How should buyers choose ethane purity grades from industrial fuel to semiconductor applications?

How should buyers choose ethane purity grades from industrial fuel to semiconductor applications?
Ethane purity selection is a cost-performance trade-off, not a 'higher is always better' rule. Industrial grade (95%-99.5%) dominates volume use: steam cracking to ethylene tolerates methane and propane impurities, but sulfur must stay below 1 ppm to prevent furnace coking and catalyst poisoning. For metal heat treatment and fuel use, 99% is sufficient. High-purity grade (99.9%-99.99%) serves standard gas calibration and environmental monitoring, where total impurity profiles matter more than the headline number. Electronic grade (99.999%-99.9999%) is mandatory for semiconductor CVD and SiC deposition, with oxygen, moisture, and nitrogen each controlled to low ppm or ppb levels. The real trap is over-specifying: using 5N product as fuel multiplies cost with zero benefit, while under-specifying for standard gas can invalidate entire calibration batches.