Sunday, November 25, 2012

The Haber Process: Why Transition Metal Catalysts are Responsible for Half of the World's Population

That's right, you heard (or read) us correctly. Transition metal catalysts are responsible for half of the world's population or more! The reason for this is its integral role in the Haber process, arguably the most significant chemical process made by man.

First, an intro into the Haber Process. The Haber process was discovered by Fritz Haber in 1909. He found out a way to synthetically make ammonia. The chemical Equation for the process is as follows:
N2 + 3H2 --> 2NH3
However, this equation does not tell the whole story. The process is actually very slow, and requires a catalyst, which in this case is Iron. Thus, a more accurate representation of the process is below:
The Haber Process uses reactants that can be relatively easily gathered, Nitrogen and Hydrogen, and reacts it with an Iron oxide catalyst to make Ammonia. The unreacted gas is also recycled to make the process more efficient.

Thus, without the iron catalyst, the Haber process (also called Haber-Bosch process since Carl Bosch industrialized the process)  would be useless.
Now, that begs the question--why is this process so important? Well MIT Press says that The Haber-Bosch process "has been of greater fundamental importance to the modern world than ... the airplane, nuclear energy, space flight, or television. The expansion of the world's population from 1.6 billion people in 1900 to today's six billion [in 2000] would not have been possible without the [industrial] synthesis of ammonia." What the Haber process does is that it produces a fixed form of nitrogen, which is essential to all living beings. Essentially, the Haber process makes fertilizer. Before the haber process, nitrogen could only be fixed naturally thorugh bacteria or lightning. In fact, only 140 million tons of nitrogen could be fixed per year by the entire world without the Haber Process. However, with the Haber Process, today, an additional 100 million tons of nitrogen is fixed per year, which is an astounding number. To add to that, Professor Vaclav Smil of the University of Manitoba, estimates that "only about half of the population of the late 1990s could be fed at the generally inadequate per capita level of 1900 diets without nitrogen fertilizer." In other words, half of the world's population would not be here withouth the Haber process! Here is a graph of the increasing nitrogen fertilizer consumption over the years, taken from Hub Pages.
As you can see, nitrogen fertilizer consumption has DRAMATICALLY increased due over the years due to the Haber process

The Haber Process even changed the crops it was helping grow--because earlier crops did not respond as expected to the added nutrients, new high-yeald varieties (HYV) were made. Today HYV crops are used all over the world, once again showing the far-reaching consequences of the Haber Process.
To sum it all up, without the Haber Process, the world would consist of much fewer people, and without the iron catlyst, the Haber Process would be useless. Thus, using simple logic, the iron catalyst played a huge part in the Earth's population today. This connects perfectly with what we are learning since it shows how catalysts are an integral part of industry, and that if the kinetics of a reaction are not taken care off, the reaction will be of no societal use.