A process and apparatus that includes a cryogenic source for providing a cryogenic fluid for vaporization, a cryogenic pump in fluid flow communication with the cryogenic source for increasing the pressure of the cryogenic fluid, an unfired vaporizer coolant circuit 110 in fluid flow communication with the cryogenic pump and adapted to accept the cryogenic fluid to form a heated stream, a direct-fired vaporizer downstream and in fluid flow communication with the unfired vaporizer coolant circuit 1 10 and adapted to accept the heated stream from the unfired vaporizer coolant circuit to form a superheated stream; and a diesel engine power unit 118 to provide power to the cryogenic pump, the unfired vaporizer coolant circuit 110, and the direct-fired vaporizer.