ابريتنغ منول

SULPHONATION PLANT

SULPHONATION PLANT

Capacity 3.000 Kg/h

Capacity 3.000 Kg/h

OPERATING MANUAL

OPERATING MANUAL

Index

Introduction Page: 3

1 Plant capacity Page: 4

2 General process description Page: 5

3 Raw material and products specifications Page: 19

4 Plant start-up operations Page: 25

5 Normal run and controls Page: 49

6 Normal shut-down Page: 57

7 Emergency shut-down Page: 62

8 Interlock system Page: 56

9 Material balance Page: 58

10 General maintenance Page: 74

11 Annexes Page: 76

11.1 Alumina Tanks T-102 A/B Page: 76

11.2 General Notes About Sulphur Filtration Page: 77 11.3 Converter Catalyst Loading Instructions Page: 82

This operating manual has been developed following the criteria that the operators have some knowledge of chemical plants and have consequently familiarity with equipment, which normally are installed in them.

For this reason the manual will describe the operations showing their meaning leaving to the operators’ experience the correct way to realize them.

For instance, when we say “start the organic pump“, the manual assumes that the suction and delivery valve have been checked and are in correct position; or “open steam to the exchanger”, the manual assumes that the steam and condensate valves have been positioned in the right way, and so on.

Moreover, this manual is addressed to people who are expert in chemistry and in chemical plants, so that they can manage the operations described there with the necessary interpretation and responsibility.

1)

PLANT CAPACITY

The plant has been designed to produce 3.000 Kg/h of duodecilbenzene sulphonic acid (LABS), starting from sulphur and linear duodecilbenzene, using a multitube falling film reactor.

On the base of 330 working days/year and continuous run the plant can produce 2.376 tons/year of LABS.

Alternatively it can work at campaigns, but it can not be managed stopping and restarting it frequently, because the time necessary for its steady conditions is too long and not compatible with frequent shut-downs. The shorter campaign time we suggest is one week.

The produced LABS is stable and can be stored as it is in stainless steal tank. It can be used inside the factory or sold outside. Its quality is in line with the international standards.

The neutralization section has been not installed at the moment, but it can be erected any time being the relevant space already foreseen.

This film reactor can also sulphonate the most common fatty alcohols used in detergency, but the plant can not now process them without the neutralization section, because the fatty alcohols sulphonic acid is unstable and must be neutralized immediately at the exit of the sulphonation reactor.

Only when the neutralization section will be functioning, the fatty alcohol sulphonation will be possible.

The nominal plant capacity in case of fatty alcohols decreases as per the following list due to the necessity to operate at lower SO3 concentration in the reaction gas:

Raw materials M.w Production kg/h

Linear alkylbenzene 242 3.000

Branched alkylbenzene 245 3.000

Lauryl alcohol c12 / c-14 207 2.700 Ethoxylauryl alcohol3 moles e.o. 339 2.550

Natural alcohol c16/c18 258 2.700

2) GENERAL PROCESS DESCRIPTION

The LAB sulphonation is a reaction between SO3 (sulphuric anhydride) and LAB where

SO3 generates the SO3H group linking itself to the benzene ring.

Raw materials of this reaction are alkylbenzene, mainly linear, sulphur and air.

Sulphur, if supplied in solid form, is melted and burned with air excess to give SO2

The exhaust gas, which after sulphonation contains some unreacted SO3, some not

converted SO2 and some dragged organics, is purified before sending it to the

atmosphere.

2 . 1 ) PROCESS CHEMISTRY

The sulphonation reaction takes place in mixed phase gas/ liquid, being the gas a mixture of sulphuric anhydride (SO3) and air and the liquid linear duodecylbenzene

(LAB) or duodecylbenzene not linear (branched)(this last is rarely used because is not biodegradable and so it is refused by the market).

The main reaction can be so shown:

C6H5-(CH2)11-CH3 + SO3 = C6H4-(CH2)11-CH3

(LAB) | SO3H

(LABS)

The LABS is a quite strong acid, liquid and stable at room temperature. It can easily be stored and shipped (see physical properties on paragraph 3) It can be neutralized by the bases (caustic soda, sodium carbonate, others).

The above reaction is exothermic and so the reaction must be cooled.

The quality of the acid is judged by the colour (measured in Klett scale), by the

unsulphonated LAB (free oil), by the free sulphuric acid (H2SO4).

To understand how to manage the reaction, we have to examine these three parameters:

It is due to the carbonisation of the organic compounds (LAB).This carbonisation takes place because of too high reaction temperature, for too high SO3

concentration, for presence of sulphuric acid in the SO3 gas stream.

- Reaction temperature.

In the falling film multitube reactors the reaction between SO3 and LAB is very

soft, because SO3 reacts on a 0,3 mm film of LAB which forms in the inner face

of each reaction pipe, thanks to a special design of the distribution head of the reactor itself.

Moreover, all the reaction pipes are cooled very deeply by means of a big mass of water.

The water temperature should be as low as possible with a delta T between inlet and outlet of 1-2 degrees centigrade.

The 80% of the reaction takes place in the first meter of the sulphonation reactor where the reaction temperature reach a maximum pick around 80 ° C. Lower is the pick lower is the Klett colour of the resulting LABS. For this reason we divide the cooling water flow in two streams: 60% on the top, 40 % on the rest.

- SO3 concentration.

As shown above, one mole of LAB reacts with one mole of SO3. This ratio must

be, of course, absolutely respected. As we will see later, this is obtained in a simple way checking the acidity at reactor exit.

But the SO3 concentration in the air is also very important to avoid

carbonisation.

Normally 5% SO3 in air is considered a good value for getting a good colour

LABS and also an acceptable plant capacity. As a matter of fact that more diluted is SO3 more gas mass must be circulated into the plant reducing, with

Any way, just to complete the picture, we can say that more diluted is SO3

smoother is the reaction and better is the colour.

- H2SO4 in the SO3/air stream

The sulphuric acid reacts strongly with LAB and out of control way, burning the LAB itself. On the basis of this reality, in the film reactor sulphonation plants much attention must be brought for avoiding its presence and formation and, if any, for eliminating it as much as possible before the reaction.

The H2SO4 presence in the SO3/air stream, in form of droplets or mist, is

generated mainly by the reaction of SO3 with moisture .That explains way we

dry the air necessary for the reaction through a drying system enough sophisticated as we will see later.

However, the air is not the only source of moisture. It can be introduced by the LAB itself and this is the reason because we require a LAB specification much restricted in this sense.

Sulphuric acid could be also present in the sulphur itself and also for this reason, but not only, during the melting and before filtration could be added some neutralising agent.

Anyway, before reaction, we have foreseen several traps where H2SO4 droplets,

if any, are collected and separated: at the bottom of the SO3/air coolers, in the

separator after coolers and at the bottom of the special filter installed just before reactor.

b) Unsulphonated LAB

This impurity has the following meaning: - LAB remained not sulphonated after reaction

The unsulphonated LAB (free oil) depends from the ratio between the moles of the reactants: SO3 and LAB.

In other words, if we increase the ratio SO3/ LAB, the unsulphonated LAB decreases,

but the Klett colour could increase. There is a balance between colour and free oil, which should be practically searched case by case.

