Are there any pressure sensor for 22 kg (~50lbs) and more?
Your problem may be that you are using sub-optimal search terms.
The kilogram is not a unit of pressure, but instead of mass.
Scales technically do not sense mass, but instead sense force.
This is assumed to be the force exerted by a resting body under earth gravity.
Pressure is force over an area, such as pounds-per-square-inch (PSI) or the Pascal which is a newton per square meter.

Anyway, the sensor you want is called a force cell.
The nice ones are rated in newtons or kilonewtons, with a kg being equivalent to 
9.8 newtons.

Here is a load cell that take up to 50 kg.
http://www.phidgets.com/products.php?product_id=3135

Sources:
http://en.wikipedia.org/wiki/Force