THE HABER BOSCH PROCESS

Mass-produced, man-made Nitrogen fertilizers have been around for over a century.  The most efficient and cost-effective method of manufacture is that using the Haber Process (Fig. 1). This essentially combines the gaseous Nitrogen in the air (80% of our natural atmosphere) with a Hydrogen source (usually Methane, making it a prerequisite), in the presence of a catalyst, The first step is ammonia gas (NH3) and from that we can derive a great variety of products including Urea, Ammonium Nitrate, Ammonium Hydroxide, Nitric Acid, Calcium Nitrates etc. – all of which are useful in either direct crop application, or in combination with Phosphate derivatives to make specialized and hybrid fertilizer products such as Mono-Ammonium Phosphate & Di-Ammonium Phosphate (“MAP” & “DAP” respectively).

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Figure 1. The Haber Bosch Ammonia Process

 

A factory handling the above process is not particularly capital-intensive considering the long term of the return on investment, and the operating costs are reasonable.  Health & Safety concerns are paramount and must be of continued importance in design, construction & operation since some of the chemicals are hazardous in concentration during the process.

 

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HYDROGEN TO PRODUCE NITRATES

That brings us to the Hydrogen source, which derives from Methane. A Methane source is required as the primary feed of the Haber Process besides water and air.  Since the age of oil dominated the planet, the oil industry has had an oversupply of methane as waste from the hydrocarbon reservoirs and natural gas discoveries have created new supplies.  One of the most productive and profitable forms of the natural gas developments in COMESA (Common Market for Eastern and Southern Africa) will be to convert the methane into fertilizer products as described above.

 

Apart from petroleum waste emission and from natural gas, the other cost-effective way to produce Methane is from coal gasification. This is a long-perfected technology, which has been around for nearly 300 years. It is now regarded as a key step in offering clean energy from coal, as well as creating new fertilizer production, using the same method that originated long before the Petroleum Industry boomed.

 

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COAL GASIFICATION

Coal Gasification is a simple process where volatiles and other impurities are first driven off low to medium grade thermal coal to yield a purer coke-carbon.  This coke reacts with water in a self-sustaining exothermic reaction creating methane together with waste gases that are separated using a water-base “gas scrubbing” process – NB:  The process is power-generative – it takes no net power from the grid.

 

All and any waste products are used to manufacture by-products that are useable elsewhere in the fertilizer process (e.g. small quantities of sulphuric acid captured from natural sulphur in the coal) and/or by-products, which are used in other industries.  These by-products are significant.  One example is bitumen – used for surfacing / “tarring” roads and thereby assisting the in the continental drive for transport infrastructure development.  A related by-product of this process is the wood-treatment product – creosote.  Creosote is the preferred method for use in preserving bio-replaceable, bio-sustainable timber-pole transmission lines for the essential electrification of Africa – offering a further reduction of strain on the environment.  All of these reduce the need for expensive, forex-consumptive imports, serving to reverse trade deficits and erosion of local currencies in Zambia and other COMESA states).

 

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AAX NITROGEN SOURCES

Zambia and Tanzania are two examples where substantial thermal coal deposits outcrop at surface, deposits which are effectively sterilized by their distances from port and by their modest qualities and values per tonne (i.e. non-metallurgical quality).  Zimbabwe, while hosting higher-grade, exportable coal, is home to tens of billions of tonnes of low to medium-grade coal reserves, which really will only ever be useful for thermal power stations or coal gasification.  Botswana has a huge proven Coal Reserve in the southeast – proven and defined, but as yet untapped.  It is these coals, which offer a cheap and ubiquitous supply of methane for a fertilizer industry to take advantage of, and one, which will last for centuries of production. Furthermore, a clean technology has been recently perfected to automate coal gasification deep underground in deeper coal seams. Through this process only the useful, gaseous products ever leave the ground (“Underground Gasification). Finally, we have the known technology of tapping Coal-Bed Methane (“CBM”), which offers a third resource from the same geology. 

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Therefore the Nitrogen component is available.  AAX has secured four Coal Licences in Southern Zambia to complete the N+P combination.