Shandong Lubei Tech Appendixes Eng 伍迪山东鲁北化工20万吨离

200,000 MTPY ION EXCHANGE MEMBRANE

CAUSTIC SODA PLANT

FOR

SHANDONG LUBEI CHEMICAL INDUSTRY CO. LTD.

TECHNICAL APPENDIXES

110711 Rev. 0

APPENDIX 1

PROCESS DESCRIPTION, DRAWINGS AND BATTERY LIMIT 110711 Rev. 0

INDEX

1.0 SCOPE OF THE PLANT

2.0 PROCESS DESCRIPTION

2.1 Electrolysis

2.2 Cell workshop

2.3 Catholyte handling

2.4 Brine system

2.5 Chlorine

2.6 Hydrogen

3.0 DRAWINGS

4.0 UHDENORA S.P.A. PATENT ESTATE – CHLOR-ALKALI ELECTROLYSIS 110711 Rev. 0 Appendix 1

2

1.0 SCOPE OF THE PLANT

For the total capacity of 300,000 MTPY NaOH (100% basis) two separate plants are

foreseen to be installed, one of 200,000 MTPY NaOH in the Phase I, and the other of

100,000 MTPY NaOH in Phase II to replace the exsting plant of 60,000 MTPY NaOH.

This proposal is for the first plant of 200,000 MTPY NaOH in the Phse I.

The following process sections define the battery limits of the plant:

No. of section Description Ref. Process Flow Diagram

11 Electrolysis room 11 AF 1026

31 Catholyte circulation (within cell room) 31 AF 1026

12 Electrolyzers maintenance room

07 Brine dechlorination and chlorate treatment 07 AF 1026

06 Secondary brine purification, Pure brine feeding 06 AF 1026

2.0 PROCESS DESCRIPTION

2.1 ELECTROLYSIS

2.1.1 Cell room design

The cell room produces 600 MTPD NaOH (100% basis), using 6 Uhde Single Element

membrane electrolyzers type BM 2.7 each consisting of 196 bipolar cell elements.

The electrolyzers, with 2 cell racks and 98 elements per rack, normally operate at a

current density of 5.46 kA/m2. The cell racks are designed to allow the installation up to

100 single elements each.

The whole plant is designed to operate in the range of 30 – 110% of the rated capacity.

2.1.2 Design of the Uhde single element concept.

A "single element" comprises the anode and cathode halfshells housing the electrodes,

the membrane, and the flange and sealing system. The anode and cathode are attached

with a continuous laser weld to the current transfer and support blades and hence to the

halfshells. The anode is made of titanium whereas the cathode is made of nickel.

The inpidual cell elements of an electrolyser are suspended in a steel frame where they

are lightly pressed together for electrical contact. Large sealing forces are not required in

the single element concept, as each element is a separate, stand alone electrolysis cell.

The feed and discharge lines of the cells are located underneath the cells and connected

to the catholyte and anolyte headers. Hence, they are easily accessible. The area above

the electrolyser is clear of piping or bus bars, simplifying access and removing the risk

of leakage and associated corrosion problems on the electrolysers.

110711 Rev. 0 Appendix 1

3

The current is conducted from cell to cell element via Ni-Ni contacts. The Ni-contacts

do not need any special treatment or maintenance, such as scraping, sanding or silver

conductivity sprays, throughout the lifetime of the cell. On the contrary other cells using

titanium contacts normally build up poorly conductive titanium oxide surfaces, so that

special treatment and maintenance are needed. These Ni-Ni contacts are made possible

by continuously laser welded explosion bonded titanium-nickel contact strips on the

anode halfshell. The electrical current completes its path to the electrodes via the current

transfer and support blades.

The brine and caustic soda feed enter the cell at the bottom while the product streams

are also discharged downwards via an internal overflow pipe. Patented internals

promote both circulation and wetting of membrane, The collecting channels at the top of

the element on both anodic and cathodic sides make complete separation of gas and

liquid destroying the foam and reduce the internal differential pressure fluctuation to the

minium ensuring an even longer lifetime of the membrane. Moreover a higher degree of

safety is achieved as the raise of upper side wall of the element allows to keep the

membrane always flooded, even in case of stand by, preventing contact between

hydrogen and chloring gases at the upper part of the electrolysis cell via the membrane.

