Ways to make Silicon carbide

2 routes in the Atlas, side by side per the same functional unit. Whether they compare is computed from their data, criterion by criterion; a warning sits next to each route it concerns.

Not comparable as they standReference product (grade, state): differs. The rows say which route each warning concerns.

Per 1 kg of Silicon carbide: inventory from each route's LCI dataset, unallocated; footprints per the functional unit of their own LCA.

Route	Tier, design maturity, review status	Geography, year	Energy	Feedstocks	Key emissions	Footprint	Comparability
Silicon carbide by the Acheson process (5000 kg/h crude SiC, concept)Acheson batch resistance furnaces (silica sand and green petroleum coke, graphite core), gas burn-off over the charge, ingot cooling, breaking and sorting with recycle of the unreacted mix, crushing and screening; 5000 kg/h crude SiC	flowsheet or hand-writtenDesign maturity: Concept (research)Not independently reviewedDataset review: unreviewed	GLO, 2026	Electric power: 9.63 kWh	Silica sand: 1.95 kg Petroleum coke (green): 1.36 kg Air drawn over the furnace surface: 9.27 kg (free)	CH4 to the environment: 0.014 kg CO to the environment: 0.507 kg CO2 to the environment: 2.12 kg SO2 to the environment: 0.0408 kg SiC to the environment: 0.0002 kg SiO2 to the environment: 0.00904 kg	2.03 kg CO2-eq1.48 to 2.87 (95 %)Climate change per 1 kg silicon carbide	Reference product (grade, state): product is no grade (basis mass, component SiC, pressure 1.01325, purity 0.98, temperature 50.0); the routes state no grade (basis mass, component SiC, pressure 1.01325, purity 0.88, temperature 50.0), no grade (basis mass, component SiC, pressure 1.01325, purity 0.98, temperature 50.0)
Silicon carbide by the Acheson process (5000 kg/h crude SiC, concept)Acheson batch resistance furnaces (silica sand and green petroleum coke, graphite core), gas burn-off over the charge, ingot cooling, breaking and sorting with recycle of the unreacted mix, crushing and screening; 5000 kg/h crude SiC	flowsheet or hand-writtenDesign maturity: Concept (research)Not independently reviewedDataset review: unreviewed	GLO, 2026	a co-product of a multi-output dataset (product:SIC besides it): its share needs the allocation of the LCI database build			no footprint	Reference product (grade, state): product is no grade (basis mass, component SiC, pressure 1.01325, purity 0.88, temperature 50.0); the routes state no grade (basis mass, component SiC, pressure 1.01325, purity 0.88, temperature 50.0), no grade (basis mass, component SiC, pressure 1.01325, purity 0.98, temperature 50.0)

How comparability is checked

Allocation: same (same allocation method: shares)
Background data (impacts): not applicable (same background data and boundary behind the impact numbers (only routes with a footprint))
System boundary: same (same system boundary of the inventory (the dataset's boundary): gate-to-gate foreground of the plant)
Data quality (TfS DQR): same (data quality: every route states a TfS DQR, none more than 1 above the best)
Functional unit: same (same functional unit (amount and unit of the reference product): 1 kg)
Reference product (grade, state): differs (same reference product: registry grade and state: no grade (basis mass, component SiC, pressure 1.01325, purity 0.88, temperature 50.0), no grade (basis mass, component SiC, pressure 1.01325, purity 0.98, temperature 50.0))
System model: same (same system model (docs/system-model.md): cutoff)

ISO 14044 requires a critical review (by a panel of interested parties, ISO/TS 14071) of a comparative assertion intended to be disclosed to the public. These routes are listed side by side for screening; a statement that one is better than another needs that review. None of these routes has had such a review.