Ethyl sulfate process in which ethylene is reacted with sulfuric acid to produce ethyl sulfate followed by hydrolysis, but this method has been mostly replaced by direct hydration of ethylene. Ethyl sulfate can be produced in a laboratory setting by reacting ethanol with sulfuric acid under a gentle boil, while keeping the reaction below 140 °C. The sulfuric acid must be added dropwise or the reaction must be actively cooled because the reaction itself is highly exothermic. If the temperature exceeds 140 °C, the ethyl sulfate product tends to react with residual ethanol starting material, producing diethyl ether. If the temperature exceeds
Ethyl Gasoline Corp. v. United States laws, and accordingly was illegal when its effect was to "regiment" an entire industry. Ethyl owned several patents on tetra-ethyl lead, an anti-knock fuel additive, and on its utilization: two patents on the chemical itself, a patent on a motor fuel—gasoline containing tetra-ethyl lead, and a patent on a method of using the fuel in an automobile engine. Ethyl established an elaborate licensing program under its several patents: Ethyl sold the fuel additive, and licensed purchasers to use it to practice the other patents. The licensing program fixed prices for the motor fuel and strictly limited the types of customer