The unsulphonables are materials which can not be sulphonated at least in the conditions we are operating and must be considered lost raw material. They are impurities of LAB and their maximum quantity is fixed in the LAB specifications (LAB sulphonability).

c) Free sulphuric acid

Although we have done as much as possible to avoid the H2SO4 formation, in the final

product we will find always a certain concentration of free sulphuric acid, mainly due to reaction of water content in LAB which reacts with SO3 in the sulphonator :

H2O + SO3 = H2SO4

Another source of free H2SO4 is the formation of anhydrides which gives free water

which reacts with SO3:

2 C6H5-(CH2)11-CH3 + 2 SO3 = C6H4-(CH2)11-CH3 + H2O

| SO2

| O

SO2

|

C6H4-(CH2)11-CH3

H2O + SO3 = H2SO4

These anhydrides are then decomposed before storage in the hydrolyses section by addition of water giving again sulphonic acid:

C6H4-(CH2)11-CH3 + H2O | SO2 | O =2 C6H4-(CH2)11-CH3 | | SO2 SO3H | C6H4-(CH2)11-CH3

2 . 2 ) PLANT DESCRIPTION

2.2.1 Air drying

2.2.3 Sulphur combustion 2.2.4 Conversion

2.2.5 Sulphonation

2.2.6 Exhaust gas treatment

2 .2.1) Air Drying (P and I: SP3-AM-1021)

The air, drawn from the atmosphere, is measured by a calibrated flange (FIR-161) and then distributed between combustion air in the sulphur furnace and quench air in the converter; the rest, if any, is sent before the demister F-104.

The atmospheric air is compressed by compressor CO-101 at 0.9 bar maximum. Really the pressure on the compressor delivery is fixed by the pressure drop through the plant at the flow rate required by the plant conditions.

CO-101 is a volumetric type, that is it compresses always the same quantity of air, being used only part of it venting the rest to the atmosphere through the valve PCV-101. CO-101 is a noisy machine, it is closed in a noise proof container, has two silencers: SL-101 on the suction and SL-102 on the delivery.

After compression the air temperature is about 130° C. This air has to be cooled and dried. For this purpose there is the exchanger E-101, cooled by water, and E-102 cooled by chilled water. After E-101 the temperature is about 30°C and no condensate is separated; after E-102 the temperature is about 3-5 °C and consequently being the air in saturation condition, the water separates and is discharged from the bottom. The separator F-102 provides to eliminate the last water mist still contained in the air stream. At the exit of F-102 the moisture content corresponds to the saturation at the temperature of 3-5 °C.

Also this small amount of moisture must be eliminated; this is realized with the driers T-102 A/B filled with activated alumina. The air enters the bottom and goes out from the top, reaching a dew point in the range of –50/-70 °C.

The driers T-102 A/B work alternatively, one in operation the other in regeneration, being 8 hours the working cycle.

The regeneration is realized in counter-current with hot air (4 hours) coming from E-108/109 exchangers at about 200° C and then with cooling (4 hours) by water in the exchanger E-103. The fan BL-101 provides the circulation of regeneration air in the heating and cooling phase.

The alumina drying system is completely automatic; it is controlled by PLC.

The exchanger E-104 is used only in start-up, when hot water from E-108/109 is not available.

For details on this system see later the appendix n.1 “drying alumina beds”.

The dried air at the exit of T-102 A/B has about 30 °C and it is ready to be sent to sulphur combustion and converter.

The chilled water necessary for the exchanger E-102 is supplied from the chilling unit shown in the P and I SP3-AM-1022.

The tank T-101 contains a 30% glycol solution in water. This solution is recycled by means of the pumps P-101 A/B through the chiller CB-101, where it is cooled at about – 2 °C. The chilled glycol/water solution enters the exchanger E-102, cooling the air in counter-current.

At the exit of the exchanger the glycol solution has a temperature of about 5°C and comes back to the tank T-101.

For detail of the chiller see the relevant technical documentation.

2 .2.2) Sulphur Melting And Filtration (P and I: SP3-AM-1023)

The sulphur is another raw material necessary for the sulphonation. It is usually supplied in solid form or melted. If in solid form it has a flakes shape. In such a case it

must be melted and, if necessary, it must be filtered before being fed to the furnace BR-101 for generating SO2.

The reason of the sulphur filtration is strictly connected to its quality, particularly to its content of ashes. In fact the ashes makes dirty the furnace ,encrust the equipment, damage the converter catalyst, but mainly give problems to the sulphur dosing pumps. The plant is equipped with a complete section designed for a deep filtration (see P and I SP3-AM-1023 ) and, moreover, with an additional light filtration after the tank T-104 (F-103A/B see SP3-AM-1024).

Being the deep filtration an always heavy operation, we suggest evaluating case by case the real necessity to filter the sulphur deeply instead of bypassing this section and use only the light filtration.

The deep filtration can be done without filter aid or with filter-aid, depending on the type of impurities contained in the sulphur.

For sulphur quality specifications see appendix n.2, raw materials specifications. The sulphur melting section is formed by:

- Melter H-101

- Filter aid tank T-105 - Filter F-105

- Filtrated sulphur tank T-104

The melter H-101 is divided in two connected parts: melting zone and mixing/pumping zone.

In the first zone sulphur is charged in the relevant hopper .On the bottom of the hopper a double order of coils, fed by 6 bar steam, provides to melt the sulphur which falls down in liquid form.

The melting sulphur temperature is around 115°C .but it has to maintain at about 150°C, because at this temperature it has the minimum viscosity.

In the mixing /pumping zone, the stirrer AG-101 maintains the ashes in suspension, so that the pump P-105 can easily transfer liquid and solids to the filter F-105.

A floating level indicator is installed on the middle.

The filter aid tank T-105 receives the liquid sulphur from H-101 by means of pump P-105 and provides to prepare the filter aid suspension to form a proper panel on the nets of the filter F-105.

The stirrer AG-102 maintains in suspension the filter aid, while the pump P-106 transfers it to the filter F-105.

A local floating level is installed.

The tank has a jacket fed by 6 bar steam.

The filter aid suggested for this use is EUROPERL® 700 (see specifications in appendix n.2)

The filter F-105 is horizontal type, multi panels and completely jacketed and heated by 6 bar steam.

For more details about sulphur filtration see annexe n° 2 General Notes About Sulphur

Filtration.

After filtration, the liquid sulphur is stored in the tank T-104, from which is fed to the sulphur burner BR-101 by means of the dosing pumps P-102A/B.

T-104 tank is vertical type, jacketed and heated by 6 bar steam. A level indicator with min./max alarm is installed. Its capacity is around 4 m3 and, when full, will assure 24 hours of production.

All the lines and equipment of this section are jacketed and heated by 6 bar steam .Much attention should be paid to a good functioning of the heating system of this section, other wise the sulphur could solidify and cause troubles to the production.

There is a simple way to ascertain that a line or equipment is well heated: put on the line or equipment a small piece of solid sulphur. If sulphur melts easily in short time the line or the equipment is properly heated.

2.2.3) Sulphur Combustion (P and I: SP-AM-1024)

From tank T-104, the sulphur is filtered again through filters T-103 A/B, and then is fed to the furnace BR-101 by the dosing pumps P-102 A/B.

The sulphur enters the top of BR-101 together with an excess of combustion air and burns falling down in the combustion chamber which is filled of well set series of refractory bricks. The sulphur place itself on the bricks surface and burns completely giving SO2.

The reaction is exothermic and the temperature of the mixture SO2/air depends from

SO2 concentration. Practically we can say that the percent concentration corresponds to

the temperature multiplied by hundred:

6 % conc. corresponds about to 600 °C 7 % conc. corresponds about to 700 °C And so on.

In the sulphonation plant we assume the furnace temperature at about 750 °C, which is optimal for material resistance and equipment capacity .That means the air we supply together with sulphur will give about 7,5 % concentration of SO2. The air quantity is

measured by the calibrated flange (FIR-162).

But for the conversion of SO2 to SO3 we have to cool the SO2/air mixture at 430 °C to

assure a good conversion yield. So, before conversion in the converter R-101, the gas passes through an exchanger/boiler E-107, where it cools up to that temperature producing 12 bar steam which is then reduced to 6 bars and sent to general steam net. The boiler E-107 is fed by soft water through the pumps P-104 A/B. The tank T-106 receives soft water from the b.l. The temperature of outlet process gas is regulated manually by a special internal by-pass of the boiler itself.

