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Pickling & Passivation

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Page 1: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

GBH Enterprises, Ltd.

Ammonia Plant Technology Pre-Commissioning Best Practices GBHE-APT-0102

PICKLING & PASSIVATION

Process Information Disclaimer

Information contained in this publication or as otherwise supplied to Users is believed to be accurate and correct at time of going to press, and is given in good faith, but it is for the User to satisfy itself of the suitability of the information for its own particular purpose. GBHE gives no warranty as to the fitness of this information for any particular purpose and any implied warranty or condition (statutory or otherwise) is excluded except to the extent that exclusion is prevented by law. GBHE accepts no liability resulting from reliance on this information. Freedom under Patent, Copyright and Designs cannot be assumed.

Page 2: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

Ammonia Plant Technology Pre-Commissioning Best Practices: PICKLING & PASSIVATION CONTENTS 1 PURPOSE OF THE WORK 2 CHEMICAL CONCEPT 3 TECHNICAL CONCEPT 4 WASTES & SAFETY CONCEPT 5 TARGET RESULTS 6 THE GENERAL CLEANING SEQUENCE MANAGEMENT 6.6.1 Pre-cleaning or “Physical Cleaning 6.6.2 Pre-rinsing 6.6.3 Chemical Cleaning 6.6.4 Critical Factors in Cleaning Success 6.6.5 Rinsing 6.6.6 Inspection and Re-Cleaning, if Necessary 7 Systems to be treated by Pickling/Passivation

Page 3: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

0 INTRODUCTION This Process Engineering guide covers Best Practices in Ammonia Plant - Pre-commissioning; PICKLING & PASSIVATION and shall apply to all GBH Enterprises (GBHE) process engineers worldwide. 1.0 PURPOSE OF THE WORK

o To remove scale, iron oxides and deposits.

o To manage a passivation of all tubes and metallic surfaces. Pickling/passivation procedures which are incorporated in welding procedures are not part of this subject. 2.0 CHEMICAL CONCEPT The chemical cleaning should include the following steps:

• Degreasing by circulating a fresh water solution of about 0.1% wetting agent, 1.5% sodium carbonate, 1.5% sodium metasilicate and 1.5% trisodium phosphate for about 4 hours under temperature up to 60 degrees Celsius or at about 12 hours at ambient temperature, subject of the deposits’ chemical analysis results.

• Draining & Forwarding the wastes into a specified slops tank.

• Acid Cleaning by circulating a fresh water solution of about 3% citric acid , about 0.5% ammonium bifluoride and 0.15% proper inhibitor at about 12 hours under temperature up to 60 degrees Celsius or of a 10% stronger solution at about 24 hours at ambient temperature, subject of the deposits’ chemical analysis results.

• Neutralization & Passivation by circulating a fresh water solution of 0.5-1.0% ammonia, followed by circulating of a 0.5% sodium nitrite water solution for about 2-8 hours, subject of the deposits’ chemical analysis results.

Page 4: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

3.0 TECHNICAL CONCEPT The cleaning fluids should be forced in circulation preferable for safety reasons with plastic, air driven, chemical resistant pumps, reinforced polyester tanks and proper plastic hoses. For Boilers two separate cleaning circuits and solutions (1 for the main boiler and 1 for the superheater ) should be applied in order to avoid the transportation of sludges from the main boiler into the superheater. 4 WASTES & SAFETY CONCEPT

• Transportation of all cleaning wastes to a specified slops tank should be effected by pumping the wastes through the chemical tank and the chemical resistant pump.

• The pumping out facilities should be fixed before starting the cleaning process in order to be stand by in case of emergency.

• During the cleaning process a specialized in the field qualified Chemical Engineer should be present in order to monitor the whole process and to ensure the safe application of the chemicals and the safe forwarding of the produced wastes.

