Demets was an industrialist and became a municipal council member (1911–1929) and burgomaster (1919–1927) in Anderlecht, then a Liberal senator (1929–1945) in the district of Brussels.
Demets was an industrialist who held municipal council member and burgomaster positions from 1911 to 1929 and 1919 to 1927, respectively, in Anderlecht. He then served as a Liberal senator for the Brussels district from 1929 to 1945.