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Fuel switch in the ammonia industry

Ammonia is the main product of the fertilizer industry. Developing countries account for the majority of worldwide production. About 77% of ammonia production is based on steam reforming of natural gas, with most of the remaining production based on heavy-oil or coal-based processes.  A further shift from heavy-oil or coal-based to gas-based processes can strongly reduce energy use and emissions.

Introduction top

Ammonia is synthesized from nitrogen and hydrogen. The required nitrogen is obtained from the air and hydrogen is mostly produced from natural gas in a steam reforming process.

The International Energy Agency estimates that 77% of ammonia production is based on natural gas. Another 14%, mainly in China, is based on coal gasification. India and China also use partial oxidation of oil products and heavy hydrocarbon fractions (IEA, 2007). Gas-based processes are the most energy efficient. Heavy-oil processes typically use 1.3 times as much energy and coal based processes even 1.7 times as much (IEA, 2007). Replacing old ammonia production capacity by new natural gas-based steam reforming processes can therefore strongly improve energy efficiency and reduce greenhouse gas emissions.

Feasibility of technology and operational necessities top

Gas-based technologies are widely used in all regions of the world. The technology is supplied by a limited number of companies and new plants tend to operate at comparable energy efficiency. The most energy efficient technology available is the auto-thermal reforming process, which combines partial oxidation and steam reforming technology and uses about 28 GJ/ton (IPCC, 2007).

A requirement for the use of gas-based technology is the availability of natural gas at a competitive price.

Status of the technology and its future market potential top

Almost all nitrogen fertilisers are based on ammonia. Production has been on the rise in developing countries which have a high fertiliser demand. In 1974, developing countries accounted for only 27 % of ammonia production capacity. By 1998 this share had increased to 51% (IPPC, 2007).

Global ammonia production was 125 million tonnes in 2008 with China being the world’s  largest ammonia producer (IFA, 2010). In China, about 70% of ammonia is derived from coal, 10% from oil products and 20% from natural gas. Coal-based processes are used in small-scale and medium sized plants.

India is the second largest ammonia producer. About two-thirds of production capacity there is based on natural gas. The remainder uses naphtha and fuel oil. Gas-based plants in India use on average 36,5 GJ/ton ammonia.

Regional distribution of ammonia production in 2008 (IFA ,2010)

Figure 1: Regional distribution of ammonia production in 2008 (IFA, 2010)

Mainly because of the differences in the type of feedstock, large differences exist between the energy intensity of ammonia production in different regions of the world (Table 1). But at gas-based plants many different energy efficiency improvement measures are also possible (IPPC, 2007). 

Table 1: Energy intensity of ammonia production in 2005 (IEA, 2007)

Region

Energy intensity (GJ/t NH3)

Region

Energy intensity (GJ/t NH3)

Western Europe

35.0

Other Asia

37.0

North America

37.9

Latin America

36.0

Commonwealth of Independent States

39.9

Africa

36.0

Central European countries

43.6

Middle East

36.0

China

48.8

Oceania

36.0

India

43.3

World

41.6

How the technology could contribute to socio-economic development and environmental protection top

The International Energy Agency estimates that in 2004, total energy and feedstock use for ammonia production amounted to 4,3 Exajoules of natural gas, 0,6 Exajoules of oil and 1,2 Exajoules of coal. Ammonia production is therefore responsible for about 20% of all energy consumption in the chemical industry.

Environmental benefits of switching to gas-based processes are reduced emission of CO2 and improved energy efficiency. But there may be an adverse effect on energy security when oil and coal are more readily available than natural gas.

A steady supply of affordable fertilizers is essential for the development of agriculture. Modernizing or replacing older and less efficient plants can help fertiliser industries to stay competitive. However, new ammonia plants require large capital investments.

Financial requirements and costs top

Prices of fuels vary from country to country. but generally speaking, natural gas costs make up 70-90% of the ammonia production costs (IEA, 2007). Whether higher gas prices result in higher ammonia prices depends on the global supply situation, so the choice of fuel can have an important impact on the profitability of the industry. A fuel switch is a fundamental process change, which requires large investments. However, modernizing or replacing older and less efficient plants can be profitable investment decisions in the long term. (IEA, 2007)

References top

International Energy Agency (2006), Energy Technology Perspectives 2006, Scenario’s & Strategies to 2050, OECD/IEA, Paris, 2006.

International Energy Agency (2007), Tracking industrial energy efficiency and CO2 emissions, OECD/IEA, Paris, 2007. Available at http://www.iea.org/textbase/nppdf/free/2007/tracking_emissions.pdf

 International Fertilizer Industry Association, available at http://www.fertilizer.org/

 IPPC (2007), Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic Chemicals- Ammonia, Acids and Fertilisers, Integrated Pollution Prevention and Control, 2007. Available at http://aida.ineris.fr/bref/bref_anglais/lvic_bref_1206.pdf

Author affiliation:

Energy research Centre of the Netherlands (ECN), Policy Studies