Ethylene from fossil ethane steam cracking and integrated separation · Calculation Rules

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
period_reference	all inventory rows	Let Q be net accepted ethylene grade mass in the reporting period. Preserve each reconciled boundary physical exchange X_i in its own units; report physical x_i = X_i / Q per 1 kg reference flow. The ethylene_product output is 1 kg. Internal paired transfers cancel; no co-product physical output is multiplied by a burden factor.	cp_mass; cp_energy; cp_water; cp_materials; cp_waste; cp_stack; cp_species	physical normalized ledger	jrc-lvoc-2017
gas_conversion	gas measurement records	n = P_abs V / (Z R T); mass = n times sum of mole_fraction_s times molar_mass_s. Use the actual gas/water composition, pressure/temperature basis and supplier background definition; separately prove applicability to any reference m3.	actual gas fields; cp_mass; cp_energy	compatible gas quantities, no default density	nist-webbook-srd69
net_heat	steam and return interfaces	Useful heat = sum of externally supplied steam mass times its specific enthalpy minus sum of actually returned-water mass times its specific enthalpy, with boundary losses/stock disclosed. Keep imported and exported headers separate, and keep gross steam/water mass in the physical ledger.	cp_energy; cp_water	supplier-compatible net useful heat	jrc-lvoc-2017
species_mass	source concentrations and losses	Integrate source flow times concentration over actual operating/event time after compatible wet/dry/P/T conversion. For carbon-based observations, use actual species composition and molecular conversion; for NO2-equivalent observations, use measured NO/NO2 proportions or keep the split pending. Final emitted mass is after actual capture/destruction, without double counting captured/routed streams.	cp_stack; cp_species	actual species mass and uncertainty	jrc-lvoc-2017; nist-webbook-srd69
element_balances	physical process diagram	Whole mass: sum actual incoming mass - sum actual outgoing mass - (closing stock - opening stock) = residual. For each E in C/H/O/N/S, replace each stream mass by its measured elemental mass; distinguish fossil/biogenic C. Include full compounds/mixtures, salt/metal/other material constituents, carrier water and actual air/O2/N2/Ar/humidity, exhaust species, captured solids and installed/coke stocks. No reaction sources/sinks enter whole mass or elemental conservation. Species: in_s + formed_s - out_s - consumed_s - stock_change_s = residual_s, with consistent reaction extents and atoms and no double-counted exchanged mass. For H2O, measured reaction formation/consumption can also enter this species balance; net atmospheric water subtracts measured incoming humidity. Quantify residual/uncertainty, never assign unknown mass to CO2/VOC or zero.	cp_mass; cp_balance; cp_stock; cp_water; cp_waste; cp_stack; cp_species	whole mass, compound, C/H/O/N/S and water QA plus residual	ipcc-chemical-2006; jrc-lvoc-2017; nist-webbook-srd69
gross_net_air	air/exhaust and compound-ledger interfaces	Use complete gross inlet air and outlet exhaust for whole-mass/atom QA; constituent masses decompose their parent stream and are not additional whole-stream mass. Include actual oxygen/nitrogen/argon, water humidity and every measured compound. Process-added atmospheric release is the source/event-matched net amount after measured inlet-carried background subtraction where applicable; preserve both gross observations and the net exchange. No fixed air ratio, complete combustion assumption, hidden unspeciated remainder or duplicate mixture-plus-component mass. Add atomic actual oxygen/purge/material/release rows when applicable; ambient carrier quantities remain explicit in the physical link matrix rather than invented positive exchanges.	cp_balance; cp_stack; cp_species; cp_water	distinct gross physical and net-release accounts	jrc-lvoc-2017; nist-webbook-srd69
period_carry	physical and burden stock accounts	For each traced stock/cohort, opening + acquired/generated - used/delivered/returned/disposed = closing, retaining original quantity units. Trace attributable burden similarly: opening carried burden + newly attributable burden - burden accompanying actual use/delivery/return/disposal = closing carried burden; this is a burden-tracing identity, not physical mass allocation. Match delivered product cohorts to Q; preserve returned burdens and recipient responsibility, avoiding duplicate supply/treatment credits. Catalyst/adsorbent/container service shares require actual duty/use/replacement evidence, never a default lifetime.	cp_stock; cp_mass; cp_materials; cp_links; cp_allocation	period-linked physical stock and burden ledgers	jrc-lvoc-2017; eu-pef-2021
provider_scale	each background link	Let r be the provider native reference quantity and L the compatible foreground quantity after evidenced property/unit/state conversion. Preserve native exchange q_j; linked exchange is q_j times L/r and its normalized quantity is q_j times L/r/Q. Preserve original/scaled units, conversion data, provider source and receiving state. Distinguish physical waste mass from service reference/duty and stock-carried burden from current acquisition; link once before residual-shared burden allocation.	cp_links; cp_stock; cp_energy; cp_waste	auditable native and scaled provider/service quantities	jrc-lvoc-2017; eu-pef-2021
burden_allocation	environmental burden ledger only	For output p, b_p = (direct burden_p + alpha_p times residual shared burden) / Q_p, retaining original burden units. Sum alpha_p = 1 for the declared eligible external product set. If justified economic allocation is used, alpha_p = value_p / sum value_j, where value uses actual accepted mass or verified useful heat times a compatible common-stage unit price. Internal fuel is excluded. Physical Y_j remains Y_j and physical normalized output remains Y_j / Q_ethylene.	cp_allocation; reconciled product and utility quantities	allocated burden per reference product plus unchanged physical outputs	eu-pef-2021

