Scientists at South Dak-ota State University are working at making a transparent, biodegradable film from crop residue and native grasses.
Srinivas Janaswamy, assistant professor of dairy and food science at the university, is using a $481,618 grant from the US Department of Agriculture to create a film that will benefit both farmers and the environment.
“We are extracting cellulose fraction from renewable agricultural residues and then solubilising it to make strong, biodegradable films,” said Prof Janaswamy, who is also a South Dakota Agricultural Experiment Station researcher.
Using the abundant supply of agriculture biomass to create biodegradable products that can replace petroleum-based plastics will reduce the impact these packaging materials have on the environment and generate extra income for farmers.
Prof Janaswamy is developing processes to extract cellulose fraction from corn stover and soybean biomass, wheat and oat straw, as well as switchgrass and prairie cordgrass.
His research has the potential to create a value-added product using renewable agricultural resources.
Farmers are baling corn stalks and leaves for livestock feed and bedding and then leaving the rest in the field to improve soil health.
“Both are important,” said Prof Janaswamy, but he sees the possibility of gaining additional profit by using a fraction of the corn residue for biodegradable plastics.
Assuming a ton of corn stover is worth $83, based on its value as livestock feed, and using a conservative yield estimate of one ton of corn stover per acre, a farmer could generate roughly $33,000 of additional revenue by selling 40 per cent of the corn stover from a 1,000-acre cornfield, while reserving 30 per cent for livestock and 30 per cent for soil health.
“Instead of putting all eggs in one basket, distributing them could be more advantageous, not only to address plastic pollution issues, but also to gain extra dollars,” Prof Janaswamy said.
The plant biomass consists of three components – cellulose, hemi-
cellulose and lignin.
In previous research the ex-traction process produced bio-degradable film from cellulose extract from corn stover that was gray due to the presence of lignin.
Through the new project, which
began in November, Prof Jana-swamy reported: “We have been able to remove the lignin and get a pure, white cellulose material from corn stover.”
“The process turned out better than I expected,” Janaswamy said, noting “this is a patentable process.”
The films should have three attributes. They should be strong
enough to resist tearing, trans-parent so manufacturers can add any colour they wish, and biodegradable.
“When you put them into the soil, they should disappear over time – 30 to 60 days is the goal,” Prof Janaswamy said.
Once the researchers are able to accomplish these goals, they will go back to the extraction steps and make sure the whole process is economical.
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