Hydrogen Production with NeqSim

Guide for modeling hydrogen production routes — steam methane reforming (SMR), autothermal reforming (ATR), partial oxidation (POX), PSA purification (blue H2), and water electrolysis (green/pink H2). Companion to neqsim-ccs-hydrogen (transport/storage/blending) and neqsim-reaction-engineering (reformer kinetics).

When to Use This Skill

• SMR fired reformer, ATR, and POX plant flowsheets with WGS + PSA
• Oxygen-to-carbon and steam-to-carbon envelope screening
• Reformer furnace heat-balance and tube-wall checks
• POX/ATR quench, refractory, soot-risk, and H2/CO screening
• PSA bed sizing and purity/recovery analysis
• Electrolyzer technology selection (PEM vs Alkaline vs SOEC vs AEM)
• Stack voltage modeling from current density (I-V curves)
• Specific energy consumption (kWh/kg H₂)
• Hydrogen plant CAPEX estimation
• Cryogenic para/ortho H₂ conversion screening
• Catalyst activity decay for SMR/WGS/ammonia cracking studies
• Blue vs green H₂ techno-economic comparison

Applicable Standards

Core Classes (Thermochemical route templates)

Thermochemical maturity map

Core Classes (Horizon 1)

Core Classes (Horizon 1.5)

Core Classes (Horizon 3 foundations)

Recipe 0 — SMR / ATR / POX route builders

Use the route builders when a task needs a runnable screening flowsheet quickly. They create feeds with correct trace syngas products, set SRK + classic mixing, wire the reactor model, and optionally add a PSA cascade.

ProcessSystem smr = new SMRHydrogenPlantBuilder().setName("SMR screening")
    .setMethaneFeedMolePerSec(100.0)
    .setSteamToCarbonRatio(3.0)
    .setIncludePsa(true)
    .build();
smr.run();

ReformerFurnace furnace =
    (ReformerFurnace) smr.getUnit("SMR screening reformer furnace");
double dutyKW = furnace.getTubeHeatDemandKW();
double heatBalance = furnace.getHeatBalanceRatio();

ProcessSystem atr = new ATRHydrogenPlantBuilder().setName("ATR screening")
    .setMethaneFeedMolePerSec(100.0)
    .setSteamToCarbonRatio(1.5)
    .setOxygenToCarbonRatio(0.60)
    .setIncludePsa(true)
    .build();
atr.run();

ProcessSystem pox = new POXHydrogenPlantBuilder().setName("POX screening")
    .setMethaneFeedMolePerSec(100.0)
    .setOxygenToCarbonRatio(0.55)
    .setSteamToCarbonRatio(0.20)
    .build();
pox.run();

Key route outputs:

• ReformerFurnace: getSyngasOutStream(), getFlueGasOutStream(), getTubeHeatDemandKW(), getAvailableRadiantHeatKW(), getHeatBalanceRatio().
• CatalyticTubeReformer: getMethaneConversion(), getHeatDuty("kW"), getTubeWallTemperature(), isTubeWallTemperatureAcceptable().
• AutothermalReformer: getOxygenToCarbonRatio(), getSteamToCarbonRatio(), getMethaneConversion(), getSootRiskIndex(), getBurnerZone().
• PartialOxidationReactor: getHydrogenToCarbonMonoxideRatio(), getRefractoryWarning(), getQuenchSection(), getSootRiskIndex().
• Every new route unit exposes getResults() and toJson() for agent reports.

Recipe 1 — Blue H₂ full chain (SMR + WGS + capture + PSA + export)

BlueHydrogenPlantBuilder builder = new BlueHydrogenPlantBuilder()
    .setName("Blue H2 screening")
    .setMethaneFeedMolePerSec(100.0)
    .setSteamToCarbonRatio(3.0)
    .setCo2CaptureFraction(0.90)
    .setCo2ExportPressure(110.0)
    .setH2ExportPressure(100.0)
    .setIncludePsa(true);

ProcessSystem process = builder.build();
process.run();

double h2KgPerHr = builder.getHydrogenProductMassFlowKgPerHour();
double capturedCo2KgPerHr = builder.getCapturedCo2MassFlowKgPerHour();
double residualIntensity = builder.getCarbonIntensityKgCO2PerKgH2();
double grossIntensity = builder.getGrossCarbonIntensityKgCO2PerKgH2();
String resultsJson = builder.toJson();

Notes

• The default sequence is SMR furnace → HT WGS → LT WGS → cooler/KO → CO2 capture → CO2 compressor → PSA → H2 dryer → H2 compressor.
• WaterGasShiftReactor treats methane, nitrogen, and oxygen as inert and reports CO conversion, H2 gain, CO2 formation, heat duty, and WGS ratio.
• ComponentCaptureUnit is a screening placeholder. Use it for CO2 capture and H2 drying when detailed amine, membrane, or molecular-sieve packages are not yet available.
• Carbon-intensity reporting counts residual direct carbon as CO2 equivalent and reports both residual and gross intensity per kg H2 product.

