The primary driver for the use of UCG Syngas in Ammonia production is the low cost of syngas compared to natural gas. The potential savings on reforming plant costs is an added bonus.
Syngas is used to manufacture ammonia by providing a source of Hydrogen. In a standard ammonia plant syngas is shifted to produce pure H2 and then catalytically reacted with nitrogen (derived from process air) to form anhydrous liquid ammonia. This step is known as the ammonia synthesis loop (also referred to as the Haber-Bosch process):
The advantage of Syngas is that the majority of the reforming has already been done and the gas is already in the range of 30- 50% hydrogen. The CO is relatively easy to reform leaving the methane which can be reformed or left to pass through the process unchanged and recovered for use in power generation or sold into a sales gas pipeline.