1

MRPL REPORTBy: Dharmik Sai Mikkilineni

2

TABLE OF CONTENTS

S.NO DESCRIPTION PAGE NO.1. INTRODUCTION 32. CRUDE 53. CDU&VDU 64. MEROX 75. VBU 86. HCU 87. CCR 108. GASOLINE BLENDING 119. DIESEL BLENDING 1110. HYDRODESULFURISATION 1211. ISOMERISATION UNIT 1212. BBU 1213. SRU 1314. ATU&SWS 1315. HYDROGEN PLANT 1416. FURNACE OIL 1417. UNITS 1418. UTILITIES 1519. EQUIPMENT & MAINTENANCE 1520. OM&S 1721. LAB TESTING 1822. MARKETING & PRODUCTION 2323. SUMMARY 24

3

INTRODUCTIONMangalore Refinery and Petrochemicals Limited (MRPL), a public sector

refinery, started up in 1996. The refinery is divided into two phases, with a third one established recently. 1996 marked the beginning of phase 1 of the refinery having a capacity of around 3.69Million Metric Tons (MMT). In 1999 this capacity increased to 9.69MMT with phase 2 commencing with a capacity of 6 MMT. However, MRPL runs at 12MMT, which is an efficiency of nearly 130%, with phase 1 running at 4.8MMT and phase 2 running at 7.2MMT. MRPL is responsible for supplying oil to the entire state of Karnataka and also to Mauritius along with small quantities exported to various other countries in Asia. The nelson complexity Index of MRPL is around 5.5 without phase 3 and the UOPK factor of the crude obtained is approximately 12. The nelson complexity index is a measure of the secondary conversion capacity of a refinery relative to the primary distillation unit, namely the Crude Distillation Unit (CDU). MRPL is large with around 1200 people comprising its workforce and covering nearly 3000 acres. Water, one of the most important utilities for a refinery, is supplied to MRPL from the Netravathi River nearly 45 Km away via, a large pipeline. All of the operations are monitored using the Distributed Control system (DCS network) where signals are sent from the field to the marshalling cabinets and then to the corresponding servers which distributes the signals among several console stations operated by the respective operators in the control room. Phase 1 is controlled using the Honeywell Experion PKS system while phases 2 and 3 are managed by the Yokogawa Centum VP system.

Petroleum products can be primarily into 3 different types: Light Distillates (LPG, Gasoline, Naphtha), Middle Distillates and (Kerosene, Diesel) and Heavy Distillates (Heavy Fuel Oil, Wax, Asphalt/Bitumen). MRPL's refinery process aims to produce bulk or major quantities of middle distillates. MRPL’s refinery process starts off with crude imported or bought and sent to MRPL jetty tankers. Crude is then transferred to the crude receipt area where the crude is billed. MRPL owns 2 jetties in order to allow adequate crude to be obtained and refined. Once the crude is paid for, it is sent to the crude feed which pumps the crude to the Crude Distillation Column (CDU). The CDU distils the crude primarily into LPG, Naphtha, Kerosene, Diesel and Reduced Crude Oil (RCO).

The sour fuel gas coming from the CDU goes to amine treatment and the resulting sweet gas is used for heating processes in the refinery. Sour water stripper strips the CDU column for sour water which goes into waste water treatment and subsequently, the deep water effluent. Some of the sour water enters the Sulfur Recovery Unit, which helps producing the sulfur found in the sulfur pit. LPG undergoes amine treatment and enters the LPG Merox Unit to remove the sulfur compounds or the Mercaptans which is then sent to the domestic market in bottled and bulk forms.

Light Naphtha undergoes caustic wash to yield marketable Naphtha and sold to fertilizer and petrochemical industries. Heavy Naphtha goes to the Naphtha Hydrotreater which then goes to the Continuous Catalytic Reformer (CCR) unit. Reformate is then sent to jetties for exporting. Naphtha also enters the gasoline blending section to yield gasoline or Motor Spirit (MS) which is consumed in local markets. Kerosene from the CDU unit enters the Kerosene Merox unit to provide mercaptan-free kerosene sent to jetties for exporting and consumed in local markets. Some kerosene is also blended with other important chemicals to provide Aviation Turbine Fuel (ATF) consumed in all local

4

airplanes. Diesel also produced by the CDU unit enters the diesel blending area and used in domestic markets.

The Reduced Crude Oil which cannot be further distilled in the CDU unit enters the Vacuum Distillation Unit (VDU). The RCO is further distilled into Vacuum Gas Oil (VGO) and Vacuum Residue. The components are sent to the HydroCracker Unit (HCU) which distils the VGO into LPG, Naphtha, ATF, Diesel and Low Sulfur Heavy Stock (LSHS). The VisBreaker Unit (VBU) then breaks the Vacuum Residue into Naphtha, Diesel and Fuel/Furnace Oil. The Bitumen Blowing Unit (BBU) subsequently takes in the heavy leftover residue to produce Bitumen and any remaining residue is recycled back to the VDU which repeats the above process.

Table 1. MRPL products and CatalystsMRPL Products MRPL CatalystsBitumen Filter ClayMotor Gasoline OHC-HCU CatalystTreated Effluent NHT Catalyst CCRDiesel (CDU) CCR Catalyst (regenerated)Diesel (0.25% S) CCR Catalyst (Spent)Aviation Turbine Fuel Chloride Guard CatalystVacuum Gas Oil ZnO CatalystRaw Effluent Reformer Catalyst (46-1 & 46-4)Diesel (GOHDS) HT Shift Converter CatalystDiesel (HCU) Activated Carbon (Walter filtering medium)Kerosene DC Balls (2304G & 2304-PSA-H2)Product Sulfur Ceramic Fiber in furnacesNaphtha Glass Wool for insulatorsFurnace Oil Silica GelMixed Xylene NaOH (Water treatment chemical)Reformate De-oiling (Poly electrolyte)Crudes H2O2 (Hydrogen Peroxide-Water Treatment Chemical)*Note: The Catalysts and Products are not corresponding to each other and in no particular order.

Table 2. Feed and Products for each Unit. No. UNIT FEED PRODUCTS1. Crude Distillation (CDU) Crude Oil LPG, Naphtha, Kerosene,

Diesel, Reduced Crude Oil (RCO)

2. Vacuum Distillation (VDU)

Reduced Crude Oil Vacuum Gas Oil (VGO), Vacuum Residue

3. VisBreaker (VBU) Vacuum Residue Naphtha (Gasoline), Diesel, Fuel/Furnace Oil

4. HydroCracker (HCU) Vacuum Gas Oil (VGO)

LPG, Naphtha, ATF, Diesel, Low Sulfur Heavy Stock (LSHS)

5. Continuous Catalytic Heavy Naphtha Reformate (High octane

5

Reformer (CCR) petrol), LPG, Hydrogen6. Isomerization Light Naphtha Isomerate (High octane

Petrol), LPG, Mixed Pentane

7. Merox LPG & Kerosene Mercaptan-free products8. Bitumen Blowing (BBU) Vacuum Residue Bitumen9. Sulfur Recovery (SRU) Amine Acid Gas Sulfur10. Amine Treatment (ATU) H2S Rich Amine H2S free Lean Amine11. Sour Water Stripper (SWS) H2S & NH3 rich sour

waterH2S & NH3 free sour water

12. Hydrogen Sweet Naphtha High purity Hydrogen13. Hydrotreater Naphtha, Kerosene,

Diesel, VGOLow Sulfur products

CRUDECrude oil is essentially hydrocarbon compounds which comprise 85-90% Carbon,

10-14% Hydrogen, 0.2-3% S, 0.1-2% N, 1-1.5% O and other metals in traces. Purchasing of the Crude is the beginning process of any refinery without which none of the products mentioned above will be produced. 90% of MRPL's crude is obtained from the following places: Iran (NIOC), Saudi Arabia, Abu Dhabi (ADNOC), Kuwait (KW) and Bombay (Bombay high). The remaining 10% is imported from various countries. This 10% is chosen from 1000 different crudes available in the world, out of which far away countries like USA and those in Europe and South America are eliminated leaving only around 200 crudes. These remaining 200 odd crudes are then inputted into a linear program to decide the best crude amongst those. MRPL uses the Aspen PIMS linear program, which determines the best crude based on price, availability, quality and other such factors.

