IDR process

Montedison developed the Isobaric Double-Recycle (IDR) process. In this process the urea synthesis takes place at 180 to 200 bar and 185 to 190°C. The NHj-to-C02 molar ratio is 3.5 to 4.0, and C02 conversion is about 70% per... 

IDR (1) [Isobaric double recycle] A process for making urea from ammonia and carbon dioxide, via ammonium carbamate ... 

The heat of condensation is recovered as 7.0 bar steam for use in downstream process steps. Urea solution leaving the IDR loop contains unconverted NH3, C02, and carbamate. These unconverted compounds are recycled to the synthesis loop108,110 ... 

The Isobaric Double-Recycle (IDR) urea process was developed by Montedison. In this process most of the unconverted material leaving the reactor is separated by heating and stripping at synthesis pressure using two strippers in series. The unconverted ammonia, C02, and carbamate in the urea solution are recycled to the synthesis loop.108110... 

Montedison, which originally participated in the Momecaiini-Fauser joint venture to market a number of total-recycle variants, and now presents its IDR (Isobaric Double Recycle process) technique. TTiis process operates at 20.10 Pa absolute, around 190 to 200, with an N/C ratio of4 to 5 in the reactor. Unconverted carbamate is decomposed in two successive gas stripping steps, one with ammonia, and the second with CO 2. in the pressure conditions of urea s nthesis, i.e.. 10 Pa absolute. 

The IDR (Integrated Dry Route) process consists of reacting gaseous uranium(VI) fluoride with superheated steam, whereupon solid UO2F2 is formed, which is reduced with hydrogen to uranium(IV) oxide. This reaction can be carried out in both a fluidized bed reactor and in a rotary kiln, whereby the latter appears more suitable. 

If the disc has reasonable compression properties, it is then attached to a holder and set in motion in the dissolution medium (water, buffer or simulated gastric fluid) we use a rotation speed of 100 rpm. A number of analytical techniques can be used to follow the dissolution process, however, UV-visible spectrophotometry and HPLC with fixed or variable wavelength detectors (or diode array) appear to be the most common. The UV system employs a flowthrough system and does not require much attention, however, if HPLC is used, then any aliquot taken should be replaced by an equal amount of solvent. The IDR is given by the slope of the linear portion of the concentration versus time curve divided by the area of the disc and has the units of mg/min cm2. 

Isobaric double-recyde process (IDR) Montedison 200 190-200 Successive stripping with NH3 and CO2 at different pressure levels NH3 CO2 ratio 4-5.1 mol/mol... 

IDR (2) [Integrated Dry Route] A process for making ceramic-grade uranium dioxide from uranium hexafluoride. Uranium hexafluoride vapor is first reacted with superheated steam to form uranyl fluoride ... 

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