Sulphur furnace and converter preheating.

Before start-up the sulphur furnace and converter must be preheated.

Sulphur has its self ignition temperature at about 300 °C and the conversion catalyst must work at 430 -450 °C. So we must bring the furnace to a temperature well higher than 300°C and the converter to 430-450 °C.

This preheating is realized using dry air from drying air section which is first heated at about 130°C in the exchanger E-105 and then brought to 500-550°C by the electric exchanger E-106.

Sulphur furnace and converter are preheated in series/parallel venting the exhausted air through the normal process line. This operation takes 5-6 hours starting from room temperature.

After preheating, the exchangers E-105 and E –106 are excluded and stopped. Furnace and converter are now ready for start-up.

2.2.4) Conversion (P and I: SP3-AM-1025)

(See Monsanto Converter Catalyst Loading Instructions, Annex 11.3)

The mixture SO2/air from the exit of E-107 is conveyed to the converter R101.

This equipment has four conversion beds filled by V2O5 catalyst in form of pellets or

rings.

The gas mixture passes through these beds and the SO2 is converted to SO3 following

the reaction:

2 SO2 + O2 = 2 SO3

This reaction is exothermic, so the gas must be cooled at each bed outlet by means of cold and dry air (quench air from compressor delivery).

The gas enters the first bed at about 450 °C and goes out at about 614 °C. The quench air cools it at 440 °C before entering the second bed. At second bed outlet the gas temperature rises to 468°C and is again cooled to 440 °C before the third bed. At third bed outlet the gas has reached 445 °C and it is cooled again to 425°C. At the fourth bed outlet the gas has practically no temperature increment. That means the conversion is already completed after the third bed, being about 80% realized after the first bed, the last operating like a guard.

The mixture SO3/air before sulphonation reaction must cooled to 50-60 °C. This is

realized cooling the gas by two exchangers E-108/E-109 working in series and cooled by atmospheric air.

The fan BL-102 sends the cooling air in parallel to the exchangers. The hot air from the exchangers exit has about 200 –220 °C and is used for regeneration of drying alumina beds (see P and I 1021)

After the cooling exchangers a mist separator is installed (F-104). From the bottom of the exchangers and F104 some quantity of oleum is collected and periodically drained to T –103 tank.

This oleum is a good quality by -product and its quantity depends, as already explained, from the moisture content in the total system (normally 4-5 Kgs/day).

It can be recovered by the pump P-103 in a portable vessel and used where necessary or sold.

2.2.5 ) Sulphonation (P and I:: SP3-AM-1026)

The mixture SO3/air 4% passes through the special filter F-202 separating the last

traces of sulphuric acid or oleum, if any. Then it enters the organic chamber in the top of the reactor R-201.

The LAB stored in T-201, is also pumped by P-201 to the organic chamber in the top of the reactor, being its quantity measured and regulated by a mass flow meter FIC-201, by means of the inverters of the pumps.

The LAB is filtered by F-201 before entering the reactor.

In this way LAB and SO3 reacts in co-current in the reactor top giving the correspondent

sulphonic acid.

The reaction heat is taken off by the cooling water circulated through the reactor shell by the pump P-204.

The delivery of this pump is divided in two streams: 60% roughly to the upper part, 40% roughly to the lower part, being this distribution regulated manually checking the outlet

The tank T-202 , kept in light pressure by the air bomb T –210 , provides in case of emergency to feed a sufficient LAB quantity to the reactor head avoiding so the burning of LAB itself because of excess of SO3.

From the reactor bottom we collect LABS, which is first sent to the separator R-202: the liquid (LABS) falls to the bottom, while the gas flows from the top to the cyclone CY-201 for the liquid last separation. The exhausted gas flows to the depuration treatment (P and I 1027)

From R-202 the LABS reaches the aging tank R-203, where the reaction is completed .Then by the pump P-202 is sent to the storage. The level regulator LIC-201 drives the extraction pump inverter.

Before storage small amount of water is added to the LABS for breaking the anhydrides and catch the unreacted SO3, stabilizing the LABS colour. This operation is lightly

exothermic and so the LABS is cooled by the plate exchanger E-202.

2.2.6) Exaust Gas Treatment (P and I: SP3-AM-1027)

The exhaust gas coming from the top of cyclone CY- 201 contains all the not converted SO2, traces of not reacted SO3, small amount of organic and traces of H2SO4. This gas,

before being discharged to the atmosphere must be treated to eliminate the above mentioned impurities.

In this section the SO3, H2SO4 and organic are caught by the electrofilter F-301, while

SO2 is absorbed in the tower R-301 by NaOH giving sodium sulphite/sulphate solution,

which can be recovered.

From the F-301 bottom we collect a dark viscous oil (the quantity depends from sulphonation conditions and from LAB quality but is in range of 0,25-0,5 lts/h ).Its composition is a mixture of

H2SO4 / oleum 30%, LAB/LABS 60%, 10% heavy sulphonated products.

This oil is generally recovered adding it to the final product.

As far as the sulphite/sulphate solution is concern, there are two ways for managing the absorption tower R-301 with two different results: at high Ph (14) with formation of only sodium sulphite or at Ph close to neutrality (7.2-7.5) with formation of roughly 80% sulphate and 20% sulphite.

This sulphite/sulphate solution can have a variable concentration between 5 and 13% depending from the operating condition.

If the absorption is carried out at almost neutrality, it is of course preferable because, after complete oxidation, the sulphate solution could be recovered in the detergent plant.

On the other hand, to operate close to neutrality requires much more accuracy.

The exhaust gas, after this depuration treatment, is vented to the atmosphere. It may contain less than 5 ppm of SOx.

3) RAW MATERIALS, CHEMICALS AND PRODUCTS

SPECIFICATIONS

3.1) RAW MATERIALS

3.1.1) Sulphur

Characteristics of Amorphous Sulphur normally used in sulphonation.

- Humidity 0.01 % - Bitumen 0.02 % max. - Ashes 0.05 % max - Titer 99.70 % min - H2SO4 0.01 % max - H2S Absent

- Arsenic Absent (0.25 ppm. max)

- Selenium Absent (2 ppm max)

- Tellurium absent - Fluorine absent 3.1.2) Linear duodecylbenzene - Sulphonability 98 % max - Molecular weight 240-255

- Aspect Liquid, limpid

- Colour APHA 10 max

- Density at 15° C 0.850 – 0.870 kg/lt.

- Water 0.05 % max.

- Iron 1 ppm max.

- Bromine number 0.05 max

- Refraction index 1.485-1.487

- Aniline point 11° - 14°

- Pour-point -70° max.

- Distillation curve 285° - 305° C

- Doctor test negative

Composition (by weight)

- Below C10 0.5 % max - C10 15 % max. - C10+C11 38 – 60 % - C12 25 – 40 % - C13 30 % max - C14 5 % max - Above C14 0.5 % max - 2 Phenyl Isomers 25 ÷ 35 % - Visocsity 9 Cps at 38° C - Flash Point 120° C 3.1.3) Branched duodecylbenzene

- Aspect Limpid, colourless, slightly fluorescent.

