{
  "authors": [],
  "basis": {
    "capacity": "6.25 t/h solid NaCN (98 wt%), 50 kt/a (ASSUMED)",
    "location": "generic (not chosen)",
    "operating_hours_per_year": 8000
  },
  "benchmarks": [],
  "chemistry": {
    "inputs": [
      {
        "chemical": "ammonia",
        "grade": null,
        "note": "feed:NH3F: liquid ammonia from the ammonia plant (ammonia-1), 0.437 kg/kg NaCN",
        "role": "feedstock"
      },
      {
        "chemical": "sodium-hydroxide",
        "grade": null,
        "note": "feed:NAOHF: caustic soda 50 wt% from the chlor-alkali plant (chlor-alkali-1), counted by mass of the solution",
        "role": "feedstock"
      },
      {
        "chemical": "methane",
        "grade": null,
        "inventory_key": "feed:NG",
        "note": "Natural gas modelled as methane (ASSUMED)",
        "role": "feedstock"
      },
      {
        "chemical": "air",
        "grade": null,
        "inventory_key": "feed:AIR",
        "note": "Process air of the converter (oxygen source); combustion air of the tail gas boiler is feed:BAIR",
        "role": "feedstock"
      }
    ],
    "outputs": [
      {
        "chemical": "sodium-cyanide",
        "grade": null,
        "inventory_key": "product:NACN",
        "note": "Solid sodium cyanide (98 wt%) to packing",
        "role": "main-product"
      },
      {
        "chemical": "carbon-dioxide",
        "grade": null,
        "inventory_key": "product:STACK",
        "note": "Fossil CO2 of the tail gas boiler flue gas, 0.49 kg per kg product",
        "role": "emission"
      },
      {
        "chemical": "wastewater",
        "grade": null,
        "inventory_key": "product:WW",
        "note": "Process water with traces of HCN and ammonia to cyanide destruction and wastewater treatment",
        "role": "waste"
      },
      {
        "chemical": "steam",
        "grade": null,
        "note": "MP steam 1500 kPa(a) from the waste heat boiler and the tail gas boiler, net of the plant's own use (product:MPSX). Upper bound: adiabatic converter, no converter, waste heat boiler or tail gas boiler losses; probably 15-20 % lower (DESIGN.md D-010)",
        "role": "co-product"
      }
    ],
    "utilities": [
      {
        "chemical": "electricity",
        "grade": null,
        "inventory_key": "feed:POWER",
        "note": "Air blower K-101 and an ASSUMED lump for pumps, vacuum pumps, centrifuge, dryer and briquetting; the chiller power (about 0.8-1.2 MW for 4.8 MW of chilled water) is not included, it belongs to the chilled-water background (DESIGN.md D-010)",
        "role": "utility"
      },
      {
        "chemical": "cooling-water",
        "grade": null,
        "inventory_key": "product:CW",
        "note": "25/35 C (ASSUMED)",
        "role": "utility"
      },
      {
        "chemical": "chilled-water",
        "grade": null,
        "inventory_key": "product:CHW",
        "note": "2/10 C (ASSUMED), HCN absorber and lean water chiller; the chiller power is carried by this background, not by feed:POWER",
        "role": "utility"
      }
    ]
  },
  "description": "An air-operated Andrussow converter (Pt/Rh 90/10 gauze, adiabatic, about 1430 K) converts a\nmethane-ammonia-air mixture at the feed ratios of an open patent example (O2/NH3 1.15,\nCH4/NH3 0.98) with an HCN yield of 62.9 % on the ammonia fed; the by-products follow a\npublished commercial converter-gas composition. A waste heat boiler raises MP steam, an\nammonium phosphate absorber/stripper recycles 99 % of the unconverted ammonia, and HCN is\nabsorbed in chilled water to 2.5 wt% and rectified to 99.5 wt%. Liquid HCN reacts with 50 wt%\ncaustic soda; the 45 wt% NaCN solution is crystallised at 70 C and 100 mm Hg, centrifuged and\ndried to 98 wt% NaCN. The hydrogen- and CO-bearing tail gas is burned in a boiler, which is the\nplant's single emission point to air.\n\nAll values are concept estimates. The converter yield and feed ratios are taken from\nUS 6,596,251 B2 and the converter-gas by-products and crystalliser conditions from\nUS 4,847,062 A; the absorption, stripping, crystallisation and duty values come from an\nindependent script, because no property package is qualified by ChemE-as-Code for aqueous\nHCN/NH3 or the NaCN/NaOH electrolyte; see DESIGN.md of the engineering files.\n",
