Aircraft emissions are often the centre of attention when considering aviation’s impact on the environment, but airframe and engine production facilities are also significant greenhouse gas emitters and sources of industrial waste.

Many aerospace manufacturers have already taken many of the obvious steps to reduce their environmental impact. Despite this, they have set tough targets for further reducing their carbon footprints – targets which must be achieved against the backdrop of rapidly-rising production rates.

One such manufacturer is Pratt & Whitney. Fresh from achieving – and in some cases exceeding – parent company United Technologies’ (UTC) sustainability goals for 2015, the engine maker is now working towards the next round of targets for 2020. These could be considerably harder to hit. Lisa Szewczul, vice-president environment, health and safety at Pratt & Whitney, says it will be “challenging” to meet the latest set of objectives – but it is a challenge the company’s leadership and employees are fully embracing.

“We will be doubling our production rate over the next five years and then it will double again, so there are all kinds of challenges with respect to reducing waste,” says Szewczul. With burgeoning order books for its PurePower family of geared turbofans, Pratt & Whitney will have its work cut out to reduce emissions and waste by the percentages requested by UTC in its 2020 Sustainability Goals.

“In the face of an unprecedented increase in ramp production volume, our reductions on the environmental side are going to be absolute,” the engine division says.

The company’s 2015 goals used 2006 as a baseline to call for a 40% reduction in greenhouse gas emissions, a 55% reduction in water usage and for 60% of industrial processing waste to be recycled. The goals for 2020 use 2015 as the baseline and demand a further 15% cut in greenhouse gas emissions, an additional 25% reduction in water usage and an industrial waste recycling rate of 90%.

Of the greenhouse gas target, UTC says: “This goal is a continuation of the 3% annual reduction target in place since 2006, and keeps UTC on a path consistent with the UN Intergovernmental Panel on Climate Change (IPCC) target of 80% lower GHG emissions by 2050.”

More than 800 projects of varying sizes across the company’s divisions combined to produce the results reported in 2015, and 1,000 projects will contribute to reaching the 2020 targets. But the Pratt & Whitney team will need to be even more creative this time around.

“It gets more and more challenging once you’ve got the low-hanging fruit,” says Szewczul. “It’s not like the days of the silver bullet – projects like replacing all the lighting have been done, so now we’ve got to be more thoughtful. Green thinking has to be built into the design of the process from the outset.”

However, she says there are still “big opportunities with manufacturing processes in terms of greenhouse gases and waste”. For instance, the recycling of coolant, which Szewczul describes as an “unpleasant waste stream”, has helped to save “hundreds of gallons” of water, and switching chemicals to less harmful ones is also having a positive effect.

“We’re finding alternatives to problem chemicals. For example, we went to IPA [isopropyl alcohol] wipes to reduce the amount of acetone used for cleaning,” says Szewczul.

UTC says it reduced its use of more than 70 targeted chemicals in the period between 2006 and 2015, exceeding its 2015 air chemical emissions reduction target of 68%. For 2020, the company says it will focus on a smaller number of chemicals that pose the most risk to the environment – principally chlorinated and brominated solvents.

“Our 2020 goal prohibits air emissions from the use of eight specific chlorinated or brominated solvent chemicals if used above a level greater than 100lb [45.4kg] per year," the company says. "The 100lb annual threshold is a de minimis level that will allow the use of small quantities of solvents as included in mixed chemical formulations.”

Szewczul says the UTC sustainability goals must be at the forefront of the design process for new buildings, to ensure that any new facilities “at least meet” energy reduction targets. To achieve this, a number of Pratt & Whitney-owned buildings now use renewable energy, such as solar power, to provide electricity.

“There has to be an above-30% improvement in energy [consumption], so when we have a new building the bar is raised, there’s a new standard,” says Szewczul.

The vast majority of Pratt & Whitney’s ground-based greenhouse gas emissions come from its manufacturing equipment, such as furnaces, grinding machines and refrigeration, which are in use at more than 60 factories around the world. Employees at these facilities are involved in ongoing projects to improve the efficiency of this equipment.

“We have a step-by-step process where we analyse and record all the environmental attributes for each phase of the process,” says Szewczul. Examples of how efficiency has been improved can be as simple as remembering to switch something off when it is not in use. “Sometimes large equipment is left on over the weekend so we ask, ‘do we really need to have it on over the weekend?’” Another example she cites is a reduction the rate of RPMs in tooling processes when a lower rate will suffice.

Bigger energy-saving opportunities are available when it comes to retooling – something the company will have to invest heavily in as it ramps up production rates. “We need to purchase new equipment to meet demands, and when we look for retooling equipment we make sure it’s more energy-efficient,” Szewczul says.

