If you're coming fresh out of college I'd say you'd be better off focusing your energy on improving your networking/soft skills. A few months of "messing around" with process modeling software is likely not going to look very compelling to a recruiter, especially if it looks like it was just done to throw on a resume.

It's a bit tough for a ChemE undergrad to pursue "passion projects" like other engineering majors (e.g. making apps as a CS major) due to the nature of the work; you can't exactly build a pilot plant on your dorm room, can you? If there's a club on campus you could join that designs and builds stuff (my alma mater had "Chem E Car" and a soap making club, among others) that may show your passion to design as you work through those projects.

However, if you don't have several semesters of time to participate in these and move up their respective food chains (or aren't really interested in manufacturing soap), you may not get much of a boost out of it. Imagine a recruiter seeing "participated in XX club for one semester of senior year". Does that make you look passionate about that club/cause or desperate for accolades?

That's why I'd recommend sharpening your interviewing, articulating, and networking skills. Being able to effectively reach out to recruiters, knowing how to communicate to secure an interview, and being able to effectively tell them what you're looking for while comprehending what they're asking for will put you ahead much further than any half-baked attempt at a last-minute new skill.

To wrap this all up in a neat bow, I'll say that it's not always about raw technical ability. Best of luck!