F O R H C l G A S H Y D R O C H L O R I C A C I D S U L F U R I C A C I D E X H A U S T G A S F L U E G A S

S Y S T E M S – O U R K N O W - H O W

®DIABON ®LICUFLON ®GENAKOR ®VULCOFERRAN®VULKODURIT ®KERABUTYL KARBATE SPECIAL METALS

C O N T E N T SForeword 3Our know-how 4 - 5HCl gas and hydrochloric acidAbsorption of HCl gas 6 - 7Production of HCl gas from hydrochloric acid 8 - 9Stripping processes 10 - 11Concentration of hydrochloric acid 12 - 13Sulfuric acidDilution and concentration of H2SO4 14 - 15Exhaust gas and flue gasSpecific performance requirementsfor heat exchangers 16 - 17Characteristics of flue gas heat exchangers 18 - 19Quench process andrecovery of hydrochloric acid 20 - 21Summary 22 - 23

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C O M P L E T E S Y S T E M S C R E AT E N E W B E N E F I T S

Industrial corrosion protection:

A host of suppliers and subcon-tractors, difficult coordination andnon-harmonized bids for materials,components, process equipment,packages and systems make efficientplanning and execution of new plantsa complex, time-consuming task.It doesn’t have to be that way.We can now offer you a fullycomprehensive range of productsand services for industrial corrosionprotection – we are the only producerin the world that is able to do so.We offer a complete system from asingle source – from optimizedmaterial selection through interfacemanagement, production, deliveryand installation right up to thewarranty.

Our system approach is based onthe combined expertise in materialsand the decades of experience ofthree leading companies in corrosionprotection.

These companies – SGL TECHNIK,HAW LININGS and KCH – havenow been merged into the newSGL ACOTEC GmbH, the German-based headquarters of the globalCorrosion Protection Business of theSGL CARBON GROUP.

You can save yourself time andtrouble in the future – by takingadvantage of our comprehensive,system-based range of productsand services.

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O U R K N O W - H O W

By using our material brands®DIABON, KARBATE and®LICUFLON in combination withhigh-alloyed special metals and therubber lining materials ®GENAKOR,®VULCOFERRAN, ®VULKODURITand ®KERABUTYL – in heatexchangers, columns, tanks andpumps – we are able to cover thecomplete spectrum of processengineering for corrosive media.From treatment of HCl by absorption,distillation, stripping or evaporationto dilution and concentration ofsulfuric acid, including the cleaningof flue gases, we can find solutionsto materials and process engineeringproblems.In the treatment of hydrochloric orsulfuric acid and cleaning of fluegases from hazardous-wasteincinerators, we bring our entire

Storage site of semi-finished ®DIABONgraphite products:QUALITY requiresmaterials schedulingwith foresight

expertise to bear. We offer everythingfrom a single source – from theoptimum material for an individualequipment item to complete systems.We develop individually tailoredsolutions which satisfy our customers’requirements in every respect. Forthis purpose, a team of experienceddesign engineers works with expertsin plant construction, processengineering and every other fieldrequired for the execution of theproject. On this basis, optimalsolutions are developed which areclosely examined before being putinto practice.Specialists ensure that every systemconforms to the latest state of techno-logical progress and the knowledgegained from operating practice. Thebest proof: On the basis of the latestdevelopments in materials science,

our systems fulfill the requirementsof chemical engineering and environ-mental protection.These requirements are:• Complete corrosion resistance• Maximum operational reliability• Cost-efficient use.

Our construction materials foroptimum service®DIABON and KARBATE graphitesfor the manufacture of chemicalprocess equipment are well knownfor their outstanding resistance tovirtually all corrosive chemicals.®LICUFLON fluoroplastic and®GENAKOR, ®VULCOFERRAN,®VULKODURIT and ®KERABUTYLrubber lining materials are used forlining columns, tanks and vessels.These materials effectively protect thesteel. This range of corrosion-resistantmaterials is supplemented by ourspecial metals, from which wefabricate equipment such as heatexchangers and columns using thelatest knowledge in materials scienceand welding technology. Thesematerials are very resistant tocorrosion even when used inprocesses requiring the handlingof mixed aggressive media withchanging corrosive constituents.Process equipment fabricated fromour corrosion-resistant materials isunaffected by sudden changes intemperature. Thanks to their anti-adhesive properties, it is virtuallyimpossible for deposits to accumulateon the material’s surface.