- Water Traces - Density at 20° C 0.870 – 0.875 kg/lt. - Molecular weight (cryoscopic benzenic) 233 - 248 - Distillation curve

(method ASTM D158) IP123

- Dry point 300° C

- 95% 297° C

- Boiling point 275° C

- Bromine number 0.01 max

- Viscosity 8 – 9 Cps at 50° C

- Aniline point 11 – 14° C

- Colour 20 Hazen (30 Saybolt)

- Refractory index 1.4855 – 1.4865 25° C

3.1.4) Caustic soda 50%

- Appearance Clear colourless liquid

- Odour None - Specific gravity (20° C) 1.49 – 1.51 - Sodium hydroxide 46.5 – 47.5 % - Sodium carbonate 0.025 % - Sodium chloride 40 ppm - Sodium sulphate 8.0 ppm - Iron oxide as Fe203 4.0 ppm - Calcium oxide 10 ppm - Magnesium oxide 1 ppm - Silica as Si02 8.0 ppm

3.2 CHEMICALS

First bed : litres 800 XLP-120 Second bed : litres 900 XLP-110 Third bed : litres 1000 XLP-110 Fourth bed : litres 1000 XLP-110 Total : litres 3700

3.2.2) Activated alumina

Type: A.A.2-5 Grade D

Aspect: high purity alumina beads Diameter: 2 to 5 mm.

Physical properties:

-smaller than 2 mm. 2% w. max. -larger than 5 mm. 2% w. max. -loss on ignition (1000°-300°C) 7% w. max.

-tapped bulk density 0,78 min.- 0,85 max. Kg/lt -surface area 300 min. m2_/gr

-particle crushing strength 14 min. daN -attrition resistance (AIF) 99% w.

-static adsorption (at 60%RH) 19 min-24 max. % w. Chemical analysis:

-Al2O3 93,8% w.

-Na2O 5.000 max. w.ppm

3.2.3) Ethylene Glycol ECOGEL: E

SPECIFICATIONS Specific Weight at 15/15°c 1.125-1.130

pH (50% water solution in vol.) 9.0-10.0 Apparent content of water 3.5 max

Alkalinity reserve 15 min.

ashes 1.5 max

Freezing point (50% water solution vol.) -38° C max

Boiling point 170° C min

Boiling point (50% water solution vol.) 108° C min Effects on the piping surfaces none

Odour light

foamy absent

Water solubility complete

Resistance to hard waters clear

3.2.4) Liquid sulphur filter aid: PERLITE FILTER AID (EUROPERL® 700)

TYPICAL PHYSICAL PROPERTIES

Physical form Dry powder

colour white

Permeability (darcy) 2.6

Cake Density (g/l) 205

Moisture (% as shipped) 1%

TYPICAL CHEMICAL PROPERTIES (% by weight unless otherwise stated) SiO2 72 Al2O3 14 Fe2O3 0.7 TiO2 0.1 CaO 0.3 MgO 0.1 Na2O 4 K2O 8.8

3.3.

PRODUCTS

Linear alkylbenzene sulphonic acid

-active matter concentration 97% w. min. -free oil 1,5%w.max. -free H2SO4 1,5%w.max.

-Klett colour 30-40 max. (5% A.M. water solution, 40 mm. CELL, n. 42 filter)

Branched alkylbenzene sulphonic acid

-active matter concentration 96,5 %w.min. -free oil 1,8%w.min. -free H2SO4 1,5%w.max.

Klett colour 50-60

4) PLANT START–UP OPERATIONS

INTRODUCTION

These operations must be considered normal start-up operations. That means the plant commissioning and the first start-up have been already performed: all the equipment has been tested and they worked properly, the electrical and process panel and all the instrumentation have been calibrated for working in the requested range and they controlled and regulated the plant run satisfactory.

All the utilities: steam at 10 and 6 bars, cooling water, softened water, compressed air and electric power are ready and available.

The raw materials LAB and solid sulphur are available to be fed to the plant. The plant is ready for normal start-up.

Plant conditions:

- Electrical power is regularly fed to the plant - All the machinery is stopped.

- The sulphur melter and the other sulphur equipment (T-105., T-104, F-105) are empty.

- The sulphur furnace is at room temperature. - The converter is at room temperature.

4.1) PRELIMINARY OPERATIONS

- Interlock exclusion - Utilities availability check

- Sulphur melting and filtration start-up - Exhausted gas section start-up - Chilling station start-up

- Air drying section start-up

- Furnace and converter pre-heating start-up

4.1.1) Interlock Exclusion

The plant interlock must be excluded in this start-up phase. That means that all the

permissions or interlocks which before linked some machineries among them or with some instrumentations have been temporally cancelled. Thus, all the machinery can be independently started.

Consequently this start-up phase must be controlled by the operator with much attention under the supervision of the plant supervisor.

4.1.2) Utilities Availability Check

1) Instrumentation compressed air:

Check the compressor is running and the pressure on the air line to the plant is in the range of 8 bars.

Check that all the instrumentation is regularly fed by air.

2) Cooling water

Be sure that the main raw water tank (main storage) is full of water.

Check the raw water make-up line is regularly in pressure feeding the cooling tower and the softening station.

Check the top fan of the tower is working properly.

Check the pressure on the inlet plant line is in the range of 3 bars.

Check that the following equipment is regularly fed by cooling water and the relevant inlet outlet valves are opened: E-101, E-103, R-201, and R-203.

Check the cooling water return line is working properly discharging to the cooling tower.

3) Steam

The main boiler must be running.

Be sure the softening station is regularly working and the alkalinised water is fed to the main boiler and to T-106 when necessary.

Check the pressure of the main boiler outlet line is in the range of 12 bars and the relevant reductions to 10 bars and 6 bars are operating.

The following equipment must be fed by steam: E-104 (10 bars), E-105, H-101, T-105, F-105, T-104, T-103 A/B, all the jacketed sulphur lines, R203, E-301, and T-301. Check the inlet and outlet (condensate) lines are properly prearranged and the steam is flowing regularly.

4) Steam condensate

All the steam condensates are conveyed to the softened water tank where they are integrated by the softening station, if necessary. After alkalinization condensates/softened water are fed to main boiler and to T-106).

Check all the condensate return lines are working regularly.

5) Softening station

Check that the softened water tank is full and all the system is running regularly. Check the level of the alkaline solution tank.

4.1.3) Sulphur Melting And Filtration Start-Up

Before starting any operation in this section, we must be sure that all the equipment, lines and machinery are hot enough to assure a temperature higher than sulphur melting point (115 °C).

Normally the right temperature adopted is 150°, which is easily reached with 6 bars steam fed to the jackets and coils.

It is practical procedure to check the temperature of lines and equipment putting a small piece of sulphur on them: if the temperature is right the sulphur will melt in a few seconds.

Check all the coils of the melter: all of them must be operating Check the heating jacket of T-105

Check the heating jacket of T-104 tank Check the heating of the filter F-105

Check the heating of all the jacketed lines and valves, including also those which at the beginning we have not planned to use.

Check the heating of filters F-103 A/B

The vertical sulphur pumps P-105 and P-106 are jacketed: do not forget to check the heating.

Check the heating of the dosing pumps P-102 A/B and be sure that the cooling water to the transmission shaft) has been opened.

ONLY WHEN WE ARE SURE THAT ALL THE SECTION HAS BEEN CHECKED AND IT IS HOT IN ALL THE POINTS, WE CAN PROCEED TO CHARGE, MELT THE SULPHUR AND START THE STIRRERS AND PUMPS.

Charge sulphur in the melter H101 and check periodically the level.

When the level reaches about 20% start the stirrer (AG –101) and check it is properly working (amperage).

Following the sulphur quality, we have to decide whether is necessary to filter it and, if yes, whether we have to perform the filtration with filter aid or without it. A sample melted in laboratory can be useful to decide.

If is not necessary to filter it, the filter F-105 has to be by-passed, sending the melted sulphur directly to the storage tank T-104.

If it has to be filtered without filter aid ,the tank T-105 has not to be used .The liquid sulphur has to be pumped directly through the filter F-105 and then to the T-104.

In case of filtration with filter aid proceed as follows:

-after the level reached 70% about in H-101, start the pump P-105 ( check it is properly working) and transfer sulphur to the T-105 tank until the level is at about 70 % .Stop P-105.

Start AG-102 and check the amperage.

