Ammonia Manufacture

Ammonia as a logical and viable contender for a carbon free fuel and energy future. Ammonia can be used in most applications where hydrocarbon fuels are traditionally used. It has been used as a fuel in various applications during last century. Ammonia is a naturally occurring substance and is the second most popular industrial chemical in the world. The manufacture of ammonia in commercial quantities without releasing carbon is the subject of research and development around the globe.

A Material Safety Data Sheet (MSDS) for ammonia is readily available. The Physiological effects of various concentrations of ammonia in air are also included (SAA AS/NZS 2022) The IDLH (Immediately Dangerous to Life and Health) for ammonia is currently listed as 300 ppm.

Ammonia air mixtures are flammable in a fairly narrow range of concentrations between 16% and 25%. The LFL for ammonia of 16% is very high when compared with other popular fuels.

Ammonia has been commercially manufactured for over a century and currently over 150 million tonnes is produced globally per annum.

Ammonia is relatively straight forward to store, transport and handle. As it is highly corrosive to zinc and copper or it’s alloys, only steel, stainless steel or aluminium can normally be used.

Where ammonia is referred to as “anhydrous ammonia” this indicates it has a water content of less than 0.2%. Ammonia liquid is usually stored in large or medium sized tanks manufactured from carbon steel and it is necessary to have a small water content of this magnitude to avoid stress corrosion cracking in these tanks.

Where ammonia is stored as a liquid at ambient temperatures it needs to be in a pressure vessel with a design pressure of 2100 kpag (saturated temperature of 53 C max). Where ammonia is stored as a liquid at atmospheric pressure it will need to be in an insulated, refrigerated vessel and will exist at a temperature of -33C.

Ammonia has a very pungent odour which is quite offensive to mammals and it will drive them away at concentrations of about one tenth of that which would do them harm. It is for this reason ammonia is known as a self-alarming substance.

Ammonia can be used as a fuel including in internal combustion engines and gas turbines.

Ammonia is an excellent carrier of hydrogen, however it is very much easier to store, transport, handle and dispense than liquid hydrogen. At one atmosphere liquid hydrogen exists at -253C (20K) whereas liquid ammonia exists at -33C (240K). Hydrogen has a very low molecular weight and it will permeate many materials which means it is very difficult and expensive to contain.

An internal combustion engine operating on ammonia fuel will emit nitrogen, water and Nitrous oxide, however no CO2 or CO will be emitted as ammonia contains no carbon.

The oil in an internal combustion engine operating on ammonia fuel is much cleaner than that in a hydrocarbon fuelled engine as there is no carbon present in the fuel.

There are many examples of where ammonia has been used as a fuel including:

  • Public transport buses in Belgium during the Second World War.
  • Chevrolet powered by “hydrofuel” in Toronto in 1981
  • Toyota GT 86 converted by Bigas to duel fuel ( ammonia and gasoline) in 2013
  • Hydrofuel Canada 2012 duel fuel vehicle ( ammonia and gasoline)
  • Garbage truck in Pisa Italy
  • Gas turbines in the USA

The fuel system required for an ammonia powered passenger vehicle is not unlike that used for an LPG  (propane) powered vehicle. The following table shows the saturated pressure – temperature relationship for ammonia and propane.

Table1

The main areas of difference are:

  • Design pressure of fuel tank, piping and components.
  • Materials for the ammonia fuel system cannot include zinc or copper or it’s alloys.
  • The evacuation of the small amount of ammonia liquid contained between the handpiece valve and the check valve in the neck of the fuel connection at the point of disconnect cannot be discharged to atmosphere as is the case with LPG. This would need to be recovered and contained or treated.

Fuel systems for the storage and dispensing of ammonia fuel at the vehicle filling station would not be unlike those used for LPG.

All of the vessels, pumps, check valves, excess flow valves, safety valves and other safety devices used in the LPG fuel systems will generally be appropriate for ammonia subject to obvious pressure rating and material changes.

