♦ Energy and greenhouse gases
As discussed in the previous section, the manufacture of ammonia and ammonia-derived products is energy-intensive, requiring natural gas as both a raw material and an energy source. The intensity of energy use and carbon emissions associated with our two main manufacturing processes is shown in the life cycle assessments for ammonia and ammonium nitrate. Assurance was obtained over our Australian GHG emissions, energy consumption and production figures for the period 1 July 2014 to 30 June 2015. The third party issued an unqualified opinion over our reported emissions, energy production and energy consumption.
Energy useIncitec Pivot used 44,070,102 gigajoules (GJ) of energy over the past year, 1,983,644 of which was purchased electricity. Approximately 80 percent of the electricity purchased was generated from non-renewable sources. Approximately 20 percent of the purchased electricity (indirect energy) was generated from renewable resources, mostly hydroelectric. Natural gas and diesel amounts used as raw materials and on-sold in our products have been included in our energy use figure. Approximately 1 percent of our direct energy is from CO2e-free sources, which includes bio-fuel oil and electricity that is generated from the heat emitted by the exothermic chemical reaction used to manufacture sulphuric acid.
Greenhouse gas emissionsWe are a ‘large emitter’ of GHG, as defined by the Australian National Greenhouse and Energy Reporting System (NGERS). During 2015 our recorded Scope 1 (direct) and 2 (indirect) absolute GHG emissions were 2.8 million tonnes of carbon dioxide equivalent (CO2e), which is an increase of 7 percent from last year and is due to increased production. The total figure comprises 2.4 million tonnes of Scope 1 (direct) emissions and 0.4 million tonnes of Scope 2 (indirect) emissions.
Read about the GHG reduction targets we achieved and set this year at Our Targets.
Improving our performance
In line with the sustainability strategy to ‘Use Less’ and ‘Care for the Environment’, our manufacturing plants continued to reduce both energy use and carbon emissions through initiatives such as lighting reviews, plant energy optimization projects and other continuous improvements. At Moranbah, Australia, a steam trap audit and replacement project in the ammonia plant was completed and cycles in the gas fired boilers were increased. These actions will decrease natural gas consumption by 34,000 GJ and GHG emissions by 1,750 tCO2e per year. A $90,000 investment in the nitric acid abatement unit at this site will further reduce potential GHG emissions by 559,672 tCO2e per year. At the Mt Isa, Australia, site, electricity is made from waste heat generated during the process of making sulphuric acid. By maximising this process during the year, purchased electricity was reduced by 15,566,685 kWh, which reduced Scope 2 GHG emissions by 13,387 tCO2e. At Dinamita, Mexico, solar street lighting and a solar operated boiler were installed, and a Business Sustainability Audit was conducted at the Simsbury, USA site with the aim of reducing energy usage by 10% in 2016.
Other emissions to air
Nitrogen oxides (NO2 and NO, referred to collectively as NOx) are released when fuels are burned at high temperatures, and when nitric acid is manufactured. Sulphur oxides (SO, SO2, SO3, referred to collectively as SOx) are emitted when fossil fuels are combusted, and in the making of sulphuric acid. Although not greenhouse gases, NOx and SOx have other environmental impacts, such as air pollution. This year our operations emitted 3,632 tonnes of NOx and 18,508 tonnes of SOx. We continued to invest in NOx reduction technology, with work beginning on the design of a Selective Catalytic Reduction unit for the Louisiana, Missouri, nitric acid plant, which will be installed in 2016.