Home / Knowledge / News / SDSU research could improve leather tanning
SDSU research could improve leather tanning
Aug '10
South Dakota State University research funded in part by the Environmental Protection Agency could lead to a cleaner, greener leather tanning industry. SDSU research associate professor Douglas Raynie has a grant of $350,000 from the EPA to study an alternative method for processing leather. The project uses liquid carbon dioxide instead of water as a carrier for the chemicals used in different stages of tanning leather.

The EPA is interested because conventional leather processing generates a lot of pollutants. The SDSU project is funded under a program to develop green manufacturing processes.

Raynie, in SDSU's Department of Chemistry and Biochemistry, said there hasn't been a great deal of change through history in the steps involved in leather tanning.

“Processors take the animal hide and put it in a solution that will remove the hair and the grease from the hides. Then they salt the hides and add, in olden days, vegetable tanning — that is, the tannins from tree bark and other plant material. In more recent times, they use chromium salts, and chromium is a heavy metal that is considered a toxic waste. This process is very lengthy, it can take anywhere from several days to a month or more, and it generates a lot of wastewater and associated wastes.”

The SDSU research uses liquid carbon dioxide — that is, carbon dioxide under a high pressure. At room temperature, as much as 800 pounds per square inch of pressure is needed. Under such conditions carbon dioxide shows some properties of a gas and some properties of a liquid. It would permeate more like a gas, and could be used as a carrier like water, for example, Raynie said.

“One of the properties of liquid carbon dioxide that is attractive for this process is that it will permeate into the leather much faster than water, so we replaced the water and use the carbon dioxide as the carrier. Now, it will allow for a much faster process and hopefully a more continuous process.”

Additionally, the carbon dioxide can be vented away as a gas once the process is complete, which means the pollutants will fall out of solution so that they can be recovered and treated appropriately. Or alternately, if the carbon dioxide is to be reused, it can be strained through a membrane to remove pollutants.

“It's much easier to remove the waste such as chromium with the CO2 process,” Raynie said. In a water solution, by contrast, removing chromium and other wastes is more difficult.

Raynie said regulatory concerns have been so great in the U.S. that most of the leather-tanning industry is now based in other countries. Raynie said a new method for tanning leather could bring some of those jobs back.

“There is still a lot of infrastructure in the U.S., as well as the growing trend for more of the cottage industries or local industries. So I could see industries on a small scale, a regional leather tanner providing material for a regional shoe company or interactions of that nature.”

Must ReadView All

Textiles | On 20th Jan 2017

TEA expects budget to upscale textile skill industry

The Tiruppur Exporters’ Association (TEA) has requested the Central...

Textiles | On 20th Jan 2017

Bangladesh could earn $60 billion in exports by 2021

Bangladesh is expected to earn over $60 billion in exports by the...

Courtesy: PIB

Textiles | On 20th Jan 2017

Govt to help Tangaliya weavers purchase looms: Irani

Government of India will facilitate Tangaliya weavers in purchase of...

Interviews View All

Karel Williams
Dow Microbial Control

'Silvadur is most rapidly adopted in areas where hygiene-conscious and...

Vidhyaa Shankar. S
A Ganapathi Chettiar

'The usage of knits is getting into the boundaries of woven fabrics'

Asim Dalal
Indo Count Retail Ventures

Today, there is no other emerging market as India, "we make in India and...

Larry L Kinn
Suominen Corporation

Larry L Kinn, Senior Vice President - Operations Americas of Suominen...

Suresh Patel
Sidwin Fabric

Sidwin Fabric is a manufacturer and exporter of polypropylene textiles and ...

Marten Alkhagen
Swerea IVF AB

Marten Alkhagen, Senior Scientist - Nonwoven and Technical Textiles of...

Yash P. Kotak
Bombay Hemp Company

One of the directors of Bombay Hemp Company, Yash P. Kotak, speaks to...

Rupa Sood and Sharan Apparao

Nayaab, an exhibition meant to celebrate Indian weaves, is in its second...

Mike Hoffman
Gildan Activewear SRL

Gildan Activewear, a manufacturer and marketer of branded clothing and...

Press Release

Press Release

Letter to Editor

Letter to Editor

RSS Feed

RSS Feed

Submit your press release on


Letter To Editor

(Max. 8000 char.)

Search Companies

January 2017

January 2017

Subscribe today and get the latest update on Textiles, Fashion, Apparel and so on.


Browse Our Archives


Subscribe today and get the latest News update in your mail box.
Advanced Search