# Offshore Methanol Process Design — Data Dictionary

This dictionary documents the public website datasets and the structured workbook fields. Values are static and traceable to the conceptual-design report or to an explicit reconciliation recorded in the QA report.

## General conventions

- Temperatures are in degrees Celsius.
- Pressures are absolute bar unless the source report states otherwise.
- Composition fields ending in `_mol_pct` are molar percentages.
- Purity fields ending in `_wt_pct` are mass percentages.
- Financial values ending in `_musd` are millions of US dollars.
- Negative financial values use the mathematical sign and indicate economic loss or negative NPV.
- `null` represents an intentionally unavailable value, such as a missing final aftercool temperature.

## Executive KPI dataset (`dashboard_kpis.json`)

| Field | Definition | Unit | Governance |
|---|---|---:|---|
| `feed_mass_flow_kg_h` | Methane-rich feed mass flow | kg/h | Report / website controlled value |
| `feed_temperature_c` | Feed temperature | °C | Report / website controlled value |
| `feed_pressure_bar` | Feed pressure | bar | Report / website controlled value |
| `feed_ch4_mol_pct` | Methane mole fraction in feed | mol% | Report / website controlled value |
| `feed_co2_mol_pct` | Carbon-dioxide mole fraction in feed | mol% | Report / website controlled value |
| `feed_h2o_mol_pct` | Water mole fraction in saturated feed | mol% | Report / website controlled value |
| `methanol_product_kg_h` | Purified methanol product mass flow | kg/h | Report / website controlled value |
| `annual_operating_hours` | Annual operating time | h/y | Report / website controlled value |
| `annual_methanol_kt_y_reconciled` | Annual methanol production reconciled from product flow | kt/y | Reconciled |
| `product_purity_wt_pct` | Methanol product purity on a mass basis | wt% | Report / website controlled value |
| `product_methanol_mol_pct` | Methanol fraction in the product stream on a molar basis | mol% | Report / website controlled value |
| `reformer_ch4_conversion_pct` | Methane conversion across the steam reformer | % | Report / website controlled value |
| `synthesis_reactive_carbon_conversion_pct` | Overall reactive-carbon conversion across synthesis | % | Report / website controlled value |
| `synthesis_narrative_alternate_pct` | Alternate rounded synthesis-conversion value in narrative | % | Report / website controlled value |
| `water_recycle_kg_h` | Water recovered after reforming and recycled | kg/h | Report / website controlled value |
| `fresh_water_kg_h` | Fresh process-water feed | kg/h | Report / website controlled value |
| `combined_water_kg_h` | Fresh plus recycled process water | kg/h | Report / website controlled value |
| `water_recycle_share_pct` | Recycle fraction of combined process water | % | Report / website controlled value |
| `reported_steam_to_carbon_ratio` | Reported design steam-to-carbon ratio | mol/mol | Reported assumption |
| `purge_fraction_pct` | Fraction of high-pressure flash gas purged | % | Report / website controlled value |
| `recycle_gas_kg_h` | Gas returned to the synthesis loop | kg/h | Report / website controlled value |
| `purge_gas_kg_h` | Gas removed from the synthesis loop | kg/h | Report / website controlled value |
| `reported_energy_efficiency_pct` | Reported overall process energy efficiency | % | Report / website controlled value |
| `reported_process_heat_transfer_kw` | Reported process heat-transfer rate | kW | Report / website controlled value |
| `fixed_capital_investment_musd` | Fixed capital investment | MMUSD | Report / website controlled value |
| `working_capital_musd` | Working capital | MMUSD | Report / website controlled value |
| `preoperational_outlay_musd` | Total pre-operational cash outlay | MMUSD | Report / website controlled value |
| `annual_revenue_musd` | Annual methanol sales revenue | MMUSD/y | Report / website controlled value |
| `annual_comd_musd` | Cost of manufacture without depreciation | MMUSD/y | Report / website controlled value |
| `annual_after_tax_operating_cash_flow_musd` | Annual after-tax operating cash flow | MMUSD/y | Report / website controlled value |
| `base_npv_musd` | Base-case net present value | MMUSD | Report / website controlled value |
| `monte_carlo_samples` | Number of samples in the reported Monte Carlo simulation | count | Report / website controlled value |
| `probability_positive_npv_pct` | Probability of NPV above zero | % | Report / website controlled value |

