PROCESSES DEVELOPPED SINCE 1928
In 1928, M. Charles Ab der-Halden invented a 
process forcontinuouscoal tar distillationusing steam injection. He filed a patent and then founded his company, PROABD®.
This process was soon very successful and then widely used in coke and gas plants all over Europe.
In order to answer the improvement requirements of the carbochemical industry, LITWIN developed and is still developing new PROABD® processes and applications such:
• Coke Oven Gas treatment
• Coal Tar Distillation
• Coal Tar Derivatives Purification and downstream production
• Pitch Treatment and Conditioning
• Phenol and PAH Extractions
• Aromatics production from petroleum feed stocks
• Water Treatment.
COAL TAR DISTILLATION AND DERIVATIVES
LITWIN has built two of the latest Coal Tar Distillation and Derivatives integrated Plants in the world : China Steel Chemical Corporation - Taiwan, and Coal Tar Refinery - Iran.
These complete optimized turnkey plants present important process improvements. For each unit designed, LITWIN has developed its own concept of process equipment to meet the required plant performances.
These included new design of vent scrubber, distillation columns,reactors, furnaces, economizers, granulators, crystallizers, liquid/ liquid extraction column..., and allowedimportant features as :
• Process simplicity
• Low and easy maintenance,high operation reliability
• Production flexibility in terms of product type andquality.
• High yield recovery
• Energy saving efficiency
• Advanced environment protection systems.
• Optimized performances for products and by-products fraction
• Improvement of sub-products separation
LITWIN can also adjust and optimize the plant design on the basis of coal tar feed quality and quantity to produce a wide range of products according to local and international market requirements.
PROABD® processes are improved to reach optimized performances for coal tar primary fractionation as well as for coal tar distillation or oils rectification.
PITCHES TREATMENT AND GRANULATION
The PROABD® process is based on continuousthermal treatment of the pitch and onoil removal. Evolution of blended coal used in the coke oven battery has modified consequently coal tar and pitch main characteristics decreasing the resins content.
LITWIN has developed a process line using this lower quality coal tar and producing all the range of products: electrode pitch, binder pitch...
All qualities of pitch can be transformed into small solid granules, which are very interesting for transportation and easy to melt.
HIGH PURITY NAPHTALENE PURIFICATION
PROABD® has developed and patented with the IFP (Institut Français du Pétrole) a low sulfur naphthalene production process.
The combined process is developed to reach purity higher than 99.9 % with less than 50 ppm of sulfur, and have demonstrated his cost effectiveness in more than 20 industrial operating plants.
ANTHRACENE AND CARBAZOLE PURIFICATION
Since 45 years, LITWIN has developed PROABD® patented purification processes.
They are considered today as the leading ones to produce all grade of purity from 40 % to more than 98 % for anthracene or 96 % for carbazole with high yield recovery.
These plants use the best environmental protection and safety conditions, like in Shanghai for Baosteel Group.
ANTHRAQUINONE PRODUCTION FROM ANTHRACENE 
PROABD® process improved the well known anthracene oxidationby air oxygen in fixed bed catalyst based on 30 years Ciba's industrial experience.
For example, LITWIN has developed this process in Shandong Province (China) for Jining Coal Chemical Company, to obtain anthraquinone purity up to 99 %.
COKE OVEN GAS (COG) TREATMENT AND BENZOL RECOVERY
The PROABD® process has become over theyears the reference benzol recovery and naphthalene removal processes from Coke Oven Gas.
LITWIN's competitive edge which has been confirmed by our client choice, like Svenkst Stal AB - Sweden, or Rautaruukki Oy - Finland.
PROABD®© developments and improvements include important features :
• More than 95% benzol yield recovery
• Simplicity, flexibility and low utilities consumptions
• Clean, safe and environmental operation.
BENZENE, TOLUENE AND XYLENE PURIFICATION
The PROABD® BTX purification process developed by LITWIN for cyclohexane production feedstock
require low investments costs and energy consumption.
The purity of benzene reach 99,9 % with less than 0,05 % non aromatic and the process present the best environment protection, like in Kaohsiung (Taiwan) plant for China Steel Chemical Corporation.
REVAMPING AND EXPERTISE
Over the years, PROABD® has acquired a large experience and an importantdatabase in the field of the carbochemical industry. The permanent contacts with our customers who are the leading companies of the industry have been an incentive for constant process improvements in the field.
PROABD® experienced engineers are prepared to study: technical improvements, revamping, investment, plant flexibility and modification, environmental protection, best operating control...
LITWIN proposes currently in the carbochemical plant the following services:
• Economical and technical feasibility studies
• Process design equipment calculation and manufacturing drawing
• Process audit and assistance
• Plant equipment expertise
• Plant revamping.
R&D AND FURTHER PROCESS DEVELOPMENTS
LITWIN disposed of a pilot hall agreed by the French agency of development, theMinistère de la Recherche et des Technologies, to realize specific works.
During the last years, furthers developments have been realized:
• The Ammonia Removal from Ammonia Liquor consist on a pre-concentration process and reuse of the treated water inside the coking plant.
• To prevent deposits of dust and pitch in the plants, LITWIN have developed an Electrostatic Tar Precipitator which presents many improvements (simple, clean and safe operation, long use, …)
• The Ammonium Sulfate Recovery from Coke Oven Gas allow to get rid of ammonia and to obtain a valuable product with a reduce plant size and low maintenance and production costs
• Coal tar and carbon particules are removed from the flushing liquor in a Flushing-liquor Decanter which require no maintenance
• The Liquor Filtration, which is used to get ride of tar droplets and solid particles suspended in the produced flushing liquor
• LITWIN has developed a “0 Reject” Treatment line using PROABD® Melt Static Crystallization (MSC) to reuse the water in the plants, recycle the drainage water in the processes and produce marketable salts.
This application can be used for other kind of industrial effluents of a similar composition and allow to reach various water purities and to recycle the pollutants in the process or to market them in a salt form.
Most of these processes have been developed for example in Sluiskil (The Netherlands) plant for ACZC.
PROABD TECHNOLOGIE PRODUCT LIST
PITCH PRODUCTION
All grades of pitch
Pitch granules
Coal Tar Enamel
COKE OVEN GAS TREATMENT AND BY-PRODUCTS RECOVERY
Benzol 94 %
Benzene 99.9 %
Naphthalene
Toluene
Xylene
Ammonium sulfate
COAL TAR PRODUCTS AND DERIVATIVES PRODUCTION OR PURIFICATION
Wide range of oils
Naphthalene 99.9 %, 50 ppm Sulfur
Anthracene 98 %
Carbazole 96 %
Anthraquinone 99 %
Phenol 99 %
3.5 Xylenols 99 %
Acenaphthene 99 % and beta-methylnaphthalene 98 %
Quinoline, Cresols 99 %
CONTACT
contact.proabd@litwin.fr