Abstract: Feedstock delivery systems for fuel processors, and fuel processing systems incorporating the same. In some embodiments, the feedstock delivery system includes at least one pressurized tank or other reservoir that is adapted to store in liquid form a feedstock for a fuel processor. The delivery system further includes a pressurization assembly that is adapted to pressurize the reservoir by delivering a stream of pressurized gas thereto. In some embodiments, the gas is at least substantially comprised of nitrogen or other inert gases. In some embodiments, the gas is a nitrogen-enriched or a reduced-oxygen air stream. In some embodiments, the delivery system includes a sensor assembly that is adapted to monitor the concentration of oxygen in, and/or being delivered to, the reservoir(s). In some embodiments, the delivery system includes a pumpless delivery system that regulates the delivery under pressure of the feedstock from the tank to the fuel processor.