Charge the filter aid to the T-105 tank: n.1 Kg of filter aid / n. 1 m2 _{of filtering surface.}

Total about 3 kg of filter aid.

Check that the valves are prearranged to recycle sulphur with filter aid through the filter F-105 coming back to T-105.

Start pump P-106, checking amperage. All the other valves should be closed. Thus, the filter aid will be set on the filter nets forming a panel, which will help the next filtration. From this moment on the pressure at F-105 inlet should be never stopped; otherwise the filter aid will come off from the filter nets and will fall down.

Leave in recycle mode for about 15-20 min. Then, close the valve at filter outlet to the T-105. Start P-105, open its delivery valve at filter inlet and close the valve on the P-106 delivery. Open the valve at the filter outlet discharging to the T-104 tank. P-106 and AG-102 can be stopped.

The sulphur filtration is now started and we are filling the storage (T-104).

Check level in H-101 and in T-104. When level in T-104 is 80 %, switch the filter outlet to T-104 to recycle back to H-101. When level in H-101 is at 80 %, close steam to the melting section.

Check the valves on the delivery of the pumps P-102 A/B to the furnace BR-101 are closed.

Regulate the pump piston stroke length at the minimum value and start the pump.

Check pump amperage and increase gradually the piston stroke length to the plan start-up value.

4.1.4) Exhausted Gas Section Start-Up

1) Electrofilter (ESP) F-301 preparation

Start BL-301

Regulate the steam to E-301 exchanger: TI-301 should be at about 80 °C

Check the total flow is distributed about equally to the four niches by the position of the relevant valves.

Check the bottom discharge valve of F-301 is closed Check the heating on the bottom is working.

Switch on the current to the ESP

2) Scrubber R-301 preparation

We suppose that the scrubber was operating at pH 7,2-7,5 and so it is now full of a sulphite/sulphate solution at about 10% concentration.

Check that the level in the 30% caustic soda tank T-301 is at maximum value. Check the level in R-301. It should be full.

Check the valve on the P-301 delivery to Na2SO3/Na2SO4 storage is closed.

Prepare the line to recycle the sulphite/sulphate solution from R-301 bottom to the top column.

Start the pump P-301 and regulate the flow at about 20-25 m3_/h.

Check that the pH meter pHIT-301 is in automatic mode and set pH at 8 value. Start the pump P-302.

4.1.5) Chilling Station Start-Up

Check level in T-101.

Choose one pump P-101, open valves on the suction and delivery. Check that the valves of the other pump are closed.

Check the inlet/outlet valves to E-102 are open.

Start pump T-101 and check pressure on the delivery and level in T-101.

Start chilling unit following the relevant instructions setting the outlet temperature of glycol solution at about –2°C.

Wait until the system has reached a steady condition.

4.1.6) Air Drying Section Start-Up

The start-up of this section requires the air compressor CO-101 start-up. The air fed by the compressor has to pass through all the plant and has to be vented to the atmosphere after the scrubber R-301. Passing through the converter this air will drag SO2 and SO3 contained in the converter catalyst, even if we are in pre-heating phase. That means the sulphur burning section, the converter, the sulphonator and the exhausted gas section must be ready to accept this gas.

4.1.6.1) Drying Section

The PLC should show available the drier T-102 just ready to work. Check that the on-off valves controlled by PLC are in the right position.

Steam to E-104 should be already to operate.

Cooling water to E-103 should be already to operate. Steam to E-101 should be already to operate.

Check that the bottom discharge of E-102 is open. Check that the bottom discharge of F-102 is closed. Start fan BL-101.

4.1.6.2) Sulphur Burning Section

Check level in the T-106. It should be at least more than 50%.

Choose one pump P-104 and prepare the line to feed water to the boiler E-107. Check that all the valves on the other pump are closed.

Prepare the feeding line on the pump delivery. Start the pump and fill the boiler.

Check that level regulation valve LIC-161 is in automatic mode. Prepare the line on the steam discharge line.

The pressure regulation valve on the boiler E-107 should be already regulated at 12 bars.

4.1.6.3) Converter Section

Close the quench air to the first, second and third beds. Close dilution air to F-104 demister.

Close the pre-heating air valve from E-106 outlet.

4.1.6.4) Sulphonator Section

Check level in T-201 .It should be at maximum value.

Check the emergency tank T-202 is full of LAB, its bottom valve is closed and the pressure is about 0,5 bar (PI-202).

Check the inlet water make-up to the cooling circuit of the reactor is open. Check the valves on the suction and delivery of the pump P-204 are open.

Start pump P-204 and check pressure and amperage. Check by the vent on the top outlet water line there is no air inside the reactor.

Set TIRCAHL –201 in automatic mode and 2°C more than P-204 delivery temperature (TI-202).

Close valve from R-202 to LG-203 and LG-204. Open valve from R-202 to T-204

Check the discharge valve from CY-201 to LG-203 is open.

Choose one P-201 pump and prepare the line for feeding LAB to the reactor head. Select one filter F-201.

Check the valve on the line from T-204 to the P-201 suctions is closed. Check the recycling line from P-201 to T-201 is closed.

Start pump P-201 feeding the reactor at 50% plant capacity (1140 Kg/h). The LAB will be collected in the T-204 tank.

When in the T-204 we have collected about 100 lts. (after about 4-5min.), open the

valve between 204 and P-201 suction and close immediately the valve on the T-201 bottom.

Now LAB is recycling from T-204 by P-201 through the reactor R-201.

Open the valve HS-201 on the gas line in the top of reactor R-201. Check the level in T-203 (hydrolysis water).

4.1.6.5 ) Exhausted gas section

As soon as the pre-heating gas starts passing through the ESP, adjust the voltage to a below value that at which the electrical discharges start.

The scrubber R-301 is ready to absorb the traces of SO2 escaped from the converter

during its pre-heating phase.

4.1.7) Furnace And Converter Pre-Heating Start-Up

Check the air valve before FR-162 to the furnace BR-101 is closed. Check the air valve on the E-106 by-pass is closed.

Steam to E-105 should be already open. Open the air valve at inlet of E-105.

Check the valve from E-106 outlet to converter is closed.

At this point the plant is ready to accept the hot gas for pre-heating furnace and converter.

Open completely in manual mode PIRCAH-101. Start compressor CO-101. Check amperage.

Close slowly the PIRCAH-101 control valve until FIRAL-161 shows about 3.000 Kg/h (about 1.700m3/h)

The pressure of PIRCAH-101 shows the value correspondent to the system pressure drop. Put it in automatic mode.

Check E-101 outlet temperature (about 130 °C). Check E-102 outlet temperature (about 3°C).

Check that E-102 is discharging water condensate from the bottom. Check the moisture after T-102 is at least –50°C.

Check temperature after T-102 is around 30°C.

Check temperature after E-105. It should be 130° or more.

Check that the whole drying regeneration system is properly working.

Start gradually to increase the air temperature at E-106 outlet operating by LCP 161 (TIRAH-163) of its electrical exchanger. Set the regulation at final stage around 500-550°C.

Now the furnace starts to be heated and, in series, through the internal by-pass of the boiler E-107, also the converter begins to heat up.

The pressure and the temperature in the boiler E-107 will gradually increase .When it will reach 12 barg and about 191°C, the pressure regulation valve will begin to discharge steam to the 6 bar net.

Because in this phase the boiler E-107 lowers the efficiency of the converter heating, after the furnace has reached about 400 °C, open the by-pass valve of BR-101/E-107 directly to the converter.

This pre-heating phase should take (starting from room temperature) about 6 hours. The average hourly temperature increment should be roughly 80-90°C /h, bringing the furnace internal temperature and the first converter bed at about 450°C.