The downcomer plate and distribution pipe achieve homogeneous temperature and

concentration profiles within the 2.72 m2element and assist in achieving uniform

current distribution. The perforated anode louver structure increases the electrode

surface area and prevents anode side blinding and associated ridging or blistering of

membranes.

Combined with the patented PTFE frame gasket, the PTFE sealing cord (no creep,

embrittlement or ageing as in case of rubber gaskets) and the electrically insulated

bolting system with external steel flanges and spring washers (elastically deformed for

stable long term compressive forces) ensuring that the cell element remains leak-proof

throughout its entire service life, a true 'single element' concept is fully realised. This

enables long term storage of pre assembled and fully tested elements (see also paragraph

1.2.2-Exchange of elements).

Laser welded cell structure and experience with high performance membranes at very

narrow gaps give UHDN the expertise and know-how to realistically offer high current

densities plant operation.

The design of the Uhde single element cell is characterised by the implemention of cell

internals promoting a homogeneous distribution of the anolyte and large electrolyte

volumes in the cell prevent disturbances in inlet flow, concentration and temperature. As

a result the Uhde Single Element bipolar cells are capable of very fast load changes,

which are only limited by maintaining a stable chlorine and hydrogen pressure. Thus,

load changes from 100 to 30% or vice versa can be easily performed within brief time

without any risk of damage to the membranes hence fulfilling the request of a high

turndown ratios combined with a fast response time of the cell room to downstream load

changes.

110711 Rev. 0 Appendix 1

4

2.1.3 Cell room brine and catholyte circulation.

Process Flow Diagrams 11-AF-1026, 31-AF-1026 and 06-AF-1026.

The cells are supplied with pure brine from the pure brine head tank 06D001 and with

diluted catholyte from the catholyte head tank 31D001.

The feed rates of pure brine and caustic soda to each single electrolyzer are controlled in

automatic by flow control loops (flowmeter plus control valve) and is regulated

according to the current load of the relevant rectifier.

Since the feed lines to and the discharge lines from the cells are at different electric

potentials stray currents are prevented by liquid current resistors (PTFE-hoses) in the

feed lines and are interrupted by corrugated hoses in the product lines.

Ultra pure brine (300-310 g/l NaCl) enters the anode compartments where chlorine is

generated at the titanium anodes. Anode and cathode compartment is isolated by a

membrane. This membrane only allows inpidual diffusion of Na+ions and a certain

quantity of water into the cathode chamber (about 3-4 moles H2O / mole Na+). A two-

phase mixture of chlorine and anolyte is discharged via the installed overflow pipe into

the anolyte header where chlorine gas is separated from the anolyte. The brine leaving

the cells is depleted to approximately 210-220 g/l NaCl.

Hydrogen and OH- ions are generated at the cathodes. This electrochemical reaction and

the dilution of the circulating catholyte stream requires water which is partly supplied by

the above mentioned H2O transport phenomenon through the membrane and partly by

addition of demineralised water. The two phase mixture comprising 32% caustic and

hydrogen flows from the catholyte compartment via the over flow pipe into the catholyte

header and then to the hydrogen separator 31F002 where the hydrogen gas is separated

from the catholyte.

The catholyte is collected in the catholyte tank 31D002. From the catholyte tank, a part

of the catholyte stream (32% NaOH product from the electrolyzers) is pumped to B.L.

as product and for various internal plant consumers.

The remaining catholyte stream is recycled to the catholyte head tank 31D001 passing

through the catholyte heat exchangers 31E001 and 31E003, where if necessary, the

catholyte is cooled in order to maintain a constant temperature for electrolysis. Then

catholyte flowing by gravity from the head tank, is diluted with demineralised water on

line and feeds the electrolysers. The catholyte cooler 31E003 is foreseen also for single

electrolyzer shut-down while the plant is in operation.

