Friday, September 30, 2011

ACRYLIC ACID ON CHEMICAL TANKERS- CAPT AJIT VADAKAYIL




               ACRYLIC ACID



Cargo temperature must be never fall less than 18 deg C or go over 35 deg C.   If at all it happens the Inhibitor will be weakened and will trigger a exhothermic reaction and the cargo will have to be jettisoned.



YOU MUST HAVE SUFFICIENT FRESH WATER ON BOARD IN CASE THE ENTIRE PARCEL HAS TO BE JETTISONED.



Names: Glacial acrylic acid (98%), Ethylene carboxylic acid, Acroleic Acid,  2-Propenic Acid,2-Propenoic Acid, Propenoic Acid, Vinyl Formic Acid.



Used for surface coatings, textiles, hydrogels for contact lenses, aerosol hair sprays and elastomers. Acrylic acid monomer can be used in latex to prevent coagulation.




Properties:


CHRIS/ ACR


Clear colorless watery liquid


Acrid irritating odor 5  


SG/ 1.049


Organic acid


Some hazard, typically having threshold limits of 100 to 500 ppm


BP/ 141C


MP/ 12 C


VH/ 25C


AH/ 28C


DH/ 25C


Marpol cat/ Y


Vapor pressure 20C (mmHg)/ 3.10


Vapor pressure 46C (psia)/ 0.4


Vapor density (air =1.0)/ 2.48


Viscosity/ 1.30 mPas


Solubility in water/ complete


Low surface tension. Cleaning chemicals not required..


Flammable vapors, combustible liquid. Vapors can flow along surfaces to distant ignition sources and flash back.


Presents no special fire or explosion hazard because of its relatively high flash point and low vapor pressure.


Poisonous gases may be produced in a fire.


FP/ 50C


AIT/ 438C


Flammable limits: 2.4 LEL to 8.02 UEL


Does not react with water.


Good cargo before the next wall wash cargo.


Alcohol resistant foam used to combat fires. Carbon monoxide and carbon di oxide may form when heated to decomposition.


A fire involving a spill on tank deck could be extinguished with dry chemical or foam. Wear full protective clothing, eye protection and self-contained breathing apparatus


Destructive to mucous membranes and upper respiratory tract.


May be fatal as a result of spasm, inflammation and edemaof the larynx and bronchi, chemical pneumonitis and pulmonary odema. Asphyxia may occur due to edema of the glottis.


Fairly severe skin irritants, usually causing pain and second degree bums after a few minutes contact


Threshold limit value/TWA/10 ppm (skin)


Acrylic acid, when in contact with skin or eyes, may result in a bum upon short contact. Vapor may present an inhalation hazard from single exposures; irritating to eyes, nose and throat


Vapors are capable of causing definite skin or eye irritation, nasal irritation and lachrymation.


STEL/ 0.5 ppm.


If contact with skin or eye occurs, immediately flush with plenty of water for at least 15 minutes. Get medical attention promptly. Immediately remove contaminated clothing and shoes.


Polymerizes readily. Should be inhibited to insure safety and stability during storage and handling. Light promotes polymerization once started.


Severely corrodes iron and steel. Glass, low carbon content stainless steel and high purity aluminum are recommended.


No inerting by nitrogen must be done as stabilizer is oxygen dependant.


USCG compatibility chart/4—see exceptions


Incompatible with strong oxidizing agents.


If possible, wear rubber gloves, face shield, protective clothing. Body shield and self-contained breathing apparatus should be available


If leak on cargo transfer system, stop the transfer and empty the line system. Flush contaminated area with a weak caustic soda solution (10%), then flush the area with large quantities of water


Acrylic Acid is an unstable product when not inhibited. The ester grade (technical grade) covered by this manual is relatively stable when properly inhibited.  Acrylic Acid is regulated for bulk transportation by the IMO, BCH and IBC codes. Following is the summary of the codes' minimum requirements:


Pollution category/D (old) —NEW Y


Fire protection/ Alcohol resistant foam


ARRANGEMENTS


Establish method for heating the cargo. Thermal oil, hot water, and/or adjacent heating is to be used. The safest way is to use adjacent heat by filling up fresh water ( not salt water) in an adjacent ballast tank and maintaining its temperature <30 deg C.


Do not use heating systems to thaw a solidified monomer.


For the transportation, and in case of rapid temperature increase ensure to have prepared plans to abandon the cargo overboard if so is required to protect the safety of crew and ship.


Stowage is to be arranged so that tanks are not filled to more than 90% full.


The cargo should never be allowed to freeze (MP 12-14C) as when cargo is remelted there is great risk of violent polymerization.


EQUIPMENT


Since temperature measurement and records are a bone of contention,--ensure


Tanks to be loaded need a minimum of two temperature sensors in each tank with high and low temperature alarms. Ullages need to be arranged accordingly so that two sensors are in contact with the cargo during the voyage in each tank. High temperature alarm to be set at 35C and low temperature alarm to be set at 18C.



PREPARATION FOR LOADING


The tank must be dry, and chlorides < 2ppm.


Check heating coils for leaks (follow procedure for non-destructive pressure testing of heating coils). Steam coils to be blown dry and blanked off if using AH.


Purge the Framo pump and check for seal tightness (use air).


