Time Machine: Making furfural

Nov 07, 2023

Quaker plant used oak hulls to produce critical organic chemical used in WWII

May. 2, 2023 5:00 am

German chemist Johann Wolfgang Dobereiner discovered the organic compound known as furfural in 1821, but it took a century before Quaker Oats began mass-producing it from agricultural byproducts in 1922.

Quaker and the furfural it made from oat hulls eventually would play a big role in supplying materials for the Allies in World War II.

Furfural is an oily liquid formed by the dehydration of sugars from feedstocks, such as oat hulls, which the Quaker plant in Cedar Rapids had in abundance.

The compound looks like maple syrup, smells like bitter almonds, is heavier than water and is primarily used as a highly acidic solvent and purifying agent.

Chemists in Quaker's research laboratory also found a number of other uses for furfural — clarifying lubricating oils and manufacturing Bakelite products, to name two.

By 1937, Quaker was producing 4 million pounds of furfural a year.

In 1942, during World War II, the Cedar Rapids’ Quaker plant was the only place producing furfural for commercial use, when it was discovered furfural could be used to manufacture synthetic rubber — a huge need during the war.

As The Gazette reported in August 1942 that the Rubber Research Co. was going to use all of the furfural Quaker could produce, asking it to increase its annual production from 7 million pounds to 12 million pounds, the plant's capacity.

Making furfural works like this:

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The oat groat used to make oatmeal is extracted from the hulls. The hulls are cleaned and ground. Diluted sulfuric acid is added to the hulls. The mixture is dumped into spherical digesters that pressure-cook the hulls.

Steam from the digesters is condensed to create a diluted furfural in water. That solution is distilled to separate the furfural from the water. The furfural is put into tank cars and steel drums for shipment.

During the war, furfural also was used in refining motor oil, as a binder for grinding wheels used in war industry, and as a clarifying resin used in plastics to make soldier helmets and aviation equipment.

Toward the end of the war, in 1945, the demand for oat hulls outgrew supply, and Quaker began using corncobs to manufacture furfural, supplying enough for nearly a million tons of synthetic rubber.

Unfortunately, while furfural waste from oat hulls was easily burned up, the process didn't work as well for corncobs. The cobs didn't grind as well as oat hulls and left pellets of vegetable matter that decomposed into smelly gas bubbles in the Cedar Rapids slough next to the Iowa Electric Light and Power Co.'s Sixth Street power station.

By 1946, the Quaker plant was producing 15 million pounds of furfural a year. The government had built a plant in Memphis, Tenn., that could produce 24 million pounds per year. Quaker bought that plant after the war, selling it in 1985 to Great Lakes Chemical.

Quaker faced a major emergency with its furfural plant in Cedar Rapids in October 1974.

The boilers malfunctioned at Iowa Electric's Sixth Street power station, and the slough by the plant could no longer accept the 65 tons of furfural residue Quaker produced each day.

The city agreed to allow two-thirds of the furfural residue at the city landfill at regular rates. Quaker wanted the county landfill to accept the remainder, saying it would have to shut down production if the county's dumping fee was too high. Quaker said it would check with the state about burning the residue at the landfill.

The second major emergency came in an explosion and fire on Friday, Nov. 3, 1978, in the building that housed the furfural residue. The fire was put out at 5 a.m., only to rekindle an hour later. On Saturday, workmen using a cutting torch on the remainder of the frame building, at Fifth Street and D Avenue NE, set it on fire again.

Furfural production at the plant had to stop since there was no place to store the residue. The facility was repaired, and production resumed.

Quaker was still producing furfural from oat hulls and corncobs in 1981 when The Gazette reported the plant's chemical section was the world's largest producer of furfural.

The compound was used "in the petroleum industry as a solvent, furfural alcohol is used in foundries in making molds, and furfural chemicals have a wide variety of uses."

The furfural residue, which resembled coffee grounds, was partially dried and then "blown" through a pipe from Quaker to Iowa Electric's Sixth Street plant, where it was mixed with coal and burned in the utility's boilers to produce steam for the downtown.

By 2004, furfural was no longer being made at Quaker, according to an Iowa Department of Natural Resources report.

In 2022, the largest producers of furfural were China, South Africa and the United States, according to S&P Global.

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