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LOHC hydrogenation (toluene to MCH)

Screening reaction energy and levelized cost (EUR/kg H2) of binding hydrogen into a toluene/methylcyclohexane liquid organic carrier for ambient-condition transport (hydrogenation leg only).

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Open Jack

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Costing

Delivered electricity price for feed pumping and recycle-gas compression auxiliaries.

EUR/MWh

Price of fresh toluene used to make up carrier losses each cycle. In a closed loop only losses are charged.

EUR/kg

Real discount rate used to compute the capital recovery factor (CRF).

Economic lifetime for levelized cost calculation.

years

Levelized hydrogenation cost (LCO_hyd)

Total annual cost divided by annual H2 bound (hydrogenation leg only)

…EUR/kg H2

Levelized cost: CAPEX component

Annualized CAPEX share of the levelized hydrogenation cost

…EUR/kg H2

Levelized cost: toluene make-up component

Carrier make-up share of the levelized hydrogenation cost

…EUR/kg H2

Scaled specific plant CAPEX

Installed plant cost per unit of hourly H2 binding capacity after scale curve and clamps

…EUR/(kg H2/h)

Total project CAPEX (all-in)

Installed plant cost plus indirect/owner costs (screening scope)

…EUR

Annualized CAPEX (CRF-based)

Total project CAPEX converted to an annual payment equivalent

…EUR/year
Scale effect vs plant throughput

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Sensitivity to toluene make-up price

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CAPEX breakdown vs scale

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Carrier mass balance

Catalyst family for the hydrogenation reactor. Affects auxiliary electricity, reference CAPEX and O&M assumptions.

Hydrogen binding rate of the hydrogenation plant (kg H2 charged onto the carrier per hour).

kg H2/h

Toluene carrier mass per kg H2

Fresh toluene needed to bind one kg of hydrogen (stoichiometric basis)

…kg toluene/kg H2

Methylcyclohexane (charged carrier) per kg H2

Mass of the hydrogen-rich liquid leaving the reactor per kg H2

…kg MCH/kg H2

Reaction heat released per kg H2

Exothermic heat the reactor cooling loop must reject (not an electricity input)

…kWh-th/kg H2

Annual balance

Average annual utilization of the hydrogenation plant. Used to annualize throughput and costs.

Annual hydrogen bound

Hydrogen charged onto the carrier over the year

…kg/year

Annual auxiliary electricity

Electrical energy for pumping and recycle-gas compression

…MWh/year

Annual toluene make-up

Fresh toluene charged to replace carrier losses (closed-loop basis)

…kg/year

Annual reaction heat rejected

Low-grade heat (180-200 C) available from the reactor cooling loop

…MWh-th/year

Effective auxiliary electricity

Pumping and recycle-gas compression per kg H2, adjusted by capacity-factor penalty

…kWh/kg
Sensitivity to capacity factor

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CAPEX breakdown

Plant equipment cost (installed basis)

Toluene inventory + hydrogenation island + balance of plant

…EUR

CAPEX breakdown: toluene inventory

Initial carrier charge (~10 days), the dominant CAPEX item

…EUR

CAPEX breakdown: hydrogenation island

Reactor, heat exchangers and recycle compressor

…EUR

CAPEX breakdown: balance of plant

Storage, utilities, controls and civil works

…EUR

About

Calculator context

Screening model for the hydrogenation (charging) leg of a toluene/methylcyclohexane (MCH) liquid organic hydrogen carrier (LOHC). Hydrogen is chemically bound onto toluene (C7H8 + 3 H2 -> C7H14) so it can be shipped and stored as an ambient, low-vapour-pressure liquid, then released downstream by dehydrogenation (excluded here). The model computes the carrier mass balance per kg H2, the exothermic reaction heat that the reactor cooling loop must reject, the auxiliary electricity for feed pumping and recycle-gas compression at ~10 bar, and a levelized hydrogenation cost (EUR/kg H2) built from annualized CAPEX (capital recovery factor), fixed O&M, toluene make-up and auxiliary electricity. Reference techno-economics follow Argonne National Laboratory (Papadias, Peng, Ahluwalia 2021, OSTI 1807903): the toluene inventory dominates plant CAPEX (~51%) and the hydrogenation island (reactor, heat exchangers, recycle compressor) is ~31%; levelized MCH production lies between ~0.30 USD/kg-H2 (closed-loop capex-only) and ~1.35 USD/kg-H2 (one-way toluene). All costs are EUR (2023) screening estimates, not a vendor quote.

Model

91 variables — inputs, calculations and outputs, with their dependencies.

