It is wasteful from a thermodynamic perspective to use the high temperature (~1000^oC) gases exiting the secondary and the primary reformer just for raising steam. It is more favorable to utilize the heat from the secondary reformer gases in a newer type of primary reformer, the heat exchanger reformer, and thus eliminate the use of the traditionally fuel-fired reformer furnace (IPTS/EC, 2007 p.62). When a heat exchanger is used, more oxygen needs to be supplied to the secondary reformer to increase the firing.

There are several processes that operate without a fired primary reformer in an advanced configuration such as the ICI LCA and the KBR KAAPplus processes (Ullmann’s, 2011 p.240). Other major characteristics of these advanced processes are isothermal shift conversion, high activity synthesis catalysts and CO₂ removal systems with solid absorbent. Figure beow shows the KBR Reforming Exchanger System (KRES) process, developed by KBR in which the natural gas stream is split into two streams after the desulfurization unit. The smaller of the two streams enters the heat exchanger and the other an autothermal reformer. The LCA and the KAAPplus processes drastically decrease CO₂ emissions as they eliminate the flue gases from the primary reformer and may also decrease NOx emissions by 50% or more (IPTS/EC, 2007 p.62). The KRES technology is in commercial operation at ammonia plants in Kitimat (Canada) since 1994 and Liaohe (China) since 2003.