Loop For Removing Double Entries In A Range

I´working on an excel sheet where i´m copying a range to another place. So far so good. Then I want to remove all double entries for each rows in the new range. I managed to get a code working for one row. When I want to loop it for all the rows in the copied range, I get a an error popoing up when the loop starts working on the second row. Error 457: "This is already associated with an element of this collection" The line creating this error is coll.Add cell.Value, CStr(cell.Value)

Sub Sortere_StederBeta()
Dim coll As New Collection
Dim lcount As Long
Dim cell As Range
On Error Resume Next
Range("B4:U33").Copy
Range("B36").Select
Selection.PasteSpecial Paste:=xlPasteValues
For i = 36 To 65 Step 1
Range(Cells(i, 2), Cells(i, 22)).Select
Set coll = Nothing........................

The problem seems to come from the fact that the Coll (New Collection) is not reseting for the next loop. I tried to set the Coll to Nothing but doesn´t have any effect.