I am completing my masters in chemical engineering. I have completed my first two semesters but was unable to find a research thesis topic to work upon. Will it be bad to complete my masters degree without a thesis, if I don't get a better option?
Whether it will be 'bad' or not depends on whether you intend to pursue further studies (PhD), also, it depends on what the university policy is regarding the completion of your Masters.
I would suggest that you discuss your concerns with your supervisors/advisors (if you have not done so already).
Another possibility is to write and submit papers for publication.
If you're mainly interested in getting a job in the industry after you graduate, it probably doesn't matter too much. Sure, a really good thesis could be a bonus, but you'll probably have have to get pretty far in the recruiting process before anyone's even going to look at your thesis, and if and when someone does, they probably won't look much beyond the abstract.
The one exception might be if you already have a fairly specific idea of what you want to do in your job, and can arrange a thesis topic that lets you demonstrate the same skills you expect to be using. But it doesn't really sound like you have that specific a vision for your future yet.
If you plan to pursue a PhD degree, though, things are completely different. What people looking for prospective PhD students are most interested in is the ability to carry out academic research and describe its results, which is exactly what a thesis demonstrates. Without a thesis, you're going to have to find some other way to demonstrate your research and writing skills. It's not completely impossible — for example, you could try writing an independent research paper and getting it published in an academic journal, as suggested in this answer to a related question — but it does have the potential to put you at a significant disadvantage.
(Background disclosure: I'm a PhD student in mathematics with several years of past experience working in the IT industry. I've also had some experience in helping to evaluate candidates for both academic and non-academic positions, although I cannot really claim extensive first-hand knowledge of that side of the process.)