Wednesday, May 5, 2010

HYDROLYZABLE CARGOES , CHEMICAL TANKERS -- CAPT AJIT VADAKAYIL















HYDROLYSIS , CHLORINATED SOLVENTS , FFA


Cargoes which react with water to form acid are called hydrolysable cargoes. 


People get squeamish about this because zinc silicate cannot take pH less than 6 and most organic epoxies cannot take pH less than 3.5 on the acid scale.

They are carried in stainless steel tanks. Examples:-- Esters ( Acetates and Acrylates ) Pthalates and certain halogenated compounds like Methylene chloride.

Hydrolysable cargoes must be carried in perfectly dry tanks with moisture content less than 100 ppm ( 200 ppm for zinc ). It is important to vent to eject aBsorbed/ aDsorbed cargo in coating. This must be done prior doing tankcleaning with water.

However certain viscous non-volatile products like DOP and Texanol cannot be evaporated by venting and must be cleaned off by warm water immediately after discharge.

Hydrolysis :-- salt + water = acid + base

Since epoxy coating absorbs cargo like a sponge , it means that two successive cargoes may require to be compatible with each other. For example after EDC if you load a cargo containing water, Hydrochloric acid will be formed which will destroy the epoxy coating.

Vinyl acetate monomer plus water gives Acetic acid. Chloroform plus water gives Formic acid.

Esters can saponify in contact with water at higher temperatures resulting in increased short chain type FFA which can be aggressive to tank coatings.

Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. This is distinct from a hydration reaction, in which water molecules are added to a substance, but no cleavage occurs.

Hydrolysis is an oxidation reaction between Chlorinated HC and residual water. Oxidation occurs due to exposure to radiation or the presence of certain catalysts and can be prevented by inhibitors. Hydrolysis is accelerated at higher temperatures.

Chlorinated carboxylic acids are very corrosive and not carried in SS tanks.

After carriage of Hydrolyzable cargoes such as Acetates, the tanks should be ventilated to remove all traces of cargo before any water is introduced.

The breakdown of vegetable and animal oil fats to fatty acids is promoted by the presence of water particularly at higher temperatures. Hydrolysis is also promoted by the action of certain micro-organisms. Tanks in which the oil is being stored or shipped should always be clean and dry before use.

Chlorinated/ Brominated solvents hydrolyse in presence of water to form Organic and Inorganic acids which spoil the paint coating. Shippers must give the moisture content in PPM. Water content should not excced 100 ppm or 0.01% especially for epoxy. Nitrogen pad is a must to exclude moisture.

Chlorinated solvents are slowly hydrolyzed to acids, SO ENSURE water tank cleaning is NOT stopped in an early stage.

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FREE FATTY ACIDS (IN VEG OILS AND ANIMAL FATS) --FFA

FFA of certain heating veg and animal oil cargoes will increase if the moisture content is too high.

Veg and animal oils have different SG at different levels after long storage. FFA of the layer closest to the coils increases faster and cause damage to the bottom— so recirc Vegetable oil and Animal oil in coated cargo tanks.

Advantages are less manual labour for squeezing after discharge and not allowing a difference in the FFA content between the lower and upper levels in the tanks.

Fat is combined with glycerine and fatty acid. When the fat is hot , it get decomposed to FFA and glycerine ( hydrolysis ). Increase of FFA means the cargo will become worse in quality. The quality of vegetable oils and animal fats is largely determined by their AV acid value. A fresh oil or fat has low AV. Parcels having different FFA shall not be commingled . Rapid heating results in increase in FFA content or discolouration of the cargo.

Vegetable oil and Animal oils have a FREE FATTY ACID content (FFA). The hydrolysis of edible fats and oils is promoted by the presence of water, particularly at higher temperatures. If hot prewashed FFA will increase rapidly to a level, which will coagulate the albumen in the Vegetable/Animal oil. This damages the surface of the zinc silicate lining.

Changes in quality of the veg fats and oils occur during shipment due to hydrolysis and oxidation , and this loss in quality is taken into account when edible fats and oils are processed further into food during refining.

Previous cargoes that are able to accelerate hydrolysis of edible fats and oils are:
acids and bases e.g. acetic acid, acetic anhydride, citric acid, fatty acids, phosphoric acid, sulphuric acid, and sodium hydroxide solution.

The general loss of quality due to oxidation (increase in peroxide values) or hydrolysis (increase in free fatty acid [FFA] content) during a voyage can be eliminated by , nitrogen-blanketing the tank, especially if the cargo is refined oil to be used directly in the food-chain without re-refining.

Normal values for refined oils in the Codex Standards indicative for oxidative or hydrolytic rancidity status are:
Peroxide value: up to 10 meq active oxygen/ Kg oil
Acid value/saponification value: up to 0.6 mg KOH/g oil.

Oxidation affects the colour and flavour (taste, odour) of the oil, producing oxidative rancidity.

Hydrolysis affects the flavour (taste, odour) and acidity of the oil, producing hydrolytical rancidity.

Analytical methods for hydrolysis are based on determination of the hydrolysis products. Hydrolysis tests are based on the determination of the FFA content, humidity, acid value (or saponification value) or hydroxyl value. The acid value is the most widely used test method. Refined oils for domestic consumption are most susceptible to hydrolysis .