Manufacture

Data from the International Fertilizer Association (IFA) indicates that a modern ammonia production facility using natural gas consumes around 30GJ of energy per tonne of ammonia produced.

Scientific modelling indicates, with present technology, ammonia manufactured using electrical energy and heat recovery with hydrogen sourced from water electrolysis, would consume somewhere around 40 to 60 GJ per tonne of ammonia produced.

The manufacture of ammonia fuel without releasing carbon from energy sources such as solar, wind, geothermal or hydroelectricity will be commercially challenging.

Research is required into large scale, highly efficient, carbon free, ammonia manufacture using existing or new technologies. The development of micro ammonia fuel manufacturing systems will also need to be a high priority.

Ammonia fuel offers a solution to the stranded energy problem. The surplus renewable energy generated at times of low demand can be used to manufacture ammonia which is stored for later consumption.

The following are a selection of literature items found to be relevant to this subject:

  1. Techno-Economic Feasibility Study of Ammonia Plants Powered by Offshore Wind.                 A thesis by Dr. Eric R. Morgan. University of Massachusetts – Amherst. 2013.                                     This thesis reviews the technologies required for all-electric, offshore wind powered ammonia production and offers a simple design of such a system. The cost models provided, are capable of calculating the capital costs of small industrial sized ammonia plants coupled with an offshore wind farm. Whilst the levelized cost per tonne of ammonia is high relative to ammonia produced with natural gas or coal, major cost reductions are possible for systems having long life, low operating and maintenance costs, or for systems that qualify for Renewable Energy Credits.
  2. A feasibility study of implementing an Ammonia Economy.                                                         A thesis by Jeffrey Ralph Bartels. Iowa State University.  2008.                                                                                              This thesis reports the results of a feasibility study performed on the concept of an Ammonia Economy, which treats ammonia as an alternative fuel and energy storage mechanism. The results showed that ammonia sourced using alternative renewable fuels was more expensive than ammonia sourced from coal, gasoline or natural gas, however it may become economical as fossil fuel costs increase and technological advances improve the alternative energy technologies.
  3. Planning for Hundred –Fold Increase in Global Ammonia Production.                                        A paper by William L. Ahlgren. California Polytechnic State University, San Luis Obispo. 2013.   The use of ammonia as fuel offers a path to effective climate change mitigation. To meet the projected demand, the ammonia industry must scale up from the second or third largest non-petroleum commodity chemical business, to the largest economic enterprise on earth, surpassing even the petroleum industry. This presents an enormous challenge, and also an unprecedented opportunity.
  4. Synthesis of ammonia directly from air and water at ambient temperature and pressure.    A paper by Rong Lan, Shanwen Tao. University of Strathclyde, and John T.S. Ervine, University of St.Andrews.      2012.                                                                                                 Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.
  5. A hybrid vehicle powered by ammonia and hydrogen.                                                                    A paper by Stefano Frigo and Roberto Gentili. Destec- Universita di Pisa , Italy .2013             An attractive solution is represented by the possibility of storing hydrogen in the form of ammonia that, at environmental temperature is liquid at roughly 0.9 MPa and therefore involves relatively low-cost and light tanks. Ammonia represents an alternative fuel to feed IC engines and, if produced in a “green” way, it could lead to a really “zero emission vehicle”.

Ammonia has been used widely in many industries for over a century. Mankind knows how to store, distribute, transport, dispense and use it safely. There is now an urgent need to start manufacturing ammonia without releasing carbon. When this is achieved we will truly be able to enter a zero emissions fuel and energy future.

Table 2

References

  1. Coregas Pty Ltd (Prepared by Risk Management Technologies) December 2008. Ammonia

Material Safety Data Sheet No: 40831002

  1. Standards Australia. AS/NZS 2022:2003
  2. ASHRAE Handbook Fundamentals 2013 Chapter 30
  3. International Fertilizer Association: Global Energy Energy efficiency benchmark 2012
  4. E.R Morgan 2013. Techno-Economic Feasibility Study of Ammonia Plants Powered by Offshore

Wind.