  "design_basis": {
    "assumptions": [
      "ASSUMED converter: air-operated Andrussow converter on Pt/Rh 90/10 gauze, adiabatic, no feed preheat, at the feed ratios and HCN yield of US 6,596,251 B2 Table 2 run 1 (O2/NH3 1.15, CH4/NH3 0.98, 62.9 % on NH3) (D-004).",
      "ASSUMED by-product split of the converter gas from the commercial converter gas of US 4,847,062 A Example 1 (NH3, CH4, CO, CO2 per HCN); O2 99.9 % consumed (D-004).",
      "ASSUMED ammonia recovery by ammonium phosphate absorption and stripping, 99 % of the converter NH3 recycled, 0.5 % to the process water, 0.5 % slip (D-006); 10 kg LP steam per kg NH3 recovered (no source).",
      "ASSUMED HCN absorption in chilled water to 2.5 wt% (US 6,596,251 B2 background: 2-3 wt%), 99.9 % recovery; stripping and rectification to 99.5 wt% HCN; 0.05 % of the HCN to the purge (D-007).",
      "ASSUMED neutralisation with 50 wt% NaOH at 343 K; evaporative crystallisation at 343 K and 13.3 kPa(a) (US 4,847,062 A examples 6-7), mother liquor 0.80 kg NaCN per kg water, cake 10 wt% liquor, all filtrate recycled; steam dryer (D-008).",
      "ASSUMED complete combustion of the tail gas with 15 % excess air, stack 423 K, no radiation loss (D-009).",
      "All absorber, stripper, crystalliser and duty values are concept estimates of scripts/nacn_balance.py (D-011); accuracy not stated."
    ],
    "source": "process/design-basis.yaml"
  },
  "engineering": {
    "description": "Concept design: solid sodium cyanide (6.25 t/h, 98 wt%) from Andrussow HCN (methane, ammonia and air over Pt/Rh gauze), ammonia recovery and recycle, HCN absorption and refining, neutralisation with caustic soda, evaporative crystallisation and drying; tail gas burned for steam. Issue ChemE-as-Code/process-library#150.",
    "name": "Sodium cyanide (Andrussow HCN)",
    "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": [
      "chemicals"
    ],
    "region": "generic",
    "unit_operations": [
      "reaction",
      "compression",
      "heat-exchange",
      "absorption",
      "stripping",
      "distillation",
      "crystallisation",
      "drying",
      "combustion"
    ]
  },
  "families": [
    "inorganic-chemicals"
  ],
  "gap_count": 6,
  "gates": null,
  "id": "sodium-cyanide-1",
  "issues": {
    "closed_count": 0,
    "list_url": "https://github.com/ChemE-as-Code/process-library/issues?q=is%3Aissue%20label%3A%22process%3Asodium-cyanide-1%22",
    "new": {
      "action": "https://github.com/ChemE-as-Code/process-library/issues/new?template=1-action-item.yml&labels=process%3Asodium-cyanide-1&process=sodium-cyanide-1",
      "change": "https://github.com/ChemE-as-Code/process-library/issues/new?template=4-design-change.yml&labels=process%3Asodium-cyanide-1&process=sodium-cyanide-1",
      "hold": "https://github.com/ChemE-as-Code/process-library/issues/new?template=2-engineering-hold.yml&labels=process%3Asodium-cyanide-1&process=sodium-cyanide-1",
      "process": "https://github.com/ChemE-as-Code/process-library/issues/new?template=6-process-development.yml&labels=process%3Asodium-cyanide-1&process=sodium-cyanide-1",
      "tq": "https://github.com/ChemE-as-Code/process-library/issues/new?template=3-technical-query.yml&labels=process%3Asodium-cyanide-1&process=sodium-cyanide-1",
      "tracker": "https://github.com/ChemE-as-Code/process-library/issues/new?template=7-process-tracker.yml&labels=process%3Asodium-cyanide-1&process=sodium-cyanide-1"
    },
    "open": [],
    "open_by_gate": {},
    "open_count": 0,
    "private": false,
    "repository": "ChemE-as-Code/process-library"
  },
  "keywords": [
    "sodium cyanide",
    "hydrogen cyanide",
    "HCN",
    "Andrussow",
    "platinum-rhodium gauze",
    "ammonia recycle",
