{
  "authors": [],
  "basis": {
    "capacity": "2000 t/d prilled urea (ASSUMED)",
    "location": "generic (not chosen)",
    "operating_hours_per_year": 8000
  },
  "benchmarks": [],
  "chemistry": {
    "inputs": [
      {
        "chemical": "ammonia",
        "grade": null,
        "note": "feed:NH3: liquid ammonia from the ammonia plant; no inventory_key, its background link is the override in lca/mappings.yaml",
        "role": "feedstock"
      },
      {
        "chemical": "carbon-dioxide",
        "grade": null,
        "inventory_key": "feed:CO2",
        "note": "CO2 from the ammonia plant's CO2 removal (98.5 mol%, ASSUMED)",
        "role": "feedstock"
      },
      {
        "chemical": "air",
        "grade": null,
        "inventory_key": "feed:AIR",
        "note": "Ambient prilling air (cooling medium); passivation air feed:PAIR",
        "role": "feedstock"
      }
    ],
    "outputs": [
      {
        "chemical": "urea",
        "grade": null,
        "inventory_key": "product:UREA",
        "note": "Prilled urea to storage",
        "role": "main-product"
      },
      {
        "chemical": "water",
        "grade": null,
        "inventory_key": "product:WATER",
        "note": "Treated process condensate, 1 ppm(wt) NH3 and urea, re-used as boiler feed water",
        "role": "by-product"
      }
    ],
    "utilities": [
      {
        "chemical": "electricity",
        "grade": null,
        "inventory_key": "feed:POWER",
        "note": "CO2 compressor (electric drive ASSUMED), HP pumps, prilling fan",
        "role": "utility"
      },
      {
        "chemical": "steam",
        "grade": null,
        "inventory_key": "feed:MPS",
        "note": "MP steam 2400 kPa(a): HP stripper, 2nd evaporator, hydrolyser (0.8 t/t urea, BREF Table 8.5)",
        "role": "utility"
      },
      {
        "chemical": "cooling-water",
        "grade": null,
        "inventory_key": "product:CW",
        "note": "25/35 C (ASSUMED)",
        "role": "utility"
      }
    ]
  },
  "description": "Liquid ammonia and CO2 (with passivation air) are brought to 14 MPa. The CO2 strips the\nreactor effluent in a steam-heated falling-film stripper; the stripper gas, the fresh ammonia\nand the recycled carbamate condense in the HP carbamate condenser, which raises the LP steam\nof the plant, and the urea reactor completes the conversion. The stripped solution is\ndecomposed in an LP rectifier at 0.3 MPa, the off-gas condensed to carbamate and pumped back\nthrough the HP scrubber. Two vacuum evaporators make a urea melt, which is prilled in a\nforced-draft tower; the exhaust is water-scrubbed and the liquor recycled. The process\ncondensate is desorbed and hydrolysed to boiler-feed-water quality.\n\nThe reactor is a conversion model (CO2 conversion per pass assumed within the range the EU\nBREF reports), unconverted carbamate is carried as NH3 + CO2, and the separations and duties\nare specified values of a provenance script: no thermodynamic model of the NH3-CO2-urea-water\nsystem is qualified in ChemE-as-Code yet. See DESIGN.md for every assumption and gated step.\n",
  "design_basis": {
    "assumptions": [
      "Synthesis: 14000 kPa(a), 453 K, N/C 2.8 at the reactor inlet (BREF Table 8.14, CO2 stripping example); H2O/CO2 0.45 ASSUMED (D-005).",
      "Reactor: conversion model of 2 NH3 + CO2 -> urea + H2O, CO2 conversion 0.58 per pass ASSUMED within the 50-80 % of BREF section 8.2.1; carbamate carried as NH3 + CO2 (D-005).",
      "Stripper: 15 % of the NH3, 12 % of the CO2 and 85 % of the water fed leave with the stripped solution, ASSUMED (D-006).",
      "LP rectifier 300 kPa(a); solution to evaporation 70 wt% urea; process condensate 6 wt% NH3, 4 wt% CO2, 1 wt% urea (ASSUMED after the BREF Table 8.8 remark, D-006).",
      "Evaporation 95 wt% at 33 kPa(a) / 403 K, then melt at 3 kPa(a) / 413 K; biuret formation lumped into the 2nd evaporator (D-007).",
      "Prilling: melt 413 K, prills 343 K, air 303 -> 343 K; fusion enthalpy 14 kJ/mol ASSUMED (D-007).",
      "All flows, temperatures and duties are concept estimates from specified splits and hand heat estimates; no qualified property method (D-008); accuracy not stated."