Crude is primarily classified into four main categories: Paraffins, Olefins, Naphthenes and Aromatics (PONA analysis). Paraffins are straight chain single bond hydrocarbon compounds with the formula CnH2n+2. Olefins are unsaturated hydrocarbons or paraffins which have been dehydrogenated with the formula CnH2n. Naphthenes are ring or cyclic single bond hydrocarbon compounds such as cyclohexane and cyclopentane. Aromatics are cyclic compounds with double bonds and include any compound with the benzene ring. Another characterization of crude is of sweet crude and sour crude, which is based on the sulfur content. Sweet crude is crude with lesser than 0.5% sulfur content and crude with greater than 2.5% is termed as sour crude. MRPL, so far, has handled crude with a maximum sulfur content of 2.8%.

As mentioned before the UOPK factor is approximately 12. This characterization factor classifies crude oil according to its Paraffinic, Olefinic, Naphthenic and Aromatic (PONA) nature. A value of 12.5 or higher indicates that the crude is highly paraffinic while 10 or lower indicates a predominant Aromatic nature. Since MRPL produces mainly middle distillates, crude should preferably contain a higher degree of naphthenes in order to convert these naphthenes to aromatics in the Reformer unit which produces a higher RON for diesel. The K factor is calculated by taking the cube root of the boiling point of crude divided by its corresponding density.

6

CDU&VDUThe primary process in a refinery is the Crude Distillation Unit. All other units

fall under the category of secondary processes. The crude feed is first sent to desalter tank, where crude is stripped of its salts. Crude oil contains a certain amount of calcium, sodium, magnesium and other metal chlorides and compounds. The main intention of desalting is to prevent fouling and corrosion of equipment due to the deposition of salts, especially chlorides. It is also to ensure the salts do not deactivate any of the various catalysts used. Desalting can be done either chemically or through electrostatic separation using water as the extraction agent. MRPL uses the electrostatic method where Demineralised (DM) water and crude is first mixed using a mixer. Due to the polar nature of water, salts are absorbed from the crude. A demulsifying agent is added to prevent an emulsion of crude and water forming and hence, allows better separation of the two components. This mixture is subject to a high voltage electrical field inside the desalting vessel where water droplets coalesce and drop down, due to gravity, and can then be stripped off from the bottom. Another important use of the desalters is to separate any water content from the crude because if moisture is present, it will get flashed in the CDU column and disturb the trays due to the high expansion coefficient of water. Desalters reduce salt content of the crude by 90-98%. The crude is then sent from the desalters to three sets of preheat trains where crude is heated to the adequate temperature and sent to the CDU column.

For any distillation process, the driving force is the relative volatility, which essentially means the difference in boiling points of the various components in the crude. The distillation column works at atmospheric pressure, which is 1 atm or 1kg/cm2. MRPL has 2 CDU columns and 2 VDU columns with one more column of each coming up in phase 3. Distillation columns can either be filled with trays or packing. Packing is a more efficient form of mass/heat transfer than the use of trays since it increases the liquid vapor contact, however packing is very expensive. Hence, trays would suffice for the CDU column since the products have large boiling point differences and high efficiency is not required. The CDU column in MRPL contains 46 trays. MRPL uses four different types of trays based on the stipulated requirements: Valve, Sieve, Bubble and Chimney trays. While, there are two types of packing: random and structured. Random packing is preferable due to increased efficiency. The Vacuum Distillation Unit (VDU) operates using packing due to the requirement of a greater degree of separation or distillation. Vacuum Distillation is used to distil the Reduced Crude Oil obtained from the CDU unit to Vacuum Gas Oil and Vacuum Residue. One of the most prominent questions asked around is why vacuum is needed in this distillation column and why atmospheric pressure would not suffice.

The answer to this question is to understand an extremely important property taken into consideration in a refinery: Lower the pressure, lower the boiling point temperature. Hence due to the very low or negligible pressure of vacuum, the components would flash or vaporize at much lower temperatures. Otherwise the distillation process would require extremely high temperature and energy, which in turn increases operation costs. These high temperatures could also lead to some amount of cracking and coke formation. A distinguishable feature of the VDU column from the CDU is the use of steam ejectors. There are 3 ejectors used to maintain vacuum in VDU.

7

These ejectors work on the basis of Bernoulli’s principle and convert the generated pressure to velocity.

Another important parameter controlled in both these columns is the reflux, which is of two types: circulating reflux and internal reflux. The use of reflux is to improve thermal efficiency and to maintain better flow of the various streams. Circulating reflux is where reflux is collected in a reflux drum from a lower plate and part of it is sent back to a higher plate in order to control the heat load. This happens due to the fact that as you go down a distillation column temperature increases and since the reflux at a lower plate is at a higher temperature, it will provide the required heat for the liquid to flash at the upper plate. Internal Reflux, on the other hand, is where some of the vapors above the condensate fall to a lower plate via the downcomer. This condensate is then vaporized to rise to the upper plate again.

Table 3. Boiling Cuts (IBP-FBP)Product Boiling cuts (°C)Naphtha 35-150

Light Naphtha – 35-90Heavy Naphtha – 90-150

SKO/ATF 150-250Diesel (HSD) 250-370VGO 370-550Short Residue (SR) (Same as RCO) 550+

MEROXThe products obtained from the distillation columns contain mercaptans.

Mercaptan is a sulfur compound designated as RSH where R is an alkyl radical attached to Sulfur which is attached to Hydrogen. These compounds can be toxic and are highly corrosive leading to the need of their removal. Merox is an abbreviation for Mercaptan Oxidation. There are two types of merox treatments possible: Extractive Merox and Sweetening Merox. LPG undergoes extractive merox while kerosene undergoes the sweetening merox. LPG goes from the CDU unit to the amine treatment unit where LPG is treated for amines which are removed. LPG then travels to the LPG merox where mercaptans are completely extracted/ removed. Kerosene, on the other hand, undergoes a caustic wash where NaOH is added to the solution. Mercaptans are then sweetened by converting the RSH compound to other sulfur containing compounds which are less poisonous and less corrosive. The reaction that takes place is given below:

NaOH+RSH → NaSR+H2O NaSR is then oxidized again to form disulfide. The reaction takes place in the presence of air and catalyst. The reaction is:

NaSR + RSH +1/2O2 → NaOH + (RS)2

This step is useful in another way by regenerating the caustic or NaOH and hence it is not required to procure this solution constantly. Since MRPL is an old refinery, merox units are present. However the disadvantage with merox units is that they produce other sulfur containing compounds especially sulfur oxides, which are major pollutants to the environment. Hence modern refineries are opting for catalytic dehydrosulfurisation

8

units, which are more economical and further processing is not required to remove the sulfur oxides present in the product.