Prepare 10% caustic soda solution for neutralization of spills.


Ensure that all handling personnel are using acid resistant protective gear.


Have respiratory apparatus, eye wash, and emergency showers ready for use.


Use splash couplings at manifold.


Adjacent tanks or ballast spaces must not contain cargo or ballast with a temperature less than 18C at any time during the loading or voyage.


If you are loading in a cold place inject warm air into the pipelines to be used for loading to keep temperature at 20C.




LOADING


The cargo should be loaded with a temperature range of 18/28C.


No samples to be retained on board.


An inhibitor certificate must be obtained. The inhibitor used is usually Hydroquinone. Acrylic acid vapor contains no inhibitor. So the condensate may polymerise inside the PV stack.


During loading cargo temperature must be checked and logged every 30 minutes.


First foot sample stop will be given by ship.


The first 24 hours after loading the cargo temperature must be checked and logged every 2 hours.


AFTER LOADING


Samples must be drawn from top , middle and bottom levels of the tank.


For line clearing use air, do not use nitrogen as the inhibitor stabilizing the cargo is oxygen dependent.


All equipment used for Acrylic Acid loading must be thoroughly cleaned before stowed away. Cargo hoses should be flushed with warm (35-40C) water and steamed before stowed away.



VOYAGE




The cargo temperatures must be monitored every four hours (00-04-08-12-16-20) and the results recorded in the "Cargo Temperature Log.".  The Log should contain the following information—


Outside temperature


Sea water temperature


AH by FW temperature


Top middle bottom cargo temperatures


Weather



The cargo temperature log must be Emailed every 24 hrs to the charterers and operator.



If the temperature falls below 18C, introduce heat using thermal oil/hot water or adjacent tank heating system. Heating coils surface temperature must not exceed 35C.


If the temperature continues to either decrease or increase to 16C or 34C respectively, urgently notify  the Chemical operator-- if the temperature change is not due to the corresponding ambient temperatures. If the temperature rises to 35C read  Jettison Procedures and be fore warned.



PRE-DISCHARGE ARRANGEMENTS


Prepare and use only clean, dry hoses.


Use acid spray shields at manifold flanges.


10% caustic soda solution can be used for neutralization of spills


All handling personnel should wear PPE..


DISCHARGE


The cargo should preferably be discharged at a temperature between 18C and 28C.


During discharge cargo temperature must be checked and logged every 30 minutes.



                TANK CLEANING


All tanks need to be stripped as per P&A Manual. Shortly after discharge all tanks are to be rinsed with clean ambient (MP--- 12C + 10C = 22C ) fresh water (not seawater or river water) to dilute any remaining acid.

This mixture is to remain in the tank until it is cleaned at sea (salt water ok) as per Marpol Regulations. Alternatively this fresh water/acid mixture may be transferred into another clean SS tank or empty (rinsed) acid tank so the tank may be cleaned in port.

Under no circumstances is the fresh water/acid mixture to be mixed with any other slops onboard (except for other Acrylic Acid slops.) After initial rinsing and transfer of slops the Acrylic Acid tank may be cleaned in port with salt or channel water collecting slops onboard along with any other compatible slops. 

This cargo can polymerize violently if contaminated or if exposed to freezing (12-14C) or excessive heat (45C) so utmost care needs to be taken when handling or cleaning from this cargo.


If heating coils have not been used for heating, remove blinds and thoroughly flush the coils with fresh water and check pH is 7..


Steam line systems, ensure to flush at all drain cocks and plugs.


Dry tank and lines.


If there are any black marks it can be removed by phosphoric acid.



SLOP DISPOSAL AND ARRANGEMENTS



The slops are to be disposed according to:


Regulations for control of pollution by noxious liquid substances in bulk, IMO, MARPOL Annex II and, when it is necessary to dispose slops to shore reception facilities, the ship must report estimated quantities to the Ship Operator and the local agent. Before mixing compatible slop residues or slops and cleaning agents consult the local agent.


  


ACRYLIC ACID JETTISON PROCEDURE




A:     Should the Cargo Temperature rise to 34C, inform company.


Begin checking the temperature every 30 minutes. Plot on graph paper. Notify EMS chemical operator.


If adjacent tanks or any tanks in vicinity are being heated stop heating these tanks. If adjacent tanks are empty fill those with ballast if possible, provided sea water temperature is between 18-30C.


Line up for circulation either through existing drop line or rig portable hoses.


B.      Should the cargo temperature rise to 41C.


Begin circulation of the cargo.


Continue temperature monitoring.


C.     At a temperature of 45C.


Prepare to pump cargo overboard.


Add cold fresh water to tank as void space permits. Continue circulation. Continue adding fresh water until tank is full, as fresh water supply permits. Closely monitor temperature.


NOTE: SALT WATER WILL NOT DISSOLVE POLYMER MAKING PUMPING MORE DIFFICULT.


D.     Should temperature rise to 49C Jettison-- NOW!!


Begin pumping cargo overboard.


Continue adding fresh water while cargo is being discharged overboard, as FW supply permits.


When tank is empty start cleaning with cold water and continue cleaning until tank is clean.




-------CAPT AJIT VADAKAYIL
29 YEARS IN COMMAND

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