Hi Meera,
No this is not possible.
Couple of way outs you can adopt are as below
1) What you can do is for food related items and you can create service orders with relevant account assignment (K,F etc) and for paying the vendors you can create service entry sheet. This will ensure PO,payment and items will not be inventorised.
2) For stationary related items you can create PO with account assignment K of F (using internal order for admin department) by this when ever GR is done for this PO items will get consumed.
3) You can create text PO (dont enter material code in PO line item just put the description) and do the goods receipt.
But in all the scenario you need to have a plant code in PO.