  1. J.R Bartels 2008. A feasibility study of implementing an Ammonia Economy.
  2. W.L Ahlgren 2013. Planning for Hundred – Fold Increase in Global Ammonia Production.
  3. Rong Lan, Shanwen Tao and J.T.S Ervine 2012. Synthesis of ammonia directly from air and water

at ambient temperature and pressure

  1. S Frigo and R Gentili 2013. A hybrid vehicle powered by ammonia and hydrogen

Until then

Kind Regards

Ammoniaman

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Ammonia as a Fuel

Ammonia-air mixtures are flammable in a narrow zone of concentrations between 16% and 25%. The products of combustion from burning ammonia are predominately nitrogen and water. No CO2 or CO are produced as ammonia does not contain any carbon. Ammonia is a carrier of hydrogen however it is far easier to store, distribute and use than hydrogen.

Ammonia can be used as a fuel in most applications where hydrocarbons are currently used. These applications include internal combustion engines, gas turbines and boilers. Most piston engines will run very well on ammonia-air mixtures with some modifications to the fuel and ignition systems. Engines running on ammonia may produce NOx however in quantities , certainly no greater than those produced by an equivalent hydrocarbon fuelled engine. An engine running on ammonia can therefore be classified as producing zero carbon emissions.

Ammonia has been successfully used as a ground transport fuel dating as far back as the 1940’s where it was used to fuel public motor buses in Belgium. One of the more recent applications has been the conversion of a 2013 model popular sports car, to a dual fuel vehicle which runs on ammonia at low speeds.

The technology and means are rapidly being established to store, distribute and use ammonia as a zero emissions fuel for transport and energy systems. The challenge now is to develop processes to cost effectively manufacture ammonia using renewable energy. That is, to discontinue using hydrocarbons to obtain hydrogen for the ammonia manufacturing process, and develop other zero carbon emission systems to efficiently produce ammonia. When this is achieved, it will “close the loop” on the ammonia carbon free fuel cycle and pave the way for a clean energy future.

A concerted global research effort is required to develop ways of “closing the loop” on the ammonia carbon free fuel cycle.

Ammonia has been least exploited as a fuel however this is where it has the most potential in attaining humanity’s dream of a carbon free energy future.

The next instalment will discuss ammonia manufacture.

Until then

Kind Regards

Ammoniaman

Ammonia as a Fertilizer

Ammonia is one of the most commonly produced industrial chemicals worldwide, second only to sulphuric acid. Around 200 million tonnes of ammonia is produced each year and the bulk of this is used in the agricultural fertilizer industry. Anhydrous ammonia liquid is direct drilled into the soil in many areas around the world. This method provides a very efficient and cost effective delivery of nitrogen to the subsoil which encourages excellent crop growth. In other situations the fertilizer is delivered to the plants as an aqueous-ammonia solution typically 25% ammonia in water. Ammonia is also widely used in the manufacture of a range of granular fertilizers.

In the US Midwest there is a network of more than 40 ammonia storage terminals interconnected with over 5000 km of piping to facilitate the distribution of anhydrous ammonia for use as a fertilizer. This network spans from Louisiana in the south to Minnesota in the north and from Indiana to Texas. Large quantities of ammonia are also transported by sea, rail and road. The US uses around 15 to 20 Million tonnes of ammonia per year in the fertilizer industry.

China is currently the largest producer of ammonia. Most ammonia is at present produced using natural gas or coal to provide the hydrogen with the nitrogen coming from air. It is possible to manufacture ammonia using renewable energy like solar, wind, hydroelectricity etc. rather than using hydrocarbons; however this is usually more expensive and therefore less popular than making ammonia with cheap natural gas or coal.