VBUVacuum Residue from the VDU goes to the VisBreaker Unit (VBU). This is a

mild thermal cracking unit that cracks high vacuum distillates and residues to give gasoline, naphtha, gas oil and furnace oil as products. Visbreaker is of 2 types: Furnace process and soaker process. MRPL implements the soaker process. The main difference between the furnace and soaker process is the use of an extra vessel known as the soaker, which is placed between the furnace and the fractionators to give extra residence time for the reaction to take place. The main reactions that take place are:Paraffins→Paraffins+OlefinsOlefins→Olefins +Olefins/Paraffins

However the VisBreaker Unit is not very popular these days with most modern refineries opting for the Delayed Coker Unit. In fact, MRPL itself has employed this unit in phase 3. Some of the differences have been listed:

The conditions/ severity, such as the temperature, of the delayed coker unit are much greater than the VBU and hence, components in the delayed coker unit undergo a much greater degree of cracking. This can be observed with the fact that the light oils percent in the VBU is only 3-5% as compared to 70% seen in the delayed coker.

The delayed coker unit works in batch process with 4 reactors, however the inlet and outlet will function as continuous processes. By the time the input reaches the 4th reactor, the first reactor needs to be cleaned of coke and input needs to be filled. Filling of these reactors is a very long process taking nearly 8 hours.

Coke formed in bottom of these reactors due to the extreme conditions and the extent of cracking seen. This coke is cleaned out using high pressure water (≈100kg/cm2) to cut the coke which is then dumped out.

Due to the existence of the batch process and the requirement of coke cleaning, delayed coker unit is one of the most difficult equipments to manage, in mechanical terms.

No catalyst or hydrogen presence is required in the delayed coker unit yielding very high olefin content in the product.

The most important disadvantage of the VBU versus the delayed coker unit is that the VBU produces fuel oil which is very low in market price (also known as black oil) whereas the delayed coker converts this black oil to white oil within the unit itself yielding much higher quality products.

HCUThe HydroCracker Unit is one of the most important units where Vacuum Gas Oil

obtained from the VDU is cracked to provide useful products, which are LPG, Naphtha, ATF, diesel and Low Sulfur Heavy Stock (LSHS). LSHS is nothing but fuel oil with less than 1% Sulfur content. Hydrocracking is nothing but cracking in the presence of hydrogen and catalyst. Cracking is the breaking of complex heavy hydrocarbons subjected to heat to form several different pieces, which are lighter and simpler. The

9

HCU in MRPL contains 3 fixed bed reactors in order to treat the VGO. Fixed bed reactors are used to treat Vacuum Gas Oil and ebulliated bed reactors used for residue.

The hydrocraker unit works in extreme conditions with temperatures ranging from 420-450°c and a pressure of almost 186kg/cm2 indicating that the HCU has the highest pressure requirement of all the units. Due to the severity, the HCU undergoes a shutdown once a year. In order to reach the pressure requirements, the HCU unit uses a series of centrifugal and reciprocating pumps. The centrifugal pump runs at nearly 10000rpm but produces a very small differential pressure change. The reciprocating pump runs at 3000rpm but increases pressure from 6 to only around 20kg/cm2. To translate this pressure to the required pressure multiple impellers and a gear box is used. The reciprocating pump consumes nearly 3.6MW of power. Hence to minimize this requirement, MRPL takes advantage of a turbine placed in front of the Feed Surge Drum (FSD). The turbine can generate nearly 2.8MW of power implying that only 0.8MW of power needs to be supplied. This turbine is known as the Power Recovery Turbine (PRT). Currently in phase 1 and 2, recycle hydrocrackers are being operated, however in phase 3 MRPL will be utilizing the once-through hydrocrackers. A once through flow is when the input flows only once in the reactor and yields the product without any of the input reprocessed in the reactor. MRPL is one of the only refineries in India to have two Hydrocracker and CCR units.

The reactions taking place in the hydrocracker unit are overall exothermic and lot of energy is released. The HCU is the biggest consumer of hydrogen in the refinery requiring large amounts of H2 gas to crack the VGO. Each reactor has 4 beds. The first bed is treated for sulfur and nitrogen, which is converted to ammonia, so the corresponding treatment catalyst, is used, while the other three beds contain the hydrocracking catalyst. Multiple beds are used rather than allowing the reactions to take place in a single bed in order to maintain the cold temperature of the hydrogen. Some reflux of the hydrogen is taken from the second bed and added to the third bed and same process repeated for the fourth bed. Cold temperature is necessary since the reaction is already highly exothermic providing very high temperatures in the reactor upon completion of the reaction. The HCU operates with excess hydrogen and due to this undergoes several other reactions in the first bed of the reactor. These reactions are same as any hydro treatment reactions:

RSH+H2→RH+H2S (Desulfurization)ROH+H2→RH+H2O (Deoxygenation)RNH+H2→RH+NH3 (Denitrogenation) RM+H2→RH+MH (Demetallation)

Due to the rising demand of gasoline and jet fuel, hydrocracker units are becoming more prevalent in refineries. This is due to the very high gasoline yield of the unit coupled with gasoline with high octane numbers providing a good Research Octane Number (RON) for marketable purposes. Another important unit similar the HCU is the Fluid Catalytic Cracking unit (FCC).The main differences are:

The FCC unit undergoes a greater degree of cracking FCC requires sulfur free and low aromatic content VGO. But the HCU can crack

gas oil with high aromatic content the HCU contains sulfur treatment in the same reactor.

10

FCC produces 50-60% light Naphtha and gasoline and the rest kerosene and diesel. The HCU, on the other hand, produces 80% kerosene and diesel.

The FCC unit has a greater degree of olefins in the product due to the absence of hydrogen as opposed to the HCU.

FCC unit is one of the most difficult instruments to manage, from a technical standpoint.

CCRContinuous Catalytic Reformer converts heavy Naphtha to High octane gasoline,

LPG and hydrogen. The high octane petrol product is known as reformate. However, the most valuable aspect of this unit is the high production quantities of hydrogen. Naphtha with high content of paraffins, olefins and naphthenes are converted to aromatics, hence yielding higher octane petrol. The main reactions that occur in this unit are:

Paraffins converted to isoparaffins Paraffins converted to naphthenes Naphthenes converted to aromatics

However side reactions occur, one of them being: Some paraffins and naphthenes crack to form butanes and lighter gases

Naphthenes are converted to aromatics by the dehydrogenation process where hydrogen is removed forming an important by-product. The CCR unit is one of the major suppliers of hydrogen and any extra hydrogen required is generated by a hydrogen plant. The reactor contains 4 beds similar to the HCU, but the reaction in this case, is endothermic. Due to this difference the reflux of hydrogen is taken from the first bed, heated and then supplied to the second bed and so on and so forth, unlike the cold hydrogen reflux in the HCU. The hydrogen reflux not only maintains temperature and flow but also avoids some amount of coking. Chlorides (anions) in the form of dimethyl chloride are added to the catalyst in order for it to form cations since the catalyst is only active in the ionic state. These chlorides are later treated and removed. The unique feature of the CCR unit is the continuous regeneration of the catalyst which becomes spent/ inactive due to coking. The coke is eliminated in the regeneration section where several hoppers are used to retain the spent catalyst for coke removal and the active form sent back to the reactors. The coke is removed by the following oxidation reaction:

C (coke) + O2 → CO & CO2

An essential part of this section is to ensure the catalyst is kept dry since it is very reactive with water. The average amounts in the MRPL regeneration section is 29600 kg of catalyst flowing down at 450lb/hr. Hence for every particle of the catalyst to reach down and get regenerated it takes nearly 6 days. The actual metal or reacting part of the catalyst is only 2%, while the rest is the area over which the catalyst acts on. This is so due to the extremely high prices of the catalyst. For example, the catalyst costs nearly 24 crores and lasts for around 10 years. For the Hydrocracker Unit, the catalyst is more valuable costing the same 24 crores but with a lifetime of only 3 years. This is due to the lack of the regeneration section present in the CCR unit. However, one positive aspect of the catalyst is that the used/spent catalyst is also highly valuable costing roughly 20 crores.

