This is the paradox of wanting to teach at the college level. If all you really want to do is teach and you don’t really like or care for research, at the very least you do unfortunately have to go through the PhD process - which is research-centric. At worst, you end up getting a job that is a mix of research and teaching.
An Ed.D. isn’t necessarily going to solve this problem. At many places, Ed.D.s are research degrees as well - just research into science education and educational administration rather than chemistry itself. At others, where the Ed.D. is more of a practice degree, you’re going to be learning more about teaching other teachers and/or supervising school districts than teaching college-level or even high-school level classes.
You also don’t quite ‘teach HS chemistry and work for the education department of a university.’ As I’m sure you’re aware, science education is a field just like chemistry or anything else. If you switched to getting a doctorate in that field, you’d still be doing research and scholarship in science education (probably really similar or identical to what you’re doing now). And if you taught in that kind of department as a professor, you’d be teaching pre-service teachers (college students major in science ed/chem ed) and conducting research in science education. Furthermore, this option usually requires some classroom K-12 teaching experience - lots of science education programs require 3+ years of classroom teaching before admitting you to the Ed.D or PhD in science education.
Based on your actual interests and stated career goals, I think you’ve got two good choices.
If you just want to teach, and teaching high school chemistry sounds about as appealing as teaching college-level chemistry, then go for the M.Ed with an initial teaching license and focus on potentially teaching high school chemistry. With an MA or M.Ed and licensure, you may even be able to get a teaching job at an independent school - and in some of those cases, the upper-level students aren’t really all that different from freshmen and sophomores at some colleges (or so I’ve heard from colleagues who teach at independent/private/highly ranked STEM schools.
If you really want to teach college students, you do have the option of going ahead and finishing your chemical education PhD. A PhD also makes it easier to find jobs at competitive independent high schools where you will find upper-level students who are well-prepared and interested in chemistry, akin to underclassmen at a college. Or at a community college, where you will be teaching basic chemistry courses to students who largely want to either transfer or finish professional AS programs. (Although you can theoretically teach community college with an MA, in practice these days it’s hard to get a full-time CC position without a PhD.)
But there are two big caveats. First, make sure that your concentration in chemical education (even if you are getting it through a chemistry department) will allow you to teach in chemistry departments. And when I say “allow”, I don’t mean theoretically - I mean what are the chances of you actually landing a job in a chemistry department? Some disciplines are more strict than others about who they’ll hire, and some would greatly prefer (for example) someone with a PhD in “sociology” vs. “social policy”. I’d ask your advisors where people who have graduated with your concentration have ended up in the last 5-7 years, and also look at the chemistry departments of some schools at which you’d like to teach and see what kinds of degrees people have.
Two, if you had dreams of teaching at a competitive liberal arts college or something like that, do note that does require research. One, you have to do research (publish paper and present at conferences) to even get the job. And two, you have to do research while you are IN the job. At some of the most elite liberal arts colleges, it’s really 50/50. MOST teaching colleges and regional/local public universities are going to have pretty low research expectations, but the top ones will have some.