91 variables shown of 91
VariableValueUnitDepends on
1——
2083kg H2/h—
90%—
60EUR/MWh—
1EUR/kg—
0.08ratio—
20years—
VariableFormulaUnitDepends on
if((<=0)+((*0.01)<0)+((*0.01)>)+(<0)+(<0)+(<0)+(<=0)+(<)+(>)>0,1,0)bool
*(*0.01)h/year
clamp(+*(-(*0.01)),,)—
/max(,)mol/kg
/max(,)mol/kg H2
abs()*kJ/kg H2
if(==,,)kWh/kg
if(==,,)EUR/(kg H2/h)
if(==,,)—
*(/max(,))^(-)EUR/(kg H2/h)
*(+)EUR
if(==,,)1/year
clamp(,,)1/year
if(<,/max(,),(*(+)^)/max(((+)^-),))—
*EUR/year
*EUR/year
VariableFormulaUnitDepends on
*/max(,)kg toluene/kg H2
/max(**,)kg MCH/kg H2
/max(,)kWh-th/kg H2
*kWh/kg
*kg/year
**kg/year
*/max(,)MWh/year
*/max(,)MWh-th/year
clamp(,,)EUR/(kg H2/h)
*EUR
*EUR
*EUR
*EUR
*(+)EUR
*EUR/year
*EUR/year
+++EUR/year
/max(,)EUR/kg H2
/max(,)EUR/kg H2
/max(,)EUR/kg H2

Assumptions

48 assumptions used in the calculations

  • Prevents division-by-zero and NaN propagation in edge cases.

    Market range Not applicable (numerical parameter).

    0.000001
    Numerical stability constant for division guards.

  • Avoids inline literals in DSL expressions per spec.

    Market range Exact.

    1
    Numeric constant.

  • Converts between grams (molar masses) and kilograms.

    Market range Exact.

    1000g/kg
    Unit conversion.

  • Converts kWh to MWh for annual energy reporting.

    Market range Exact.

    1000kWh/MWh
    Unit conversion.

  • Converts reaction enthalpy from kJ to kWh-thermal.

    Market range Exact.

    3600kJ/kWh
    Unit conversion.

  • Used for capacity-factor annualization.

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

    8760h/year
    Calendar-year hours convention.

  • Converts the gravimetric capacity expressed in wt% to a fraction.

    Market range Exact.

    0.011/%
    Unit conversion.

  • Required because the DSL has no strings.

    Market range Not applicable.

    1
    Numeric selector encoding for Pt catalyst.

  • Required because the DSL has no strings.

    Market range Not applicable.

    2
    Numeric selector encoding for Ni catalyst.

  • Validates the selector domain.

    1
    Input validation bound.

  • Validates the selector domain.

    2
    Input validation bound.

  • Represents non-ideal auxiliary operation at lower utilization in a simple way.

    0
    Screening utilization penalty coefficient.

  • Prevents the penalty from improving performance below the reference consumption.

    Market range 1 (by definition).

    1
    Clamp lower bound for the penalty factor.

  • Avoids unrealistically large penalties at low capacity factors in a screening model.

    1.3
    Clamp upper bound for the penalty factor.

  • Stoichiometric H2 uptake per toluene molecule.

    Market range 3 (exact, stoichiometric).

    3mol H2/mol toluene
    Reaction stoichiometry of toluene hydrogenation.

  • Converts moles of toluene to mass.

    Market range 92.14 (exact).

    92.14g/mol
    Molar mass of toluene.

  • Molar mass of the charged carrier (documentation/cross-check).

    Market range 98.19 (exact).

    98.19g/mol
    Molar mass of methylcyclohexane.

  • Converts hydrogen mass to moles.

    Market range 2.016 (exact).

    2.016g/mol
    Molar mass of hydrogen.

  • Cross-checks the stoichiometric carrier mass and gives MCH per kg H2.

    Market range 6.1 wt% (toluene/MCH system).

    6.1wt%
    Gravimetric hydrogen storage capacity of MCH-TOL.

  • Documents the volumetric storage density (context for transport advantage).

    Market range 47 kg H2/m3 (ambient).

    47kg H2/m3
    Volumetric hydrogen density of MCH-TOL.

  • Endothermic dehydrogenation enthalpy; hydrogenation is its exothermic reverse.

    68.3kJ/mol H2
    Reaction enthalpy of MCH dehydrogenation.

  • Drives the exothermic reaction heat that must be rejected by the cooling loop.

    Market range -69 to -67 kJ/mol H2.