So the air pushed by the compressor CO-101 and dried through the drying system, is heated in E-105/106, passes through the sulphur furnace and conversion section where some traces of SO2/SO3 can be drawn. Then it enters the sulphonation reactor where

meets fresh LAB, which is recycling through the reactor head; finally reaches the exhausted gas section where it is depurated from traces, if any, of SO2/SO3.

When the furnace and the converter beds have reached about 450°C the preheating can be considered finished and the plant can be started.

PLANT CONDITIONS AFTER SULPHUR FURNACE AND CONVERTER PREHEATING

Compressor CO-101 is running. The pressure of PIRCAH-101 will sign the value correspondent to the system pressure drop and the FIRAL-161 will show 3.000 Kg/h (about 1.700 m3_/h).

Chiller CH-101 is running, cooling the air at about 2-3°C. Air drying section is running.

Sulphur melting section T-104 is full of liquid sulphur; P-105 is running recycling back through the filter F-105 to H-101, sulphur melt is stopped, P-102 is running and recycling back to T-104.

Sulphur furnace is hot and E-107 is working. Preheating phase is still operating. Converter is hot and BL-102 is running. Preheating phase is still operating.

Sulphonation reactor LAB is recycled from T-204 to reactor head at 50% of plant capacity, the cooling is working.

4.2 ) PLANT START-UP

We decide to start at 50% plant capacity.

Start-up flow rate 1500 Kg/h of LABS. 4,5% by volume SO3 in the reaction gas.

Because the sulphonation reaction is normally managed and controlled by the analysis of sulphonic acid at reactor outlet (acidity), the start-up parameters are fixed in not rigorous way being they in second time adjusted following the analysis results.

We assume:

Air temperature = 30°C Air pressure = 0,5 Kg/cm2

Air density 0° and 760mm.Hg = 1,29 kg/m3

Temperature correction factor = (273+30) / 273 = 1,11 Pressure correction factor = 1,0/1,5 = 0,67

Total correction factor = 1,11 X 0,67 = 0,74 From material balance we get:

Plant flow rate 50% of max. capacity = 1500 Kg/h of LABS Sulphur = 152 Kg/h

LAB = 1140 Kg/h

Total air = 3223 Kg/h /1,29 x 0,74 = 1849 m3_/h

Combustion air = 1860 Kg/h/1,29 x 0,74 = 1067 m3_/h

Air regulation

The air flow rate regulation is realized operating on the compressor vent valve installed in the compressor delivery. Operating with the PIRCAH-101, the valve PCV-101 drives automatically part of the air compressed by CO-101 to the furnace and converter passing through the calibrated flange FIRAL-161 where the total air is so measured. The air pressure signed by PIRCAH-101 is that corresponding to the pressure drop of the down stream system for that flow rate.

Put in manual mode PIRCAH-101 and, operating on the pressure set, decrease the total air flow rate at about 1067 mc/h (FIRAL-161)

Sulphur regulation

The liquid sulphur flow rate is regulated by the piston stroke length of the pump P-102. Regulate the piston stroke length of the P-102 at 150 Kg/h by calibration curve.

LAB regulation

The LAB flow rate is controlled by the mass flow meter FIRCAL-201, which actuates the inverter of pump P-201.

Regulate FIRCAL-201 at 1140 Kg/h

IMPORTANT RULES FOR THE SULPHONATION REACTION:

1) THE QUANTITY OF SO3 NECESSARY FOR SULPHONATING A CERTAIN

AMOUNT OF LAB IS CONTROLLED BY THE ANALYSIS OF ACIDITY CHECKED PERIODICALLY AT THE REACTOR OUTLET.

THE ACIDITY IS THE QUANTITY OF SULPHONIC ACID + H2SO4 CONTAINED IN THE PRODUCT AT THE REACTOR OUTLET.

FOR PRACTICAL REASONS THE ACIDITY IS EXPRESSED AS THE MILLIGRAMS OF KOH NECESSARY FOR NEUTRALIZING THE ACIDITY CONTAINED IN 1 GR. OF PRODUCT.

FOR 98% SULPHONIC ACID AND 1% H2SO4, WHICH CAN BE RIGHT

VALUES OF SULPHONATION, THE FINAL ACIDITY IS IN THE RANGE OF 180.

2) WHEN THE RIGHT RATIO SO3/ LAB HAS BEEN REACHED, SMALL

ADJUSTMENTS CAN BE DONE VARYING THE LAB FLOW RATE. NEVER MOVE THE SULPHUR FLOW RATE.

WHEN THE PLANT OUTPUT HAS TO BE DECREASED, FIRST DECREASE SULPHUR , THEN LAB AND FINALLY THE AIR FLOW RATE.

ABSOLUTELY AVOID THE SO3 EXCESS WHICH BURNS LAB GIVING BLACK

COLOUR AND CARBON MATTERS WHICH OBLIGE TO STOP THE PLANT AND TO CLEAN THE REACTOR HEAD.

4.2.1) Sulphur furnace

Stop preheating: close steam to E-105 and cut the power to E-106 Close the hot air valve to the converter (by-pass of BR-101/E-107) Open the valve on air line to BR-101 before FIR-162.

Close the air inlet valve to E-105. Regulate FIR-162 at about 1067 mc/h.

Open the valve on the delivery line of P-102 to the furnace BR-101 and then close the valve on the recycling line to T-104.

Check through the sight glass SG-161 when liquid sulphur is falling down on the internal bricks and if it ignites immediately.

The furnace temperature will increases rapidly: check TIRAH-160; when it approaches to 750 °C, regulate FIR-162 to maintain it. Remember that the temperature increases when the SO2 concentration increases and vice versa. If necessary increase the air

pressure operating on PIRCAH-101.

Regulate the gas outlet E-107 temperature at 450 °C, operating with the by-pass valve of the boiler: closing the by-pass the temperature should decrease; opening it the temperature should increase.

4.2.2) Converter section

As soon as the SO2 concentration increases in the gas stream, the first bed outlet

temperature (TIRAH-182) increases, up to about 615 °C.

Start to open cooling air to the first bed outlet bringing back the temperature to 440 °C. For this operation the needed total air (FIRAL-161) will increase. Thus, increase the total air (FIRAL-161) operating on PIRCAH-101 to satisfy the quantity of needed air, keeping constant FR-162.

Also in the second bed the temperature will increase up to about 468 °C (TIR-184). Start to open cooling air to the second bed outlet bringing back the temperature to 440°C. Increase the total air flow rate as before.

In the third bed the temperature will arise up to about 445°C (TIR-186), but, opening the cooling air, it will be brought back to 440°C. Increase the total air flow rate as before. In the fourth bed, if the oxidation of SO2 to SO3 has been managed properly, the

temperature at the outlet will be around 425°C.

Check at this point the flow rate of the total air signed by FIRAL-161: It should be equal or less than value foreseen by the material balance. If it is less, add the remaining air through the line between E-109 and F-104. So open the relevant air valve to the F-104 and increase the total air flow rate up to the foreseen value actuating the PIRCAH-101. Check flow rates and temperatures adjusting them, if necessary.

As soon as the temperature at converter outlet starts to increase, open the valve on the BL-102 delivery cooling E-108 and E-109.

At E-108 outlet the process gas should maintained at about 250°C, while at the outlet of E-109 the gas temperature should be around 70 °C

At this point the total air necessary for diluting the SO3 at 4,5% concentration is

distributed among:

1) The furnace BR-101, where its quantity is regulated by the furnace temperature (750°C).

2) The three quench airs to the converter, where also is regulated by the temperature at second, third and fourth bed inlets.

4.2.3) Sulphonation Reactor

As soon as sulphur starts to burn in the furnace, it generates SO2 and then SO3 through

the converter.

The converter temperatures start to increase in the four beds.

Starting from this time, we maintain LAB in recycle for some minutes, checking the acidity continuously.

