How can I delete a journal batch that has no journals or lines?

You need to use the Find Batches window to find the Batch on the Enter Journals form. From there, you can delete the batch. The first window that is displayed when you navigate to the Enter Journals form is the Find Journals window. You can not find the Batch using this window, since there are no journals associated with the batch. See Note 1036784.6 for detailed instructions.