Industrial uses for grain
August 01, 2007
by Meyer Sosland
The world is getting used to the idea that grains and oilseeds aren’t only used for food. Grain-based ethanol and diesel fuel made from vegetable oils have dramatically altered international commodity markets.
But the range of potential non-food uses outside the fuel market is enormous. Plastics, lubricants, coatings and paints can all be made from crops.
"There is one big thing as far as non-food use goes — polylactic acid (PLA)," Nick Weber, communications manager at the National Corn Growers Association told World Grain. "That’s something that’s growing." He pointed out that U.S. retail giant Wal-Mart had made a switch to corn (maize)-based plastics for the clamshell containers used for storing fresh produce.
"With this change to packaging made from corn, we will save the equivalent of 800,000 gallons of gasoline and reduce more than 11 million pounds of greenhouse gas emissions from polluting our environment," said Matt Kistler, vice-president of Product Development and Private Brands at Wal-Mart’s Sam’s Club division, in the original announcement of the change. Wal-Mart said at the time that PLA’s maker — Nature-Works — could provide a stable price product in contrast to the climbing price of the mineral oil used to make conventional packaging.
Recently, DuPont Tate & Lyle Bio Products, LLC, an equally owned joint venture of DuPont and Tate & Lyle, constructed a facility in Loudon, Tennessee, U.S. that produces its Bio-PDO product, made from corn sugar. Bio-PDO has a huge range of uses, including cosmetics, liquid detergents and industrial applications such as anti-freeze and plastics.
The U.S. government has welcomed the growth of crop-based technologies. "It’s encouraging to see industry
team up to make incredible advances in bio-based technology, building upon the Department of Energy’s efforts to reduce our reliance on imported oil, aggressively confront climate change and help maintain our nation’s competitive edge in the global marketplace," U.S. Secretary of Energy Samuel W. Bodman said at the launch of the new plant in Loudon.
ENVIRONMENTALLY FRIENDLY Another proponent of PLA is Kevin Curran, managing director of U.K.-based packaging company TriStar Packaging. "We believe it to be one of the more environmentally friendly products," he said. "It’s a completely sustainable source."
Corn-based products even had an advantage over paper. "Corn has a very short lifespan," he said. "It’s not like trees with paper, where they take 30 years to grow. Corn comes up every year." He also identified biodegradability as a further major environmental advantage.
However, it’s not just its "green" credentials that make PLA an interesting product for the packaging industry. Much of Curran’s business is in sandwich packs. "For packaging food products, which are often impulse purchases, clarity is important," he said. "It’s glass clear."
PLA can also be made lighter. "Because of the material’s makeup, you can downgauge slightly," he said. "If you need 350 microns with PVC (polyvinyl chloride), you can often go down to 320 or 310 microns. PLA is more rigid, so in some cases you use slightly less."
TriStar’s belief in the advantages of PLA has made it a pioneer in the material’s use. In 2004, the company produced the world’s first sandwich wedge, as the package is known, using PLA.
The PLA used by TriStar comes from NatureWorks, a standalone company wholly owned by Cargill. According to NatureWorks, the company’s plant in Blair, Nebraska, U.S. will produce 136,080 tonnes of PLA a year at full capacity, requiring 340,200 tonnes of corn (at 15% moisture). At full capacity, that means, according to NatureWorks, that it will use 0.11% of the total corn for grain production in the U.S.
According to NatureWorks, the production process of its polymer uses 62% to 68% less fossil fuel resources than traditional plastic materials. It also estimates that it reduces greenhouse gas emissions by 80% to 90%.
"It’s not going to be earth shattering, but it is a destination for corn," said Weber. "It doesn’t register on the USDA numbers, but it is a growing market."
Plastics are also proving an interesting new area for using soy, according to John Campen, New Uses Program Manager for the United Soybean Board (USB). "Probably the most promising technology that we’re involved in is soy polyols, used in polyurethane applications all the way from construction to the automotive industry," he said. "It’s also used in coatings and paints."
A PRICE ADVANTAGE Campen said the primary advantage in using the soy in plastics is price.
"With the way world petrochemical prices have gone, soy is very competitive," he said. "With a major rise in petrochemicals, a lot of companies are
looking for feedstock. Soy is a very good fit for them. The other factor is that the performance is all there and there is supply availability. We can deliver soy anywhere in the world. It’s got all the right characteristics."
Even so, the total is still a tiny fraction of overall plastic production. "Polyol production in the U.S. is around 3.5 billion pounds," he said. "You can triple that on a worldwide basis. The market is huge."
That means soy-based plastic is no threat to the conventional material. "We’re not going to substitute for all that," he said. "It’s sizeable enough for everybody to play in."
There are many other applications besides plastics, Campen said. "We’ve been involved with a lot of different products," he said. "Another one is electrical transforming fluid. That is a sizeable market, and it’s growing fast."
Cargill and electrical equipment manufacturer Cooper Power Systems have developed Envirotemp FR3, a soybased transformer fluid that is being used in electrical transformers throughout the Midwestern U.S. According to the USB, tests have shown that it can extend transformer power life by three to four times what is achieved with petroleum-based mineral oils.
Making plastic from soy is nothing new. According to the USB, the first well-recognized soy product was an automobile panel made from soy plastic by Henry Ford in 1933. The USB has helped fund developments including soy plastics and foams, soy methyl esters and soy inks. It estimates that over 90% of America’s daily newspapers are printed with soy ink and points out that John Deere and Case New Holland are both using soy plastic to manufacture sheetmolded paneling for their tractors.
Phil Sarnacke, an industry consultant with OmniTech International, which works for the USB, identified the need to use renewable materials as a priority but questioned whether biodegradability is always desirable. "Biodegradable is not necessarily what you want," he said. "You don’t want a car seat that is going to fall apart."
"We make certain plastics, because we want them to last," he said. "Renewable resource applications and potential reductions in (carbon dioxide) are the real issues."
Although PLA can be composted, there are problems in making sure that happens in the right way. "In the U.S., the landfill sites we have are not for the most part the best way to biodegrade," he said "They are not designed to do that."
There is also a conflict with the food supply. "The real problem is how much substitution is possible without chang- ing the world’s eating habits," he said "I guarantee there’s not enough cropland in the world to replace all the oil-based plastics."
One advantage of producing nonfood products from oilseeds is that it can reduce dependence on subsidies. He stressed that the product developments by the USB have not depended on subsidy. "The problem with subsidies is that they seem never to end and they distort the capital formation process," he said.
"We’re offering an alternative," he said. "There are some economic benefits. It will have an impact on the economics of plastic production."
In Britain, the National Non-Food Crops Centre has the job of providing information on non-food crops and technologies. Although PLA is the major product in the area, it’s not being made from U.K. wheat, said Dr. Alison Hamer, the Centre’s communications and information manager. She sees a role for consumers in getting industry to look harder at non-food uses. "The U.K. consumer has a role in driving the U.K. industry into getting involved in supporting manufacturing," she said.
She identified linseed as one crop that could be important in the U.K. "We’re seeing an increase in the amount of linseed used for non-food," she said. Like soy oil, linseed oil is used in paints and inks where its high level of polyunsaturated fatty acids aid drying.
There were also some more novel alternatives for farmers, like borage. "It’s grown on smaller areas for high value oil, which is used in a lot of applications," she said. "That is increasing a lot in the U.K."
Sarnacke said that using grains and oilseeds is only part of the answer to environmental concerns. "The right answer to all of this is conservation — use as little as you can, and recycle as much as you can," he said. WG
Chris Lyddon is World Grain’s European editor. He may be contacted at email@example.com.