Last year saw aluminum products supplier Alcoa cut its normalized water use by 4.5 percent from 2010 levels, but increase the amount of waste it sent to landfill by 10 percent, according to the company's 2011 sustainability report.
In 2011, Alcoa used 4.2 cubic meters of water per metric ton of production, down from 4.4 cubic meters of water per metric ton of production the year before. In 2005 the company used 5.3 cubic meters of water per metric ton.
Alcoa's 2020 goal was to reach 4.8 cubic meters of water per metric ton, a target it met in 2010. This year Alcoa has pledged to bring its 2030 target of 4.0 cubic meters of water use per metric ton of production forward to 2020. The company's total use of freshwater slightly increased in 2011 versus 2010 due to the restarting of idled capacity, the report says.
The company's Pinjarra, Australia refinery is installing a pipeline that would deliver secondary-treated waste water from a nearby municipal treatment plant to the refinery for use in its processes, the report says.
Alcoa's total carbon emissions rose 4.1 percent year-on-year from 45.4 million metric tons of carbon dioxide equivalent emissions in 2010 to 47.3 million metric tons of CO2e in 2011.
Alcoa's direct emissions accounted for roughly two-thirds of the absolute total. The company's direct emissions rose 3.7 percent from 2010 to 2011. Alcoa attributes this jump to sporadic process instability and restarts it its smelting capacity.
The company's global primary products business met its 2020 target for carbon intensity in 2010, meaning that Alcoa is using this sustainability report to bring the division's 2030 emissions intensity target forward to 2020. The company's global primary products business will now target a 30 percent reduction in its emissions intensity by 2020 and a 35 percent cut by 2030 over 2005 levels, the report says.
The success in the global primary product division came from increasing the use of hydroelectric power, sharing best practices between facilities and targeting energy efficiency, the report says.
The energy intensity of the company's global rolled products division fell just shy of six percent year-on-year, while its global primary products division's energy intensity rose slightly.
In 2011, Alcoa's global rolled products division used 16.5 GJ of energy per metric ton of aluminum produced, down from 17.5 GJ per metric ton in 2010. The division's 2020 and 2030 goals are 14.4 and 12.6 GJ per metric ton - a 20 percent and 30 percent drop on 2005 levels, respectively.
Last year, 54.5 percent of the company's purchased electricity came from hydro electricity and 25.3 percent of its purchased electricity came from coal. Natural gas accounted for 9.6 percent of its purchased electricity in 2011.
Natural gas leads the way as the direct power source used most, accounting for 62.8 of Alcoa's direct energy consumption in 2011. Oil and coal provided 18.2 and 17.7 percent of the company's direct energy consumption, the report says.
The Pinjarra refinery has two-gas powered cogeneration units, and a year’s electricity from each of Pinjarra Refinery’s cogeneration units saves around 450,000 metric tons of greenhouse gas emissions annually, compared to a similar-sized coal-fired plant., according to the report. In addition the cogeneration plants reduce refinery emissions by 270,000 metric tons a year through more efficient steam generation, the report says.
The company has a goal of sending 99,000 metric tons of waste to landfill in 2020, representing a 75 percent reduction in such waste over 2005 baseline levels. In 2011, Alcoa sent 322,000 metric tons of waste to landfill. This represents a 10 percent increase on 2010 levels but a 19 percent decrease on 2005. By 2030 Alcoa wants to send zero waste to landfill (See graph, below).
The company has made progress on the amount of waste it recycles or sells. In 2011, Alcoa recycled or sold 806,000 metric tons of waste. This represents almost a 22 percent increase on 2010 levels.
An April 2012 study released by Maplecroft ranked Alcoa, GE, Johnson Controls, Ford and Intel as the leaders in innovation of clean-tech solutions and products, mitigation of climate change-related risks and management of carbon emissions. The Maplecroft Climate Innovation Indexes studied 360 large, multinational US companies and how they adapt to climate-change issues.
