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Steam reforming of hydrocarbons for ammonia production was introduced in 1930. Since then,
the technology has experienced revolutionary changes in its energy consumption patterns. Ranging
from an early level of 20 Gcal/tonne (79.4 MBtu/tonne) to about 7 Gcal/tonne (27.8 MBtu/tonne) in
the last decade of the 20th century. The energy intensive nature of the process is the key driving force
for improving the technology and reducing the overall cost of manufacturing.
Figure 1: Overall Layout of a Steam Reforming Plant for Ammonia Synthesis
Looking further ahead, we'll review some potentially significant developments and concepts that may
impact the manner in which ammonia is produced. Some of these manufacturing routes are being
tested or employed at a few plants around the world, but have yet to be fully developed into
commercial processes. We'll also review more traditional approaches to ammonia manufacturing
along the way.
Developments
1. Reforming Section
In the conventional process, steam reforming is carried out in a fired furnace of the side fired
or top fired type. Both need large surface areas for uniform heat distribution along the length
of the catalyst tubes. This process has several disadvantages. For example, it is a thermally
inefficient process (about 90% including the convection zone) and there are mechanical and
maintenance issues. The process is difficult to control and reforming plants require a large
capital investment.
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