A deep-seated commitment to be a role model for responsible business operations is a cornerstone of the corporate culture at Dubai Aluminium (Dubal) – the entirely state-owned corporation that owns and operates the world’s largest single-site primary aluminium smelter using pre-bake anode technology.

Strong evidence of this can be found in the well-entrenched policies and procedures, plus certification to international quality standards and systems that support Dubal’s openly stated quest to minimise the impact of the business on the environment, according to a spokesperson for Dubal.

Primary aluminium smelting involves an electrolytic process that reduces ore directly to metal. The major environmental impacts of Dubal’s operations are thus consumption of raw materials, combustion of fossil fuels and water, gaseous and particulate emissions to the atmosphere, and generation of waste (both hazardous and non-hazardous). “Dubal therefore endeavours to make its production processes as efficient as possible so as to minimise the use of resources and control the release of pollutants into the environment,” the spokesperson said.

With this in mind, a BS EN ISO14001:2004 Environmental Management System has been fully implemented, thus ensuring that Dubal’s operations are aligned with the most stringent international environmental standards. Good progress was made by Dubal during 2012 against all key environmental parameters monitored and managed, as outlined below:

• Raw materials – The main raw materials used are alumina (which is refined from bauxite), aluminium trifluoride, petroleum coke and pitch. Through improvements in Dubal’s production efficiencies, the ratio of raw material input to aluminium produced improved to 2.4 tonnes in 2012 (2011: 2.38  tonnes). This was achieved even though aluminium production increased by 2 per cent over the same period.

• Energy – the Dubal smelter complex includes a captive power station with the capacity to generate 2,350 MW (at 30°C); and is thus mostly self-sufficient in terms of power production (using purchased pipeline natural gas). Nevertheless, Dubal strives continually to minimise the power consumption of its operations. The total energy consumption by Dubal in 2012 was 162.89 million gigajoule (GJ), which translated into 14.73 DC MWh/t aluminium produced – thus continuing the declining trend in energy consumption per tonne of aluminium produced since 2000.

The company’s power plant

The focus on energy-savings is corporation-wide. As a member of the DSCE (Dubai Supreme Council of Energy), Dubal has whole-heartedly adopted the directives issued by Sheikh Ahmed Bin Saeed Al Maktoum (president of Dubai Civil Aviation, chairman of Emirates Airline Group and chairman of DSCE) to all DSCE member companies in April 2011 regarding the measures which the Dubai Government is taking to minimise energy consumption in Dubai in fulfilment of the Dubai Integrated Energy Strategy (DIES) 2030. Dubal’s efforts in this area saved approximately 17,375,000 kWh over the first 21 months of implementing the directives (up to December 2012).

• Water – Dubal is self-sufficient with regards to water supply; all the corporation’s water needs are met through the processes of its on-site Desalination Plant (no ground water or other water source is utilised). The Dubal desalination plant produces potable water and distilled water. Most of the distilled water is used for industrial applications within Dubal, whereas the majority of the potable water produced is sold to external consumers.

The corporation is continually on the look-out for ways to reduce its water consumption and recycle water wherever possible. For example, the Dubal water filling station has been re-engineered to capture spilled water, which is used to irrigate the landscaped areas within the Dubal site. Extensive use is also made of recycled grey water (treated sewage effluent from Dubal’s on-site sewage treatment plant) for irrigation purposes. Also, in some production processes, water is re-used in a closed-looped system to cool machinery and production lines. This uses the same quantity of water for repeated cycles, only taking in small quantities of top-up water periodically, when needed.

• Biodiversity – Dubal has implemented a green belt concept whereby a vegetated buffer zone around the perimeter of the site has been developed. The green belt comprises 1,840 specimens, including a species that is fluoride-tolerant, yet sensitive to hydrogen fluoride emissions, and therefore acts as a type of “early warning system” on higher than expected emission levels. Vegetation surveys are conducted regularly by a vegetation expert to measure and monitor the impacts of the fluoride emissions from the operations on the vegetation. The most recent survey, according to the Dubal spokesperson took place in March 2012 and the expert vegetation consultant concluded:   “Overall, the generally excellent health of the plants is a credit to Dubal. It is the result of very low emission rates, low rates of fugitive emissions and investment in first-class landscaping and pro-active management of the plants.” 

• Emissions – Air emissions are generated from a number of sources at Dubal, most notably from power generation and the smelting process. On-going efforts to minimise all airborne emissions are monitored by continuously measuring ambient air quality at strategically located stations around Dubal’s Jebel Ali site. The volume of sulphur dioxide (SO2) emissions in 2012, at 15.1 kg/t Al, was 13.4 per cent lower than in 2009. Oxides of nitrogen (NOx) volumes continued to decrease and, since 2007, have declined by 30.5 per cent. Total emissions of hydrogen fluoride (HF) – a noxious gas that evolves from the electrolysis process – were contained at 0.60 kg/t Al.

The Fume Treatment Plant at Dubal

With regards to greenhouse gases (GHGs), power production accounts for almost 80 per cent of GHG emissions at Dubal – primarily as carbon dioxide (CO2). During abnormal conditions of pot operations, the smelting process also emits perfluorocarbon (PFC) gases that have a GHG warming potential substantially greater than CO2. Concerted efforts to reduce Dubal’s total GHG emissions have led to a consistent downward trend, with the volume declining to 9.4 million tonnes of CO2eq in 2012 (2011: 9.52 million tonnes of CO2eq).

• Waste – The waste from Dubal’s waste streams – namely spent potlining (SPL), dross metal, scrap metal, carbon dust, non-hazardous process waste, hazardous medial and liquid waste, and food waste – is recycled, land-filled or treated on site. All liquid waste is treated on-site and the sludge residue is sent to a hazardous waste landfill site.

Waste recovery and recycling activities led to the recovery of 91.23 per cent of the waste generated by Dubal in 2012 (2011: 87.73 per cent). This high level reflects the practice of feeding certain “waste” materials back into the production process as raw material (such as aluminium scrap, spent anodes and dross).

A strategic objective to eradicate land-filling of SPL led to an agreement with a cement factory in the UAE, signed in 2010, whereby SPL-refractory material is used as an alternative fuel and raw material. The tonnage of SPL recycled has risen incrementally each year, and reached 100 per cent in 2012.

At community level, Dubal’s commitment to protecting the environment – thus contributing to the sustainability of the region – is also evident through its participation in key initiatives on a regular basis. For example, Dubal is an active proponent of the international Earth Hour movement and marks World Environment Day each year, most often by planting trees.

Support is also given to the annual World Clean-Up campaign, through the national Clean-Up UAE initiative, as well as through active participation the aluminium drinking can recycling efforts of the Emirates Environmental Group. A culture of recycling is actively nurtured throughout Dubal through the placement of recycling stations at strategic locations across its Jebel Ali premises, which give employees a convenient opportunity to sort waste at source and participate in material recycling. This, together with continual emphasis on the responsible use of energy and other natural resources (especially water), encourages both UAE nationals and expatriates employed at Dubal to become responsible citizens.