5.0 TARGET RESULTS On completion of the chemical cleaning process, all the surfaces of tubes, drums and headers should be in a 100% clean process, free of sludges, foreign materials, scale, grease and oxides deposits. Under the washed surfaces a grey up to black magnetite color should be appeared. 6.0 THE GENERAL CLEANING SEQUENCE MANAGEMENT a. Preparing the Area, Equipment and Personnel for Cleaning b. Pre-cleaning or “physical cleaning” c. Pre-rinsing d. Chemical cleaning. Critical Factors in Cleaning Success f. Rinsing

Page 5: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

g. Inspection and re-cleaning, if necessary Preparing the Area, Equipment and Personnel for Cleaning Proper preparation is necessary to ensure the safety of your employees and the effectiveness of the cleaning. To ensure safety, all electric equipment to be manually cleaned should be disconnected from the power source. Some equipment may be rinsed and spray-cleaned when it is running. In this case, workers should be trained to keep their hands away from moving parts that may cause injury. Motors, switches, and other electrical components may require covering; consult the equipment manual or manufacturer if unsure. A piece of equipment may require disassembly for safety reasons before cleaning. Disassembly also enables cleaning to be more effective by improving accessibility and the employee’s ability to see the surface to be cleaned. It is a common practice to put disassembled equipment parts on a table or rack, or in a tub, for cleaning. The plant environment during cleaning can be hazardous to employees unless proper precautions are taken. Slippery floors, high pressure hot water hoses, and cleaning chemicals can all be dangerous. Workers should dress appropriately for the task of cleaning. Boots with non-skid soles, waterproof aprons and gloves are commonly worn. Ideally, pants should not be tucked into boots because doing so makes it much easier to accidentally pour hot water or a chemical solution into the boot. The label on each container of cleaning chemical should list any special precautions that should be taken when using that chemical. In addition, there should be a Material Safety Data Sheet (MSDS) available for each chemical in use. By law, signs must be posted that inform employees of the MSDS location. 6.6.1 Pre-cleaning or “Physical Cleaning: The purpose of this step is to remove large pieces of debris so that later use of water and chemicals is more efficient. Pre-cleaning may involve picking up packaging debris, scraping equipment surfaces, and sweeping or squeegeeing the floor. The importance of this step is sometimes overlooked. If done properly, it will save you money by reducing water and chemical costs. Some processors combine pre-cleaning with the next step, pre- rinsing.

Page 6: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

6.6.2 Pre-rinsing: In this step, the surfaces to be cleaned are rinsed with water. Just as in physical cleaning, pre-rinsing removes some debris and reduces the need for chemicals. Generally speaking, the pre-rinse will be more effective if warm or hot water is used because the solubility of many components of the debris is greater at higher temperatures. If excessively hot water is used, there is a risk of “cooking on” the small amounts of protein. Experience and monitoring will guide your choice of water temperature. Once the best temperature is determined, monitoring should be done to ensure that this temperature is actually used. However, microbial biofilms and/or mineral deposits may remain on equipment. The later step of chemical cleaning should not be skipped without conclusive supporting evidence that it is unnecessary. 6.6.3 Chemical Cleaning: Cleaning chemicals are intended to lift debris from the equipment surface and keep it suspended in water so that it can be rinsed away. No single cleaning chemical does this effectively under 0 conditions. Instead, we use mixtures that may contain several different chemicals to ensure that the job is done well under normal plant conditions. 1) Water – The cornerstone of chemical cleaning is water. Water used in cleaning should be potable, and low in suspended matter and impurities that might affect odor and taste. Ideally, the water should be low in hardness minerals. Hard water inhibits the ability of some cleaning compounds to suspend debris and can result in mineral deposits on equipment surfaces. 2) Surface Active Agent (Surfactant) – The major ingredient in most mixtures is a surfactant. Its function is to suspend debris components that normally do not stay suspended in water. Of the three types of surfactants, anionic, non-ionic, and cationic, the anionic surfactants are most commonly used.