Ammonia is a massive contributor and essential to efficient world food production. Its use can only grow in future as the global appetite for food grows.

In the next session we will discuss the potential for ammonia as a carbon free, zero emission fuel. This is where ammonia has the most to offer in preserving the future of our planet.

Until then,

Kind Regards

Ammoniaman

Ammonia as a refrigerant

Prior to 1850, a brilliant Australian Engineer, James Harrison invented the vapour compression refrigeration system by “closing the loop”. He was aware that when ether evaporated it made printing type set cold when used for cleaning. His invention collected the evaporated gas, compressed it, condensed it and fed it back as a liquid to be re-evaporated, thereby forming a closed loop. Refrigeration was born. By 1855, Harrison was manufacturing  ice machines operating on ether in the closed refrigeration circuit, while the rest of the world were still cutting ice blocks from frozen rivers and lakes. In 1856, Harrison was awarded patent No. 747 for his invention.

In the 1860’s, ammonia started to be used in refrigeration as it was seen as a much safer alternative than ether.  Ammonia quickly gained popularity and by 1900 it dominated the world of refrigeration as the refrigerant of choice. The ammonia domination remained through until the 1930’s when the first synthetic refrigerants known as CFC’s were introduced.  CFC’s and subsequently HCFC’s and HFC’s then took over and dominated the commercial, domestic and transport refrigeration and air conditioning sectors, confining ammonia to the Industrial refrigeration world. Recent decades have seen the phasing out of the synthetic refrigerants in recognition of their extreme environmental damage.  There has been a resurgence of the use of ammonia as one of three naturally occurring refrigerants attracting huge support worldwide, the other two being carbon dioxide and hydrocarbons.

From a thermal engineering point of view, ammonia is an excellent refrigerant achieving vapour compression, cycle efficiencies better than virtually all other refrigerants.

In a refrigeration system, the refrigerant is a working fluid which circulates around a closed loop, carrying heat from one location to another. The refrigerant is not consumed, and only needs topping up if some leaks out. Therefore the consumption of anhydrous ammonia for refrigeration purposes is only a tiny fraction of the amount of ammonia manufactured each year. The amount would be in the order of a fraction of one per cent. The total amount of ammonia manufactured worldwide each year runs to tens of millions of tonnes, whilst that used in refrigeration would be in the order of tens of thousands of tonnes.

The world has been using ammonia as a refrigerant for 150 years; it has proven itself as a star performer from an efficiency, environmental and safety point of view. For these reasons, it can do nothing but grow in popularity into the future.

In the next instalment we will discuss the profound impact ammonia has on the world as a fertilizer

Until then, Kind Regards

Ammoniaman

Introduction to Ammonia

Welcome to the world of Ammonia.

Ammonia is a naturally occurring substance with a molecular structure comprising one Nitrogen atom and three hydrogen atoms expressed as NH3.

Ammonia has also been manufactured in commercial quantities around the world for over a century.

Its properties are very well known with full MSDS details readily available. It is usually referred to as “Anhydrous Ammonia” which describes it’s very low or negligible water content. The Salient features of ammonia are that it is highly alkaline, it is toxic in medium concentrations and it has medium flammability when mixed with air in relatively high concentrations.

The world wide manufacture of ammonia presently runs into the tens of millions of tonnes per year, and the manufacturing process currently used involves the consumption of hydrocarbons.

The bulk of Anhydrous Ammonia manufactured at present is used in the fertilizer industry to efficiently deliver nitrogen fertilizer for agriculture world wide. Much smaller amounts are used in refrigeration , water treatment and other forms of gas treatment.

In future I will try to convey the benefits and enormous potential of this wonderfully versatile substance we call Ammonia. In the next installment I will attempt to cover the huge contribution Ammonia has made to the world of refrigeration.

Until then ,  Kind Regards

Ammonia Man