GASOLINE BLENDING

11

The two most important variables in gasoline blending are the octane number and the Reid Vapor Pressure (RVP). The main objective of the CCR is to increase the octane number of gasoline to provide a higher Research Octane Number (RON). Octane number is the amount of isooctanes in the product which measures the ignition quality of gas, where 100% isooctane reads a 100 RON while 100% normal heptanes translates to a 0 RON. To understand the octane number better it is essential to understand the car engine and the idea of knocking first. A gasoline engine comprises of a gas tank, fuel pump, carburetor, cylinder, piston and a spark plug. The only difference with this engine and the diesel engine is that the diesel version does not have the spark plug. This spark plug is responsible for igniting the fuel-air mixture at a specific time based on the piston stroke cycle. However due to low octane number and inadequate compression or high temperature or pressure, the fuel air mixture might ignite improperly creating an explosion and interfering with the cycle. This leads to the knocking sound heard from the engine and hence termed as knock. The octane number represents the amount of aromatics, which have a unique feature of resisting self-ignition. Hence, higher the octane number, higher the compression ratio and longer the power stroke and more powerful the engine. This provides greater resistance to knocking. The octane number can be characterized in two parts:Research Octane Number (RON): simulates driving under mild conditionsMotor Octane Number (MON): run under more severe conditions and simulates operations under load or at high speeds and tries to achieve conditions as close as possible to the actual engine.

What is seen on gasoline pumps is usually the average of these two values. Octane number is also increased with the addition of lead in the form of TetraEthyl Lead (TEL) or TetraMethyl Lead (TML). Another special property of this lead is it increases the RON without affecting other properties such as the RVP. However it is highly toxic and limited to minute quantities in gasoline (less than 0.5%).

The other important parameter is the Reid Vapor Pressure, which is measure of the volatility of this gasoline. RVP represents the fuel’s evaporation at 100°F. The RVP varies with seasons, since it is dependent on temperature. The gasoline must be able to withstand the two extreme conditions:

On cold starts, enough gasoline (≈10%) must vaporize to give an ignitable mixture and the rest of the gasoline should subsequently burn too.

When engine is completely warmed up the vapor must not expand so much that no air can be mixed. Mixture should still be ignitable.

The Indian standards of motor spirit (M.S) are a minimum RON of 91, minimum MON of 81 and a maximum RVP of 60. To obtain these specifications, gasoline from various units such as the CCR, CDU, Isomerisation unit, etc are all blended in the blending section.

DIESEL BLENDINGDiesel engines, on the other hand, do not have the spark plug. The fuel ignites

itself. The property that measures the ignition quality of diesel is the cetane number. Higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane is an un-branched alkane hydrocarbon (C16H34). Hence paraffins are more desirable in diesel due their low self-ignition temperatures. Therefore diesel is not

12

produced in the CCR unit, which increases the aromatic content of fuels. Regular diesel normally contains 40-45% cetane, while premium diesel has 45-50%. Premium diesel has a lighter range, more volatile fractions and is better for cold starts. Diesel is blended in the blending unit similar to gasoline.

HYDRODESULFURIZATION (HDS)The HDS unit is used to treat sulfur and reduce the content to meet the

environmental requirements. This unit is also known as the Hydrotreater Unit The sulfur is catalytically hydrogenated to form H2S and removed from the product. Sulfur needs to be removed to reduce sulfur oxide emissions (a major pollutant) which are formed upon the combustion of automotive fuels. Another necessity of the removal is that sulfur can poison the catalyst making it permanently inactive. MRPL has two HDS units: Kerosene Hydrodesulfurization (KHDS) and Gas Oil Hydrodesulfurization (GOHDS).

Other reactions that happen in this unit are the denitrogenation, deoxygenation and demetallation reactions mentioned above in the HCU. The excess hydrogen is separated from cooled products in a high pressure separator drum, which is recycled back to the reactor. Hydrotreating is used to improve the burning characteristics and enhances the smoke point, providing cleaner compounds. The GOHDS unit produces premium high speed diesel, where HSD with a sulfur content of about 0.5% is inputted to yield diesel with sulfur less than 50ppm in order to meet the specifications of Euro 3 and Euro 4 levels. KHDS unit, on the other hand, takes in kerosene and produces ATF. Aviation Turbine Fuel (ATF) is kerosene with special characteristics. ATF is produced by removing surfactants, water, mercaptans from kerosene in KHDS and the Merox units.

ISOMERISATIONIsomerisation is a chemical process where one molecule is transformed to another

with the same molecular formula but with a different arrangement of the atoms. The objective of this unit is to produce high octane, low aromatic gasoline. This product is more commonly known as isomerate. The main difference between this unit and the CCR is the aromatic content. Aromatics containing benzene rings need to be limited since benzene is highly carcinogenic. The main reaction of the isomerization unit is to convert the straight chain paraffins to their branched chain counterparts since more clustered atoms add to a higher octane level. The reaction that happens is: n-paraffins → isoparaffins (Eg: n-butanes → isobutanes; n-pentanes → isopentanes)

The product stream is then sent to the gasoline blending section to blend with gasolines from other units with different properties in order to meet the stipulated requirements. The isomerate can also be sent to the CCR unit if more aromatic conversion is necessary.

BBUBitumen/Asphalt is categorized into four types: Straight run, blown, cutback and emulsion.

1. Straight run bitumen is a black/dark brown high viscous solid material. Flashing at very high temperatures of the vacuum residue is required in order to produce this bitumen. There are two major characteristics of bitumen:

13

Softening point: It is the temperature at which an object with a standardized weight and shape will start to sink into the asphalt. Common practice is to use steel balls, which is what MRPL follows. Commercial softening points range from 80-340°F. Penetration: Hardness of asphalt once load is applied. The range is from 0 (very hard) – 250 (very soft)

2. Blown bitumen is produced by blowing hot air into softer grades of the asphalt causing a chemical reaction yielding more rubbery and harder asphalt.

3. Cutbacks are yielded from the addition of a thinner to the bitumen in order to reduce the temperature requirements giving softer asphalt. However after asphalt has been applied the thinner/diluent evaporates yielding a hard, durable asphalt. Examples of the diluent include Naphtha (for rapid curing) and kerosene (for longer curing). Cutbacks can be problematic however, due to air pollution caused by the evaporation of the diluent.

