Diesel evaporation as the first step of hydrogen production

Diesel constitutes the major fuel utilized in ships. Hence, diesel reforming is foreseen as one of the options for marine fuel cell applications. Evaporation of diesel fuel is an important stage in the diesel reforming processes. Thermal decomposition of the heavy feedstock that occurs primarily in the high temperature domain of the evaporation process leads to carboneous material formation and may plug the evaporator. Carboneous materials can also accumulate on the catalyst surface and cause serious problems in desulfurization and pre-reformer units. The diesel evaporator design is one of the key parameters to minimize carbon formation. The operating conditions must be optimized as well. In this study, the evaporation heat was supplied by two different ways. In the first evaporation system, the evaporation heat of the diesel fuel was supplied by an electrical furnace. In the second system, diesel was evaporated in a tube-and-tube heat exchanger via indirect heat supplied by hot nitrogen gas. The latter case was chosen to simulate the utilization of fuel reforming off-gases. Results indicate that evaporation by the hot gases results in much lower thermal decomposition of the diesel fuel compared to the utilization of the electrical energy.