Page 7: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

3) Acid or Alkali – One or more compounds will be included to adjust the pH (degree of acidity or alkalinity) of the cleaning solution. Alkaline cleaners are recommended for high- fat debris, particularly when this debris has been heated. Chlorinated alkaline cleaners are used for removing many different types of debris and work especially well against high- protein debris. Acidic cleaners are very useful for removing mineral deposits. In the apple from the apples and soil can support microbial growth over time cider processing plant, a chlorinated alkaline cleaner is commonly used. An acidic cleaner may be periodically useful if mineral deposits develop. Phosphoric acid and gluconic acid are two acids commonly used for this purpose. 4) Chlorine Compounds – Chlorine-containing compounds are sometimes included in an alkaline cleaning mixture. In this application, the chlorine is intended to react with protein in the residue, with little chlorine remaining to kill micro-organisms. 5) Water Softeners – Some cleaning mixtures will contain components, called either water softeners or chelators, that chemically bind water hardness minerals. Examples of chelators include certain polyphosphates, gluconates, and EDTA (ethylenediamine tetra- acetic acid). 6.6.4 Critical Factors in Cleaning Success a. Temperature of cleaning mixture In general, warmer temperatures result in more effective cleaning. Avoid excessively high temperatures that cook debris onto the surface. Regular monitoring of the cleaning mixture temperature and adjusting it as necessary will help you clean more consistently and effectively. b. Concentration of cleaning mixture When adding cleaning mixtures to water for use, always follow the manufacturer’s directions. Increasing the concentration will usually not proportionally increase the effectiveness of cleaning. The directions are written so that typical amounts of debris can be easily removed. Amateur chemistry experiments with cleaning chemicals are absolutely prohibited.

Page 8: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

Combining mixtures can result in neutralization of components and loss of cleaning ability, e.g. adding an acid mix to an alkaline mix. Mixing chemicals can also create toxic compounds, e.g. mixing acid and sodium hypochlorite resulting in the release of chlorine gas c. Force associated with application The force is in the turbulent flow of the cleaning mixture resulting from the pump force or acceleration due to gravity as the liquid runs down equipment sides. d. Contact Time Generally speaking, a longer contact time is needed if little force is used in applying the cleaning chemical mixture. For example, foam and gel cleaning applications require a longer contact time than a high pressure spray application. 6.6.5 Rinsing Once chemical cleaning is done, the cleaning mixture and suspended debris are removed by rinsing. Rinsing should be thorough and is typically done with warm water to prevent debris from being re-deposited. As with the pre-rinse step, this rinse should be done from the top to the bottom of a given piece of equipment. An easy and rapid way to check if your rinsing is thorough is to touch a piece of pH paper to a freshly rinsed surface. If the color of the pH paper indicates that the pH is dramatically different from the pH of the rinse water, then there are either residues or cleaning chemicals remaining on the surface. 6.6.6 Inspection and Re-Cleaning, if Necessary This step is sometimes forgotten as employees look forward to the end of the working day. All cleaned surfaces should be visually inspected to be sure that proper cleaning took place. If residues are still visible, then cleaning must be re-done. Off-odors indicate a serious cleaning problem, because odors only become detectable when very large numbers of microbes are present.

Page 9: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

7.0 Systems to be treated by Pickling/Passivation. 1. Steam Boilers 2. All Steam Systems used as live steam or induction steam for turbines as (SLL 1) Induction Steam for CO2 compressor turbine

(SL 22) Induction Steam for Process Air Compressor turbine

(SM 21) Live Steam for turbines of the following equipment.

• Sea Water Pumps • Sea Water Circ. Pumps • CO2 Compressor • Process Air Compressor • Natural Gas Compressor • HP-Boiler Feed Water Pumps • Semi Solution Pump • Semi Lean Solution Pump • Combustion Air Fan • Flue Gas Fan • Closed Loop Circ. Pump • Critical Loop Circ. Pump

(SSH 21) Live Steam for Syngas Compressor and Refrigeration

Compressor Turbines SM 21 and SSH 21 pipe work have to treated completely. Branch lines as connections to steam traps or users others than turbines are not part of the pickling and passivation circuits. All pipe sections to be treated in the SL 22 and SLL 1 steam systems have to be selected in accordance with the Turbine Manufacturer. Pickling/Passivation of the steam systems do not eliminate further cleaning by steam blowing.

Page 10: Pickling & Passivation

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com