Page 55 - TEXtalks International July/August 2022

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The Origin alkaline wastewater helps to neutralize the acid
125 years ago, Indigo was derived from the Indigo wastewater from BASF whilst BASF monitors the
plant, which was cultivated in huge plantations on the wastewater flow and guaranties a full protection of
Indian subcontinent. The complicated extraction the environment.
process and the high market demand urged for an
industrial synthesis of Indigo. It took over 17 years of Sustainability topics continue to be the fundamental
development and enormous financial investment – basis for DyStar’s operations. Industrial automation,
around 18 million Gold Marks, an amount exceeding the integration into the BASF supply for key
the company's share capital of the day – before the intermediates, loops for recycling of solvents and
first Indigo Pure BASF was manufactured and environmental protection facilities, integrated Energy
brought into the market in July 1897. Management System (DIN ISO 50001), the
state-of-the-art waste gas treatment are some
The Highly Efficient Indigo Production Plant significant efforts that make DyStar the last notable
The Indigo production plant in Ludwigshafen is manufacturer of the coveted blue dye outside of
unique. It is the oldest and yet possibly the most China.
efficient Indigo production plant that is still in
operation today. DyStar continues this great heritage The Process Based on Heumann Synthesis
of Indigo excellence in the same production facilities, The current process is similar to the process from
where the BASF started back in 1897. Remaining the 125 years ago. DyStar is producing according to the
last dyestuff producer in Europe, DyStar “Heumann Synthesis” which consists of two raw
manufactures Indigo in a way that is paved with materials used as the basis for this synthesis. The
continuous innovations and improvements. For first one is PGN (Phenyl-glycine-nitrile), which is
example, the waste gas treatment plant is catalyst delivered by BASF via pipeline, and the other one is
based and burns the carbon content in the waste gas pure sodium, delivered by railway tankers. After the
from the aniline recovery process. With an effective first reaction steps using both raw materials,
German Review consumption. This is important as they continue to together in a melting vessel. And the Indigo German Review
saponification of PGN, and amidation of Sodium with
energy management system, DyStar started to
Ammonia, the two solid products are brought
integrate carbon dioxide usage into their energy
production starts following an oxidation step. Next, the
work on the reduction of their primary energy
product goes through a filtration step. During filtration,
consumption as well as on carbon dioxide emission.
the Indigo paste will be filtered and washed to reduce
the content of alkaline and aniline. Hydrogenation is
The strategic location of the Indigo plant is unique
further applied to get a solution approximately 20%
too. Today, the plant remains embedded in the
Indigo content. The evaporated content delivers the
functional network of supply and discharge within the
premium product DyStar Indigo Vat 40 % Solution.
BASF Site in Ludwigshafen.
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Alternatively, the 20% solution delivers a side-product
Nearly all raw materials continued to be delivered by named Indigo Grain 60%, which is used for DyStar’s
pipeline. None of the raw materials are delivered by other production processes.
trucks, except for Sodium being supplied by railway
tankers. Operationally, this has resulted in a large From Solid to Indigo Solution with a new organic reducing agent. This technology ning of the Indigo process. DyStar’s core expertise is
reduction of the Carbon footprint. In addition, this In 1998, after almost a century of synthetic Indigo represents the first salt-free Indigo dyeing process in the reason that they decided to take over the production
network also guarantees a high recycling rate of powder application, DyStar set one of the most history, by complete elimination of hydrosulphite in of Sodium Amide at the Ludwigshafen plant.
125 years of Indigo waste chemicals, which are used in other plants as introducing the first pre-reduced DyStar Indigo Vat the application of Indigo. Furthermore, the DyStar 125 Years of Indigo Excellence
remarkable milestones in Indigo history by
raw material or can be fully recycled. DyStar mainly
Indigo Coat, the DyStar Indigo 4B Coll liq and the
40% Solution to the market. A technology that
recycles Ammonia water solution, Aniline, n-Methyl
DyStar 60% Vat Grains are the results of decades of
This year, DyStar celebrates the 125th Anniversary of
Synthesis - A Story of Success Aniline, Potassium- and Sodium hydroxide. This transforms Indigo into its soluble Leuco form by continuous innovation and Indigo chemical Synthetic Indigo. Together with their Subject Matter
using Hydrogen as the reducing agent instead of
Sodium hydroxide recovery is a multi-effect
engineering.
Experts, DyStar will drive sustainability as their core
Hydrosulphite. This innovation made the Indigo ready
evaporation and dewatering process, resulting in a
to use for the dyeing process, which is more
competency so as to continue to enable key stake-
100% salt, which is used as a melt in further
Reformulated Sodium Amide to Meet Industry Needs
Dystar Ludwigshafen production steps. sustainable, efficient, and much safer for the workers Another milestone reached in the history of Indigo holders, direct customers, Brand and Retailers,
in the Denim Mills. It also resulted in more stable
manufacturers, and wider supply chain to benefit
relates to Sodium Amide, which is one of the main
dyeing processes with less shade variations.
As a site partner of the BASF, DyStar discharges
from the efficient process and production.
intermediates used from the start of the Indigo synthesis
wastewater into the highly sophisticated, central
effluent-treatment-plant (ETP) on the same premises. DyStar’s recent development for the Denim Industry process. Sodium Amide was also reformulated for the DyStar and Cadira are registered trademarks of
pharmaceutical industry in 2008. The basics of how to
®
This is a win-win situation for both parties. Their “Cadira Denim” combines this pre-reduced Indigo produce Sodium Amide were known since the begin- DyStar Colours Distribution GmbH, DE.
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