NOVELTY - The hydrogen generation assembly (46) has a hydrogen-producing fuel processing system (64), and a pressure swing adsorption assembly comprising adsorbent beds and a temperature-based detection system. Each adsorbent bed has adsorbent region containing adsorbent adapted to adsorb the other gas. The temperature-based detection system comprises temperature sensor(s), and a controller.    USE - For generating hydrogen used in electrochemical fuel cell for generating electric current.    ADVANTAGE - The hydrogen generation assembly is economical and prevents malfunctions.    DETAILED DESCRIPTION - The hydrogen generation assembly has a hydrogen-producing fuel processing system, and a pressure swing adsorption assembly comprising adsorbent beds and a temperature-based detection system. The hydrogen-producing fuel processing system is adapted to produce a mixed gas stream of hydrogen gas and other gases from one feedstock. The pressure swing adsorption assembly is adapted to receive a portion of the mixed gas stream and to remove impurities from the gas stream and to produce a product hydrogen stream of high hydrogen purity than that of the mixed gas stream. Each adsorbent bed has an adsorbent region containing adsorbent adapted to adsorb the other gas. The temperature-based detection system comprises temperature sensor(s) adapted to measure temperature (T) associated with a portion of the adsorbent region, and a controller adapted to compare the temperature (T) with reference temperature and to selectively control the operation of the pressure swing adsorption assembly. INDEPENDENT CLAIMS are included for the following:    (1) prevention of breakthrough in pressure swing adsorption assembly; and    (2) operation of pressure swing adsorption assembly.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic view of energy producing and consuming assembly.    fuel cell (20)    energy producing system (22)    hydrogen generation assembly (46)    energy producing and consuming assembly (56)    fuel processing system (64)