How to increase range of IR emitter
That circuit is not very good for driving the LED. In fact it is very likely to damage it and too slow to drive the LED with the required carrier frequency. As anyone can try to copy your design, you should fix the circuit as most likely people don't understand why the circuit works poorly or burns up LEDs.
The poor range can be due to LED being already damaged as it is driven without a current limiting resistor in series. Replace the LED and this time use a resistor in series to prevent damage to the LED.
If that does not help, another issue can be that the transistor might not be able to turn on and off quickly enough at the necessary carrier frequency. The transistor can be extremely slow to turn on and off with only 10k at the base. Also the 10k can be too high a value even at DC to drive the base hard enough to get enough LED current - it is possible that you would get better range without transitor and only the LED with 100 ohms in series. In an actual circuit, you would use smaller base resistor to get fast enough LED drive and then use a series resistor with LED to keep current high but not too high - IR LEDs are typically pulsed at 100mA or so.
Also check that you are using the correct IR carrier frequency for your device. There can be a significant reduction in the range if the carrier frequency is wrong.