life and the implied cost of one membrane set.

Charge per mole of electrons in the U0 energy.

Market range Exact.

Converts the charge per mole of Cl2 into a charge per tonne.

Electrons transferred per Cl2 molecule.

Market range Exact.

Thermodynamic floor of the cell voltage, used only for the heat-and-losses output.

Market range No independent range cited.

Unit conversion for the U0 energy.

Market range Exact.

Converts steam heat (GJ) into MWh for the heat-and-losses output.

Market range Exact.

Bipolar membrane-cell chlor-alkali, 2 NaCl + 2 H2O -> 2 NaOH + H2 + Cl2 (BREF §2, PDF p.40). Functional unit = 1 ECU = 1 t Cl2 + 1.128 t NaOH (100 %) + about 28 kg H2. Energy boundary of BREF Table 3.13 (PDF p.96): dry compressed Cl2, low-pressure dry H2 and 50 wt-% NaOH, from salt, water, electricity and steam. Cl2 liquefaction and vaporisation are excluded. Physical cell-voltage form w = A·U0 + A·K·j (Equation 1, PDF p.89) is shown for transparency only: K and A are not published per plant, so the cell electricity is a model value chosen by the reference case (EU median or new bipolar at 6 kA/m2), adjustable only through a bounded factor.

Market range Not applicable.

LCO_ECU = (CAPEX x CRF + annual fixed cost) / annual ECU + variable cost - H2 credit: both annual terms are spread over the chlorine actually produced, so both carry the 1 / utilisation load penalty. CRF = i/(1-(1+i)^-n), real annuity on constant-EUR costs with no escalation, no tax and no construction period: a simplification of the zero-NPV discounted cash flow that IEAGHG 2017-02 uses to define a levelised cost. Because Cl2 and NaOH come in a fixed ratio, EUR/ECU equals EUR per tonne of Cl2 produced, the basis of BREF Table 4.18. No split between Cl2 and NaOH is made: no sourced allocation key was found.

Market range Not applicable.

Costs are in EUR at about 2010 (Euro Chlor 2010 / Prochemics 2007 data in BREF 2014). The default fuel price is in EUR 4Q2014 (IEAGHG); it values both the H2 credit and the steam, and is applied without deflation, so the default H2 credit (about 20 EUR/ECU) and steam cost (about 17 EUR/ECU) are mixed-year figures. No escalation is applied anywhere. The Table 4.18 comparisons are therefore not in a single price year for steam; they are decomposed line by line rather than read as one gap.

Market range Not applicable.

Electricity is an inlet in MW, period hourly (invariant I3), carrying the annual average (annual MWh / 8760) because project mode multiplies an hourly value by 8760 without re-applying utilisation. Steam is an inlet in t/yr and H2 an outlet in t/yr. Chlorine, caustic soda and salt have no canonical commodity in OpenJack, so they are not exported as flows: their value stays in the calculator outputs. The H2 outlet is flagged as main product only because it is the single outlet; a project LCO on it would load the whole chlor-alkali cost on 28 kg H2 per ECU, which is not a hydrogen cost. Electricity and steam are priced by the project through their inlets and are therefore NOT repeated in the variable opex.

Market range Not applicable.

CAPEX BOUNDARY. costs.capex.isbl exports the plant CAPEX = specific CAPEX retained x capacity: EUR 1 000 per t/yr of Cl2 capacity scaled by BREF Equation 2 (or the user's Customized all-in figure, in EUR 2010). The 1 000 is a sentence of §4.1.2 ('approximately EUR 1 000/t annual Cl2 capacity' for a completely new membrane plant), given by comparison with the 100 kt/yr conversion of Table 4.5 (same source, Euro Chlor 2010). The Table 4.5 total includes Engineering, Pro-rata and start-up costs, Miscellaneous (10 %) and Escalation and financial costs: the compared figure is an all-in total, so battery_limit is 'fully_financed' and project mode adds no working-capital or contingency layer (x1.00), which would double count the 10 % line and the financial costs. Table 4.5 also includes Cl2 liquefaction, which the model's electricity excludes. The 100 kt/yr anchor of the 1 000 is a reading of the context (the sentence names no size), kept and stated as such. No installation or indirect factor is applied inside the calculator.

Market range Not applicable.

Table 4.18 steam (2.08 t/t Cl2) is about twice the Table 3.11 + 3.12 medians (1.02 t/t Cl2), and its electricity (3 000 kWh/t) is above the 2 750 kWh/t median sum. Its depreciation (EUR 121/t at 500 kt/yr) is well above the capital charge the calculator derives from EUR 1 000 per t/yr and Equation 2 at the same size: 64.7 EUR/ECU at 8 % and 80 % utilisation, i.e. 46.5 % below. The BREF states neither the depreciation period nor the asset base, so the gap is published (output capex_charge_vs_bref_depreciation_pct) and not calibrated away. At the nominal point (100 kt/yr) the cash cost is 438.6 EUR/ECU against the printed EUR 442/t Cl2 produced (-0.8 %) and the cost before the H2 credit 543.4 against EUR 563/t (-3.5 %). These are NOT like-for-like: Table 4.18 is a 500 kt/yr plant on its own consumptions. Line by line: electricity -17.5 (2 750 vs 3 000 kWh/t), steam -20.0 (1.02 vs 2.08 t/t, priced at 16.7 EUR/t from the 4Q2014 fuel price against 18 EUR/t in ~2010 EUR), fixed costs +34.1 (120.1 vs 86: maintenance and taxes/insurance scaled to the 100 kt/yr CAPEX), capital -16.2 (104.8 vs 121 depreciation). The small net gaps are offsets of larger opposite moves, not an agreement. At 500 kt/yr and 80 % utilisation the fixed costs equal the printed 86 by construction (they are calibrated on that line), so this is not a validation.

Market range Not applicable.