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To enable us to select the combinationof materials and service conditionsthat are most suitable and cost-efficient for you, please provide uswith as accurate a description aspossible of the media used in theplant.

Our quality managementfor your plantsAs a leading producer of corrosion-resistant process equipment, plantsand systems, we are certified inaccordance with DIN EN ISO 9001.All process equipment can bemanufactured, tested anddocumented in conformity withall the usual national andinternational standards, such asAD codes, TÜV rules, or ASME,BS, CODAP, ISPESL andSTOOMWEZEN standards.

Special metals:Heat exchangersfor fine chemicalsproduction

Our process engineering for greaterreliabilityOne of the greatest benefits we offerour customers is our expertise incomplete systems. This is evidencedabove all by the fact that asmanufacturers of corrosion-resistanthigh-tech materials, we are alsofamiliar with the relevant processesand systems. For decades, we haveworked with leading engineeringand design consultants and with thechemical and environmentalprotection industries. In doing so wehave further optimized the use of ourmaterials and process equipment.The capacities and dimensions of theplants are matched to our customers’individual requirements. Processengineers elaborate the thermal andmechanical details with the aid ofup-to-date 3 D CAD and processsimulation programs. The under-lying equilibrium data also takeinto account thermodynamiccharacteristics of the media usedwhich deviate sharply from idealconditions.

Our systems and their specialadvantages• Modular design for greater

flexibility• High acid concentrations

achievable• Compact, space-saving design• Flexible design matched

to customers’ requirements.

®VULCOFERRAN rubber sheetstorage site: A special climateguarantees a QUALITY product

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H C l G A S A N D H Y D R O C H L O R I C A C I D

Isothermal absorption systemwith block heat exchanger,scrubber, pumps and tank

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A B S O R P T I O N O F H C l G A S

The absorption of hydrogen chloridein water or dilute hydrochloric acidis a central operation in theproduction of hydrochloric acid.However, this technique is also oftenused for cleaning waste gases fromchemical production plants or wasteincinerators.The HCl gas is admitted at the bottomof a column, while the absorbingliquid is fed in at the top. Gas andliquid flow in counter-current toensure optimum absorption. Theheight, diameter and internals aredesigned to ensure that the desiredacid concentration is obtained andthe purity of the gas is maximized.The hot stream of acid is cooled inan integral or separate heatexchanger.The dissolution of HCl in water isfollowed by a strongly exothermicreaction in the liquid.To obtain a solution with a maximumHCl concentration, removal of theappropriate amount of heat isnecessary – isothermal absorption.For this reason, water-cooled falling-film absorbers are used for theproduction of hydrochloric acid.With lower HCl concentrations inthe feed gas, adiabatic absorptionis an alternative. Because theabsorption rate decreases at lowerconcentrations, multi-stage scrubbersare required; these are designed ascolumns with trays or with randomor structured packings.

For recovery of hydrogen chloridefrom inert gas streams with fluctuatingconcentrations, we offer a system forabsorption with water followed byproduction of HCl gas by distillation.

Construction materialsTo ensure optimum resistance tocorrosive substances such ashydrochloric acid, various corrosion-resistant materials are used inabsorption systems:• ®DIABON or KARBATE graphites

for column shells, heat exchangertubes, random and structuredpackings

• ®GENAKOR, ®VULCOFERRAN, ®VULKODURIT or ®KERABUTYL rubber linings for piping and for acid storage tanks.

Capacity and available sizesThe absorption systems can bedesigned for a capacity of 0.5 to360 t/d of 100 % HCl per system.The equipment sizes are matched tothe customer’s needs.