2.1.4 Cell pressure control.

110711 Rev. 0 Appendix 1

5

Maintaining a constant pressure difference between the cathode and anode compartment

is essential for safe operation of the cells. The hydrogen pressure is always kept a

constant pressure higher than the chlorine pressure. This ensures that the membrane only

touches the anode and is kept in this defined state. Cell pressure control valves on H2

lines and Cl2 lines are provided to take care of this.

-In case the pressure of chlorine or hydrogen increases excessively, the automatic valves to the waste gas dechlorination/stack will open.

-In case H2 gas pressure drops too low, N2 gas will be automatically injected to H2 main header.

2.1.5Monitoring system for membrane electrolysis plant - UHDE Evaluator TM

The UHDE EVALUATOR TM safeguards and analyses automatically the performance of

the cell room beginning from each single element up to the whole cell room by

executing the following operations:

?Measurement of all single element voltages with a frequency of 1/s per element

?Indication of all single element voltages in the control room

?Indication of all elements with high voltages (e.g. electrode overvoltage/membrane

overresistance) and with low voltage (pinhole detection)

?Monitoring of the DC circuit for earth faults by means of the "two voltmeter method"

?Indication of voltage trends for all single elements

?Event report

?Calculation and indication of current voltage curves allowing conclusions on

membrane and coating conditions

?Evaluation of standardised voltages of single elements, current efficencies and power

consumption, electrolyser as well as the complete cell room based on UHDE

EVALUATOR? voltage measurements; process data from DCS and Analyses from

the laboratory data base

The measuring circuits are located nearby the electrolyser and are connected to a central

safety PLC. The present measuring values are transmitted from the PLC to the central

data processing and presentation unit (PC) for further processing.

In case of any electrical deviation above the set point, the safety PLC will send a signal

to the conversion unit for the appropriate shut down. A shut down will be caused by the

following faults:

?high deviation of single element voltage from average element voltage of the electrolyser

?higher than maximum allowed cell voltage of a single element

?earth fault measured at the DC bus bars by "two voltmeter method"

2.2 CELL WORKSHOP

110711 Rev. 0 Appendix 1

6

A cell workshop meets the requirements for the assembly and disassembly of the cells

and for all manipulations necessary in the cell room.

2.2.1 Pre-treatment of new membranes.

The membranes are shipped fully conductive i.e. in the sodium form as received. Prior

to mounting the membranes in the cell elements, a pre-treatment is necessary to fully

expand the membrane and to prevent undesirable wrinkles.

Moreover, the membranes are kept well moistened until the cells are put into operation

by filling alkaline demiwater into both the anolyte and catholyte compartment and

sealing all 4 nozzles of the element. Hence, the Uhde single element technology solely

allows the storage of ready-to-use elements.

2.2.2 Exchange of cell elements.

An exchange of single elements in the electrolyzer may be necessary due to:

?scheduled exchange of membranes,

?scheduled recoating of electrodes,

?unexpected problems of a single element like high voltage, leakage, etc..

Then, the following procedure applies to exchange elements in an operating electrolyzer.

This electrolyzer has to be cut-off from the current circuit by DC isolators. It is then

flushed with fresh pure brine, catholyte and nitrogen, so that chlorine and hydrogen are

removed from the cells to waste gas dechlorination unit and stack respectively.

Subsequently, the electrolyzer is cooled down to approx. 50°C by supplying cooled feed

brine and caustic via the heat exchangers.

Due to this flushing and cooling, the diffusion phenomena are significantly reduced.

Prior to taking out a single element, the electrolyzer is drained. Then, the relevant

contact pressure springs and inpidual flange connections to the feed and discharge

lines are loosened and the concerned element is taken out, transported to the

neighbouring cell workshop, and exchanged by a pre-assembled spare element.

Eventually, the electrolyzer is refilled with brine and caustic of approx. 50°C and after

heating up, the electrolyzer can be again energised.

The overall downtime of an electrolyzer to exchange one element - including cooling

down and heating up - amounts to approx. 5 h. Two men are required for the mechanical

work.

The essential advantage of the Uhde single element concept is that the exchange of

elements in an electrolyzer does not affect the remaining elements. In the opposite, the

filter press concept does require the disassembly of the electrolyzers complete sealing

system risking the drying up of membranes.

