Phosgene

Abstract

Phosgene is a colorless, low boiling liquid which is manufactured by the reaction of carbon monoxide and chlorine over activated carbon. It is a very toxic substance and extensive safety procedures and equipment have been developed to help ensure safety of handling. Because of its low boiling point and high toxicity, measures must be taken to prevent the entrance of phosgene into sewers and drains. Phosgene is a widely used intermediates. Practically all phosgene is captive, ie, used in the manufacture of other chemicals within the plant boundary. The major portion of phosgene produced goes into the production of isocyanates. It is also used in the production of polycarbonates and fine chemicals. The possiblity of phosgene–free technology may impact the market for phosgene.

Impact of the chlorine value chain on the demand response potential of the chloralkali process

“…The synthesis takes place in a multitubular reactor and is catalyzed by activated charcoal with a temperature around 150 • C up to a maximum of 400 • C close to the reactor inlet [18]. The educts are mixed stoichiometrically, with a slight excess of carbon monoxide to ensure complete reaction of chlorine [50]. For safety reasons, chlorine should be free of oxygen [18].…”

“…Phosgene is highly toxic and corrosive [50]. Therefore, storing it should be avoided whenever possible [49].…”

Selective Oxidative Carbonylation of Aniline to Diphenylurea with Ionic Liquids

“…[22] Heating the reaction mixture under CO to 80 8C( trace 5) led to ab roadening of the signals to the extent that the ligand signala lmostdisappearedi nto the background, but in addition, it also resulted in the formation of a new signal at d = 24.82 ppm. Heating to 110 8C( trace 6) caused the signals of both free PPh 3 13 C{ 1 H} NMR spectra were also recorded before,d uring,a nd after the HP-NMR experiment.T he d = 186-182 ppm range of the spectrumr ecorded at the end of the experiment after cooling is shown in Figure 4. The spectrum featured free CO at d = 184.8 ppm with as houldera td % 185 ppm as the most dominant signals and at riplet at d = 184.0 ppm, which wasa ssigned to the Pd-carbamoyl complex.…”

“…[1] In this context, the oxidative carbonylation of amines to obtain ureas (Scheme 1) has received much interest over the past 50 years [2] as an alternative to the traditional phosgenation process. [3] The reactioni sp erformed in the presenceo fametal catalysto ro rganocatalyst, an oxidizing agents uch as I 2 [1,4] or O 2 /air, [5] and CO pressure. Among transition metals and organocatalysts, Mn, [2] Pd, [4c, 5h-q, 6] Cu, [5a, 7] Au, [5b-c] Co, [5d-e] W [1, 4a-b] Ni, [5f] Rh, [5g] Ru, [5h] S, [8] and Se [9] are effective.…”