Hey guys, do you know if chemical engineers work in the energy sector except for petroleum?
Do they work in sustainable energy, such as hydro energy, solar energy, wind energy and etc ... nuclear energy etc etc etc
Hydro energy - not so much. This is almost all mechanical and electrical engineering.
Solar energy - some, in the groups that are designing batteries and I believe a couple of groups working with chemical photoreceptors. Most of those technologies aren't at the production stage, however, and bench stage chemistry doesn't involve much engineering.
Wind energy - again, almost all mechanical and electrical.
Nuclear energy - all nuclear engineering, a sort of hybrid between mechanical engineering and particle physics.
However, there is a lot of demand for chemical engineers in the alternative fuels end of sustainable energy, which you seem to have ignored altogether in your list. Biodiesel processes, ethanol production, methane-to-liquid fuel production, fuel cell development, and chemical energy storage (battery) employ quite a few chemical engineers. Any chemical process developed in a lab that is going into production will require intensive chemical engineering.