Abstract: In the disclosed electrogenerative process for converting alcohols such as ethanol to aldehydes such as acetaldehyde, the alcohol starting material is an aqueous solution containing more than the azeotropic amount of water. Good first-pass conversions (<40% and more typically <50%) are obtained at operating cell voltages in the range of about 80 to about 350 millivolts at ordinary temperatures and pressures by using very high flow rates of alcohol to the exposed anode surface (i.e. the "gas" side of an anode whose other surface is in contact with the electrolyte). High molar flow rates of vaporized aqueous alcohol also help to keep formation of undesired byproducts at a low level.

Abstract: Methanol can be oxidized to formaldehyde gas, and ethanol can be oxidized (e.g. in two steps) to acetic acid, in an "electrogenerative" or "voltameiotic" cell (i.e. a fuel cell designed to produce useful oxidation products). The structure of the anode and the contact time with the anode are important factors helping to determine the degree of oxidation of the oxidized products.

Abstract: Acetaldehyde is obtained from an ethyl alcohol "fuel" anodically treated in a fuel cell, and the acetaldehyde (along with any evaporated, unreacted ethanol "fuel") is ultimately recovered in anhydrous or substantially anhydrous form. Further chemical and electrochemical transformation of acetaldehyde in the presence of the fuel cell anode is stopped or minimized to avoid the formation of condensates or polymers or more highly oxidized products (e.g., acetic acid or aldol condensates) which may act as catalyst poisons. For example, ethyl alcohol can be vaporized and fed to the gas side of a gas-permeable fluid-impermeable electrode, in which case up to 60 mole-% or more of the acetaldehyde product stays with the vapor stream and avoids further chemical reactions or side reactions, substantially the balance going into solution in the electrolyte, from which it can be recovered, e.g., by low temperature distillation.