The Chief officer on a chemical tanker must smell the tanks before they are loaded or unloaded and look into them during loading and unloading. Smell is a very sensitive sense. The purpose of deodorization is to reduce the level of free fatty acids and to remove odours, off-flavours and other volatile components, such as pesticides and light polycyclic aromatic hydrocarbons. Deodorization of edible fats and oils is done by distillation.

Neutralization ( alkali refining) is performed on edible fats and oils to reduce the content of free fatty acids and oxidation products of free fatty acid.

FFA of veg/ animal oils attack zinc silicate paint which can cause zinc to shed contaminating cargo-- Zinc Silicate paint cannot take pH < 6 . Recirc of veg/ animal oil in Zinc coated tank is a must to equalize the FFA content between the upper and lower layers.


-------CAPT AJIT VADAKAYIL ( 28 YEARS IN COMMAND )

15 comments:

  1. Dear Captain,

    Greetings.
    Looking forward to your valuable guidance (whenver you have a couple of mins more :O) )

    AAA)
    I'm planning to go to music classes (& possible drawing classes if time permits)..
    As my son(2.5 yrs) is growing (who is always eager to learn) and another young one is due by Dec.... I feel I should have something in me to teach.

    Neither know head nor tail about music, although I always love to hear classic instrumentals (anything from tamboori to veena)

    Looking forward to your priceless guidance, if I should focus on any particular music instrument to learn (& unlearn / destress).
    (PS: Cannot affort costly instruments Captain given my current situation).


    BBB)
    (sorry to seek extending your guidance, given your time constraints...If you have another couple of mins, would be helpful to get your valuable inputs)
    My entire 15 years of career has been in IT.. don't know if I've already become Mandhbuddhi (or 'shallow minded' if I use your terminology).

    Going through a lot of stress, as I've plans to end my career in IT (shore job with golden handcuffs - Ref : Pep talk to your cadets) and looking to switch for an alternative source of income (own business);
    I'm looking forward to a decent income to keep my family and self happy.... No high goals, career etc... planning to get in to just plain buy and sell kind of business.
    (My deep inner voice is always sided on agriculture.. however some day I would have my own land and will start agriculture / farming)

    Had already tried working on ecommerce startup... but didn't click..(rather it was due to my introvert nature)
    Read the 'Core Values - What must be', Maturity Lessons which were a great piece of wisdom, put across precisely.

    Would be greatful, if you could let me know what are the key points/ principles, qualities that I need to always stick to and nurture in me Captain? considering the shift I intend to do in the next couple of months.

    Going forward, I want to be a 'Free willed' person without 'wrinkles like you, doing my duties , managing my family responsibilities duly.
    At 35, I've more wrinkled lines, when I smile (than a normal aged person at age 60) although I'm slim and most times mistaken for a 25 yr old.

    (I know you would say you are a bad role model, nonetheless there can never ever be another man like you with your real time experience across the globe with the your kind of perception)

    Always remember your interview with Sindon and it brightens me up :0)

    Grace & Peace,
    JTA

    ReplyDelete
    Replies
    1. LET HIM LEARN THE KEYBOARD

      ONCE HE KNOWS THE BASIS FROM A MUSIC TEACHER HE CAN LEARN ON HIS OWN.

      THERE IS NO SUBSTITUTE FOR HARD WORK

      Delete
  2. Dear Captain,

    Thank you for very much for your valuable guidance... :0)
    Will do as suggested reg music and a huge 'Yes' to give my best in all what I intend to do.
    (Only efforts can be ours, results are HIS)..Thanks again Captain.

    Wishing you and your family, a very happy and wonderful 'Gowri - Ganesha festivities' in advance.


    Captain, I've another question (not related to above topic)

    You had told that, most of the Gods/ dieties whom we do pujas are cosmic allegories personified for easy understanding ( powers of nature).

    The reason I ask is "We are celebrating Ganesha festival".. You had mentioned that Ganesha also is a cosmic allegory who is the guardian of Mooladhara chakra.
    Only if he unties the moolagranthi, the energy at the Mooladhara chakra can raise to Sahasraara.

    My doubt is "Would these powers apart from doing their duties (balancing/ maintaining the creation), can they hear and respond directly to us humans ? (creations with lower frequencies)."
    I do agree, that in everybody's experience, maybe atleast once, everyone would experience our prayers(requests) get answered.

    (The only thing that I'm aware is, when we do as part of Puja is we are thankful / show gratitude for all what the Lord / creator has showered).

    How does that really work and why would it vary from one individual to another.
    (Please excuse/ ignore if my question sounds stupid)

    Grace & Peace,
    JTA

    ReplyDelete
  3. Dear Captain,

    Nice to see you couple... Wonderful pic :0) in the recent blog (Justice cannot be blind).

    May God's blessing be upon you and your family always.

    Many of your readers haven't met you in person.. however that something (do not the exact word) is keeping us like the bees in the hive to your blog. Could notice from all the birthday wishes from your avid blog readers.