110711 Rev. 0 Appendix 1

7

Since pre-assembled single elements can be stored for several months the Uhde Single

Element concept minimises electrolyzer downtime during maintenance work. Thus, we

strongly recommend to keep some assembled elements in store.

2.3 CATHOLYTE HANDLING

Catholyte handling outside electrolysis room will be provided by the BUYER according

to his own technology (not included in the plant battery limits).

2.4 BRINE SYSTEM

The electrolyte feeding the electrolyzers is an aqueous solution of sodium chloride at

300-310 g/l NaCl. The electrolyzer brine feeding flow rate is held at a value

proportional to the rated production capacity of the electrolyzers so as to ensure that the

brine leaving the electrolyzer will contain 210-220 g/l NaCl.

2.4.1 Depleted brine dechlorination and chlorate decomposition

Process Flow Diagram 07-AF-1026

The dechlorination is carried out in two process steps. The first step is brine

acidification followed by a Cl2-desorption under vacuum created by means of vacuum

pump 07U001. In the second step the remaining free chlorine in the brine is chemically

destroyed.

The depleted brine outgoing the electrolyzers, releasing chlorine, is acidified in the

anolyte acidification pot 07D005 using the acidic brine from the chlorate decomposition

and the hydrochloric acid added under pH control. The anolyte is then received in the

anolyte tank and is pumped to the dechlorination tower 07C001 where the free chlorine

in brine is stripped off at vacuum pressure and is sent to the main chlorine header. The

water of the saturated chlorine gas is condensed in the vapour condenser 07E001. From

the dechlorination tower anolyte is collected in the dechlorinated brine tank 07D002 and

is then directed to the brine saturation by means of lean brine pump 07P002A/B. Caustic

soda is added in the dechlorinated brine tank under pH control, followed by a sodium

sulphite injection on the suction line of lean brine pump, that realize the final chemical

dechlorination.

A Chlorate decomposition unit is foreseen to prevent the accumulation of NaClO3.

Chlorate is decomposed by means of hydrochloric acid at high temperature. A side

stream of anolyte from anolyte pump is sent to a mixing tank to be acidified with HCl

and then it flows to the reactor where steam is injected under temperature control of the

reactor. The dechlorated brine then flows to the anolyte acidification pot and is used for

acidification of anolyte.

110711 Rev. 0 Appendix 1

8

2.4.2 Brine saturation, primary treatment, clarification and filtration

These sub-sections of brine system will be provided by the BUYER according to his

own technology (not included in the plant battery limits).

2.4.3 Brine secondary purification.

Process Flow Diagram 06-AF-1026.

The filtered brine from plant battery limits is controlled and adjusted for pH value and is

collected in the filtered brine tank 05D002 from where it’s pumped to resin towers

passing through a heat exchanger that, if necessary, can heat brine up to approx. 60°C.

The filtered brine then undergoes the secondary purification process with resin tower

suitable to reduce the Ca, Mg ans Sr hardness as required by the membrane cells process.

High purification levels are reached by ion exchange treatment in columns packed with

chelating resins having high selectivity towards the alkaline earth cation impurities of

the brine.

There are installed two columns in series in merry-go-round configuration, one is in

operation and the other one is in regeneration or as safety on line. Each column is

designed for full capacity. The operation and regeneration sequence of the columns are

automatically controlled by the DCS.

2.4.4 Pure brine feeding to electrolyzer.

Process Flow Diagram 06-AF-1026.

From the resin towers ultra pure brine flows through brine heat exchangers 06E001 and

06E002 where, if necessary, ultra pure brine temperature is adjusted to the required one

for electrolysis, then reaches the head tank 06D001, from where pure brine flows by

gravity to the electrolysers. An overflow line on this head tank is foreseen to keep brine

level constant, the overflow brine goes back to the filtered brine tank. The heat

exchanger 06E002 (heating and cooling service) is also foreseen for single electrolyser

start up/shut down while the plant is in operation.

Acidification with diluted HCl (18%) of brine feeding each electrolyser is foreseen

under rectifier load control in order to maintain to a low oxygen content in Chlorine also

when efficiency decreasing due to membrane ageing.

2.5CHLORINE

Process Flow Diagram 11-AF-1026.