4. Emulsion is a mixture of 50-70% bitumen and 30-50% water. The mixture remains mixed with the aid of an emulsifying agent, like soap. Due to the high cost of this agent though, it comprises about only 1%. Emulsion is similar to cutbacks where the water evaporates after application leaving hard asphalt behind.

MRPL only produces straight run and blown bitumen. However, they are looking into advantages and basics of producing emulsion asphalt. The blown bitumen is produced in this Bitumen Blowing Unit (BBU). Air is blown through the molten feed, which is the vacuum residue via an air distributor at the bottom of the column.

SRURecovery of H2S gas is mostly done by solvent extraction using diethanolamine

(DEA). The Sulfur Recovery Unit (SRU) does not necessarily make a profit, since sulfur is not such a valuable product. But it is necessary due to the very strict environmental regulations these days and since H2S is a highly poisonous and flammable gas, it needs to be eliminated. Hence, all the H2S formed from all the hydrotreating units and as byproducts in any other units is converted to solid sulfur. Sulfur recovery efficiencies generally range from 95-98% based upon the feed composition and plant configuration. MRPL follows the Claus process, which is the most significant gas desulfurizing process. The Claus process can be divided into a thermal and a catalytic stage. Some of the Hydrogen Sulfide in the feed gas is thermally converted to SO2 and sulfur in the reaction furnace, which is the thermal stage. In the catalytic stage, the remaining H 2S reacts with the SO2 to form sulfur in the element form. These reactions are illustrated below:

2H2S + 2O2 → SO2 + S + 2H2O (thermal stage)2H2S + SO2 → 3S + 2H2O (catalytic stage)

Most refineries, including MRPL, store and ship the molten sulfur formed. The sulfur can be indefinitely stored in a dry state called a pile. MRPL stores this pile in an area called the sulfur recovery pit. Sulfur has wide applications, including manufacturing sulfuric acid, cosmetics and fertilizers, to name a few.

ATU & SWSThe removal of H2S, mercaptans and other sour gases is essential, as mentioned

before. These gases are removed by dissolving them in amine solvents, referred to as

14

sweetening processes, since the products no longer contain the foul odors of the sour gases. Most common solvents used in refineries are alkanolamines such as monoethanolamine (MEA) and diethanolamine (DEA). The Amine Treatment Unit comprises of an absorber and a regenerator section. In the absorber, the solvent and sour fuel feed flow in countercurrent directions. The solvent dissolves the sour gases from the fuel and exits from the bottom which goes to the regenerator section. In the regenerator section the H2S and sour gases are stripped and thus lean (H2S-free) amine is produced from rich (H2S-heavy) amine.

Sour Water Stripper (SWS) is another treatment unit which treats sour water coming from all the units. Water is primarily used to dissolve ammonia, which is a very good absorbent in water. However some H2S also dissolves. To treat the water from these two compounds, the SWS system is designed. The SWS section can either function using low pressure steam or a steam fired reboiler as the heat source. The ideal pH for stripping H2S is below 5 while the optimum pH for stripping ammonia is above 10. Hence to compensate for both these pH values, the typical pH of the steam ranges from 8 to 10.

HYDROGEN PLANTThe main source of hydrogen is the CCR unit. However since that H2 amount is

not sufficient to run the entire refinery, MRPL generates that extra H2 from a hydrogen plant. A possible solution of generating H2 is through the Steam Methane Reformer (SMR) mechanism. However methane being a natural gas is very hard to obtain. Hence many refineries, such as MRPL, have opted for the Steam Naphtha Reformer (SNR). The sweet naphtha entered into the system undergoes cracking producing various different olefins along with methane and hydrogen. The reactions that methane undergoes are the same as those that occur in the SMR, which are:

CH4 + H2O → CO + 3H2 (Reforming reaction)CO + H2O → CO2 + H2 (Shift Conversion Reaction)

FURNACE OILFurnace oil is an important utility in the refinery. It is also referred to as number 2

fuel, distillate fuel, two oil or fuel oil. It is the most popular petroleum heating oil. The reasons for using furnace oil include: carries more heating capability than lighter hydrocarbons (LPG, naphtha and kerosene), cheaper to transport than LPG/natural gas since pressure equipment is not required, not as susceptible to accidental/explosive ignition as naphtha, easier to burn than residual fuels since they don’t have to be heated before injecting into the fire box and easier to render pollution-free than residual fuels due to less complex chemical constituency. Two important parameters are the flash point and the pour point. Flash point is the lowest temperature at which enough vapors form a combustible mixture. It measures volatility and inflammability and set to a specific safety limit. Pour point is the ability of a petroleum product to flow at low temperatures. It is normally 5°F higher than the temperature at which the oil stops flowing. In MRPL, for every 100 metric tons of fuel oil produced, 7 metric ton is used for heating purposes. Hence 7% is consumed for personal use.

UNITSThe units present in MRPL are summarized below:

15

2 Crude Distillation Units (CDU)2 Vacuum Distillation Units (VDU)2 VisBreaker Units (VBU) 2 HydroCracker Units (HCU)2 Continuous Catalytic Reformer units (CCR)2 Hydrogen plants1 Gas Oil HydroDeSulfurization (GOHDS)1 Isomerization unit 3 Sulfur Recover Units (SRU)

UTILITIES

The important utilities required, without which a refinery cannot run are:1. Steam:

Low Pressure (LP – 4-5kg/cm2) Medium Pressure (MP – 13-17kg/cm2) High Pressure (HP – >40kg/cm2)

2. Power – Energy requirement3. Water

Utility Water Demineralised water (DM water- upon removal of all metals and salts )

4. Nitrogen: Important in purging and evacuation of hydrocarbons especially during shutdown.

5. Air: Normal air Instrument air (dry and moisture free –present in all pumps and valves)

6. Flushing oil (LGO)7. Fuel Oil (FO)8. Fuel Gas

EQUIPMENT & MAINTENANCEOther than all the above mentioned units there are many other equipment used

such as pumps, compressors and valves. Pumps & compressors: Pumps are designed to handle liquids, while compressors generate pressure for gas streams. Pumps and compressors are of two types: centrifugal and reciprocating. Centrifugal pumps impart pressure to the fluid by generating kinetic energy using impellers. Reciprocating pumps, meanwhile, develop pressure head by the linear movement of a plunger acting on the fluid to transfer it to various heights. Centrifugal pumps can pump large volumes of fluid but develop very low pressure heads. Reciprocating pumps handle lower volumes can generate higher pressures. Control Valves: MRPL follows two color codes for all its valves: Red Valve: Automatically stops flow during failure/excess flow (most valves). Green Valve: Automatically starts/continues flow even during failure (eg: heaters). The other characterization of valves is Gate, Globe and non-return. Gate Valve (A.K.A on-off valve): Either allows complete flow or stops all flow. It is comprised of a rectangular plate to stop the flow. Globe Valve: Shaped as a globe, this valve permits only the desired

16

level of flow, whether it is 50%, 10% and so on. Non-return Valve: This valve allows flow in only one direction. Steam Droplet Collector: Steam travels long distances, via pipes, from its main source, the steam generation plant. After certain distances, the temperature drops and steam condenses. This water needs to be removed from the pipes to avoid disturbance and faster condensation rates and is collected in this steam collector bucket. Steam trap: The steam trap ensures none of the steam is lost by opening the tap to the steam droplet collector when the steam is in liquid form and closing when steam in the vapor form is present. Heat Furnaces: There are four types of drafts used in industrial systems:Natural Draft: It is a draft based on the chimney process with no external source of heat. Instead, it is based on the density difference between hot gas in the chimney and the air outside. Forced Draft: Draft system that uses a centrifugal fan to deliver air to the furnace and provide heat. Induced Draft: A centrifugal fan is used to draw air from the furnace and ensures combustion air flows through the system. Balanced Draft: This draft is a combination of the forced and induced draft systems.