Tank

Pump

Hydrochloricacid

Isothermalabsorber(can becombined witha quencher)

ScrubberAbsorption water

HCl gas

Vent gas

LICADIC

FIC

Isothermal absorption of HCl gas

AIC

Adiabatic absorption of HCl gas

LIC

FIC

Inert gases

Cooler

CondenserCooling water

e.g. HCl 33 %Hydrochloric acid,

HCl gas

Pumps

Tank

Absorption column

Absorptionwater

P R O D U C T I O N O F H C l G A S F R O M H Y D R O C H L O R I C A C I D

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HCl gas is produced by distillationof hydrochloric acid solutions witha concentration of 25 - 35 % underpressure. The hydrochloric acidsolution can be produced in anabsorption system, as shown in theflow diagram above.The HCl gas may originate froma combustion process or an HClsynthesis plant. HCl gas from anHCl synthesis plant always containsan excess of hydrogen for completereaction of chlorine. In this case, thehydrogen is removed from the HClgas by absorption followed bydistillation.Absorption is usually carried out atatmospheric pressure. Depending onthe resulting absorption temperature,the absorption solution has to becooled in a downstream heatexchanger. To minimize theconsumption of steam and coolingwater, the feed stream to the columnis heated with hot, azeotropic acid.The preheated solution is fed into thecolumn below the reflux stream.Water-containing HCl gas is distilled.The concentration of the HCl gas

increases in the first condenser andin subsequent gas coolers. In theseheat exchangers, water is removedfrom the gas stream. After passingthrough a high-performancedemister, a moisture content of5 - 10 ppm in the product gas canultimately be achieved.

The special advantages of our HCldistillation plants• Production of highly pure, dry

HCl gas with low inert gas andmoisture contents

• No risk of explosion• Gas pressure and temperature in

accordance with customer’s wishes• Long service life, low maintenance

cost• Modular design of system,

including pipework, instrumentationand control equipment

• We engineer, erect and commissionthe plant.

Construction materialsTo offer you the maximum possiblesafety and reliability, distillation plantsare fabricated solely from ourcorrosion-resistant materials:• ®DIABON and KARBATE

graphites for heat exchangers• ®DIABON graphite and

®LICUFLON fluoroplastic for columns

• ®GENAKOR, ®VULCOFERRAN, ®VULKODURIT and ®KERABUTYLrubber linings for distillationcolumns, tanks and piping

• ®DIABON graphite or plastic forcolumn internals

• DIAPACK carbon orMELLACARBON™ CFC for column packings.

Capacity and available sizesDistillation columns can be fabricatedin all standard sizes up to 3 metersin diameter. Distillation units can bedesigned for capacities of 3 to 360t/d of 100 % HCl per column.

Production of HCl gas from hydrochloric acid:Absorption/desorption

LIC

LIC

Tank

TankForced-circulation evaporator

Pump, concentrated HCl Pump, azeotropic acid

Untreated gascontaining HCl

Absorption waterAbsorptioncolumn FIC

Steam

HCl gas

Demister

CoolerCondenser

Distillationcolumn

Recuperator

Cooler

FIC

PIC

TIC

LIC

Vent gas

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S T R I P P I N G P R O C E S S E S

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Hydrochloric acid is sometimescontaminated with undesirablevolatile constituents such as chlorineor chlorinated organic substances.These impurities can be removed bystripping or rectification in a relativelysimple process.In this process, the feed stream entersat the top of a stripping column.Column internals bring aboutintensive contact between the liquidand the upward-flowing strippingmedium. As a result, low-boilingorganic substances and a smallamount of hydrogen chloride arevaporized. The purified hydrochloricacid leaves the system at the bottomof the column. The stripping mediumis air, live steam or steam producedin an evaporator. Overhead vaporscan be condensed in order toseparate recyclable liquid phases.

Construction materialsTo ensure optimum resistance tocorrosive substances at the particularservice conditions, the most suitablematerials for each equipment itemare used:• ®DIABON and KARBATE

graphites for stripping columns and heat exchangers

• ®LICUFLON fluoroplastic forstripping columns with largerdiameters

• ®GENAKOR, ®VULCOFERRAN, ®VULKODURIT or ®KERABUTYLrubber linings for piping and for acid storage tanks.

Capacity and available sizes®LICUFLON stripping columns areable to treat up to 300 t/h ofhydrochloric acid solution. Rubber-lined columns are capable of evenhigher capacities. Equipment sizesare matched to the customer’srequirements.

