Export Steam

Table 37. Increase of plant efficiency by steam export (GJ/t NHj)...

Achieved net energy consumption is about 28 GJ/t NH, and UHDE s engineers expect values of below 27 GJ/t NH, when a gas turbine and large steam export is included [1088]. 

The combined plant is a significant steam exporter and is typically highly integrated in the chemical complex surrounding it. 

Economics Thanks to the high efficiency of the process and equipment design, the total energy consumption (evaluated as feeds + fuel + steam import from package boiler and steam export to urea) is lower than 6.5 Gcal/metric ton of produced ammonia. 

Typical utilities, per metric ton of cumene High-pressure steam, metric ton Low pressure steam export, metric ton Power, kWh... 

Ammonia, kg Carbon dioxide, kg Nitric acid (56%), kg Steam, 23 bar, 330°C, kg Electric power, kWh Water, cooling (AT= 10°C), m Steam export, 4 bar, saturated, kg Steam condensate export, kg Process condensate export, kg... 

The crude aldehydes are split into n- and isobutanals in the distillation column (5). The heat required is supplied by the hydroformylation itself the reboiler of the distillation is a falling-film evaporator which is incorporated in the synthesis reactor using n-butanal as the heat carrier. This system has clear advantage over the classical hydroformylation processes, as the RCH/RP process not only uses the heat of reaction efficiently but is also a net steam exporter. 

Electricity 28.6 MMBtu/h. Process unit Exothermic reaction MMBtu/h MP Steam export 65.5 MMBtu/h... 

The HTCR reactor consists of a number of bayonet reformer tubes and combines basically the radiant section and the convection section of a conventional HSR in a single piece of equipment. The reaction heat is provided by the flue gas fiowing on the outside of the reformer tubes and by reformed gas fiowing in an upward direction in the bayonet tubes. This results that is about 80% of the fired duty is utilized in the process, and steam export is minimized. 

Convective reforming can also improve the productivity of the fired reformer by utilising the hot product gas for supplementary heat input to the process, i.e. by chemical recuperation of the heat in the process gas instead of raising steam [426] [427]. This can be done in various ways. In the Topsoe Bayonet Reformer (TBR) the product gas may simply be passed through the reformer tube in a bayonet t5 e arrangement, i.e. counter-current to the flow through the catalyst bed. In this way, the capacity of the reformer furnace can be increased by 25% and the steam export reduced by 30% [426]. 

With this approach, it is possible to increase the capacity of a hydrogen plant by 30% with the same tubular reformer or reduce the steam export by 40%. 

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