MRPL employs only natural and balanced draft heaters. These drafts work at negative pressure, which is pressure slightly below atmospheric pressure. The heaters, due to their high temperatures, experience convection and radiation zones which act in a countercurrent manner to each other.

There are many other types of equipment, which will not be covered here. To maintain all these equipment, MRPL has setup two workshops: instrumentation and mechanical. The four primary parameters that need to be measured and controlled are: Pressure, Temperature, Flow and Level. To measure these parameters field instruments are used. Field instruments comprise the valves, sensors and other instruments mentioned above. To measure the field instrument a pre-calibrated test instrument is used. These test instruments are measured using a master instrument, which are subsequently compared to reference values from Cochin. The Cochin values are referenced with measurements in Delhi and so on and so forth. In this way, the instruments are measured against national and international standards. Master instruments are tested once in three years, while the field and test instruments are tested every year. In total, 48 test instruments are tested in a given calendar year. The accuracy limit of the field instrument is 1%, that of the test instrument is 0.5% and that of the master instrument is 0.1%. Thus, the role of the instrumentation workshop has been identified.

MRPL’s mechanical workshop is divided into Heavy Equipment, Machining and welding & fabricating. MRPL uses two types of welding processes: Sheet Metal Arc Welding (SMAW) and Tungsten Inert Gas (TIG). Metal Inert Gas (MIG) welding is not done here. Arc welding is a manual welding process which uses a consumable electrode coated with a purifying agent, known as flux, to lay the weld. TIG is an arc welding process using a tungsten electrode to produce the weld. MRPL uses the following materials along with corresponding grades: Stainless Steel (304, 308, 316, and 347), Alloy (P5, P9, P11, and P22), Carbon steel and Inconel. These materials are cut to the desired and shape using two methods: Plasma Cutting for stainless steel and DA cutting (oxygen with Acetylene cylinder – used due to its ability to achieve high temperatures)

17

for alloy and Carbon materials. MRPL has 3 qualified welders and 2 fabricators. The welders are qualified by completing the Indian Reboiler Welding Course (IRWC) from Bangalore. In the machining section, MRPL uses various machines to cut the material to the desired shape and size. These are: Hydraulic Hacksaw Machine, Drilling Machine, Boring Machine, Hot Tapping Machine, BFW Milling Machine, Tool and Cutter Grinder, Grinding Machine, Lathe Machine, Slotting Machine and Shaping Machine. The heavy equipment of MRPL contains 4 cranes (240, 150, 40 and 20 tons), tractors, forklifts and 3 Hydra (5, 8 and 12 tons).

2 types of equipment inspections occur in MRPL: predictive and preventive maintenance. Predictive maintenance (a.k.a condition based maintenance) is an activity that attempts to predict when a unit should be shut down for maintenance, in order to prevent a failure. Preventive maintenance is a maintenance performed at predetermined intervals intended to reduce the probability of an item not meeting an acceptable condition. There are totally around 3000 equipments in phase 1 and 2 combined and another 2000 coming up in phase 3. All of these have to undergo the maintenance program with the frequency depending on how critical the equipments are. Critical equipments, those which do not have a standby, have vibration measurements taken every week. Semi-critical and noncritical equipments have vibration measurements taken every 15 days.

OM&SOil Movement and Storage (OM&S) unit becomes a vital function in the refinery due

to the handling of large quantities of oils. Storage is necessary to accommodate intermediate, finished products and crude. Three types of storage tanks are used based on the material being collected:

Fixed Roof Tanks: These tanks are used to store products of low volatility. The products are Kerosene, Diesel and Residual Crude Oil.

Floating Roof Tanks: Floating roof tanks are used for storing products with high vapor pressure. These products cannot be stored in fixed roof tanks due to higher pressure and hence, greater evaporation loss. The roof rises and falls based on the liquid level in the tank. One issue with this tank though, is that rain water and snow can accumulate on the roofs sinking them in. All crude and light products are stored in this type of tank.

Floating cum Fixed Roof Tanks: These tanks are designed to store light products, while ensuring rainwater is not allowed. These tanks are used to store ATF, Reformate, etc.

Horton Spheres: These spherically shaped pressure vessels are used to store LPG, which is an extremely volatile product. The use of spheres in eliminating corners, which would be the lowest pressure points.

Oil is transported either using pipelines or transferred in bulk in trucks. Pipelines can be connected to either ships, other pipelines or connected to the oil marketing companies.

In fact, there is a pipeline connecting to Bangalore transferring MS at a rate of almost 500m3/hr. Pipelines will transfer the oil straight from the storage tank units. In the marketing department, on the other hand, trucks are loaded in bulk quantities. There are

18

two sections in this department with two different loading areas. The first section contains 6 bays for MS, Mixed Xylene, ATF and Naphtha. 11 bays are present in the second section used to load various different grades of bitumen and fuel oil. MRPL however, has not developed its marketing department to a great extent, with a small area for truck loading. Hence, they are planning to build a larger and superior marketing department with more than 20 bays in one area. One of the bays used currently now transfers crumb rubber modified bitumen (CRMB). This specialized bitumen is used for airport roads, which requires greater withstanding of friction and needs to be harder. CRMB is made by mixing a small amount of rubber and MRPL uses Tinna Bitumen Modifier (TBM). Bitumen can be filled directly into the truck or filled into drums, transferred to different areas. On an average 3000 drums can be filled in a given day, but this rate depends on bitumen demand. This section holds a heater in order to constantly reheat the bitumen, which will stop flowing due to high viscosity under cool temperatures. The Marketing department is computerized by the Truck Automation System (TAS). The truck that needs to be loaded is weighed before and after the product has been filled and compared with the sensor that is administered by the TAS software.

LAB TESTINGMRPL has a well made laboratory with imported equipment mainly from France

and other European countries. A large investment has gone in to make this lab which is worth more than 35 crores rupees. The Laboratory is extremely essential to ensure the quality of products meet the customer and environment requirements. There will be many instances where the product will not meet the specifications and the entire product produced in that unit will have to be reprocessed in the necessary unit. Since MRPL functions round-the-clock 365 days in a year, the products need to be tested regularly too. Products in high sensitive areas are checked twice a day, while those in low sensitive areas are checked once a day. ATF, being highly sensitive, is tested every four hours and if it fails to meet the requirements it will be dumped in to the kerosene unit. The unique property of crude though, is that there are no major changes of properties and hence testing of crude is done only once in three years. The properties will also not need to be evaluated since they will already be provided in an assay given by the company that supplies the crude.

