Turning biomass into the height of fashion

Steam is essential for clothing and textile giant Gildan, a constant - and hitherto costly - supply of steam to heat the company’s knitting, bleaching, dyeing, finishing and cutting facilities.
Initially famous for producing blank T-shirts and sweatshirts for others to put their logo on, Montreal-based Gildan manufactures activewear, socks, and underwear at its facilities in Central America, the Caribbean Basin, the US and, on a smaller scale, Bangladesh, and employs some 43,000 people worldwide.
Like most textile and socks manufacturing plants, the company traditionally relied on fossil fuels, particularly bunker oil, to produce all the steam required. Today, however, following an environmental rethink and some significant financial investment, 53% of Gildan’s total energy comes from biomass.
Bunker fuel consumption is down 70% compared to 2010 and greenhouse gas emissions down 45%. Waste recycling is up to 90% of total waste and waste sent to landfill down 21% (compared to 2010).
The transition to biomass makes sense for so many reasons: environmentally, for local communities and financially, says Peter Iliopoulos, senior vp for public and corporate affairs.
“Biomass energy is a reliable carbon-neutral energy supply and the impetus to move to biomass was initially environmental, allowing us to contribute to climate change mitigation by significantly reducing our greenhouse gas emissions. Biomass crop combustion also generates less ash than coal and the ashes generated are used in the maintenance of the roads at the company's manufacturing complex in Honduras.
“Over the past 10 years we have made significant investment in environmental and social compliance and developed robust programmes so that Corporate Social Responsibility and sustainability are now central to our overall business strategy. I believe we are now an industry leader.”
Indeed, Gildan is named by Maclean's Magazine as one of Canada’s fifty best corporate citizens and is a member of the Dow Jones Sustainability World Index.
In the Dominican Republic, the new system substitutes fossil fuel with biomass such as agricultural residues as well as Gildan’s own non-fossil production and packaging waste such as yarn cones, cartons and pallets, explains corporate sustainability manager Julie Cournoyer.
In Honduras, the burning biomass consists of a variety of agroforestry residues, mainly African Palm, cultivated crops harvested from agricultural energy plantations and, again, Gildan’s own non-fossil industrial residues.
Converting to biomass has also allowed Gildan to invest indirectly in local communities. “Biomass supports the development of agro-industries for the production of renewable and clean energy. Moreover, biomass crops are locally sourced and dedicated energy crops provide numerous jobs in urban and rural communities which also reduces migration to the cities,” says Iliopoulos.
And from a business perspective, using locally sourced crops increases the company’s energy autonomy and makes it less vulnerable to fluctuating oil prices. “Biomass is a reliable, long-term fuel supply so we are able to insure ourselves against risks such as the increasing scarcity and rising costs of non-renewable energy,” says Iliopoulos.
While transition required significant investment in building biomass digesters and finding biofuel suppliers, this was not a complicated procedure. The biggest challenge, says Cournoyer, was in perfecting the recipes for feeding the digesters. “It is not like a traditional boiler that just needs stoking; the correct blend of products is essential and perfecting our recipe has been a real learning curve. We get better each year.”
Today, with the expansion of the biomass steam generation system completed at Gildan’s giant Rio Nance complex in Honduras, not only is 100% of steam required for manufacturing biomass-generated but also the steam required for air conditioning in the textile factories which is expected to generate yearly savings of 400,000,000 kwh.
As so often happens when a company moves to more sustainable policies, one initiative opens the door to others. Following the expansion of their biomass systems, Gildan has now replaced its electrical chillers with high efficiency absorption chillers which run mainly on the steam produced by the biomass steam generation expansion.
In a further bid to cut energy usage, the vacuum system which, explains Cournoyer, is used to suck socks out from the machines and on to storage and then packaging has been optimised at the hosiery factories by closing unnecessary outlets. This has resulted in annual energy savings or around 688,000 kwh.
These are significant contributions to the reduction of its overall energy consumption - in other words its purchased energy.
“Improving energy efficiency and thereby reducing our environmental impact remains a priority at all of our facilities,” says Iliopoulos.
The installation of a bunker heating control system and condensate recovery process at three textile facilities and two hosiery facilities in Honduras have resulted in a savings of approximately 10,000 gallons of bunker fuel per month.
High rates of condensate returns mean substantial conservation of both water and energy. Condensate, the liquid resulting after steam energy has been used in a heat transfer process, is warm water containing chemical additives that can be reused to produce steam, at just one-third of the cost of generating steam from fresh water and new chemicals.
Several heat recuperation systems have been incorporated into the condensate return loop and by using these heat recovery systems, Gildan is able to pre-heat water and have it available when required by different processes, thus reducing the amount of steam needed to reach process temperature.
This way, Gildan reduces its energy consumption costs and engages in effective water conservation.
Moreover, by installing hot water heat recovery systems with lint filtration the company is able to reduce solid material contained in the wastewater by some 70% which improves the efficiency of the company’s Biotop effluent cleaning lagoons - Gildan's biological wastewater management system that uses gravity, microorganisms and sunlight to remove chemicals and dyes from wastewater and render it safe for use in local agriculture.
Sometimes, indeed, energy savings can be deceptively simple, such as changing 75W bulbs for 59W bulbs or the installation of of skylights in the Honduras textile factories to make greater use of natural light. “Of course there is always more room for improvement,” says Cournoyer. “Further savings we can make, more inefficiencies to discover.”
“Our sustainability programme is constantly evolving,” says Iliopoulos, “and we continue to challenge ourselves by planning new projects and setting new targets. With the biomass expansion completed, we are now working on our next initiatives.”