I see RELEVANT inconsistency in the information you have provided and the question that you have asked.
I have blogs in different niches.
The above means that you have more than one blog : multiple blogs
Write answers in blog name or my personal name?
However, "blog name" indicates that you have only 1 blog.
If you will write answers in your blogs' names, then you will need multiple Quora accounts. If you have just blog, then you can have a Quora name that matches with your blog name.
Though there are Quora users using a company or a business name as their Quora name, however, do bear in mind, that as per https://www.comparably.com/companies/quora/faqs, "On Quora, you are required to use your real, full name for your account". And per https://www.comparably.com/companies/quora/faqs, "If Quora Moderation believes that a user is not using their real name, the user may be asked to provide supporting evidence".
So, if you will use a blog name as your Quora name, then it would be helpful for you to be ready to provide supporting evidence, if ever needed, because you do not want to lose all the efforts and time that you would "invest" into Quora, to go to waste, incase they ask for supporting evidence & you are unable to provide it.