    -68.3kJ/mol H2
    Reaction enthalpy of toluene hydrogenation.

  • Documents the reactor pressure that sets recycle-gas compression duty.

    10bar
    Reactor operating pressure.

  • Documents the reactor temperature and grade of rejected heat.

    240C
    Reactor operating temperature.

  • Sets the recycle-gas duty (excess H2 above stoichiometric is recompressed).

    4mol H2/mol toluene
    Reactor feed H2-to-toluene molar ratio.

  • High single-pass conversion supports the near-complete carrier charging assumption.

    Market range >99% demonstrated.

    99%
    Toluene conversion in the hydrogenation reactor.

  • High selectivity supports treating the product as essentially pure MCH.

    Market range ~99% demonstrated.

    99%
    MCH selectivity in the hydrogenation reactor.

  • Carrier make-up needed to replace losses each charging cycle.

    0.0051/cycle
    Per-cycle toluene loss fraction.

  • Screening auxiliary electricity intensity for a Pt-catalyzed reactor at 10 bar.

    0.6kWh/kg
    Auxiliary electricity per kg H2 (Pt catalyst).

  • Screening auxiliary electricity intensity for a Ni-catalyzed reactor.

    0.8kWh/kg
    Auxiliary electricity per kg H2 (Ni catalyst).

  • Anchors the specific-CAPEX scale curve at the ANL reference plant size.

    Market range Order 1000-3000 kg H2/h for mid-scale plants.

    2083kg H2/h
    Reference H2 throughput for the scale curve.

  • Reference installed plant cost per unit of hourly H2 binding capacity for a Pt catalyst.

    34800EUR/(kg H2/h)
    Reference specific CAPEX (Pt) at the reference size.

  • Reference installed plant cost per unit capacity for a cheaper Ni catalyst.

    30000EUR/(kg H2/h)
    Reference specific CAPEX (Ni) at the reference size.

  • Represents economies of scale for the hydrogenation plant.

    0.7
    Scale exponent for plant CAPEX (Pt).

  • Represents economies of scale for the hydrogenation plant.

    0.7
    Scale exponent for plant CAPEX (Ni).

  • Prevents unrealistically low specific costs from scaling outside the intended range.

    12000EUR/(kg H2/h)
    Clamp minimum for scaled specific CAPEX.

  • Prevents unrealistically high specific costs from scaling outside the intended range.

    90000EUR/(kg H2/h)
    Clamp maximum for scaled specific CAPEX.

  • Allocates plant CAPEX to the carrier inventory (dominant share).

    0.51
    Toluene inventory share of plant CAPEX.

  • Allocates plant CAPEX to the reactor/HX/compressor island.

    0.31
    Hydrogenation-island share of plant CAPEX.

  • Allocates the remaining plant CAPEX to storage, utilities, controls and civil works.

    0.18
    Balance-of-plant share of plant CAPEX.

  • Installation is already included in the reference specific CAPEX; no extra factor applied.

    Market range 0 here; 0.2-0.6 if starting from a bare-equipment cost.

    0
    Installation factor on equipment cost (zero to avoid double counting).

  • Indirect and owner costs are already included in the reference CAPEX; no extra factor applied.

    Market range 0 here; 0.1-0.5 if starting from an installed-equipment cost.

    0
    Indirect/owner factor on installed plant cost (zero to avoid double counting).

  • Represents routine maintenance, staffing and catalyst service for a Pt reactor.

    0.031/year
    Fixed O&M fraction of total project CAPEX (Pt).

  • Represents routine maintenance and catalyst service for a Ni reactor.

    0.0351/year
    Fixed O&M fraction of total project CAPEX (Ni).

  • Prevents implausibly low O&M fractions.

    0.0151/year
    Clamp minimum for the O&M fraction.

  • Prevents implausibly high O&M fractions.

    0.061/year
    Clamp maximum for the O&M fraction.

  • Documentation anchor for the upper bound of the levelized hydrogenation cost.

    Market range Upper bound ~1.35 USD/kg-H2 (one-way carrier).

    1.35USD/kg H2
    Reported levelized MCH production cost.

  • Documentation anchor for the lower bound of the levelized hydrogenation cost.

    Market range Lower bound ~0.30 USD/kg-H2 (closed loop, capex only).

    0.3USD/kg H2
    Reported capex-only hydrogenation cost.

Sources

Primary reference

Argonne National Laboratory (Papadias, Peng, Ahluwalia 2021, OSTI 1807903) — Hydrogen carriers: toluene hydrogenation techno-economics; Wikipedia LOHC; Chiyoda SPERA.