Recipe 1b — PSA-only purification block

PressureSwingAdsorptionBed psa = new PressureSwingAdsorptionBed("PSA", koVap);
psa.setSorbent(PressureSwingAdsorptionBed.SorbentType.ACTIVATED_CARBON);
psa.setRecoveryTarget(0.88);
psa.run();

double purityH2 = psa.getH2Purity();
double recoveryH2 = psa.getH2Recovery();
double[] tailComp = psa.getTailGasComposition();

Use the standalone PSA block when a shifted syngas stream is already available from a custom flowsheet.

Recipe 2 — Green H₂ Electrolyzer

// Water feed to the stack — molar flow sets the H₂ production target.
SystemInterface water = new Fluid().create("water");
Stream feed = new Stream("water", water);
feed.setFlowRate(100.0, "mole/sec");      // ~10 kg H₂/hr at η_F = 1
feed.setTemperature(298.15, "K");
feed.setPressure(1.0, "bara");
feed.run();

Electrolyzer el = new Electrolyzer("PEM stack", feed);
el.setTechnology(ElectrolyzerTechnology.PEM);  // applies V/j/η_F; retains inlet T/P
el.setIVCharacteristic(new ElectrolyzerIVCharacteristic(ElectrolyzerTechnology.PEM));
el.run();

double power_kW = el.getStackPower();
double sec      = el.getSpecificEnergyConsumption_kWh_per_kg_H2();
double V_cell   = el.getCellVoltage();   // recomputed from I-V at run time

Technology selector

Distinguish current efficiency from LHV/HHV energy efficiency. Treat the table as implemented screening inputs and arithmetic, not measured technology performance. For alkaline, use Ulleberg (2003), Eq. (9), Table 3 PHOEBUS parameters (f1=250 (mA/cm²)², f2=0.96, 80 °C, reported 7 bar), DOI 10.1016/S0360-3199(02)00033-2. Evaluating at 400 mA/cm² extrapolates beyond Fig. 6; it has no established uncertainty interval or off-design qualification. Supply measured efficiency after setTechnology; that call overwrites prior voltage/efficiency settings and retains the inlet T/P. Set feed T/P separately. Consult the equipment guide and open #4682 before using legacy defaults in a benchmark. At alkaline nominal j/T, the existing I–V model gives 1.7064354 V and 47.33637 kWh/kg instead of the fixed-voltage result. Do not infer a validated SEC from either model or use SOEC heat substitution as evidence of current efficiency.

I-V curve internals

getCellVoltage(j, T_K) = E_rev(T) + A · log10(j / j0) + R · j

• E_rev(T) = 1.229 V + (-0.85 mV/K) · (T - 298.15) (Larminie & Dicks)
• Tafel slope A, exchange current j0, ASR R are technology defaults
• Below j0 the model returns E_rev (no spurious negative overpotential)

Recipe 4 — Multi-bed PSA cascade

PSACascade cascade = new PSACascade("H2-PSA", koVap);
cascade.setConfiguration(PSACascade.CascadeConfiguration.BEDS_6);  // 6 beds, 2 PEQ
cascade.setSorbent(PressureSwingAdsorptionBed.SorbentType.ACTIVATED_CARBON);
cascade.setPerBedRecoveryTarget(0.82);   // single-bed equilibrium recovery
cascade.setCycleTime(300.0);             // seconds per bed cycle
cascade.run();

double purity   = cascade.getH2Purity();        // > 99.9 %
double recovery = cascade.getH2Recovery();      // single-bed + cascade uplift
Stream tail     = cascade.getTailGasStream();   // for SMR fuel-gas balance

Cascade uplift table (pressure equalisation steps → recovery gain over a single bed):

Total cascade recovery is capped at 0.93 (industrial benchmark for H₂ PSA on shifted syngas).

Recipe 5 — PSA cascade CAPEX

PSACostEstimate cost = new PSACostEstimate(cascade);   // derives N_beds, sorbent, mass
cost.calculateCostEstimate();
double usd = cost.getPurchasedEquipmentCost();

• Reference per-bed vessel cost: USD 250 000 at 2 m × 4 m TL-TL, scale exponent 0.6.
• Valve skid: USD 60 000 per bed (manifold + actuators + cycle controller).
• Sorbent inventory: USD 4/kg AC or USD 10/kg Zeolite 13X.
• Balance-of-plant strip (setIncludeBalanceOfPlant(false)) removes ~25 % for vessel-only quotes.
• CEPCI 2024 = 800 reference; multiply by CostEstimationCalculator.getCurrentCepci()/800.