The chlorine gas, coming from the electrolysis room header, saturated with water vapour,

flows to the battery limits for downstream handling. The chlorine pressure is controlled 110711 Rev. 0 Appendix 1

9

by a control valve on the main header, another control valve for safety on main header is

foreseen to vent chlorine to battery limits towards absorption system in case of over

pressure or emergency.

2.6 HYDROGEN

Process Flow Diagram 11-AF-1026.

The hydrogen gas, coming from the electrolysis room header, saturated with water

vapour, flows to the battery limits for down stream handling. The hydrogen gas pressure

is controlled by differential pressure compared with chlorine gas pressure and another

control valve for safety is also foreseen on the header to vent hydrogen gas to battery

limits towards a stack in case of over pressure or emergency.

3.0 DRAWINGS

06-AF-1026 Secondary brine purification (process flow diagram)

07-AF-1026 Brine dechlorination and chlorate decomposition (process flow

diagram)

11-AF-1026 Cell room (process flow diagram)

31-AF-1026 Catholyte circulation (process flow diagram)

M-0500-0 BM2.7 Electrolyser assembly (B.L. for piping and bus bars)

95-BA-1101 Tentative layout

4.0UHDENORA S.P.A. PATENT ESTATE – CHLOR-ALKALI ELECTROLYSIS

See attached list.

110711 Rev. 0 Appendix 1

10

May 15, 2008

UHDENORA S.P.A. PATENT ESTATE

REF. NO. 115 :

Title : Shortcircuiting device for electrolyzers and method for using the same

REF. NO. 132 DD

Title: Electrochemical cell provided with ion exchange membranes and bipolar metal plates

REF. NO. 134

Title Shortcircuiting System for Use in Monopolar and Bipolar Electrolyzers

REF. NO. 141

Title: Improved type of ion exchange membrane or diaphragm electrolyzer

REF. NO. 144

Title: Improved method for the electrolysis of aqueous solutions of hydrochloric acid

PROPRIETARY AND CONFIDENTIAL INFORMATION OF UHDENORA S.p.A.

May 15, 2008

REF. NO. 179

Title: Dual Section System for the Discharge of Bi-Phase Gas-Liquid Mixtures

REF. NO. 180

Title: Electrolysis cell with gas diffusion electrode operating at controlled pressure

REF. NO. 181

Title: New bipolar assembly for filter-press electrolyzer

REF. NO. 189

Title: Bipolar element for hydrochloric acid electrolysis

REF. NO. 192

Title: Electrolysis cell with gas diffusion electrode

REF. NO. 193

Title: Resilient current collector

PROPRIETARY AND CONFIDENTIAL INFORMATION OF UHDENORA S.p.A.

May 15, 2008

REF. NO. 239

Title : Electrolysis cell with optimised shell design and minimised membrane surface area

REF. NO. 242

Title : Bipolar plate for electrolyzer comprising a single wall

REF. NO. 248

Title : ELECTROLYTIC CELL COMPRISING AN INTERIOR THROGH

REF. NO. 253

Title : Electrolysis cell with optimised shell design and minimised membrane surface area

REF. NO. 254

Title : Electrolysis cell with optimised shell design and minimised membrane surface area

REF. NO. 256

Title : Electrolysis cell with optimised shell design and minimised membrane surface area

PROPRIETARY AND CONFIDENTIAL INFORMATION OF UHDENORA S.p.A.

May 15, 2008

REF. NO. 266

Title : Elastic Current Distributor for Cells Equipped with Percolator

REF. NO. 273

Title : Chlor-Alkali Electrolyzer Equipped with Gas Diffusion Cathode

REF. NO. 274

Title : Process Chlor-Alkali Electrolyzer Equipped with Gas Diffusion Cathode

REF. NO. 277

Title : Micro-structured insulating frame for electrolysis cell

REF. NO. 280

Title : Welding method for thin metal sheets

REF. NO. 282

Title : Electrolysis Cell with Curved –type Electrode Structure

PROPRIETARY AND CONFIDENTIAL INFORMATION OF UHDENORA S.p.A.

