It's a refund for the business. So you are entitled to the money and a federal tax refund is not taxable income. So all you have to do is figure out how to cash the check. If you don't have a business bank account anymore I would go back to the bank where you did have it and see about either cashing the check or re-opening the bank account long enough to deposit the check and then withdraw the cash and close the account.
@cfinvests