Recipe 6 — Para/ortho H₂ correction for cryogenic screening

double para20K = ParaOrthoH2Correction.getEquilibriumParaFraction(20.0);
double heatJPerKg = ParaOrthoH2Correction.getNormalToEquilibriumHeatJPerKg(20.0);
double cpCorrection = ParaOrthoH2Correction.getCpCorrectionJPerKgK(40.0);
double conductivityFactor = ParaOrthoH2Correction.getThermalConductivityCorrectionFactor(20.0);
double tauSeconds = ParaOrthoH2Correction.estimateEquilibrationTimeSeconds(
    77.0, ParaOrthoH2Correction.ConversionCatalyst.HYDROUS_FERRIC_OXIDE);

• Normal hydrogen is 25% para; equilibrium hydrogen approaches >99% para near 20 K.
• getNormalToEquilibriumHeatJPerKg(T) returns positive exothermic heat release.
• getCpCorrectionJPerKgK(T) is equilibrium minus frozen-normal rotational heat capacity.
• Thermal-conductivity correction factors are bounded screening multipliers for normal-H₂ correlations.

Recipe 7 — Catalyst deactivation activity factor

CatalystBed bed = new CatalystBed();
CatalystDeactivationKinetics kinetics = new CatalystDeactivationKinetics(
    CatalystDeactivationKinetics.CatalystFamily.NICKEL_REFORMING)
        .setTemperature(973.15)
        .setSulfurPpmv(0.05)
        .setCarbonPotential(0.5)
        .setSteamToCarbonRatio(2.5)
        .setOperationHours(8000.0);

double activity = kinetics.applyTo(bed);
double timeTo80 = kinetics.estimateTimeToActivity(0.80);
String mechanism = kinetics.getDominantMechanism();

• Families: NICKEL_REFORMING, IRON_CHROMIUM_HT_SHIFT, COPPER_ZINC_LT_SHIFT, RUTHENIUM_AMMONIA_CRACKING.
• Mechanisms: sulfur poisoning, chloride poisoning, coking, and thermal sintering.
• Use vendor/lab/historian coefficients before detailed run-length guarantees.

Recipe 3 — Electrolyzer CAPEX

el.initMechanicalDesign();
ElectrolyzerMechanicalDesign mech =
    (ElectrolyzerMechanicalDesign) el.getMechanicalDesign();
mech.calcDesign();   // populates totalPowerKW

ElectrolyzerCostEstimate cost = new ElectrolyzerCostEstimate(mech);
cost.setTechnology("PEM");
double usd = cost.getPurchasedEquipmentCost();

• Specific CAPEX (2024 USD/kW, CEPCI 800): PEM 1250, Alkaline 800, SOEC 2500, AEM 1500.
• Scale exponent 0.85 vs reference 1 MW.
• setIncludeBalanceOfPlant(false) strips ~35% for stack-only quotes.
• Numbers are AACE Class 4–5 — do not use for FID without vendor budget quotes.

Color taxonomy and route map

Common pitfalls

• Thermochemical scope: ReformerFurnace, AutothermalReformer, and PartialOxidationReactor are route-screening models, not vendor reactor designs. Use them for heat balance, O2/C and S/C envelopes, soot/refractory warnings, and handoff to WGS/PSA/CO2 capture. Use vendor data or detailed CFD for radiant-box, burner, and tube-rating guarantees.
• Trace products: Gibbs syngas models need product components present in the feed. The route builders and HydrogenProductionUtils.ensureSyngasComponents() add hydrogen, CO, and CO2 at trace levels.
• ATR/POX controls: ratio controls rebuild the controlled inlet clone from methane moles before running. Disable ratio control only when a measured or externally generated feed composition must be preserved exactly.
• PressureSwingAdsorptionBed.run() mass balance: product purity is computed from feedH2 × recovery ÷ remaining light gases. Always set the recovery target before run(); default is 0.85.
• Electrolyzer voltage: when no ElectrolyzerTechnology is set, the legacy fixed-voltage path (V = 1.23 V, η_F = 1.0) stays active for backward compatibility.
• Specific energy: getSpecificEnergyConsumption_kWh_per_kg_H2() is stackPower_kW / (n_H2 · MW_H2 · 3600). Below ~33 kWh/kg means the model is predicting >100% LHV efficiency — recheck inputs.
• Cost estimate: requires mech.calcDesign() before construction so totalPowerKW > 0.
• Para/ortho scope: ParaOrthoH2Correction is a screening correction, not a complete liquefaction process model.
• Catalyst life scope: CatalystDeactivationKinetics default coefficients are order-of-magnitude values. Tune them to vendor or historian data for plant-specific forecasts.

Tests for verification

Deferred (Horizon 2/3)

• Rate-based amine absorber for CO₂ capture upstream of blue H₂
• Full cryogenic H₂ liquefaction train with expanders and heat integration
• High-fidelity reformer radiant-box view factors, burner CFD, and vendor tube-rating integration
• Ammonia cracking kinetics for H₂ delivery from NH₃
• Hydrogen LCA per production step
• LOHC and photo-electrolysis