Adrien Chenot

Adrien C. B. Chenot (born on August 30, 1803; died November 27, 1855) was a French engineer best known for his inventions in metallurgy as well as his research on manufactured gases. He is notably the inventor of one of the first modern methods of direct reduction of iron ore, based on the use of coal reacting with the ore in retorts . He exhibited the first samples of pre-reduced iron ore at the Lisbon Universal Exhibition of 1849, and was awarded the "Grandes Medailles d'Or" (Gold Medal of Honour) at the Paris Universal Exposition of 1855.

Early life Born in Bar-sur-Aube, he went to school in Nancy then in Paris. In 1820, he entered the Ecole des mines de Paris, and on leaving this school, he was attached to the General Secretariat of the Department of Bridges and Roads. He left this post some time after to operate mines in Auvergne. He was only 52 years old and active in his final days, although very weakened by the toxic gases inhaled during his experiments.

Contributions

Chenot method of direct reduction The Chenot process is one of the first direct reduction processes to succeed blast furnaces. Despite the presence of a cooler under the retorts, designed to restore its heat to the loaded ore, the “Heating method is […] very imperfect; more heat is lost outside than it is used in the retort itself”. Indeed, to produce one tonne of pre-reduced iron ore, the Chenot process consumes 350 kg of charcoal and 780 kg of hard coal, which is much more than the blast furnaces of the time which carried out both smelting and reduction, by consuming less than 1000 kg of coke; the thermal efficiency of the process is then estimated at 26%, compared to 70 or even 80% of blast furnaces of the period. Thus, Isaac Lowthian Bell estimates the fuel cost 2.3 times higher, and the loss 3.5 times higher than a blast furnace and Bessemer converter.

The ore used must be of excellent quality (80 to 82% hematite), and stays for nearly 8 days in the apparatus (half the time in the retort, then in the cooler). However, loading and emptying are partial and therefore more regular: there is a processing capacity of 1.2 to 1.5 tonnes per day of ore, i.e. 400 tonnes per year per unit of production, far from the production capacities of blast furnaces. The iron sponge obtained contains 13% of waste rock, which must be heated and slashed, or melted, to obtain a usable mass of iron. He suffered from the after-effects of carbon monoxide poisoning suffered during his numerous experiments. He was particularly seriously intoxicated in 1846, while working in the factories of the Marquis de Sassenay, in Prussia. According to him, “the carbon monoxide turns into carbonic acid causing deadly deoxidation. […] The cause of the pathophysiological disorders could also be a sudden increase in temperature due to the overoxidation of carbon in the blood”. Of course, Chenot, who "Admits that carbon monoxide plays in the blood the [same] role of reducing body as in metallurgy", can only offer a partial explanation since it does not carefully analyze the physiological aspects. Despite limitations of his analysis, Chenot remains among the first to propose a chemical theory of the mechanism of poisoning by this gas.

Miscellaneous Adrien Chenot also campaigned for the repeal of the law relating to the establishment of major railway lines in France .

Publications and works Adrien Chenot publications