みず蒸気 じょうき改質 かいしつじゃなかったです
mizu jōkika ishitsujanakattadesu

Noun
Desu Copula

The polite, past negative form of 水蒸気改質

1. Wasn't steam reforming.; Wasn't water vapor reforming.

Past/Perfective
Negative
Polite
Casual Register
Chemistry