I believe it's kali from German Kaliumhydroxid[0] (KOH, what it uses to dissolve CO2), from the same "potassium" root as al-kali in English, from medieval Arabic[1]. (And also metonymically a name for the coastal salt-marsh plant[2] from which medieval workers sourced potash/potassium[3]. I actually submitted that plant to HN [4] a few days ago, but no one was excited about it. They were once an essential ingredient in glassmaking, hence their other name, "glasswort").
The literal meaning is indeed potassium apparatus / device / contraption. The Kali part is indeed shortened from Kaliumhydroxid.
Strangely enough, the modern German name is Fünf-Kugel-Apparat, "five balls apparatus". I found that one simply by going through "Other languages" on Wikipedia.
And benzene is called Benzol in German. And gasoline is called Benzin - that word has false friend potential because it seems more similar to benzene. It is also not derived from the name of Carl Benz of Mercedes-Benz fame who used it in the first practical automobile that he invented.
https://en.wikipedia.org/wiki/Kaliapparat