How much value do papers without new scientific information have, i.e. seminar papers such as overviews of or examples for current methods in CS?
This is akin to a review article, in the sense that you're interpreting and reporting on existing work, rather than creating something new. There's nothing wrong with a review article, and many scientists do write them during their careers (but usually not before they've started a doctoral program!). 

That said, while I believe that it is not nearly as good as a "standard" research paper in establishing one's capabilities to do original research, it may have some merit. If the schools to which you are applying allow you to submit additional documentation, then you could consider sending it in, if you believe it is of sufficient quality.