Mcguire: The commercial synthesis of urea involves the combination of liquid ammonia and gaseous carbon dioxide in a reactor at high pressure (150-200 bar) and high temperature (180-190°C) to form ammonium carbamate, urea and water. Modern energy-efficient processes foresee the decomposition of the carbamate, not transformed into urea, in a stripping equipment working at the same pressure as the reactor, while the off-gas from the stripper is condensed in the carbamate condenser also working at the same pressure. Ammonium carbamate at these temperature and pressure is extremely aggresive to materials. For this reason, SS 316L urea grade, 25Cr22Ni2Mo stainless steel, 22Cr5Ni duplex stainless steel, Ti and Zr are used as construction or lining materials in the reactor, pumps, decomposers, strippers and condensers. Besides this major problem (carbamate), there exist the probability of process contamination with corrosive agents, such as H2S (along with CO2). Then, I am looking for information about the effect of the presence of traces of H2S in CO2 gas feed stream at this pressure and temperature. Specifically, the value at what the H2S content should be lowered to avoid corrosion problems.