Hydrogenated oils are commonly used to make margarine and shortening.
Tips
memory
加 (add) + 氢 (hydrogen) + 油 (oil) = "hydrogen-added oil". Vegetable oil + H₂ under catalyst makes solid fat. The character 氢 is the same one in 氢气 (hydrogen gas) and 氢弹 (hydrogen bomb).
culture
Behind the term sits a major public-health story: partially hydrogenated oils were the main dietary source of artificial trans fats. Mainland China issued labeling rules in 2013, and many countries are phasing them out outright.