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
route_identity	applicability	Actual fossil-ethane feed, front-end demethanisation, C2 hydrogenation, gas delivery and treatment interfaces must match the declared route; do not use a classification label as process evidence.	supplier assays; P&ID/process diagram; actual SKU/grade; custody and receiving records
flow_chain	every UUID-bearing exchange	Search hit, direct state-100 identity, CAS/name/comment/route, type, actual compartment, reference property and unit-group/unit must all agree. Product identity does not establish provider quantity compatibility. Specific unresolved flows retain blank UUIDs, not a nearby proxy/correction flow.	retained original lookup and support-row evidence outside canonical PCR
full_period	quantities and emissions	Same representative period across denominators, products, inventories, startup/shutdown, decoking and waste; report uncovered hours, detection limits and uncertainty rather than assuming zero.	cp_mass through cp_allocation originals
complete_species	emissions and carbon origin	Keep actual chemical and isomer species, fossil/biogenic CO2 and methane, and non-overlapping PM. Extend for all actual additional species; do not erase ethane/biogenic CO2 due to reporting conventions.	actual stream/CAS assays; source-specific methods; reconciled balances
no_default_factors	external evidence	BREF tables and historical national/single-site data support only their own stated context; none supplies a universal recipe, positive emission or quantity for this route.	source locators, conditions and actual foreground collection
ready_dataset	first dataset completion	Missing reference identity, provider basis, steam net-heat basis, emission speciation, recipient chain or material-balance closure blocks a complete usable dataset; record each debt and its needed evidence. Methodological scientific review is a separate requirement.	identity/property/unit evidence; actual collection; independent methodology review

9. Validation Rules

rule_id	Applies to	Rule	source_ids
validate_reference	reference_flow and ethylene_product	Require exactly one 1 kg accepted ethylene output, the declared gas/grade/feed/route/custody qualifiers, and compatible verified flow/property/unit-group references before UUID-bound dataset completion. No proxy reference is accepted.	jrc-lvoc-2017; nist-webbook-srd69
validate_balances	physical versus burden accounts	Check complete whole-mass/C/H/O/N/S, full compounds/mixtures, net water/humidity, actual oxygen/air and exhaust, energy datum/heat recovery, installed/coke and other stocks, returns, containers/maintenance and matched link pairs. No reaction source terms in conserved whole mass/atoms; reaction terms enter species balances once. Check uncertainty/residual and carried stock burdens. Allocation must not reduce actual co-product output or internal transfer quantities.	jrc-lvoc-2017; ipcc-chemical-2006; eu-pef-2021
validate_emissions	elementary rows	Check substance/isomer CAS, actual air compartment, carbon origin, physical species mass and independent NOx/N2O handling. Reconcile aggregate VOC observations on the same source/period/basis to separately measured species and disclose only the unspeciated residual; the residual cannot mask known compounds/isomers or be double-added to them. Physical biogenic origin requires original source evidence, not a cleaning-solvent trace or assumed biomass. No biogenic CO2 is omitted, and nested PM fractions are not summed twice. Unknown speciation, controls or quantity basis remain incomplete.	jrc-lvoc-2017; ipcc-chemical-2006; nist-webbook-srd69
validate_interfaces	route and background links	Require compatible source-specific feed/utility references and receiving treatment boundaries. No in-boundary separation is duplicated by external purification; C4 extraction/aromatics/polymer stages remain external. Waste transfer is not a direct-water elementary release.	jrc-lvoc-2017; epa-ethylene-2006
validate_links	upstream and receiving-service matrix	Verify every source identity/hash, native reference quantity/property/unit, complete native exchange list and actual original-to-scaled calculation; check gas/steam/condensate/phase/grade/geography and service entry state against the real interface. Trace supplier/recipient return and stock burdens once, then direct versus shared service burdens in cp_allocation. Hard opposed source route/state fields cannot be repaired by a name match or invented grade. Unknown actual fields block the corresponding link, not automatically the method. Withdraw an opposed inventory UUID while keeping its specific physical row and gap visible. Only an unresolved actual method, reference or measurement blocker requires draft maturity; an ordinary coproduct-identity gap alone does not.	jrc-lvoc-2017; eu-pef-2021
validate_completeness	actual dataset	Distinguish quantity-check coverage, flow-identity verification, factory-record completeness and independent methodology review. A lookup/authentication failure cannot be reported as no-match or a completed audit. Unresolved reference or support fields block UUID-bound production.	eu-pef-2021

