If your empty columns are really empty character columns, something like the following should work. It will need to be modified if your "empty" character columns include, say, spaces.
Sample data:
mydf <- data.frame(
A = c("a", "b"),
B = c("y", ""),
C = c("", ""),
D = c("", ""),
E = c("", "z")
)
mydf
# A B C D E
# 1 a y
# 2 b z
Identifying and removing the "empty" columns.
mydf[!sapply(mydf, function(x) all(x == ""))]
# A B E
# 1 a y
# 2 b z
Alternatively, as recommended by @Roland:
> mydf[, colSums(mydf != "") != 0]
A B E
1 a y
2 b z