## Stream dataset (`key_streams.json`)

| Field | Definition | Unit |
|---|---|---:|
| `stream` | Aspen/report stream identifier | text |
| `section` | Process section used for filtering | text |
| `service` | Engineering description of the stream | text |
| `temperature_c` | Stream temperature | °C |
| `pressure_bar` | Stream pressure | bar |
| `phase` | Reported physical phase | text |
| `mass_flow_kg_h` | Total stream mass flow | kg/h |
| `ch4_mol_pct` | Methane composition | mol% |
| `h2o_mol_pct` | Water composition | mol% |
| `h2_mol_pct` | Hydrogen composition | mol% |
| `co_mol_pct` | Carbon monoxide composition | mol% |
| `co2_mol_pct` | Carbon dioxide composition | mol% |
| `ch3oh_mol_pct` | Methanol composition | mol% |

## `compression_train.json`

| Field | Definition | Unit |
|---|---|---:|
| `stage` | Compressor identifier | text |
| `inlet_pressure_bar` | Stage inlet pressure | bar |
| `outlet_pressure_bar` | Stage outlet pressure | bar |
| `inlet_temperature_c` | Stage inlet temperature | °C |
| `discharge_temperature_c` | Compressor discharge temperature | °C |
| `aftercool_temperature_c` | Temperature after intercooling | °C |
| `shaft_power_kw` | Reported compressor shaft power | kW |

## `reactor_cascade.json`

| Field | Definition | Unit |
|---|---|---:|
| `reactor` | Synthesis-reactor identifier | text |
| `diameter_m` | Reactor diameter | m |
| `length_m` | Reactor length | m |
| `inlet_temperature_c` | Reactor inlet temperature | °C |
| `outlet_temperature_c` | Reactor outlet temperature | °C |
| `temperature_rise_c` | Adiabatic temperature rise | °C |
| `inlet_pressure_bar` | Reactor inlet pressure | bar |
| `outlet_pressure_bar` | Reactor outlet pressure | bar |
| `reported_reactor_conversion_pct` | Individual reported reactor-conversion field | % |

## `capex_distribution.json`

| Field | Definition | Unit |
|---|---|---:|
| `group` | Equipment group | text |
| `cost_musd` | Allocated fixed-capital cost | MMUSD |
| `share_pct` | Share of fixed capital | % |
| `risk` | Qualitative capital-materiality label | text |

## `utility_costs.json`

| Field | Definition | Unit |
|---|---|---:|
| `item` | Utility consumer or utility group | text |
| `annual_cost_musd` | Annual utility cost | MMUSD/y |
| `share_pct` | Share of annual utility cost | % |

## `cash_flow.json`

| Field | Definition | Unit |
|---|---|---:|
| `year` | Project year | year |
| `phase` | Project phase | text |
| `discounted_cash_flow_musd` | Discounted cash flow in the year | MMUSD |
| `cumulative_discounted_musd` | Cumulative discounted cash flow | MMUSD |
| `cumulative_nondiscounted_musd` | Cumulative nominal cash flow | MMUSD |

## `economic_sensitivity.json`

| Field | Definition | Unit |
|---|---|---:|
| `scenario` | Named economic scenario | text |
| `npv_musd` | Scenario NPV | MMUSD |
| `driver` | Scenario driver | text |

## `process_temperature_profile.json`

| Field | Definition | Unit |
|---|---|---:|
| `order` | Display sequence | count |
| `stage` | Compact process-stage code | text |
| `label` | Full process-stage label | text |
| `temperature_c` | Representative process temperature | °C |
| `zone` | Process zone used for chart semantics | text |

## `reformer_heat_flux.json`

| Field | Definition | Unit |
|---|---|---:|
| `normalized_position` | Normalized axial reactor position | 0–1 |
| `heat_flux_kw_m2` | Applied heat flux | kW/m² |

## `qa_controls.json`

| Field | Definition | Unit |
|---|---|---:|
| `id` | QA control identifier | text |
| `topic` | Reconciliation topic | text |
| `source_values` | Conflicting or supporting source values | text |
| `website_value` | Controlled public value | text |
| `logic` | Reconciliation rationale | text |
| `status` | QA status | text |
| `severity` | Materiality level | text |

## Monte Carlo summary (`monte_carlo_summary.json`)

The file contains summary statistics only. The website does not reproduce the 50,000 random draws at runtime. Statistical fields are expressed in MMUSD, and `varied_parameters` is the list of input families sampled in the source model.

## Environmental metrics (`environmental_metrics.json`)

Direct reformer-furnace emissions and indirect steam-generation emissions are separate accounting categories. They must not be combined or represented as a verified life-cycle footprint without an explicit system boundary.

## Workbook formulas

- Annual production = methanol product flow × operating hours / 1,000,000.
- Water recycle share = recycled water / combined water × 100.
- Operating margin = annual revenue − COMd.
- Purge share = purge gas / (purge gas + recycle gas) × 100.
- Stream composition check = sum of the six displayed molar percentages.

## Source hierarchy

1. Stream table or explicit equation.
2. Detailed equipment/economic appendix.
3. Narrative text or rounded executive value.
4. Figure-only qualitative evidence.