10. Published Dataset Profile

Field	Value
dataset_role	Foreground route-specific ethylene production; physical ledger and separately derived allocated burden ledger.
downstream_use	secondary_dataset; background_dataset, only after the required evidence and reviews are complete.
allowed_use	Chemical supply LCA using the same accepted gaseous ethylene grade, fossil-ethane route, feed origin, period, boundary and allocation.
excluded_use	Other feedstock/manufacturing/recovery routes; independently purified purchased ethylene; liquid dispatch; pure butadiene/butene production; downstream extraction or polymer manufacture; use as an approved method merely because a projection/quantity check succeeded.
required_metadata	PCR id; actual reference identity/support references; product grade/CAS/phase/P/T; feed and provider origins; diagram and configuration; period; custody; actual co-product/waste composition and recipient; utility quantity definitions and net heat; internal links; physical balances; allocation; data owner and review state.
required_quality_disclosure	Identity and provider-basis debts; measurement/speciation coverage; abnormal events; detection limits; source-rule applicability; physical versus allocated quantities; balance residuals; treatment references; uncertainty and allocation sensitivity; excluded processes; independent review status.
update_trigger	Feed origin/composition; furnace/separation/refrigeration configuration; delivery phase/grade; sulfur dosing; utilities/provider definitions; treatment recipient or control changes; material measured imbalance or newly identified species; changed allocation or review findings.

11. Data Sources

Source id	Type	Reference	Used for
jrc-lvoc-2017	official_guidance	European Commission JRC, 2017 LVOC BREF, JRC109279, EUR 28882 EN, DOI https://doi.org/10.2760/77304; official PDF https://bureau-industrial-transformation.jrc.ec.europa.eu/sites/default/files/2019-11/JRC109279_LVOC_Bref.pdf. Chapter 3 §§3.2.1–3.2.3, 3.3.1.1–3.3.1.5, 3.3.2–3.3.6; Figures 3.2–3.3, printed pp.126–156 (PDF pp.164–194).	Route limitations, integrated separation/recirculation, actual co-products, caustic/drying/hydrogenation, decoking, waste/water/energy interfaces and species monitoring needs. Table 3.3 printed p.133 explicitly gives exemplary once-through yields, not overall recycle-adjusted yields or products present at every plant; none is a default quantity.
epa-ethylene-2006	official_guidance	U.S. EPA, Ethylene MACT Compliance Manual, July 20 2006, printed p.2-5 (PDF p.16), https://www.epa.gov/sites/default/files/2015-06/documents/ethylene_mact_compliancemanual_final-1-24-07.pdf.	Historical manufacturing-unit boundary and distinction between integrated associated cuts and downstream butadiene/aromatics manufacture. No claim of current legal applicability, universal emission factors or a plant recipe.
ipcc-chemical-2006	official_guidance	2006 IPCC Guidelines, Volume 3 Chapter 3 §§3.9.2.1, 3.9.2.3–3.9.2.4, 3.9.4; printed pp.3.63–3.67, 3.81–3.83, 3.88; https://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/3_Volume3/V3_3_Ch3_Chemical_Industry.pdf.	Characterisation of feed/product/by-product carbon and energy interfaces, actual source measurements and duplicate-combustion avoidance. The Tier 2 national-inventory assumption that non-CO2 carbon becomes CO2 is expressly not adopted as species-resolved LCI; no historical default factors adopted.
eu-pef-2021	official_guidance	Commission Recommendation (EU) 2021/2279, Annex I §4.5, Annexes PDF pp.63–64, http://data.europa.eu/eli/reco/2021/2279/oj.	Generic multifunctionality hierarchy, proof of a physical relation, justified economic fallback and disclosure; no sector-specific livestock/paper recipe or allocation factor is transferred.
shell-monaca-2025	literature	Shell, Our growth projects, Shell Polymers Monaca section, page last updated 30 October 2025, https://www.shell.com/business-customers/chemicals/about-shell-chemicals/our-growth-projects.html.	Actual producer illustration of shale-gas-derived ethane origin; not a product yield, ethylene capacity, energy intensity or default configuration. Polyethylene capacity is not an ethylene inventory denominator.
nist-webbook-srd69	dataset	NIST Chemistry WebBook SRD 69, actual substance/CAS records, https://webbook.nist.gov/chemistry/; ethylene https://webbook.nist.gov/cgi/cbook.cgi?ID=C74851&Units=SI; named species are selected by their individual CAS.	Chemical/CAS identity and molecular interpretation only; no Tiangong UUID, environmental compartment, plant phase, production recipe or background provider basis is inferred.