Why shouldn't it be possible?
The Op'amp only cares about the voltage between it's 2 supply pins (and that the voltages at input and outputs pins are within the allowed limits compared to the supply pins).
Don't forget that a voltage like "-8V" or "+12V" is just a shortcut to say that the voltage difference between this point and ground is "-8V" or "+12V". But you have no obligation to use a ground as reference for your op-amp.
One classical way to use op-amps, is to tie one supply to GND, and the other one to +Vcc (when you don't need negative voltages, and don't want to provide one for the supplies)
Some example op-amp circuits as followers, all perfectly valid. They all do the same thing, ie output voltage = input voltage. The only difference is the allowed range. If we consider a rail-to-rail (both input and output) op-amp, then for each circuit, the input range is :
- +500 to +510V
- 0 to +24V
- -5 to +12V
- -24 to -12V
![schematic](https://cdn.statically.io/img/i.sstatic.net/tCIwM8zy.png)
simulate this circuit – Schematic created using CircuitLab
Basically, just choose whatever supply voltages respecting the following constraints :
- the input range is between those supply voltages (with enough margin if your op-amp is not rail to rail input)
- the output range is between those supply voltages (with enough margin if your op-amp is not rail to rail output)
- the difference between the input supplies don't exceeds the specification of your op-amp (for example, an op-amp specified for -24 +24V can be used for -5 +36V, or 0 +48V or +12 +60V, but not for -24 +36V)
- often, you want the supply voltage range to be "safe" for the downstream circuit (in case your op-amp saturates). It's not mandatory if you can guarantee that your output will never reach those "forbidden" values
- if possible, use voltage rails you already have in your circuit
- if your circuit saturates, make sure you take into account the right supply voltages in your computations (some formulas take shortcuts like assuming that supply voltage is -Vcc and +Vcc)