When the acidity is around 50/60, open the bottom valve of T-201 and close the T-204 bottom valve.

Now we are feeding fresh LAB to the reactor head, always collecting the reactor bottom in the T-204 tank.

Check continuously the acidity.

After 20’ the sulphonation reaction should have reached 70-80 and the reactor outlet can be switched to LG-203 and R-203.

In this way we will have collected in T-204 about 500 lts. of a mixture LAB/LABS about 50/50 which will be recovered little by little later.

Check continuously the acidity.

Prepare the suction and delivery line of the P-202 pump for sending LABS to the storage.

Open water to R-203 jacket and then also steam just to heat the jacket for maintaining the LABS at about 50°C.

Close the outlet valves of R-203 leaving LABS coming out from the higher outlet. Start R-203 stirrer.

When LABS overflows from R-203, start P-202 and regulate the level by LIC-201. Check always acidity.

The final acidity should be around 170/180. To adjust this value operates only with small variations of the LAB flow rate followed by acidity checks. Never touch the sulphur flow rate.

Open suction and delivery valves of pump P-203, start the pump and regulate FI-201 at about 7 lts/h (0,05% ).

Open cooling water to E-202. TI-207 should be around 30/35°C.

4.2.4) Exhaust Gas Treatment

4.2.4.1 Electrostatic precipitator

The operation of the electrofilter is very simple. The gas is passing now through the filter.

Adjust the voltage to a value a little below that at which the electrical discharges start. During the operation if there are frequent discharges or even a continuous arc, the voltage drops and hence the filtering efficiency decreases: the voltage must be reduced by hand until the discharges cease.

On the other hand, an attempt should be made from time to time to increase voltage in order to restore filtering efficiency, which may be reduced if the filter is dirty.

During the operation the ESP is automatically cut out, ceasing to operate, and gives an acoustic alarm if:

-the transformer oil temperature exceeds the permissible level

-there are frequent high intensity discharges (sign of excessively high voltage). -voltage at filter is too low (sign of short-circuit in the filter).

-the filter current is too high.

4.2.4.2 Scrubber

SO2 contained in the exhausted gas is now arriving to the scrubber.

From material balance we get that at 50% capacity the plant produces 17,7 x 0,5 = 8,85 Kg/h of 100% sulphite which at 10% concentration gives 88,5 Kg/h (about 80 lt.) of solution which we must be sent to the storage. So regulate manually the FI-302 at about this value, transferring this hourly amount to the storage.

Set back the ph to the previous value (7,2-7,5 ): P-302 will stop and it will start again when the ph will reach this value.

4.2.5 ) Interlock System

The interlock, which was excluded at the beginning of the start-up phase, must now be again included.

4.3 ) CAPACITY INCREASE

Now the plant start up can be considered finished but we have to reach the maximum capacity, which is one of the main targets of the plant.

We suggest remaining at 50% capacity for 2-3 hours, and then proceed to increase gradually the capacity.

The major part of process parameters will not change much, especially temperatures and pressures; while the flow rates will change generally proportionally.

We report here the range of the main process parameters you should meet in the plant management writing in red colour those which change substantially due to capacity change:

AIR COMPRESSION AND DRYING P AND I 1021

TI-105 CO-101 delivery 130-150 °C

PI-102 after E-101 0.5-1,0 bar

TI-103 before E-102 20-50 °C

PI-103 after E-102 0.5-1,0 bar

TI-104 after E-102 2,0-5,0 °C

TIRAHL-101 after F-102 2,0-5,0 °C MIRAHL-101 after T-102 -30/-80 °C PIRCAH-101 after T-102 0,3-0,9 bar

PI-104 after T-102 0,3-0,9 bar

TIR-104 after T-102 20-50 °C

TIR-102 BL-101 suction 20-230 °C TIR-103 after E-103/104 20-230 °C TI-106 BL-101 suction 20-250 °C

CHILLING UNIT P AND I 1022

TIR-121 after CB-101 -2 / +0,5 °C TIR-122 before T-101 +5 / +10 °C

TI-121 T-101 tank +5 / +10°C

SULPHUR MELTING AND FILTRATION P AND I 1023

TIAL-141 sulphur melter H-101 145-155 °C (?)

TI – 142 T-104 tank 145-155 °C

SULPHUR BURNING P AND I 1024

FIRAL-161 FIR-162

total air from T-102 combustion air

50-100% capacity 50-100% capacity

1849-3698 m3/h 1067-2134 m3/h Piston stroke length P-102 sulphur pump 50-100% capacity 152-304 Kg/h

FIRAL-161 air in preheating phase 3000 m3/h

TI-161 after E-105 in preheating phase 130-150 °C TIRAH-163 after E-106 in preheating phase 500-600 °C

TR-162 BR-101 top 650-750 °C

TIRAH-160 BR-101 outlet 700-800 °C

TIRAH-161 BR-101 outlet 700-800 °C

TR-164 E-107 outlet 440-460 °C

PI-160 steam from E-107 11-12 bar

PI-163 steam from E-107 11-12 bar

PI-164 steam from E-107 after reduction 5,5-6,5 bar

PI-161/162 P-104 delivery 12-15 bar

SO2/SO3 CONVERSION - P AND I 1025

PI-161 before converter R-101 0.5-0,4 bar

TIR-181 first bed inlet 445-455 °C (Monsanto 450°C)

TIRAH-162 first bed outlet 600-620 °C (Monsanto 614°C) TIR-183 second bed inlet 435-445 °C (Monsanto 440°C) TIR-184 second bed outlet 460-470 °C (Monsanto 468°C)

TIR-185 third bed inlet 435-445 °C (Monsanto 440°C)

TIR-186 third bed outlet 440-450 °C (Monsanto 444°C) TIR-187 fourth bed inlet 420-430°C (Monsanto 425°C) TIR-188 fourth bed outlet 420-430°C (Monsanto 426°C) PI-182 converter R-101 outlet 0,45-0,35 bar

TI-182 process after E-108 200-250°C

TI-184 cooling air after E-109 120-170°C

TI-183 air to regeneration 200-220°C

PI-183 after F-104 0,4-0,3 bar

SULPHONATION REACTION – P and I 1026

TI-201 before F-202 55-65 °C

PI-201 before F-202 0,4-0,3 bar

PI-202 T-202 top 0,5 bar

PI-210 after T-210 0,5 bar

TIRAHL-202 process gas reactor head 55-65°C

PI-203 process gas reactor head 0,35-0,25 bar

TI-210 R-201 cooling water upper outlet 29-33°C TI-211 R-201 cooling water lower outlet 29-30°C TIRCAHL-201 R-201 cooling water outlet 29-31°C

PI-206 P-204 delivery 3-6 bar

TI-202 P-204 delivery 28-30°C

TI-209 T-201 tank 20-40°C

PI-204 /205 P-201A/B delivery 1-2 bar

FIRCAL-201 LAB to reactor top (50-100 % capacity) 1140-2280 K/h

TI-205 R-201 bottom 30-50 °C

TI-204 R-203 aging 40-50°C

PI-209 Vent to exhaust gas treatment 0.2-0.15 bar

TI-208 Vent to exhaust gas treatment 40-50 °C

PI-207 P-202 delivery 3-10 bar

TI-206 After MX-201 50-55°C

FI-201 P-203 delivery (50-100% capacity) 7-15 lt./h

PI-206 P-203 delivery 3-5 bar

EXHAUST GAS TREATMENT – P AND I 1027

Adjust the voltage F-301 as per previous instructions

TI-301 after E-301 80-90 °C PI-301 after F-301 0.1- 0,05 bar TI-302 after F-301 40-50 °C FI-301 P-301 recycle 20-30 m3/h FI-302 P-301 delivery 80-160 lt./h PhICAL after MX-301 7,2-7,5 TI-303 R-301 40-50°C