Making such broad-based changes to reduce emissions and waste does not come cheap. For Pratt & Whitney it involves “multi-million dollar investments”, Szewczul says, although she insists that these investments are being made through choice rather than obligation.

“Regulations don’t drive our goal sets. I can’t remember anyone saying when we set our goals, ‘what’s the UN directive on this?’ We’re aware [legislation] is out there but it really was a drive to do better. It’s in our DNA.”

Like Pratt & Whitney, Boeing is also working to a five-year waste- and emissions-reduction plan. While the Hartford-based engine manufacturer has just started work on achieving its latest set of targets, the Seattle-based airframer is nearing the end of a list of sustainability goals it laid out in 2012 for completion by the close of 2017.

But where Pratt & Whitney aims to reduce greenhouse gas emissions by 15% by 2020 compared with 2015 levels, Boeing’s 2017 goal of maintaining its 2012 emissions, water use and solid waste to landfill levels appears less ambitious. Boeing has also said its hazardous waste generation will grow “at a rate no more than the rate at which our business is expanding”, so one could be forgiven for wondering if the airframer could have gone a little further.

However, Amy Bann, director of sustainable materials at Boeing Commercial Airplanes, is keen to point out that while the company met its 2012 objectives, it is “now exceeding all goals” set for 2017.

“Throughout 2015 we reduced all levels by between 6% and 11%,” says Bann. Boeing is currently “in the goal-setting process” for the next five-year cycle, and Bann says the company will “go as far as we possibly can in challenging ourselves to reduce as much as we can”.

The use of renewable energy and the incorporation of energy conservation technologies and sustainable materials into new building designs have a key role to play in meeting and exceeding these targets. A recent example of these principles put into practice is the $1 billion 777X composite wing centre (CMC) in Everett, Washington, which opened in May 2016.

Bann says the 121 million m² (1.3 billion ft²) facility was “built with sustainable manufacturing in mind”. Boeing followed the Leadership in Energy and Environmental Design (LEED) certification programme developed by the US Green Building Council (USGBC) when designing the building, meaning it had to obtain a certain amount of points for the building’s ability to reduce waste, water and emissions.

Employees in the CMC facility work in a “culture of environmental awareness”, says Bann, and the building is divided into different stations to facilitate waste management. To help reduce waste from outside, Boeing has been pressing suppliers to cut down on the amount of packaging they use.

“Over the past year we’ve put in new supplier requirements. In the past, products were cushioned with foam but now we say that all packaging has to be recyclable or made so it can be reused,” says Bann.

Ironically, the product made at the factory – composite wings for the 777X – cannot easily be recycled. “The products in that facility are carbonfibre heavy,” says Bann, adding that Boeing is “working very hard internally” on finding a way to get excess carbonfibre “back into our manufacturing process”. There are also third parties that “can do a lot with” scrap pieces of carbonfibre.

While research continues into recycling and reusing composite materials, Bann says that Boeing is “working very hard to calibrate tooling” in order to “avoid creating extra waste and scrap”.

The use of renewable power features highly in Boeing’s emissions-reduction strategy, with almost half of its electricity consumption coming from renewable sources. A variety of alternative energy sources are used to supply its factories, depending on their geographical location. Washington State is a leading producer of hydroelectric power, so the airframer is able to make good use of this energy on its home turf.

Boeing’s 737 manufacturing site in Renton is 100% powered by renewable energy, thanks to an agreement with Puget Sound Energy to provide hydroelectric power, together with renewable energy credits from wind energy purchased from the local utility. Hydroelectricity also provides the majority of power at Boeing’s Everett and Seattle sites.

In much sunnier South Carolina, Boeing’s North Charleston site gets 100% of its energy from 10 acres (4.05ha) of solar panels on the roof of the final assembly building. And in southern California, 20% of the power at Boeing’s facilities comes from wind turbines.

Not to be outdone, Airbus has five focus areas for sustainable manufacturing under its Blue5 initiative: energy, water, waste, carbon dioxide and volatile organic compounds. The European airframer says it has made “significant gains” in each area over recent years.

Airbus is a founding member of not-for-profit International Aerospace Environmental Group (IAEG), which last July published an updated version of its greenhouse gas reporting guidance for the aerospace industry. This is a set of voluntary guidelines written to help the industry reduce its impact on the environment. The latest version moves beyond offering advice on how to report direct and indirect emissions to include emissions resulting from employee commuting and both upstream and downstream transportation.

IAEG chair Sally Gestautas said on unveiling the updated guidance that its role had become “even more vital to our industry, as the world’s eye is upon us”.

Source: FlightGlobal.com