A drive mechanism is provided for a door operator, comprising a drive member and a driven member. The Zr content in the Si\u2014O\u2014Zr bond, represented by Zr, is 0. The twin rollers press down on the material with equal force due to the central pivot point, which improves the feed of the material. Alternatively, the surfactant can be formed by first reacting an alpha-olefin stream having a broad distribution of carbon numbers ranging from 12 to 28 or more with SO3 to form the olefin sulfonic acid that is subsequently used to alkylate an aromatic feedstock.