    "ammonium phosphate",
    "absorption",
    "neutralisation",
    "caustic soda",
    "evaporative crystallisation",
    "gold mining"
  ],
  "lca": null,
  "lci_gaps": [
    {
      "dataset": "solid-sodium-cyanide-from-andrussow-hcn-6.25-t-h-nacn",
      "key": "product:CHW",
      "link": "technosphere",
      "type": "output"
    },
    {
      "dataset": "solid-sodium-cyanide-from-andrussow-hcn-6.25-t-h-nacn",
      "key": "emission:HCN",
      "link": "biosphere",
      "type": "emission"
    },
    {
      "dataset": "solid-sodium-cyanide-from-andrussow-hcn-6.25-t-h-nacn",
      "key": "consumable:pt-rh-gauze",
      "link": "technosphere",
      "type": "input"
    },
    {
      "dataset": "solid-sodium-cyanide-from-andrussow-hcn-6.25-t-h-nacn",
      "key": "consumable:phosphate-makeup",
      "link": "technosphere",
      "type": "input"
    },
    {
      "dataset": "solid-sodium-cyanide-from-andrussow-hcn-6.25-t-h-nacn",
      "key": "disposal:consumable.phosphate-makeup",
      "link": "technosphere",
      "type": "output"
    },
    {
      "dataset": "solid-sodium-cyanide-from-andrussow-hcn-6.25-t-h-nacn",
      "key": "consumable:hcn-stabiliser",
      "link": "technosphere",
      "type": "input"
    }
  ],
  "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": "Degussa AG (2003) Hydrogen cyanide synthesis process. US 6,596,251 B2",
      "url": "https://patents.google.com/patent/US6596251"
    },
    {
      "title": "E. I. du Pont de Nemours and Company (1989) Process for production of sodium cyanide. US 4,847,062 A",
      "url": "https://patents.google.com/patent/US4847062A/en"
    },
    {
      "doi": "10.1002/14356007.a08_159.pub2",
      "title": "Cyano Compounds, Inorganic. Ullmann's Encyclopedia of Industrial Chemistry (Wiley-VCH); route reference lead, not read in this run"
    }
  ],
  "repository": {
    "access": "public",
    "path": "processes/sodium-cyanide-1",
    "url": "https://github.com/ChemE-as-Code/process-library"
  },
  "representations": [
    {
      "bytes": 41358,
      "id": "BFD",
      "kind": "bfd",
      "preview": "artifacts/sodium-cyanide-1/BFD.svg",
      "source": "process/BFD.xml",
      "status": "preview",
      "title": "Block flow diagram"
    },
    {
      "bytes": 183859,
      "id": "PFD",
      "kind": "pfd",
      "preview": "artifacts/sodium-cyanide-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": "simulation",
      "kind": "simulation",
      "source": "process/simulation.yaml",
      "status": "viewer",
      "title": "Process simulation"
    },
    {
      "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": "Methane, ammonia and air react over a Pt/Rh gauze to HCN (Andrussow); unconverted ammonia is recovered and recycled, HCN is absorbed in chilled water, refined and neutralised with caustic soda, and sodium cyanide is crystallised under vacuum and dried. The tail gas raises steam. Concept stage, assumed basis, preliminary gate-to-gate inventory.",
  "title": "Solid sodium cyanide from Andrussow HCN (6.25 t/h, 50 kt/a)",
  "validation": {
    "notes": "Concept PFD with closed mass, component and element balances (cheme validate: 0 errors; cheme process streams: every block and step balanced). The converter outlet is calculated by cheme from conversions that reproduce a sourced HCN yield and a sourced converter-gas composition, and its adiabatic energy balance closes (duty 0.06 kW at 1429 K). Capacity, feed states, recoveries, the crystalliser and every duty are ASSUMED or come from scripts/nacn_balance.py; no property package covers HCN at converter temperature, aqueous HCN/NH3 or the NaCN/NaOH electrolyte, and cheme's crystallizer refuses the free NaOH, so energy closure of the separations is not evaluable in core. cheme maturity: calculation maturity none. Not reviewed. 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/sodium-cyanide-1/",
    "stale": false,
    "tool": "cheme-as-code 1.6.0",
    "views": [
      "checks",
      "streams"
    ]
  }
}