    Sincerely thank you from the bottom of my heart, for all the knowledge you share ( & to know something which is going to happen in future - your revelations) and SOS replies. :O).

    Grace & Peace,
    JTA

    ReplyDelete
  4. Dear Captain,

    Greetings.
    Need your guidance.

    Wifey is in 8th month and she's still recovering from the after-affects of hospitalization (due to Dengue)
    Do not want the mother's experience affect the kid's mental and character imprints, when in womb.

    For first baby, she used to read Bhagavatha by herself very diligently.
    However after the incident(Dengue related), she's not very keen on reading Bhagavatha, even after I keep asking her to do repeatedly.

    I remember, on the day of my first kid's delivery, had read the chapter to wifey where Brahma praises the creator Narayana.
    This time, I'm a bit worried as many things went haywire and not much she could focus.

    Please could you recommend any ragas / mantras, which is very good for both the kid and mother, as we have just another 6-8 weeks (due date).

    Grace & Peace,
    JTA

    ReplyDelete
    Replies
    1. JUST LET HER BE HERSELF

      KEEP HER HAPPY

      ALL WILL BE OK

      Delete
  5. Dear Captain,

    Sure, will do as suggested so she is happy from within.
    I'm hoping for the same.

    Thank you very much :0).

    Grace & Peace,
    JTA

    ReplyDelete
  6. Dear Captain,

    Wishing you and your family, a safe, happy & wonderful Deepavali festivities.

    May the festival of lights, enrich your ever-high spirited souls further with the creator's blessings.

    Grace & Peace,
    JTA

    ReplyDelete
  7. Dear Captain,
    May be it sounds stupid... however couldn't resist and therefore posting this questiosn.
    Please reply, if you find valid.

    1) Is the creation / creator or Brahman, partial towards evil (things / people / characters ....etc)
    All the good (things, people)in the past & current, have always received the short end of the stick..(they go through the suffering /pain ...etc and what not Millions of lives have been destroyed few couple of centuries back)

    Today... only what is bad / worse for a human being in terms of habits, food, culture is always at

    ex: the entire world has been run, ruined by only a few (Mslm/Mghl rulrs, who enjoyed all possible things beyond the best of people's reach).

    You may say Karma...etc still... long back it was with few stupid ppl who ruined and today it's with few retarded idiots(R-grp/n-wo/bldbg), who is ruining.

    (Even few mythological characters...did all the ruining only to be killed by Vishnu avatars and they suffered the pain for few minutes only during their death)


    2. You had mentioned, that the Brahman keeps receiving feedback from jivanmukth souls...

    What feedback, can you expect from these souls, as these souls raise themselves beyond the normal and for them everything they see as part of nature and therefore all in the same weigh scale... (Gold and stone are the same..no difference and same with good/ bad aswell)

    (for ex: it doesn't matter to them the materialistic life/things in the current world; however the root cause of all the evil is this)

    3. Do you think the n wo / R / bldbg club have mastered some of any rituals / mantras / tantras..etc so they keep ruining the entire world and still go scot-free ?
    (As they had access to all our Vedic texts which they got it translated).

    Looking forward to your replies for each of the above qstns..Thx.

    Grace & Peace,
    JTA

    ReplyDelete
  8. Dear Captain,

    Greetings.

    Very glad to inform you that, I've been blessed with a baby boy y'day evening (normal).
    Both baby and mother are doing fine. This is my second child.
    (Most surprisingly, today is our marriage anniversary :-)

    Sincerely, thank you for all the guidance received, till date.

    Request your blessings, Captain.
    (Would be great, if Ma'm could also join you in blessing the new born... :o) )

    (Have always felt that unseen /unknown happiness and joy brimming within me, whenever I see your couple pics :0) )

    Grace & Peace,
    JTA

    ReplyDelete
    Replies
    1. HI P6

      CONGRATULATIONS

      MAY YOUR NEW BORN PROVIDE YOU AND FAMILY WITH IMMENSE JOY AND PRIDE

      Delete
  9. Dear Captain,

    Thank you very very much for your divine blessings :)))))

    Grace & Peace,
    JTA

    ReplyDelete
  10. Dear Captain,

    Greetings.

    Request your valuable guidance; this is regarding the blood test results of my new born.


    We got our baby the mandatory BCG and blood tests done after a week from the hospital.

    Baby's blood group was B+ve.
    We couple are O+ve and our first kid aswell; Also from my side, parents, brother are all O+ve.
    (I'm not too sure on the Wife's side regarding blood group).

    The blood group being B+ve was surprising for us and RH+ve. (Wifey is O+ve with RH -ve)


    Generally, is the new grouping possible ?

    Also, Wifey was admitted to hospital fro Dengue. she was given the Donor platelets - random (RDP) - 12 satchets & single (SDP) - 4 satchets.


    Would there be a possibility that this has influenced the blood grouping (due to receiving platelets)?
    Sorry for my ignorance on the blood grouping part. Looking forward to your clarification.

    Grace & Peace,
    JTA

    ReplyDelete
    Replies
    1. (Wifey is O+ve with RH -ve)

      YOU ARE TOTALLY CONFUSED

      CALM DOWN

      Delete