Capacity increase from 50% to 100%

Proceed by steps, increasing the capacity by 10% each step. The total capacity increase time should take about two-three hours. 50% total air 1849 m3_/h combustion air 1067 m3/h sulphur 152 Kg/h LAB 1140 Kg/h 60% total air 2219 m3_/h combustion air 1280 m3_/h sulphur 182 Kg/h LAB 1368 Kg/h

70% total air 2588 m3_/h combustion air 1494 m3_/h sulphur 213 Kg/h LAB 1596 Kg/h 80% total air 2958 m3_/h combustion air 1707 m3_/h sulphur 243 Kg/h LAB 1824 Kg/h 90% total air 3328 m3/h combustion air 1921 m3_/h sulphur 273 Kg/h LAB 2052 Kg/h 100% total air 3698 m3_/h combustion air 2134 m3_/h sulphur 304 Kg/h LAB 2280 Kg/h

So now proceeding as per priority just before reported, we start to increase the plant output as follows:

From 50% capacity to 60% capacity:

1) Increase the total air flow rate from 1849 to 2219 m3_{/h, operating with PIRCAH 101.} 2) Increase the LAB flow rate from 1140 to 1368 Kg/h operating with FIRCAL 201. 3) Increase the combustion air from 1067 to 1280 m3_{/h operating with the manual valve}

4) Increase sulphur feed to the furnace from 152 to 182 Kg/h operating with the piston

stroke length of the P-102.

5) Maintain the outlet gas temperature from furnace at 750°C. If necessary readjust the

combustion flow rate.

6) Check the acidity is in the range of 170-180. If necessary readjust the LAB flow rate. 7) Increase proportionally the hydrolysis water by pump P-203 (FI-201).

8) Increase proportionally FI-302 on the pump P-301 delivery). 9) If necessary, increase the voltage of the ESP.

10)Remain at this capacity for about 20 minutes.

11)The following others key parameters will change and must be brought back to the

previous value:

- Air temperature to driers TIRAHL-101 (increase the cooling effect of the chiller).

- SO2/air temperature to converter TR-164 (regulate the internal by-pass of the

E-107).

- All the converter beds temperature (regulate the quench air to the beds). - Outlet process temperatures of E-109(regulate the cooling air of the fan BL-102).

- Aging tank temperature (TI-204) (increase steam in the jacket water bath of R-203, if necessary).

- LABS temperature to storage (TI-207) (increase cooling water to E-202).

After about 20 minutes proceed to the next step from 60% to 70% operating in the same way, assuming that the quantity of air, LAB and sulphur are just as shown before.

The same procedure up to 100% capacity.

If necessary, increase stand-by among each step.

When 100% capacity has been reached, verify that all the plant parameters listed before in the PLANT START-UP chapter are included in the indicated range. If some of them are out of their range, report it to the plant manager.

After some experience of plant start-up, we believe it could be convenient to increase the plant capacity from 50% directly to 100% or to the final chosen capacity.

5) NORMAL RUN AND CONTROLS

As soon as the plant has reached the 100% capacity, or, in any case, has reached the capacity judged final in that moment, the plant enter normal run.

In this phase all the plant parameters should be stable and regular. In details and for the key points:

P and I 1021 air compression and drying

- compressor delivery pressure must be constant at value maximum reached which corresponds to the pressure drop of the system at that capacity. It should be 0,9 bar max.

PIRCAH-101 should be in automatic mode.

- air temperature before driers (TIRAH-101) must be stable at 2-3 °C - moisture meter (MIRAHL-101) should sign –40°C min.

- drying system must work automatically. Every 8 hours the driers should invert their function:

Operation and regeneration.

- E-102 bottoms must discharge regularly the condensate. - E-104 has to have the steam line close.

During the regeneration heating phase the hot air coming from E-108/9 should be sucked regularly by the fun BL-101 .If necessary close a little the valve on the vent line.

P and I 1022 refrigerating group

The glycol temperature (TIR-121) should be stable. P and I 1023 sulphur melting and filtration

- sulphur melting should start again. So open steam to the melting coils.

Check level in H-101 and switch the F-105 outlet from H-101 recycle to T-104 - Check the level in T-104

P and I 1024 sulphur burning

- FIRAL-161 and FIR-162 should be stable and constant.

- By SG-161 and SG-162 check sulphur is flowing regularly and is burning completely

in the upper chamber.

- TIRAH 160/161 must be stable and constant.

- LICAHL-161 must be stable and constant at prefixed value. - PIRCAH-160 must be stable and constant.

P and I 1025 SO2/SO3 conversion

- Converter beds temperatures: after a first adjustment time these temperatures must

be straight and parallel lines. -TI-185 should be around 70 °C P and I 1026 reaction and aging

- Acidity must be checked at the beginning every hour for the first 8-10 hours after

start-up. Then, if the key parameters of the plant are constant and regular, it can be checked every two hours.

-FIRCAL-201 should be stable.

-TIRCAH-201 should have about 2°C more than TI-202.

-TI-210 should not be higher than TI-201. If necessary, operate with the relevant manual valves on the pump delivery.

-Level LIC-201 must be absolutely constant.

In this phase should be necessary to proceed to recover the partially sulphonated LAB collected in T-204, because the level in this tank should be kept enough low to receive, in case of emergency, the content of the tank T-202.

On the other hand, the T-204 tank should not be completely empty, because in case of emergency it could be useful to have available some LAB to be promptly recycled.

100 lt. always in the tank is advisable.

P and I 1027 spent gas cleaning

-F-301: be sure that the voltage is at maximum value before getting arc discharges. -Open the bottom valve: leave it opened only if gas is not going out.

-pHCAL-301 should be constant.

-FI-301 and FI-302 should be constant.

-Check that LCV-301 is maintaining constant the level in R-301

-Check that an almost not visible plume is going out from the R-301 stack.

THE OPERATOR MUST PERIODICALLY DO THE FOLLOWING CHECKS AND WRITE THE RESULTS WITH CARE IN THE RELEVANT CONTROL CHART.

Although today the chemical plants are rich of automatic controls, alarms and interlocks which of course assure a safe plant running and a good operator safety, we think that in no case the operators should disregard the compilation of the daily control chart.

This service, besides the reading of many local indications not reported to the panel board, obliges the operator to go on site and consequently to inspect the equipment

pointing out many plant signals as not normal noises, not usual vibrations, leakages of liquids and gases and so on, which would not be noted from panel board.

For these reasons we recommend the daily chart compilation, following the hourly timing here shown:

AIR COMPRESSION AND DRYING P AND I 1021

ITEM WHERE EXPECTED VALUES WHEN

TI-105 CO-101 delivery 130-150 °C every two hours PI-102 after E-101 0.5-1,0 bar “ “ “

TI-103 before E-102 20-50 °C “ “ “

PI-103 after E-102 0.5-1,0 bar “ “ “

TI-104 after E-102 2,0-5,0 °C “ “ “

TIRAHL-101 after F-102 2,0-5,0 °C every one hours MIRAHL-101 after T-102 -30/-80 °C “ “ “ PIRCAH-101 after T-102 0,3-0,9 bar “ “ “

PI-104 after T-102 0,3-0,9 bar every two hours

TIR-104 after T-102 20-50 °C “ “ “

TIR-102 BL-101 suction 20-230 °C “ “ “ TIR-103 after E-103/104 20-230 °C “ “ “

TI-106 BL-101 suction 20-250 °C “ “ “

CHILLING UNIT P AND I 1022

TIR-121 after CB-101 -2/+0,5 “ “ “

TIR-122 before T-101 +5 / +10 °C “ “ “

TI-121 T-101 tank +5 / +10°C “ “ “ PI-121/122 delivery P-101 A/B 2-5 bar “ “ “