The Solvay process (named after Ernest Solvay, who perfected it)
is used to make sodium bicarbonate (NaHCO3) and sodium carbonate
(Na2CO3) from limestone and brine, using ammonia as a catalyst. In
the US, the Solvay process is no longer used because we have
deposits of the mineral Trona in Wyoming, and it's cheaper to mine
these products than to synthesize them.