You would use a brush chipper.  This equipment comes in a wide range of sizes to cover the homeowner and commercial markets.  

Be sure to read all instructions prior to operating the chipper and only use it when you are wearing the appropriate safety gear.  These are great machines for mulching unwanted tree limbs and other brush around your home but they can also be dangerous to operate if you don’t do so properly.  

Stop into any one of the Volvo Rents stores nationwide and they can review the safety issues with you and help you determine what size is best for your needs.