These days, the chemical engineering candidate pool is getting smaller and smaller. As an employer, this means that you're going to have to work harder to generate interest from the top chemical engineers. Rather than simply posting a job post for chemical engineer employment, you should consult an engineering recruiter. Often recruiters will have ties with a pool of candidates, giving you a headstart in your search for qualified candidates.
You will work closely with this recruiter to ensure that only the best candidates walk through your doors, so be sure that communication between the two of you is open and consistent.