How to run DC 12 volts power adapter without AC outlet?

I have small electrical item… Its electrical plug which I call adapter output is DC 12 volts… So when I plug this adapter into AC outlet of 220 volts… My item starts running.
Now I need to run this item at remote location where there's no electricity… Possibly for one hour or more… I have power bank to charge my iPhone… Can I use that… Or can I run it thu normal alkaline batteries… Can i run it by car battery… Need some easier and simpler solution.

It would be helpful if we knew what device you were trying to power.

Regardless, you will need to run the device from a battery. This would best be done with a 12v battery, although a higher voltage battery could be used with a voltage adaptor, or lower voltage batteries could be wired in series to get the correct voltage.

For a 12v battery, simply fully charge the battery and then get an electrical connector that is identical to the one on the power adapter. Wire the positive wire to the positive terminal on the battery, and the negative wire (usually is marked with a solid line or dashes) to the negative terminal. The battery will then power your device until the charge runs down.

First off standard house plugs are 110 V/ 60 HZ, not 220(that would be big AC unit or some washer/dryers). They make inverters for 12 V car to cell. You just need to get the 12V insert for the lighter plug with the plug end for a USB for your cell phone.

This power adapter is no more useful in your case where has no 220V ac available.
Only one way to power your device by use 12V battery pack ( 8 piecse 1.5V cell or 10 pieces1.2V cell ) or using car battery that can run your device over hundreds hour.

It can work on car battery also it can work on alkaline battery. But you have to connect 8 alkaline batteries in series to get the required voltage.

The short answer is that you can use a car battery to power whatever electronic device is running on 12VDC. You may need to make your own power cable to attach to a 12V socket, or you might be able to use something already on the market. Note that if the electronic device is very sensitive (computer, circuit board, etc) and it doesn't have any power conditioning built in, you should use a DC to DC power supply. The electrical system of a car produces a lot of spikes, drops, and EMF that might harm your device. These power supplies are in the range of 100-500USD.

If you have the plug for your device(and I assume you have one)
connect it to your car battery, but a small coil in series and an Eelco 120pf should suffice parralel and your all good to go.
The eelco+coil will take the punishment from any peeks and EMC problems from the car.

Don't forget to start the car every once in a while if it takes longer than the hour! Wouldn't want to be stranded in the middle of nowhere.

You seem to think the power bank for your IPhone might solve your problem, so possibly it has a 5 volt battery or a bit higher voltage battery that will possibly operate your device. If your device needs more volts you can possibly add one or more cells in series with your power bank. It is however, risky without a volt meter to determine the volts and polarity. Worse many modern devices are damaged when you attempt to disassemble or use them for another purpose.
A few places have 220 volts, more have 120, 230 or 240 volts