Acrylic Acid (Glacial) - China

Brief Overview
Acrylic acid, having the chemical formula CH2=CHCO2H, is an unsaturated carboxylic acid. This clear and colorless liquid is characterized by its acrid odor. Due to the presence of a polar carboxylic acid functional group, it exhibits solubility in water and miscibility with relatively polar organic compounds like alcohols, ethers, and chloroform. Acrylic acid is sensitive to air and water, readily reacting with free radicals and electrophilic or nucleophilic agents. Polymerization can occur in the presence of acids, alkalis, amines, peroxides, and iron salts. Prolonged exposure to heat or light can also induce polymerization, and if confined, it may lead to an explosion even at room temperature. The corrosive nature of acrylic acid extends to metals and tissues. Utilized in various forms, including free acids, ammonium, and alkali salts, acrylic acid finds applications as thickeners, dispersing agents, flocculants, wetting agents, coatings, textile finishes, and protective colloids for stabilizing emulsions and polymer dispersions. Its versatility is evident in its participation in additional reactions with a broad range of organic and inorganic compounds, making it a valuable feedstock for producing numerous low molecular compounds. For example, acrylic acid can be employed in the production of derivatives of propionic acid involving water, alcohols, amines, halogens, and chlorinated hydrocarbons. Additionally, it can react with other substances to generate unsaturated fatty acids, heterocyclic compounds, and Diels-Alder addition products. Given its tendency to polymerize explosively, acrylic acid must be stabilized with an inhibitor like hydroquinone before shipping. The removal of the stabilizer is typically unnecessary, as its effects can be compensated for by adding an excess initiator.

Manufacturing Process
The predominant method for producing acrylic acid involves the vapor-phase oxidation of propylene through acrolein. Propylene, often a byproduct of ethylene and gasoline manufacturing, is typically Chemical-Grade (CG) propylene. In a two-step oxidation process, CG propylene is combined with steam and air. Initially, propylene undergoes oxidation to form acrolein, which is then further oxidized to yield acrylic acid. These oxidation reactions occur in tubular, fixed-bed reactors, utilizing the exothermic reactions' heat to generate steam.