Rillieux

The ceremony was attended by ACS President Eli Pearce, Dillard President Michael L. Lomax, and members of Rillieux's extended family. Talks were given by Chris Benfey, a historian, and D. H. Michael Bowen, former ACS secretary and director of the ACS Publications Division.

The society established the landmarks program in 1992 to commemorate seminal events in the history of chemistry and to heighten public awareness of the role chemistry has played in the history of the U.S. and around the world.

Rillieux is little known today, but his invention, the multiple-effect evaporator under vacuum, revolutionized sugar processing. Rillieux patented his invention in the 1840s. The basic design is still in use in sugar processing and other industries. The Rillieux evaporator was one of the earliest innovations in chemical engineering and remains the basis of all modern forms of industrial evaporation.

Rillieux's New Orleans birth record reads: "Norbert Rillieux, quadroon libre, natural son of Vincent Rillieux and Constance Vivant. Born March 17, 1806. Baptized in St. Louis Cathedral by Père Antoine." New Orleans, given its French heritage, differed from the rest of the antebellum South because of the presence of a large caste of "free people of color." Rillieux and his mother belonged to this group.

Like many young men of his social milieu in New Orleans, Rillieux was sent to France to study. Early on he showed an interest in engineering, and by the 1830s he was an instructor at the École Centrale in Paris. He not only understood the principles of thermodynamics and latent heat but also applied that knowledge to the technical needs of the sugar industry.

Rillieux began working on the multiple-effect evaporator in France. As George Meade, a sugar expert, wrote in 1946, "The great scientific contribution which Rillieux made was in his recognition of the steam economies which can be effected by repeated use of the latent heat in the steam and vapors."

Before this invention, planters in Louisiana employed an open-kettle system--called the "Jamaica Train"--for reducing sugarcane juice. This system exploited the labor of many slaves armed with long ladles skimming boiling sugar juice from one open kettle to another.

Unsuccessful attempts had been made to harness the energy of the steam rising from the boiling juice. It was Rillieux who discovered that by using condensing coils in a vacuum chamber it was possible to lower the boiling point of the sugarcane juice by employing a series of three or four closed evaporating pans in which vapor was piped out of each pan to heat the juice in the next, with the vapors in the end going to a condenser. At the same time, pressure in the system was reduced by pumps, which created a partial vacuum. Rillieux's innovation greatly reduced the cost of sugar refining.

Wealthy Louisiana planters quickly understood the significance of Rillieux's discovery. Rillieux was invited back to New Orleans, and in 1843 two planters, Thomas Packwood and Judah P. Benjamin, installed Rillieux's evaporators on their plantations. Three years later, Packwood and Benjamin won prizes for producing the best sugar.

The success of his evaporator made Rillieux, according to a contemporary, "the most sought after engineer in Louisiana," and he acquired a large fortune. But while his invention no doubt enriched sugar planters, Rillieux was still, under the law, "a person of color" who might visit sugar plantations to install his evaporator but who could not sleep in the plantation house. As the Civil War approached, the status of free blacks deteriorated with the imposition of new laws and restrictions on their ability to move about the streets of New Orleans.

Sometime around the start of the Civil War, Rillieux returned to France, where he became interested in Egyptian hieroglyphics. He died in 1894 and was buried in Paris' famous Père Lachaise cemetery.

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