The fascinating profusion of uses of soy: Green chemistry

In a previous article (click here) we address the basic and traditional processes for obtaining large lines of industrial inputs, from soybeans. In this article we will comment on a new line of obtaining inputs and industrial transformation, green chemistry.

Green chemistry uses renewable sources to produce inputs, replacing fossil fuels, such as oil, gas or coal. An iconic example is soybeans with a high oleic acid content, which results in oil that remains stable at high temperatures, an essential factor for obtaining automotive fuels and lubricants. Other categories of products obtained with soy are adhesives, coatings, fibers, paper, plastic, paints, rubbers and solvents.

Emulsified soybean oil is a cost-effective process technology for groundwater bioremediation. The process is effective and lasts longer due to the slow degradation and release of hydrogen than other available processes. Soybean oil formulations are also being used as crude oil recovery aids.

A binding agent produced with soy flour, used in insulation in buildings, eliminates the release of volatile organic compounds (VOCs), such as formaldehyde, which is a carcinogen. Formaldehyde-free resins are obtained from soybean bran or flour and incorporated into wood composites such as plywood, panels, chipboards and flooring.

Chemically modified soy protein-based adhesives provide strong, heat-resistant bonds when adhering to paper substrates, including fast-drying liquid adhesives for packaging. They are also used as noise reducers in environments.

Research conducted at Iowa State University, funded by the Iowa Soybean Association, resulted in soybean-based asphalt. The product combines 100% recycled asphalt pavement, mixed with a soy-derived polymer, increasing durability and longevity and reducing maintenance costs.

From tires to paints

Since 2017, Goodyear has been producing tires using soybean oil, with a guaranteed durability of 140 kilometers. The company's goal is to eliminate dependence on oil by 2040, a good indicator for future demand for soybeans. Using the same technology, Skechers running shoes are made with soybean oil.

Many daily newspapers in the United States and other countries use soy ink in their presses. It can also be used in toner for copiers and computer printers. New inkjet printing technologies will replace traditional methods such as offset, gravure, flexography and screen printing in the coming years, increasing demand for soybeans.

Soy is present not only in paint, but in the paper industry. Applications in the paper and paperboard industry include sizing agents, adhesive removal agents, retention and drainage aids, surfactants and barrier coatings, binders and lubricants. Soybean meal lipoxygenase is used to eliminate sticky substances in pulping and papermaking. Both pure lipoxygenase and soy flour prevent the deposition of adhesives or artificial lipids, substitutes for artificial membranes or cellulosic fiber sheets.

There is a process for obtaining water-resistant packaging paper, which incorporates a combination of soy lecithin and a small amount of soy protein. Still in the paper industry, replacing 33% of linseed oil with soybean oil in the coating of vegetable paper reduces costs by 8%, by eliminating the labor that was used to remove waste, in addition to disposal costs. and reduction of coating stickiness.

Green chemistry is a strong future-bearing trend. Global society is pushing for more sustainable processes to obtain consumer products that replace fossil sources. This is a great opportunity to expand the uses of soybeans.

Décio Luiz Gazzoni, researcher at Embrapa Soja, founding member of the Soja Brasil Strategic Committee and the Sustainable Agro Scientific Council