    ],
    "source": "process/design-basis.yaml"
  },
  "engineering": {
    "description": "Urea by CO2 stripping with total recycle, LP recirculation, vacuum evaporation and prilling, 2000 t/d, with ammonia and CO2 from an ammonia plant outside the boundary (issue ChemE-as-Code/process-library#120)",
    "name": "Urea (CO2 stripping)",
    "requires": "cheme-as-code>=0.8",
    "stage": "concept",
    "stages": [
      {
        "id": "concept",
        "title": "Concept and feasibility"
      },
      {
        "id": "basic",
        "title": "Basic engineering"
      },
      {
        "id": "detail",
        "title": "Detail engineering"
      }
    ],
    "tool": "plantcode"
  },
  "facets": {
    "feedstock_basis": [
      "fossil"
    ],
    "product_classes": [
      "fertilizers"
    ],
    "region": "generic",
    "unit_operations": [
      "compression",
      "reaction",
      "stripping",
      "absorption",
      "evaporation",
      "prilling"
    ]
  },
  "families": [
    "fertilizers"
  ],
  "gap_count": 2,
  "gates": null,
  "id": "urea-1",
  "issues": {
    "closed_count": 0,
    "list_url": "https://github.com/ChemE-as-Code/process-library/issues?q=is%3Aissue%20label%3A%22process%3Aurea-1%22",
    "new": {
      "action": "https://github.com/ChemE-as-Code/process-library/issues/new?template=1-action-item.yml&labels=process%3Aurea-1&process=urea-1",
      "change": "https://github.com/ChemE-as-Code/process-library/issues/new?template=4-design-change.yml&labels=process%3Aurea-1&process=urea-1",
      "hold": "https://github.com/ChemE-as-Code/process-library/issues/new?template=2-engineering-hold.yml&labels=process%3Aurea-1&process=urea-1",
      "process": "https://github.com/ChemE-as-Code/process-library/issues/new?template=6-process-development.yml&labels=process%3Aurea-1&process=urea-1",
      "tq": "https://github.com/ChemE-as-Code/process-library/issues/new?template=3-technical-query.yml&labels=process%3Aurea-1&process=urea-1",
      "tracker": "https://github.com/ChemE-as-Code/process-library/issues/new?template=7-process-tracker.yml&labels=process%3Aurea-1&process=urea-1"
    },
    "open": [],
    "open_by_gate": {},
    "open_count": 0,
    "private": false,
    "repository": "ChemE-as-Code/process-library"
  },
  "keywords": [
    "urea",
    "CO2 stripping",
    "total recycle",
    "carbamate",
    "prilling",
    "biuret",
    "hydrolyser",
    "fertiliser"
  ],
  "lca": {
    "allocation": "none",
    "backend": "factors",
    "boundary": "cradle-to-gate",
    "categories": [
      {
        "id": "climate-change",
        "method": "GWP100",
        "title": "Climate change",
        "unit": "kg CO2-eq"
      }
    ],
    "contributions": [
      {
        "basis": "ipcc2021-gwp100 (124-38-9, air, fossil)",
        "category": "climate-change",
        "impact": 9.04429e-05,
        "key": "emission:CO2",
        "phase": "operation",
        "share": 1.0,
        "status": "PUBLISHED"
      }
    ],
    "data_sources": [],
    "factors_status": "published",
    "functional_unit": {
      "amount": 1,
      "chemical": "urea",
      "grade": null,
      "label": "1 kg urea",
      "product": "UREA",
      "product_name": "Urea",
      "product_title": "Prilled urea to storage",
      "unit": "kg"
    },
    "goal": "Preliminary gate-to-gate life cycle inventory of prilled urea from a CO2-stripping total-recycle plant, for the process library: the foreground exchanges per kg of urea at the gate (raw materials, utilities, emissions, wastes) from the concept flowsheet, ready to be linked to background datasets later. Not an impact assessment: no background is linked.",
    "inventory": [
      {
        "direction": "input",
        "key": "feed:NH3",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.565306,
        "title": "Liquid ammonia from the ammonia plant",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:CO2",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.738097,
        "title": "CO2 from the ammonia plant CO2 removal",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:PAIR",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.0139162,
        "title": "Passivation air (ambient)",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:AIR",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 8.4784,
        "title": "Prilling air (ambient)",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:POWER",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.096132,
        "title": "Electric power",
        "unit": "kWh"
      },
      {
        "direction": "input",
        "key": "feed:MPS",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.408,
        "title": "MP steam 2400 kPa(a)",