The lab also has an expensive imported test engine, which simulates the car engine. This engine tests the RON and MON and the cetane number for both diesel and Motor spirit. A mini distillation column is also present in order to distil crude and obtain the boiling cuts of the various products. This experiment is known as the True Boiling Point Distillation and used occasionally. There are numerous other distillation columns for conducting distillation of the various other products along with an expensive vacuum distillation column, in order to simulate distillation in vacuum. Some of the specifications of the various products are given below. These specification values are from the 2011 report:

M.S – B.S III (Bharat Stage 3)PROPERTY REQUIREMENT ACTUAL VALUEDensity @ 15°C, kg/m3 720-775 756RON Minimum 91 92

19

MON Minimum 81 84.2Sulfur, % weight Maximum 0.015% 0.001%Lead Content, % Volume Maximum 0.005% <0.01%Reid Vapor Pressure (RVP) @ 38°C, in kPa Maximum 60 52Vapor Lock Index Maximum 750 for

summer, 950 for winter

695 for summer

Benzene Content, % Volume Maximum 1% 0.62Olefin Content, % Volume Maximum 21% 0.9%Aromatics Content, % Volume Maximum 42% 41%Distillation, Recovery upto 70°C, % Volume 10-45% 25%Distillation, Recovery upto 100°C, % Volume 40-70% 50%Distillation, Recovery upto 150°C, % Volume Minimum 75% 85%Distillation, Final Boiling Point, °C Maximum 210 189Distillation, Residue, % Volume Maximum 2% 1%

SKOPROPERTY REQUIREMENT ACTUAL VALUEDensity @ 15°C, kg/L N/A 0.7925Distillation, Recovery below 200°C, % Volume Minimum 20% 63.5%Final Boiling Point, °C Maximum 300 244Flash Point, °C Minimum 35 42Smoke Point, mm Minimum 20 23Sulfur, % Mass Maximum 0.25% 0.13%Burning Quality, char value, mg/kg Maximum 20 18

HSD – B.S IIIPROPERTY REQUIREMENT ACTUAL VALUEDensity @ 15°C, kg/m3 820-845 826.2Kinematic Viscosity, CST Minimum 91 92Cetane Number Minimum 51 55.2Flash Point, °C Minimum 35 46Sulfur Content, mg/kg Maximum 350 330Water Content, mg/kg Maximum 200 190Ash percent, % 0.01% <0.01%Distillation, Recovery upto 360°C, % Volume Minimum 95% 96.5%

Fuel Oil (380 CST)PROPERTY REQUIREMENT ACTUAL VALUEDensity @ 15°C, kg/L Maximum 0.9900 0.9632Kinematic Viscosity, mm2/s Maximum 380 371Ash Content, % mass Maximum 0.10% 0.046%Sulfur, % weight Maximum 4% 3.15%Vanadium, mg/kg(ppm) Maximum 200 170Sodium, ppm Maximum 100 20

20

Water Content, % Volume Maximum 1% 0.20%Flash Point, °C Minimum 66 72Pour Point, °C Maximum 20 -6Asphalt, % Mass Maximum 14% 8.6%

BitumenPROPERTY REQUIREMENT ACTUAL VALUEDensity @ 15°C, g/mL No requirement 1.0341Flash Point, °C Minimum 220 264Penetration @ 25°C, 100g, 5 sec, 0.1mm 50-70 50Softening Point, °C Minimum 47 49

ATF (Jet A1)PROPERTY REQUIREMENT ACTUAL VALUEParticulate Contamination, mg/L Maximum 1 0.8Acidity Total, mg KOH/gm Maximum 0.015 0.011Aromatics, % Volume Maximum 25% 17.7%Sulfur Content, % weight Maximum 0.30% 0.24%Flash Point, °C Minimum 38 45Freezing Point, °C Maximum -47 -51Smoke Point, mm Minimum 19 23Electrical Conductivity, pS/m 50-600 190

Treated EffluentPROPERTY REQUIREMENT ACTUAL VALUEpH 6-8.5 7.7Sulfide Content, mg/L Maximum 0.5 NDOil & Grease Content, mg/L Maximum 5 2.8Phenols Content, mg/L Maximum 0.35 0.16Dissolved Oxygen Content, mg/L No requirement 5.1Suspended Solids Content, mg/L Maximum 20 14

Mixed XylenePROPERTY REQUIREMENT ACTUAL VALUEDensity @ 15°C No requirement 0.8656p-Xylene, % weight Minimum 18% 20.11%Ethyl Benzene, % weight Maximum 20% 16.45%Toluene, % weight Maximum 0.5% 0.07%Non aromatics, % weight Maximum 2% 1.85%Sulfur Content, mg/kg Maximum 1 0.2Dry Point, °C Maximum 143 140

LSHSPROPERTY REQUIREMENT ACTUAL VALUEPour Point, °C Maximum 60 18

21

Flash Point, °C Minimum 66 100Kinematic Viscosity, CST Maximum 100 60Sulfur Content, % weight Maximum 1% 0.87%Water Content, % Volume Maximum 1% 0.1%Ash Content, % Mass Maximum 0.1% 0.047%Acidity, % Volume 0% 0%Sediment Content, % Mass Maximum 0.25% 0.05%

Some of the important properties for the various different products have been listed above in the tables. To measure these properties and others not listed here, multiple different experiments are available with most of the experiments not requirement too much manual calculations and work. This is because all the experiments are digital along with the facility to work with a program known as the Herzog software. There are more than 50 experiments conducted at different frequency levels in MRPL. Some of these are listed below along with their significance:

Anton Paar Measurement: Density is automatically calculated using an automated instrument known as Anton Paar. The sample amount and temperature is inputted, but standards require the density to be provided at 15°C. This will automatically be calculated by the Anton Paar equipment. Density calculations are extremely important in calculating mass of product.

Viscosity: Viscosity is measured by using various different types of viscometers. Viscosity calculations are necessary in order to determine if the product will flow or not.

Sulfur: Sulfur is an extremely important property to test for and meet the environmental specifications. There are several experiments to test for sulfur. One of it is the X-Ray Fluorescence (XRF) method which calculates sulfur ranges from 0.02% to 5%. The sample is placed in a beam emitted from an X-ray source, which accumulates the count and illustrates the sulfur content. Another method is the bomb method which calculates sulfur content of more than 0.1% in products like diesel and fuel oil. The sample undergoes complete combustion in oxygen which converts the sulfur to sulfur dioxide and upon further subjection converts to sulfur trioxide. The sodium trioxide then forms sulfuric acid estimated gravimetrically and reported as % weight. A third method is the lamp method which calculates sulfur concentrations from 0.01% to 0.4%. The sample is burned in an enclosure and the oxides formed are oxidized to sulfuric acid with the help of H2O2. The sulfuric acid then undergoes titration to determine the sulfur amounts.

Flash Point: Flash point, as defined before, is the lowest temperature at which sufficient vapors form a combustible mixture. MRPL follows two methods for this test: Abel and Pensky-Martin Closed-Cup (PMC) method. The abel method is used for materials with flash points below 70°C and those above that temperature use PMC method. This experiment determines the flammability of the material and ensures that it meets the fire and safety regulations.

Pour Point: Pour point is the lowest temperature at which the oil is able to flow and is expressed as a multiple of 3°C. MRPL follows two types of instruments:

22

One that works on tilting the sample in a cup and observing if liquid pours, which is the manual method. The other process functions by blowing air onto the liquid and determines if a disturbance at the top of the liquid is observed, which are sensed by optical detectors. This is the automatic method. This test indicates the conditions the material should be stored in.

Smoke Point: This is the maximum height of the flame, in millimeters, ATF and kerosene samples burn without smoke. The sample is burned in a standard lamp with a graduated millimeter scale on the back to measure the flame height. The smoke point indicates the properties, such as the aromatic content, of the fuel.