Organic substancesUntreatedacid

Recuperator

Condenser

Forced-circulationevaporator

Vent gas

Separator

Hydrochloric acid

Pump

FIC

LIC

LIC

TIC

Stripping column

Tank

Pump

Purified acid

Stripping column in ®DIABON graphite forpurification of hydrochloric acid

HCl stripping process with steam stripping columnfor purification of hydrochloric acid

One of the major standard opera-tions in environmental protectiontechnology is the evaporation ofliquid wastes. ®DIABON graphiteheat exchangers represent the lateststate of the art in the evaporation ofdilute acids, aggressive flue gasscrubbing water, landfill leachatesand industrial effluents.• Evaporation systems are used if

salts or other high-boilingsubstances have to be removedfrom HCl solutions. HCl and waterare evaporated; the waste productsare retained in the concentrate.

• Concentrated hydrochloric acidcan also be recovered from heavilydiluted solutions. These hydro-chloric acid solutions can beconcentrated by evaporation toapprox. 20 % HCl (azeotropic).Even higher concentrations can beachieved by means of CaCl2distillation, in which evaporationplays a crucial role. CaCl2 modifiesthe chemical equilibrium in such a way as to enable selectivedistillation of HCl in a column.The CaCl2 solution is diluted bythe residual water; this diluted

CaCl2 solution can be re-concentrated in a followingevaporation stage.

• If traces of other substances buildup in the CaCl2 circuit or if the useof this chemical is undesirable, analternative option is to use pressure-

swing distillation for recovery ofHCl from dilute hydrochloric acidsolutions. At high pressure, theazeotropic HCl concentration islow (16 - 18 %). At low pressure,it rises to 22 - 24 %. This makes itpossible to remove water bydistillation in a column operated at low pressure. The concentrate in the bottom of this column is pumped into another column operated at high pressure, where

HCl gas is distilled. The azeotropicbottom product flows back into thelow-pressure column.

Construction materials• ®DIABON and KARBATE

graphites for heat exchangersand final condensers

• ®DIABON, KARBATE, ®GENAKOR, ®VULCOFERRAN, ®VULKODURIT, ®KERABUTYLand ®LICUFLON brands or tantalum for lining of separators.

Capacity and available sizesThe design and capacity of theevaporation systems are matchedto the customer’s requirements.

C O N C E N T R AT I O N O F H Y D R O C H L O R I C A C I D

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Blind flange ofa ®LICUFLONevaporation vessel

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Production of HCl gas:Pressure-swing distillation process

Production of concentrated hydrochloric acid:CaCl2 distillation process

LIC

LIC

TIC

FIC

FIC

PIC

TIC

LIC

Distillationcolumn

Steam-jetvacuum pump

LIC

LIC

TIC

Tank

Tank Natural circulationevaporator

Concentrated HCI Azeotropic HCI

Dilute acid, e.g. HCI 10 % FIC

Steam

HCL gas

Demister

Condenser

column p>1bar Distillation

Recuperator

Cooler

FIC

PIC

TIC

LIC

column p<1barDistillation

Waste water

Steam

H2O Vent gas

Steam

CondenserHCI

Tank

TankNatural circulationevaporator

CaCl2 + H2O Concentrated CaCl2

Dilute acid, e.g. 10 % HC

Steam

H2O tovacuum pump

Demister

stage CaCl2 concentration

Recuperator

Cooler

Steam

Absorption water

Concentrated hydrochloric acid,e.g. 33 %

Waste water

Steam-jet vacuum pump

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Dilution of sulfuric acid®DIABON and KARBATE graphiteheat exchangers for dilution ofsulfuric acid produce a homogeneousacid with a constant temperature.In this way, downstream piping isprotected. The resistant materialsselected for this process are extremelyreliable. The acid concentrationcan be controled manually andautomatically.

S U L F U R I C A C I D – D I L U T I O N A N DC O N C E N T R AT I O N O F H2 S O4

Complete pre-assembled module for dilution of sulfuric acidand tempering of electroplating baths

Sulfuric acid dilution system

TIC DIC

FIC

Dilute acidAcid coolerAcid mixer

Concentrated sulfuric acid

Dilution water

out

in

Coolingwater

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Concentration of sulfuric acidThis process was developed in orderto maximize the energy efficiency ofresource recovery and waste disposalprocesses. Two- and three-stageconcentration systems are character-ized by 45 % and 65 % lower steamconsumption respectively comparedwith single-stage designs. Suchsystems are aimed chiefly at reducingthe cost of waste disposal andtherefore have to pay for themselvesin a short time.