        "unit": "kWh"
      },
      {
        "direction": "output",
        "key": "product:UREA",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.0,
        "title": "Prilled urea to storage",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:VENT",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.0190292,
        "title": "LP absorber vent to atmosphere",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:EXHAUST",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 8.55213,
        "title": "Scrubbed prilling tower exhaust to atmosphere",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:WATER",
        "kind": "material",
        "phase": "operation",
        "provenance": "calculated",
        "quantity": 0.224544,
        "title": "Treated process condensate to battery limit",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:CW",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.524328,
        "title": "Cooling water return",
        "unit": "kWh"
      },
      {
        "direction": "output",
        "key": "emission:BIURET",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.0,
        "title": "BIURET to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:CO2",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 9.04429e-05,
        "title": "CO2 to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:H2O",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.198818,
        "title": "H2O to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:N2",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 6.42292,
        "title": "N2 to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:NH3",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.000269448,
        "title": "NH3 to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:O2",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.94882,
        "title": "O2 to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:UREA",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.000232675,
        "title": "UREA to the environment",
        "unit": "kg"
      }
    ],
    "no_total": {},
    "not_computed": [],
    "pcf": [
      {
        "basis": "climate-change",
        "key": "fossil",
        "unit": "kg CO2-eq",
        "value": 9.04429e-05
      },
      {
        "basis": "climate-change",
        "key": "dluc",
        "unit": "kg CO2-eq",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "other_biogenic",
        "unit": "kg CO2-eq",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "excluding",
        "unit": "kg CO2-eq",
        "value": 9.04429e-05
      },
      {
        "basis": "climate-change",
        "key": "withdrawal",
        "unit": "kg CO2-eq",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "withdrawal_other",
        "unit": "kg CO2-eq",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "stored_biogenic",
        "unit": "kg CO2-eq",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "including",
        "unit": "kg CO2-eq",
        "value": 9.04429e-05
      },
      {
        "basis": "climate-change",
        "key": "product_carbon",
        "unit": "kg C",
        "value": 0.199661
      },
      {
        "basis": "climate-change",
        "key": "biogenic_carbon",
        "unit": "kg C",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "fossil_carbon",
        "unit": "kg C",
        "value": 0.199661
      },
      {
        "basis": "climate-change",
        "key": "ccu_carbon",
        "unit": "kg C",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "ccu_non_fossil_carbon",
        "unit": "kg C",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "biogenic_co2_emitted",
        "unit": "kg CO2",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "biogenic_co2_uptake",
        "unit": "kg CO2",
        "value": 0.0
      },
      {
        "basis": "climate-change",
        "key": "stored_co2",
        "unit": "kg CO2",
        "value": 0.0
      }
    ],
    "publishable": true,
    "result": {
      "classification": "partial",
      "gaps": 5,
      "label": "partial screening carbon footprint",
      "publication": "public"
    },
    "sources": [
      "lca/README.md",
      "lca/dataset.yaml",
      "lca/factors.yaml",
      "lca/gaps.csv",
      "lca/inventory.csv",
      "lca/lca.yaml",
      "lca/mappings.yaml",
      "lca/results.csv",
      "lca/results.md",
      "lca/uncertainty.csv"
    ],
    "totals": {
      "baseline": {
        "climate-change": 9e-05
      }
    },
    "withheld_reason": null
  },
  "lci_gaps": [
    {
      "dataset": "urea-by-co2-stripping-total-recycle-prilling-2000-t-d",
      "key": "feed:CO2",
      "link": "technosphere",
