Solar farm atop a PrimeAsia Leather Corp. leather tannery in Vietnam. Courtesy photo via WWD.
Tanning is an intense chemical process which transforms decomposable rawhide into leather, but not without discharging serious pollution into water; Around 250 chemicals are used in the process, with chromium sulfate being the most dangerous. In Monday's issue of WWD, Footwear News investigated three leather tanneries at the forefront of greening up their processes, from reducing water use to adding solar farms on factory rooftops. Click through for 3 ways leather tanneries today are cutting their emissions (and saving a buck):
1. Reusing Water and Reducing Fresh Water Use
Image via TreeHugger
Simona Tanning, whose clients include Clarks, Keen, Nike, and Timberland, opened its leather tanning facility in Huizhou City, China in 2006 and has created a system to reduce water waste: A membrane bio reactor reduces the amount of suspended solids and organic pollutants in water used to re-tan the hides and a reverse osmosis system filters the treated water so it can be reused in the tanning process. According to WWD, the system has reduced the facility's fresh water use and water discharge by 40 percent.
2. Solar Power Provides Clean Energy (and Saves Money, Too)
At PrimeAsia Leather Corp., one of their biggest energy users is heating the water in their boilers, according to WWD. With the installation of a 16,000-sq.-ft., 768-panel solar farm on its Vietnam tannery, they expect it to heat 100,000 liters of water a day and pay for itself in 17 months.
A reed bed for water filtration at Simona Tanning. Courtesy photo via WWD.
3. Measuring Every Step of the Manufacturing Process
At ISA TanTec in Guangzhou, China and Saigon, Vietnam, measuring every stage of the manufacturing process is the key to ensuring efficiency and savings. An example, from WWD, below.
Hydraulic cooling systems have replaced fans in several pieces of equipment, meaning no extra electricity is needed to run the fans, and the water that is heated as it cools the fans later can be pumped into the boiler, where it won't require as much energy to heat. In the China tannery, and especially in Vietnam, which was built with the green adaptations in mind, such changes have reduced energy consumption by 35 percent and water use by 50 percent.
The developments in leather tanneries to date is only the beginning of more advancements to come. Each tannery noted has plans to further develop their green programs, from exploring geothermal to measuring the carbon-dioxide emissions per square foot of leather. Read more on these tanneries plans for the future over at WWD Footwear News.