The acid solution usually flows bynatural circulation through a heatexchanger and is evaporated in aseparator. The steam which leavesthe separator is condensed in afollowing evaporation stage or afinal condenser.Complete turnkey units of modulardesign with heat exchangers, pumps,piping, control equipment andstructural steelwork can be supplied.For further information, pleaseask us for our brochure „CorrosionProtection in Sulfuric Acid Plants”.

Construction materials• ®DIABON and KARBATE

graphites for heat exchangers andfinal condensers

• ®DIABON, KARBATE, ®GENAKOR, ®VULCOFERRAN, ®VULKODURIT, ®KERABUTYL and®LICUFLON brands or tantalum for lining of separators and H2SO4

mixers.

Capacity and available sizesSulfuric acid dilution systems can beconstructed for capacities rangingfrom 0.5 to 100 m3/h of dilutedH2SO4. The capacity and size of theconcentration systems are matchedto customers’ requirements.

Single-stagesulfuric acidconcentration systemfor low flow rates

ConcentratedH2SO4

Tank

Tank

Steam

TIC

PIC

LIC

LIC

Condensate

Evaporator

H2SO4 feed

Condenser

Steam-jetvacuum pump

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Exhaust gas treatmentDue to the aggressiveness of thesubstances involved, corrosionproblems can occur in almost anyprocess aimed at preventing pollutantemissions and recovering harmfulsubstances from exhaust gases. Bycombining our expertise in the fieldof exhaust gas cleaning and heatrecovery with our range of corrosion-resistant materials, we can offertailor-made engineering solutions foryour particular problem:• Equipment and complete systems

for cleaning hydrogen halide-containing exhaust gases and recovering hydrogen halides

• Quenchers and absorbers for cooling and subsequent absorptionof pollutants from flue gases and exhaust gases

• Equipment and systems for coolingand reheating flue gases

• Plant components and equipmentfor thermal decomposition of waste,including subsequent exhaust gascleaning and recovery of acid components

• Systems for recovering heat fromthe exhaust gases of large heatingplants.

Flue gas treatment®DIABON graphite modular heatexchangers for flue gas treatmentare used in the power generationindustry and in waste incinerationin combination with wet scrubbingprocesses. In these processes, hotflue gases are cooled to condensationtemperature in a heat exchanger,scrubbed, and then reheated in thesame heat exchanger.

Modular heat exchangers are oper-ated as gas/gas heat exchangersor as condensers. By this meanssignificantly improved heat transferand complete condensation areachieved. The saturated flue gasescan be cooled in the condensers towell below the dew point. ®DIABONgraphite is an optimum material forsuch applications, as it has excellentthermal conductivity.

The corrosive substances containedin the gases, such as HCl, HF or SO3,and other water-soluble substances,e.g. Hg, are absorbed in the conden-sing water. As a result, the conden-sate is very corrosive. Since our®DIABON graphite heat exchangersare resistant to almost all concen-trations of these gaseous or conden-sed substances, there is no risk ofcorrosion at temperatures up to300°C respectively. Damage bypitting, crevice corrosion or stress-corrosion cracking is unknown with®DIABON graphite.

Specific performance requirementsfor heat exchangersFlue gas heat exchangers which areused in condensation processes areclassed as heavy-duty equipmentand have to meet very demandingrequirements:• Leakproofness must be absolutely

guaranteed even at hightemperatures. This requirement iscritically important during startupand shutdown, when the materialis subjected to additional stress and attack due to thermalexpansion and corrosivecondensates.

• In cooling of flue gases,condensation of sulfuric acid andhence severe corrosion can occurat temperatures of about 160°C, resulting in the destruction of non-resistant materials in the equipment.

• In the temperature range in whichwater condenses, the HCl and HFgases present in the flue gases areabsorbed as hydrochloric and hydrofluoric acid respectively.

• Combinations of the phenomena described can occur during startupand shutdown if all the temperatureranges are passed through slowlyand corrosive vapors flow throughthe heat exchanger.

For further information, pleaseask us for our brochure „CorrosionProtection in Phosphoric AcidPlants”.