      "type": "input"
    },
    {
      "dataset": "urea-by-co2-stripping-total-recycle-prilling-2000-t-d",
      "key": "emission:UREA",
      "link": "biosphere",
      "type": "emission"
    }
  ],
  "maintainers": [
    {
      "name": "Artur Schweidtmann"
    }
  ],
  "maturity": "concept",
  "preliminary": true,
  "provenance": {
    "library_commit": "c3ab3488c602bc797fdc98feffd4578375150dd0",
    "previews": {
      "sheets": [
        "BFD",
        "PFD"
      ],
      "source_commit": "c3ab3488c602bc797fdc98feffd4578375150dd0",
      "tool": "cheme 1.6.0 (pyDEXPI 2.1.0)"
    },
    "previews_stale": false,
    "source_commit": "c3ab3488c602bc797fdc98feffd4578375150dd0"
  },
  "publication": {
    "license": "CC-BY-4.0",
    "status": "public"
  },
  "references": [
    {
      "title": "European Commission JRC (2007) Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic Chemicals - Ammonia, Acids and Fertilisers (LVIC-AAF BREF), chapter 8 Urea and UAN",
      "url": "https://bureau-industrial-transformation.jrc.ec.europa.eu/sites/default/files/2022-03/LVIC-AAF.pdf"
    },
    {
      "doi": "10.1002/14356007.a27_333.pub2",
      "title": "Meessen, J.H. Urea. Ullmann's Encyclopedia of Industrial Chemistry (identity verified; not numerically audited)"
    },
    {
      "doi": "10.1002/cite.201400064",
      "title": "Meessen, J.H. (2014) Urea synthesis. Chemie Ingenieur Technik 86:2180-2189 (abstract only; not numerically audited)"
    }
  ],
  "repository": {
    "access": "public",
    "path": "processes/urea-1",
    "url": "https://github.com/ChemE-as-Code/process-library"
  },
  "representations": [
    {
      "bytes": 41526,
      "id": "BFD",
      "kind": "bfd",
      "preview": "artifacts/urea-1/BFD.svg",
      "source": "process/BFD.xml",
      "status": "preview",
      "title": "Block flow diagram"
    },
    {
      "bytes": 195023,
      "id": "PFD",
      "kind": "pfd",
      "preview": "artifacts/urea-1/PFD.svg",
      "source": "process/PFD.xml",
      "status": "preview",
      "title": "Process flow diagram"
    },
    {
      "id": "process-model",
      "kind": "process-model",
      "source": "process/flowsheet.yaml",
      "status": "viewer",
      "title": "Flowsheet and stream table"
    },
    {
      "id": "equipment-list",
      "kind": "equipment-list",
      "source": "equipment/equipment-list.yaml",
      "status": "viewer",
      "title": "Equipment list"
    },
    {
      "id": "lca",
      "kind": "lca",
      "source": "lca/lca.yaml",
      "status": "viewer",
      "title": "Life cycle assessment"
    }
  ],
  "summary": "Fertiliser urea from ammonia and CO2 (both from an ammonia plant outside the boundary) by high-pressure CO2 stripping with total recycle, low-pressure recirculation, two-stage vacuum evaporation and prilling with exhaust scrubbing. Concept stage, assumed basis, preliminary gate-to-gate LCI.",
  "title": "Urea by CO2 stripping, total recycle, prilling (2000 t/d, concept)",
  "validation": {
    "notes": "Concept PFD with closed mass, component, element and reaction-extent balances (cheme validate, cheme process streams: all 5 blocks and 22 steps ok). Fresh feeds 565.3 kg NH3 and 731.8 kg CO2 per t urea against 567 and 733 kg/t reported for CO2 stripping (BREF LVIC-AAF Table 8.3): the element balance, not a model validation. Reactor and hydrolyser outlets are calculated by cheme (conversion reactors); the separator outlets and all duties are specified/hand-estimated values of scripts/urea_balance.py (no property package is qualified for aqueous NH3-CO2-urea-carbamate). Energy closure not evaluable in core. Utilities against the BREF benchmarks: steam 0.8 t/t (taken from BREF Table 8.5), electricity 96 kWh/t (BREF 110), cooling water 45 m3/t (BREF 60): the estimate is incomplete for minor drives and coolers. Preliminary gate-to-gate LCI (lca/inventory.csv); lca/dataset.yaml is in the Atlas build, marked preliminary, with feed:CO2 and emission:UREA listed as gaps (DESIGN.md D-014). cheme maturity reaches no level (assumed feeds, unsourced specified separations), so `concept` here is the schema's lowest value, not an evidenced level. Agent-reviewed only (reviews/2026-10-27-pfd-lci-review.md); no human review. Main products and feeds are listed under chemistry with their chemicals registry entries (issue #251).",
    "status": "unreviewed"
  },
  "viewer": {
    "commit": "c3ab3488c602bc797fdc98feffd4578375150dd0",
    "dirty": false,
    "sheets": [
      "process/BFD.xml",
      "process/PFD.xml"
    ],
    "skipped": [],
    "snapshot": "snapshots/urea-1/",
    "stale": false,
    "tool": "cheme-as-code 1.6.0",
    "views": [
      "checks",
      "streams"
    ]
  }
}