How many and which effects are applied?
How many and what kind of hard drives?
Desktop or laptop, and if laptop does it have only one 5400rpm hard drive?
Without knowing the detailed specs of your video (or the detailed specs of your computer hardware), I'd say that most likely it's that your phone video using a high compression that Premiere Elements has to decode and then re-encode. And that can take time.
With standard video on a decently powered computer, it usually takes about the running time of the video to create a DVD. But phone and other non-camcorder video can take twice the video's running time -- or more, depending on how fast your processor is.
Everything is from a phone or highly compressed source as you mentioned. My rendering and DVD burn times match your 2x run time estimate, or longer. Thank you.