E X H A U S T G A S A N D F L U E G A S – S P E C I F I C P E R F O R M A N C ER E Q U I R E M E N T S F O R H E AT E X C H A N G E R S

Gas/gas heatexchanger of

modular designfabricated from

®DIABON graphite and glass tubes,

for cooling fluegaswith fresh air

T E C H N I S C H E D A T E N 17

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C H A R A C T E R I S T I C S O F O U R F L U E G A S H E AT E X C H A N G E R S

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The tubes of flue gas heat exchangers in ®DIABON graphite are joined toboth tube sheets without seals. The ends of the tubes, and the holes in thetube sheets, are conical in shape. These conical components are cementedtogether with an adhesive consisting of synthetic resin and cementingpowder. The joint produced is gasproof and used under normal conditionsup to a material temperature of approx. 200°C. If specially impregnatedmaterial is used, service up to approx. 300°C is possible. The maximumpermitted gas temperatures are about 10°C above these levels.

Gas/liquid heat exchanger of modular design,made from ®DIABON graphite, for condensationof flue gas with cooling water

The sealing between tube and tubesheet must withstand thermal stressesand also be resistant to hightemperatures and corrosion.This requirement is fully met by ourjoining technique. As the tubes andtube sheets are made of the samematerial, variations in temperaturehave no adverse consequences; nostresses due to thermal expansionarise.The combustion gases are passedthrough the inside of the tubes.Owing to the high gas velocity, nodust deposition problems occur evenif the electrostatic dust precipitatorfails.

The cleaned gases pass through theshell space of the heat exchanger.To ensure trouble-free operation, thegases should be free from saltdroplets.The steel structure is lined with aresistant material, which is selectedaccording to the gas compositionand temperature.Experience shows that flue gas heatexchangers fabricated from®DIABON graphite ensure highoperational reliability and longservice.

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Q U E N C H P R O C E S S A N D R E C O V E R Y O F H Y D R O C H L O R I C A C I D

Gases from incineration systems oftencontain considerable amounts ofhydrogen chloride and elementalchlorine. To facilitate the treatmentof these exhaust gases in downstreamsystems, they must be reliably cooledto temperatures close to the saturationpoint (60 - 90°C) either immediatelyfollowing incineration or after heatrecovery in a steam generator or aflue gas heat exchanger. In addition,recycling of the HCl gas as industrial-grade hydrochloric acid is desirable.Finally, any Cl2 present in the fluegases must also be removed. Systemsmade from ®DIABON graphite fullymeet these requirements. On its wayto the stack, the gas flows through aquencher, an HCl absorption columnoperated with fresh water, and finally

an alkaline absorption unit for Cl2removal, which is operated withwater, NaOH and a reducing agent(e.g. Na2SO3). In the quencher, thetop-fed gas causes evaporation ofthe circulating liquid. Gas and liquidflow together through the quenchingpipes, which allows the gases to bequickly and reliably cooled totemperatures close to the saturationpoint. The circulating liquid can becooled in a heat exchanger. Thisincreases the HCl recovery rate if thetemperature of the HCl solution is toohigh after the absorption stage.

Quench process with recovery ofhydrochloric acid in an absorption columnand removal of chlorine in analkaline absorption unit

LIC

EmergencywaterAbsorption water

Flue gascontaining HCI

Quencher

to stack

Alkaline absorption

FIC

FICFIC FIC

LIC

LIC

AIC

Hydrochloricacid

H2ONaOHreducingagent

Waste waterSalt solution

Absorption column

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In the first absorption column, theHCl gases are absorbed in counter-current by fresh water. This columnis usually operated at atmosphericpressure. The HCl solution is addedto the circulating quenching liquid.In the second absorption column(packed section), the inert gases areabsorbed in counter-current by amixture of water, NaOH and areducing agent (e.g. Na2SO3).• The first absorption column ensures

complete saturation of the gases after quenching and complete absorption of hydrochloric acid

• The quencher can be combined with a falling-film absorber for removal of very large quantities ofheat

• In certain cases, high hydrochloricacid concentrations can only beattained by means of an integraldistillation stage

• In subsequent treatment stages,highly pure hydrochloric acid canbe produced by removal of chlorineor metal salts

• We can handle the engineering,erection and commissioning.

