Hello Helson!
Supplier Id is available in Store Manager for PrestaShop.
Also, you can export suppliers in XLS, HTM file with id.
See screen-shot -
http://screencast.com/t/BRHdQayX
Are you talking about product export ?
But we have Supplier Ref. in Field list - see screenshot -
http://screencast.com/t/2mnejWEk
What type of export do you mean ?