May 15, 2008

REF. NO. 283

Title : Electrolysis Cell

REF. NO. 287

Title : Measuring Cell for Electrodes and Electrode Coating

REF. NO. 290

Title : Elastic Current Collector for Electrochemical Cells

REF. NO. 292

ID-No. 10274

Title : Device for the electrolytic treatment of liquids in anodic and cathodic compartments.

ID-No. 10297

Title : Sheet electrodes with holes and transverse indentations

PROPRIETARY AND CONFIDENTIAL INFORMATION OF UHDENORA S.p.A.

May 15, 2008

ID-No. 10321

Title : Method for electrolyzing of liquid electrolytes

ID-No. 10322

Title : Electrolyser for producing halogen gases

ID-No. 10329

Title : Electrolytic unit for electrochemical process, e.g. for producing

chlorine from aqueous alkali-halogenide solution

ID-No. 10340

Title : Electrolysis apparatus for producing halogen gases

ID-No. 10450 :

Title : Elektrolysis Apparatus

PROPRIETARY AND CONFIDENTIAL INFORMATION OF UHDENORA S.p.A.

APPENDIX 2

DESIGN BASIS 110711 Rev. 0

INDEX

1.0 PLANT SECTIONS

1.1 Process sections

1.2 Utilities sections and units

1.3 Miscellaneous units

2.0 DESIGN CAPACITIES AND CHARACTERISTICS OF THE PROCESS

SECTIONS

2.1 Electrolysis section

2.2 Brine system

2.3 Catholyte circulation within cell room

2.4 AC/DC electrical conversion unit for electrolysis

3.0 BASIC DESIGN DATA

3.1 List and specifications of feedstocks

3.2 Specification of the depleted and dechlorinated brine

3.3 List and specifications of chemicals and consumables

3.4 List and specifications of utilities

4.0 EXPECTED QUALITY OF THE PRODUCTS

4.1 Caustic soda

4.2 Chlorine

4.3 Hydrogen gas

5.0 EXPECTED CONSUMPTIONS

5.1 For electrolysis, brine system and catholyte circulation

6.0 EFFLUENTS AND ENVIRONMENTAL CONSIDERATION

6.1 Brine secondary purification - resin tower regeneration effluents

6.2 Filtered water from pump seals, safety seal, hydraulic seals and washing hoses

7.0 ENVIRONMENT CONDITIONS

7.1 Temperature

7.2 Relative humidity

7.3 Barometric pressure

7.4 Rainfall

7.5 Wind velocity

7.6 Earthquake

7.7 Snowfall

7.8 Frost depth

110711 Rev. 0 Appendix 2

2

8.0 CODES AND STANDARDS

8.1 Process equipment and material

8.2 Electrical equipment and material

8.3 Instrumentation

9.0 DIMENSIONS, MEASUREMENTS AND ABBREVIATIONS

9.1 Dimensions and measurements

9.2 Abbreviations

10.0 RECOMMENDED PLANT OPERATION STAFF

110711 Rev. 0 Appendix 2

3

1.0 PLANT SECTIONS

1.1 PROCESS SECTIONS

1.1.1The following process sections define the battery limits of the plant:

Ref. PFD - Electrolysis room 11AF1026

- Catholyte circulation (within cell room) 31AF1026

- Electrolyzers maintenance room

- Brine system including:

. Brine dechlorination and chlorate treatment 07AF1026

. Secondary brine purification, Pure brine feeding 06AF1026

1.1.2 The design and supply of the following process sections are assumed to be in

BUYER's scope of supply

- Catholyte handling (outside cell room)

- Brine saturation

- Brine primary treatment

- Brine clarification and prefiltration (if any)

- Brine filtration

- Sludges treatment

- Hypochlorite emergency unit

- Chlorine handling

- Hydrogen handling

1.2 UTILITIES SECTIONS AND UNITS

The following utilities sections and units integrate the process ones and shall be

provided by BUYER:

- AC/DC conversion unit

- Electric power distribution

- Process water distribution

- Cooling water production and distribution

- Chilled water production and distribution

- Demineralized water production, storage and distribution

- Plant and Instrument air production and distribution

- LP and MP steam production and distribution

-Nitrogen distribution

110711 Rev. 0 Appendix 2

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