The quench process and the processfor recovery of hydrochloric acidcomply with the requirements of allthe current international emissionstandards.

Capacity and available sizesQuenchers can be fabricated up toa maximum diameter of approx.2,700 mm. This enables very largevolumes of flue gas (up to approx.160,000 Nm3/h) to be treated in asingle unit. Depending on the chosendesign (e.g. with or without a coolingring), ®DIABON graphite quencherscan be used at temperatures from150 up to 1,500°C.

The obtainable HCl concentration inthe recovered acid depends on thecomposition of the flue gas. Normalconcentrations are 15 to 30 %.

®DIABON graphite pipe quencher withseparate quenching circuit for removal of saltsfrom flue gas and recovery of industrial-gradehydrochloric acid in an absorption column

Flue gas scrubbingwith ®DIABONgraphite pipequencher (installedheight 1.3 mapprox.) mountedon a co-currentscrubber. Liquid feed:to pipes at left, tocooling ring at top

Liquiddistributor

Pipe quencher

Clean gas

Demister

Spray pipe

Emergency water

Steel bellows

Quenchingliquid

Hydrochloric acidto pumpDischarge

Hydrochloric acidto pumpDischarge

Flue gas

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S U M M A R Y

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The illustration at the left and our cover photo demonstrate the way in which our systematicsolutions harmonize with our environment. On the cover photo of this brochure, ponds forproduction of sodium chloride are visible in the background. The raw material salt wasthe reason for building a chemical plant based on the use of chlorine near the source ofthe raw material (NaCl). Sodium chloride is used for the production of chlorine, which isthe raw material for HCl production. The blue sky makes it clear that the operation of anindustrial plant without harming nature is a reality today.

We make a contribution to this: By using our material brands ®DIABON,KARBATE and ®LICUFLON – in combination with high-alloyed special metalsand the ®GENAKOR, ®VULCOFERRAN, ®VULKODURIT and ®KERABUTYLrubber linings – in heat exchangers, columns, tanks and pumps, we areable to cover the entire spectrum of process engineering for corrosive media.From the treatment of HCl by absorption, distillation, stripping or evaporationto the dilution and concentration of sulfuric acid, and also in the cleaningof flue gases, we can find solutions to materials and process engineeringproblems. Our range of products and services is rounded off by floorcoating and tiling systems, as well as a wide corrosion protection productportfolio for secondary containment systems, channels and pump casings.To enable us to give our customers a quick and precise answer to theirtechnical questions, we list below the most important requirements forspecifying a system.

Plant for HCl synthesis and HCl absorption,assembled from three prefabricated modules.In the foreground are hydrochloric acid storagetanks

Specification of feed• Flow rate• Source• Composition• Temperature• Pressure• Variations and impurities• Physical properties

- Heat capacities- Density- Viscosity

Specification of product• Concentration (e.g. H2O, HCl, Cl2)• Temperature• PressureHeating and cooling media• Available quantity (analysis)• Temperature• Pressure

Acceptance inspection standards• TÜV, ASME, ....Scope of supply• Process equipment• Piping and valves• Instrumentation, control equipment,

computer process control system• Complete module (including

structural steelwork)Price• Budget price +/- 30 %• Guide price +/- 10 %• Fixed priceDesign concept• Absorption• Concentration• Stripping• Dilution• Quenching• Heat transfer• Distillation• Desorption

© SGL ACOTEC GmbH, Siershahn, 2002® registered trademark of SGL CARBON GROUP companiesThe data contained herein represent the current state of our productknowledge and are intended to provide general information on ourproducts and their application spectra. In view of the variety and largenumber of application possibilities, these data should be regardedmerely as general information that gives no guarantee of any specificproperties and/or suitability of those products for any particularapplication. Consequently, when ordering a product, please contact usfor specific information on the properties required for the applicationconcerned. On request, our technical service will supply a profile ofcharacteristics for your specific application requirements without delay.SGL-401/08-2002e Printed in Germany

Werner-von-Siemens-Straße 18D-86405 Meitingen / GermanyPhone +49 (82 71) 83-15 64Fax +49 (82 71) 83-21 01bspe@sglcarbon.dewww.sglcarbon.com/cp

Corrosion ProtectionBusiness Unit

SGL ACOTEC GmbH