Answer:
Norbert Rillieux, widely considered to be one of the earliest chemical engineers, revolutionized sugar processing with the invention of the multiple effect evaporator under vacuum. Rillieux’s great scientific achievement was his recognition that at reduced pressure the repeated use of latent heat would result in the production of better quality sugar at lower cost. One of the great early innovations in chemical engineering, Rillieux’s invention is widely recognized as the best method for lowering the temperature of all industrial evaporation and for saving large quantities of fuel.
Vincent Rillieux was an inventor himself who designed a steam-operated press for baling cotton. He appears to have had a long relationship with Constance Vivant, “a free woman of color,” and one of their sons, Norbert, became what is now called a chemical engineer. The use of the father’s surname and the baptism in New Orleans’ cathedral indicate the paternity was publicly acknowledged.
As a boy the precocious Norbert showed an interest in engineering, and his father sent him to France for his education. By the age of 24, Rillieux was an instructor in applied mechanics at the Ecole Centrale in Paris. Around 1830, Rillieux published a series of papers on steam engines and steam power.
While in France, Rillieux began working on the multiple effect evaporator. 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.” What Rillieux did, and what became the basis for all modern industrial evaporation, was to harness the energy of vapors rising from the boiling sugar cane syrup and pass those vapors through several chambers, leaving in the end sugar crystals.
Rillieux’s evaporator was a safer, cheaper, and more efficient way of evaporating sugar cane juice than the method then in use, the Jamaica train. In this system, teams of slaves ladled boiling sugar juice from one open kettle to another. The resulting sugar tended to be of low quality since the heat in the kettles could not be regulated, and much sugar was lost in the process of transferring juice from kettle to kettle.
Some Louisiana sugar planters quickly understood the significance of Rillieux’s invention, and he returned to New Orleans in the early 1830s, years that coincided with a sugar boom. Rillieux tinkered with his invention over the next decade, and in 1843 he was hired to install an evaporator on Judah Benjamin’s Bellechasse Plantation. Benjamin, a Jewish lawyer who later served as secretary of war in the Confederacy, became Rillieux’s staunchest supporter in Louisiana sugar circles. Benjamin wrote in 1846 that sugar produced with the Rillieux apparatus was superb, the equal of “the best double-refined sugar of our northern refineries.”
The success of his evaporator apparently 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. (Nor, for that matter, could a man of Rillieux’s accomplishments be expected to stay in slave quarters. Some planters, it appears, provided Rillieux with a special house with slave servants while he visited as “a consultant.”). As the Civil War approached, the status of free blacks deteriorated with the imposition of new restrictions on their ability to move about the streets of New Orleans and other draconian laws.
