Sulphonation/Sulphation
Desmet’s SULPHUREX film sulphonation technology presents outstanding
advantages over the competing processes, namely:
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superior performance in terms of product quality, especially when sensitive
raw materials are processed
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exceptionally good conversion rate and colour with maximum achievable
absorption of SO3 gas
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simpler construction which entails easier maintenance
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lower operating pressure
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no extra cooling requirements and nor the need of chilling water equipment
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extra low energy consumption
Desmet has implemented the world’s largest sulphonation plants
(24.000 Kg/h as 100% active surfactant) and is constantly optimizing its process
through the continuous work of its R&D Centre. Particularly it has developed
proprietary Know-How and processes for surfactant upgrading downstream the
sulphonation process, i.e.: Dioxane stripping and Drying process for pure dry
surfactant production.
Desmet can offer standard plant design for capacities ranging from 1
to 8 ton/hr and customized design for larger capacities.
Listed below are the main features of the process sections of a Desmet
SULPHUREX plant
Process Air Drying
The atmostheric air is compressed up to 0,6 Kg/cm2 as requested by the
downstream sulphonation process.
The compressed air is dried by refrigeration condensation of the water contained
in the atmospheric air and subsequent absorption takes place by means of a
dessicant bed.
Main features of the unit:
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Low operating pressure design (0,7 Kg/cm2 max.)
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Process Air Dew Point lower than -70°C
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Fully automatic regeneration of absorbent medium (silicagel/Al2O3)
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Low energy consumption due to the recovery of the hot air from SO3
production unit for absorbent medium regeneration
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High reliability and efficiency
SO3 Production
Liquid sulphur is burned with the process air in a special furnace to produce a
gas containing 7% by volume of SO2.
The SO2 is then converted to SO3 in a special conversion tower equipped with 4
catalyst beds and intercoolers to optimize cynetically and thermodynamically the
reaction yield. The SO3 gas is finally cooled to 50-60°C as requested by the
sulphonation process.
Main features of the unit:
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Very high reaction yield : 98,5% guaranteed and possibility to achieve 99,5%
with the use of special Cesium catalyst
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High reliability, safety and long plant lifetime due to the use of air as a
cooling medium, instead of water, to minimize corrosion risks
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Special design of sulphur furnace (no preheating burner nor sulphur spraying
system) ensuring high operating reliability and easiness
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High energetic efficiency thanks to the use of hot cooling air for silicagel
regeneration in the Air Drying Unit
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Very compact design of the conversion tower with internal intercooler
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Reduced plant start-up time due to a special sulphur furnace which does not
require preheating
Sulphonation Unit
The SO3 gas outcoming the SO3 production unit is filtered by a special high
efficiency brink filter to eliminate any trace of carried-over oleum. Then is
fed to the top of the Multitube Falling Film sulphonation reactor where also the
organic raw material is fed under mass flow control. The reaction of SO3 gas
with the organic raw material takes place in the MTFR. At the outlet of the
reactor the gas/liquid mixture is separated in a special gas/liquid separator
and in a downstream gas cyclone. The sulphonic acid is sent to a special
ageing/stabilizing unit when Linear Alkylbenzene is processed, or straight to
the neutralization unit when Fatty Alcohol or Ethoxylated Fatty Alcohol are
processed.
Main features of the unit:
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Product quality meeting the highest international standards
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High operating flexibility thanks to the capability to process any raw
material used in detergent and surfactant industry
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High reliability and operation easiness
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Automatic in-line control of sulphonation degree
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Low energy demand thanks to the low pressure drop of the MTFR
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Optimized design achieved through over 300 industrial Film Sulphonation
plants implemented and operative worldwide
Main features of the Desmet ’s Multitube Film Sulphonation reactor
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Outstanding results in terms of product quality
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Very high heat transfer efficiency that enables an accurate control of the
temperature profile in the reactor
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Low pressure drop (0,3 Kg/cm2 average) resulting in a reduced energy
consumption of the whole sulphonation plant
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Once through design. The sulphonation reaction is accomplished within the
residence time of the reactants in the reactor (less than 1 minute) without
need of external recycling loop. This enables the automatic in-line control
of the sulphonation degree through the reactor
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no extra cooler requirements and no need of chilling water equipment
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High flexibility with possibility of product flying change-over with minimum
product contamination
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Operation easiness
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Easy scale-up of the reactor as all distribution heads and reaction tubes
are identical. Scale-up is achieved simply increasing the number of reaction
tubes with practically no limitations on reactor size and capacity
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High reliability and longer lifetime thanks to the use of sophisticated
corrosion resistant alloys for critical parts
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