Cheap And Sturdy Paper Bags Can Be Reused And Converted Into Biofuels

Part of the problem with paper bags is their relatively short life cycle. They are incompatible with moisture and lack practical use after being used as fragile containers for a short time.

Researchers at Pennsylvania State University have decided to address these challenges and have created a product that may benefit consumers and the environment. Through some cheap heating and chemical operations, scientists have created a paper product that is strong enough to be reused for many times, resistant to water exposure, and can eventually be used as a good source of biofuels.

Jaya Tripathi, the chief researcher, said: "Reuse is mainly limited by the strength of the bag, while typical paper bags are unlikely to be reused for many times, because their durability after wetting is very low." He used to work at Pennsylvania State University, and now he works at the California United Bioenergy Research Institute. "The use of expensive chemical processes to improve the wet strength weakens the eco-friendly and cost-effective characteristics of paper in commercial applications, so it is necessary to explore non chemical technologies to improve the wet strength of paper bags.

The technology advocated by Tripathi is heat treatment, that is, slowly heating the cellulose of paper in an oxygen deficient space to increase its tensile strength when wet. After 40 minutes of pyrolysis, the wet tensile strength of the paper reached a peak of 1533% at 392 ° F (200 ° C), and decreased steadily with the increase of temperature.

She said: "I am studying other things, that is, how high temperature decomposition affects the glucose production of cellulose as a biofuel matrix. But I noticed that as we cook cellulose, the strength of paper is also increasing. This makes me think it may be suitable for packaging, which is a completely different application."

This stronger product can see that a paper bag endures wet and dry after use. However, kinking reduces its effectiveness as a biofuel product and greatly reduces the glucose output of the product. To solve this problem, researchers treated paper with alkaline sodium hydroxide solution. Paper has changed from 690mg/g biomass matrix (at 392 ° F cremation temperature) to 933mg/g 10% alkaline treatment.

Tripathi said, "We can eliminate most of the waste by changing to stronger, reusable paper shopping bags. The technology shown in this study -- if it can be improved -- including using worn bags as the substrate for biofuel production, its impact will be huge."

Although this laboratory study shows the prospect of this durable paper model, it is obviously far from practical application. However, extending the life cycle of paper, making it more durable, and finding a use for it after being discarded can largely offset the environmental costs of its production, making it a viable alternative to plastics.

"When the primary use of these paper products ends, their secondary use makes them more sustainable," said Daniel Ciolkosz, a researcher and associate professor of agricultural and biological engineering at Pennsylvania State University. "This is a concept that we think society should consider".

The study was published in the journal Resources, Conservation and Recycling.