How do I render each time increment on Premiere Pro CS5/6?
I would honestly suggest outputting the whole thing to a lossless format and then using another tool to split the file.  Depending on if you have audio, it could be particularly easy to do by exporting as an image sequence and simply moving and renaming the images for each 30 second clip and then encoding each.  If they have audio, then you'd want to actually use something like FFMpeg for splitting the file though.