Abstract: A system for analysis of vent gas of a urea plant, comprising: a Raman spectroscope; a sampling conduit that connects the spectroscope to a main pipe of the urea plant configured to convey a sample stream to be analysed to the spectroscope; and a temperature-adjusting device, operated by a temperature controller and acting on at least one thermal treatment portion of the conduit configured to adjust the temperature of the sample stream circulating in the conduit.

Abstract: A duplex stainless steel for use in a urea production plant and/or in a urea production process, containing in weight percentage (% w): C 0.03 or less; Si 0.5 or less; Mn 2.5 or less; Cr from more than 30.0 to 35.0; Ni from 5.5 to 8.0; Co from 0.01 to 0.8; Mo from 2.0 to 2.5; W 2.5 or less; N from 0.3 to 0.6; Cu 1.0 or less; and having one or more of: Ca 0.0040 or less; Mg 0.0040 or less; one or more rare-earth elements in a total amount of 0.1 or less; the balance being Fe and impurities; and satisfying the relationship: Z=1.062 (Ni+Co)+4.185 Mo is between 14.95 and 19.80.

Abstract: A system for analysis of vent gas of a urea plant, comprising: a Raman spectroscope; a sampling conduit that connects the spectroscope to a main pipe of the urea plant configured to convey a sample stream to be analysed to the spectroscope; and a temperature-adjusting device, operated by a temperature controller and acting on at least one thermal treatment portion of the conduit configured to adjust the temperature of the sample stream circulating in the conduit.