Seminar on Storage of Hc

8/9/2019 Seminar on Storage of Hc

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GUIDED BY:

Mr. PIYUSH VANJARA

PREPARED BY:

Ms. MANISHA VAID

SEMINAR ON

STORAGE OF HYDROCARBONS INTANK FARMS OF A REFINERY COMPLEX


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INTRODUCTION TO THE TOPIC

Vapor PressureReid Vapor Pressure

Classification of liquids

CLASS 1: liquids having flash point below 37.8c

Class 1 a : flash points below 22.8c and boiling point below 37.8c

Class 1 b : flash points below 22.8c and boiling point at or above 37.8c

Class 1 c : flash points at or above 22.8c and boiling point below 37.8c

CLASS 2 : liquids having flash point at or above 37.8c

CLASS 3 : liquids having flash point at or above 60c

Class 3 a : liquids having flash point at or above 60c and below 93.4c

Class 3 b : liquids having flash point at or above93.4c


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STORAGE OF PETROLEUM

PRODUCTS NEED OF STORAGE

BASIC CLASSIFICATION OF STORAGE (BASED ONPHASE)

Storage of liquids Storage of gases

based on internal pressure

based on roof shape based on service


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BASED ON INTERNAL

PRESSURE ATMOSPHERIC TANKSInternal pressure slightly above atmospheric pressure

pressure varies from atmospheric up to 0.5Psi above atmospheric

pressure

LOW PRESSURE TANKS

Higher pressure from atmospheric up to 15Psig

PRESSURE VESSELS

Pressure above 15Psig


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BASED ON ROOF SHAPE FIXED ROOFTANKS

Cone rooftanks

: bottom is flat and top made in form of shallow cone

: storage of large quantity of fluids

: roof rafters and support column

Umbrella and dome rooftanks

: tank roofs are self supporting

FLOATING ROOFTANKS

External floating roofs

: diameter 30 100 ft.

: roof is steel deck having annular compartment that provides buoyancy

: double deck built for small floating roofs

: strong and durable because of double deck: suitable for large diameter tanks

Internal floating roofs

: pan roofs are simple sheet steel disks

: bulk head pan roof

: skin and pontoon roofs


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BASED ON SERVICE PRESSURE VESSELS

Unfired

Cylindrical

: Bullets

: Reactors (with agitator): Columns

: Road tankers

Cuboidal

Spherical (HORTON SPHERE)

Fired

Boilers

Heaters


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TYPESOF VERTICAL CYLINDRICAL

TANKSFO

R PET

ROLEU

MLIQUIDSPETROLEUM LIQUID TYPE OF TANK

CLASS 1:Petroleum (flash point below

21c e.g. motor and aviation gasoline)

(a) floating roof

(b) non pressure fixed roof with

internal floating deck

(c) pressure fixed roof

CLASS 2 : Petroleum (flash point

between 21c and 55c) e.g. kerosene,

special boiling point liquids

(a) Floating roof

(b) Non pressure fixed roof with

internal floating deck(c) Non pressure fixed roof with

atmospheric vent

CLASS 3 : Petroleum (flash point

above 55c ) e.g. diesel and gas oils,

medium and heavy fuel oils, lubricatingoils and bitumen

Non pressure fixed roof with

atmospheric vent.Tanks which content

heavy fuel oils or bitumen areinsulated and heated


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STORAGE OF GASES GAS HOLDER

Liquid seal holder :Seal tanks : size up to 2,80,000 m3 andFlexible fabric diaphragm

SOLUTIONOFGASES INLIQUIDScertain gases will dissolve readily in liquidsexample : ammonia in water, acetylene in acetone and hydrochloric acid in

water

STORAGE IN PRESSUE VESSLES,BOTTLESAND PIPELINESGasses are stored under pressure

A storage pressure vessel is usually a permanent installation, storing a gasunder pressure and liquifying it at ambient temperaturefor example : carbon dioxide

Bottle is usually applied to a pressure vessel that is small enough to beconveniently portable

Bottles range from about 57 lit. (2ft3) down to CO2 capsules of about 16.4ml(1 in3 )example : air , Hydrogen , Nitrogen , Oxygen etc

PipelinesPipes buried in series of connected parallel lines and used for storage

Storage is also obtained by increasing the pressure in operating pipe lines and thus usingthe pipe volume as a tank


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LOSS MECHANISMS

GENERAL DISCRIPTION

Evaporative losses :

Finite vapor pressure produced by the liquid stockdepending on surface temperature and composition of

liquid.Establishment of an equilibrium concentration of

vapors above the liquid surface.

Floating roof tanks are exposed to dynamicconditions disturbing equilibrium and leading to

additional evaporation.Evaporative losses primarily occur duringstanding storage and influenced by ambient wind.


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Design losses RIM SEAL LOSS:vapor loss from Rim

establishment of low pressure zone above floating roof.

DECK FITTING LOSS:

fittings have openings that allow stock vapors to flow to

atmospheremechanism governing is vertical mixing.

DECK SEAM LOSS:

when seams are not completely vapor tight they become source of

evaporative loss.

WITHDRAWAL LOSS:

as floating roof descends during stock withdrawal some of the

liquid stock clings to the inside surface of the tank shell and it exposed

to the atmosphere.


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CAUSES OF LEAKS AND SPILLS

AND

THEIR PREVENTION Causes of Losses

Leak or spill source Characteristics Root causes Preventive measures

Corrosion most common in tank bottoms and corrosion; materials selection; careful design and engineering,

Underground piping; low rate; lack costs of corrosion prevention inspection per API 653; tank

Or warning; may continue for years methods management programUndetected; large volumes released

Over long periods; column

Operations

Overf il ls or Transfers Larger quantit ies released; operator error; instrumentation or tank management program having Quickly discovered; hazardous equipment failure; lack of written operating procedures;

Potential for fires; relatively training; failure to maintain training and drills; periodic

Common overfill systems testing of instrumentation

Roof drains large volumes released; easi ly equipment fai lure; fai lure to use tank management program having

Discovered; usually occur in secondary containment properly written operating procedures;

Stormy weather; relatively rare training and drills; periodic

Testing of instrumentation

Leaks leaks relatively common in piping, tank management program having

Valves, and fittings, pump seals, written operating procedures;

Or in penetrations through training and drills; periodic

Secondary-containment areas testing of instrumentation

Tank breakage Brittle fracture occurs in cold weather; material selection; poor careful design and actual

Catastrophic failure mode; entire fabrication details; failure to solution; assessment of brittle

Tank contents can empty; extremely hydrotest fracture and seismic after each

Rare significant charge of service;


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SUMMARY

TYPESOFSTORAGE VESSELS

FACTORSTO BE CONSIDERED DURINGSTORAGE THAT

ISSTORAGE BASED ON CLASSOF PETROLEUM LIQUID

LOSSESAND SPILL PREVENTION


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BIBLIOGRAPHYBOOKS :

Encyclopedia of Chemical Technology vol. 23

By: KIRK OTHMER

Chemical Engineering. Book

By: PERRY

Process Equipment design

By : M. V. JOSHI

JOURNALS :

I.P.C.L. , BARODA

WEBLINKS :

www.Google.com

www.altavista.com

www.sciencedirect.com

www.hydrocarbonprocessing.com

www.chemweb.com

Documents

Seminar on Storage of Hc