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Zero Waste

Urea Production

Over the past 70 years Maire Tecnimont Group’s innovation and license company,

Stamicarbon, has been developing its own proprietary urea technology. The set-up it
has today guarantees that nearly all emissions from the individual process steps can

be converted to valuable feedstocks.

Harold van der Zande, Business Development Manager Stamicarbon (Maire Tecnimont Group)

n most industrial production processes and thus been developing its own proprietary urea techno-
also in fertilizer production processes in general logy. The set-up it has today guarantees that nearly
there are side products which cannot be further all emissions from the individual process steps can
processed. Examples of such products that are be converted to valuable feedstocks. They are all
out of specification, intermediates, and by-pro- returned to the production process to avoid waste
Iducts, all of which normally end up as waste. streams and/or by-products and therefore this urea
These waste streams are either dumped in landfills, technology can be considered a zero waste pro-
incinerated, or otherwise wasted, putting a burden duction technology. In addition, the technology has
on the environment and resulting in a negative eco- the capability to upgrade possible return streams
nomic impact for fertilizer producers. into premium end-products.
The urea production technology layout (figure 1)
Stamicarbon’s sustainable basically consists of the following essential ele-
ments:
solution • urea melt plant;
•
urea granulation (or prilling) plant;
Over the past 70 years Maire Tecnimont Group’s • MicroMist™ Venturi scrubber, which removes
innovation and license company, Stamicarbon, has both the gaseous (ammonia) emissions from
the urea melt plant, as well as the particulate
matter emissions (urea dust) from the air circu-
lated in the granulation plant;
• waste water treatment section, which cleans
the effluent from the urea melt plant.
The target of the different sections is to reduce the
emissions to air and water to such low levels, that
the required environmental emission levels are met.
In specific cases even the remaining small emis-
sions can be further treated with incineration or fla-
ring to zero emission levels, such that we even can
speak of zero emission production. Obviously this
goes at the cost of increased NO and CO emis-
2
x
sions. In the framework of this article, the specific
details of such a layout will not be further elabo-
rated, while this has already been addressed in a
separate article by Stamicarbon.
The emissions of the urea melt and granulation
plant are converted to feedstocks which can be
reprocessed in the urea melt or granulation plant,
in order to obtain zero waste production. Each in-
dividual unit, is needed to obtain the zero waste
production layout.
Fig. 1 - General layout of the Stamicarbon urea plant

Impiantistica Italiana - Maggio-Giugno 2018 41