Lots of mechanical engineers are hired by chemical companies to work on the chemical processes. Mechanical engineers are needed to help with the materials used, in designing the mechanical equipment, and lots of other related processes. The great thing about engineering is that it is very interdisciplinary. In my roles in the chemical industry, I worked right along side many mechanical engineers and oftentimes we were doing similar or parallel types of work. With engineering, it's more about the problem solving skills you have than sometimes the actual degree you end up with!