Freezing Point: It is the lowest temperature at which ATF remain free of hydrocarbon crystals, which are formed on cooling. These crystals restrict the flow of the ATF and can create issues for the aircraft. The sample is cooled until formation of crystals and then warmed up with temperature at which the crystals disappear reported. This is an extremely important specification for aviation fuels which could form crystals during prolonged cold soaking at high altitudes. Under these conditions the crystals should not restrict the flow of the fuel and hence, the importance of the test.

Penetration: This test determines the hardness of the bitumen and is measured by piercing the needle into the bitumen material under the standard conditions of 100gm load, time of 5 seconds, and temperature of 25°C and measured to the nearest 0.1mm. Based on these tests the grades of bitumen are provided. MRPL produce three different grades of bitumen: 30/40, 60/70 & 80/100.

Softening Point: This is temperature at which a standardized material, specifically the steel ball, which starts to sink into the bitumen. The softening point measures the consistency and hardness of the bitumen similar to the penetration. The temperature reported is when the steel ball touches the bottom plate.

These are some of the important tests done along with their respective significances. However, there are a number of other tests done not provided here. The laboratory has also just setup a Research and Development (R&D) section 1 year back, which is in its initial stages. Currently this department is looking at prospects in bitumen emulsion and polymer added bitumen. They are also analyzing surrounding ground water and attempting to purify it to drinking water.

MARKETING AND PRODUCTION

Table 4. MRPL Customers ListPRODUCT CUSTOMERSLPG HPCLNaphtha Domestic & ExportsMotor Spirit OMCs, Mauritius & ExportsKerosene OMCs ATF Domestic, Mauritius & ExportsHSD OMCs, Mauritius & ExportsFO Domestic, Mauritius & ExportsBitumen Domestic – Road Contractors like PWD

23

Sulfur Domestic OMCs (Oil Marketing Companies) – Include Hindustan Petroleum Corporation Limited (HPCL), Bharat Petroleum Corporation Limited (BPCL) and Indian Oil Corporation Limited (IOCL).

Marketing is done by these OMCs. Transferring of oil is easy to these companies through pipeline since they are next door to MRPL. MRPL also sends some of its oil to Mauritius, which is a three year term. The amount send to Mauritius, in Thousand Metric Tons TMT), is:

Motor Spirit: 125TMTATF: 270TMTHSD: 375TMTFO: 480TMT (2 grades: 180CST, 380CST)

Bitumen Demand is variable and depends on bitumen demand, which is usually peak in summer time. Bitumen is sold to road contractors like PWD (Public Works Department). Kerosene Demand has been going down and dropped by nearly 20 percent because villages are developing electrically and hence less kerosene needs to be burned for electrical causes.

Table 5. Quantity of Products produced per Annum

Product Amount Product (TMTPA2)Crude 12817Liquefied Petroleum Gas (LPG) 290 (2.26%)Motor Spirit (MS) 1010 (7.88%)Naphtha 1298 (10%)Superior Kerosene Oil (SKO) 323 (2.52%)Aviation Turbine Fuel (ATF) 1195 (9.32%)High Speed Diesel (HSD) 5187 (40%)Fuel Oil (FO) 2192 (17%)Bitumen 260 (2%)Remaining – Mixed Xylene, Sulfur, etc. Remaining 9%1All numbers in this table are only approximate values and not exact figures2TMTPA-Thousand Metric Tons Per Annum

Table 6. Applications of MRPL productsProduct Some ApplicationsLiquefied Petroleum Gas (LPG) Fuel – Food industry, Glass manufacturing, Cement

manufacturing, Metal industry, Automotives, Aerosols, etc.Motor Spirit (MS) Fuel – Automotives, solvents, in small appliances like

lawnmowers, cement mixers, etc. Naphtha Feedstock for producing gasoline, Industrial solvents, oil

painting medium, shoe polish, fertilizer and petrochemical industries, fuel for stoves and other applications, cleaning fluid, hydrogen production, etc.

Superior Kerosene Oil (SKO) Residential heating and lighting fuel, Feedstock to produce

24

ATF, solvents, pesticides, paints, degreaser, etc. Aviation Turbine Fuel (ATF) Fuel for aviation industryHigh Speed Diesel (HSD) Fuel in transportation sector, residential heating, back-up

power generators, extraction agent (high sulfur diesel) etc. Furnace Oil (FO) Major heating fuel, fuel for bunkering (ships), feedstock in

fertilizer plants, etc.Bitumen Roofing, flooring, paving of roads, hydraulics, etc. Mixed Xylene Solvents in printing, pharmaceuticals, paints & perfumes,

electroplating, feedstock for producing meta, para and ortho Xylene, etc.

Sulfur Feedstock to produce sulfuric acid and sulfuric compounds (vast applications), pesticides and fertilizers, hardening agent for rubber, gunpowder, etc.

Petroleum Coke Raw material for carbon and graphite products, reducing agent, fuel, etc.

SUMMARYWe all travel in cars or other forms of transportation without paying too much

attention to the fuel that runs the vehicle. MRPL has not only surprised me to an extent but opened my eyes on the amount of chemistry involved to produce this fuel and other petroleum products that we use on a daily basis. This report is in fact, only a summary of the processes that happen in a refinery. There is a great deal of planning and design development in order to set up the refinery. Not only all of the chemistry involved in this report, but in order to set up the refinery, various other factors such as business, safety issues, employment of qualified workers, etc has to be taken into account. For example, when taking into account safety issues: losses due to 100Nm3/hr LPG vaporized are Rs. 190 lakhs/yr while losses due to 100 Nm3/hr hydrogen flared is Rs. 1 crore/yr. Hence, the magnitude of losses and costs are illustrated here.

I have also learned the complexity in simply maintaining the equipment. For example, on a visit to the Hydrocracker field the Power recovery turbine failed. The valve was not working and the bearings needed to be fixed. The bearings, which are extremely small, have to be repaired using lubricating oil and estimate the temperature and this process takes a minimum of 2 days. Two days, might seem normal for us, however two days makes a major difference to the refinery with large amounts of products not produced. Hence, to cover up for these losses, lot of critical equipment are built in redundancy, where one of the equipments can run if the other one fails.

However all of these requirements add to the costs and that is where the business model is extremely important to do a cost analysis. Another shocking aspect is that all of these costs are only around 20% of the costs. 80% of the cost is to purchase the crude oil. Crude costs so much due to the large investment made in oil exploration where oil has to be drilled out from deep into the ground. In India there are primarily 4 oil exploration companies: Oil and Natural Gas Corporation (ONGC), Oil India Limited (OIL), Essar Oil Company and Reliance industries. These companies can extract around 40 Million Metric Ton Per Annum (MMTPA). However the Oil refineries in India can process around 140 MMTPA and hence the remaining crude needs to be imported. The refineries are divided

25

into public sector (IOC, BPCL, HPCL, ONGC-MRPL, and ONGC) and private sector (Reliance, Essar and Nagarjuna).

This is the big picture of the oil sector in India. Visiting MRPL was extremely beneficial where I could see the theory I learned in classes in practical applications. The importance of the refinery was also observed with an entire state of Karnataka and the entire Mauritius country dependent on its oil from MRPL. I think it was a great learning experience with a great and accommodating working staff. I would like to thank everyone involved in assisting me and in conclusion it was a great stepping stone for further learning in the future.