PUT BOTH QUESTIONS AND ANSWERS HERE ITSELF

Limkar Gajanan Vishnudas (2011CH70163) 1.What is the role of permeate spacer in spiral wound RO Membrane? Ans- To create turbulence & reduce the path blockage by salt deposition. 2.Which factors play role in providing stability to membranes? Ans-Cross linked polymers, plastisizers, CO2 Degasifiers. 3.What is minimum energy required for desalination equivalent to? Ans: Energy equivalent to heat of mixing of solutes in water (sea water – 0.7kWhr/m3). 4.Why is HCl added in Brackish Water Reverse osmosis (BWRO) plant at initial stage? To decompose the carbonates, bicarbonates in feed water. 5.Why MicroFiltration (MF) Unit is provided in Brackish Water Reverse osmosis (BWRO) plant before Reverse Osmosis? To reduce the load on Reverse Osmosis (RO) unit.

Faheem Shereef (2011CH70157)

1. What is the allotropic state of sulfur extracted from the carbon-disulfide solution after flashing?

2. What is meant by a ‘bottleneck’ in a chemical manufacturing process? 3. What is the use of adding live steam to an evaporator? 4. Where does the raw material for Insoluble Sulfur production come from? 5. Why use a flash column and not a distillation tower for the process?

AAYUSHI DIXIT (2011CH70141) 1. What are the various stages of drug development ? (Ans: Discovery, pre-clinical, phase-I, phase-II, phase-III testing)

2. What are biosimilars? (Ans: Biosimilar is a biopharmaceutical drug designed to have active properties similar to one that has previously been licensed)

3. Which reagent is usually used for breaking of the inter and intramolecular bonds present in the protein molecule? (Ans: Cysteine. The bonds are broken by the nucleophillic attack of thiol group)

4. What is the significance of R-square value in statistics? (Ans: It determines goodness of fit of the data)

5. Which property of molecules is utilized for their separation using hydrophobic interaction chromatography? (Ans: Hydrophobic interaction chromatography (HIC) separates molecules based on their

hydrophobicity)

Priyanka Gupta (2011ch70177) 1.Why do we use spike concentration in HCP method? Ans. To check system error. 2. Limit after which we can quantify our values? Ans. Quantitation Limit 3. Based on signal-to-noise ratio, what is the typical value of detection limit? Ans. 3 4. For accuracy, should we check all values or average value? Ans. All values 5. How do we check accuracy in LC method Ans. By checking % recovery and % purity. Chinmay Joshi (2011CH70152)

1.What is the average timeline of a production process in chemical industries from R&D to manufacturing? – 5-10 years.

2.Name any 3 widely used separation equipment in industries? – Distillation, Extraction, Flash columns.

3. What are the most prominently applied pressure conditions in industrial distillation columns? – Atmospheric & Vacuum.

4.Name a process simulation software. – Aspen.

5.List some commonly used industrial utilities. – Steam at various pressures, water.

RINI KAPOOR (2011CH70179)

1) What are the raw materials used in sulphuric acid production?

Sulphur, air and water

2) What is the use of startup scrubber and why is it called “startup scrubber” in SAP (Sulphuric Acid Plant) ?

Ans. To reduce the SO2 content before venting and it is only used during the startup of the plant for maximum 1-2 hour .

3) What is the effect of using impure Sulphur as raw material?

Ans. If As, Te, Se are present, it gives volatile oxide which will reduce the activity of catalyst.

4) What is the byproduct of sulphuric acid production?

Ans. Sodium sulphite

5) What is the life of the catalyst used in SAP ?

Ans. 8-10 yrs

ABHINEET NAYYER (2011CH70142)

Q1 Which is the most hazardous chemical being used in OCCL ?

A. CS2 (highly volatile and poses health hazards)

Q2 What is the difference between polymeric and elemental sulfur ?

A. Solubility - (polymeric sulfur is not soluble in CS2, elemental Sulfur is soluble)

Q3 How does viscosity of sulfur vary with temperature ?

A. Increases rapidly till 185 and then decreases smoothly

Q4 How is CS2 supposed to be stored ?

A It should be stored in tightly closed containers under water or under inert gas.

Q5 What do the 5 S’s in the 5 S methodology stand for ?

A Sort, Set in order, Shine, Standardise, Sustain

Shivangi (2011CH701181) 1.Which property method used for polar liquid involving water as one of the components? -NRTL Property Method 2.What alternative used to involve impurities when their mechanism is unknown? -Directly add them into the reactor along with the feed 3.Which is the most economical solution to separate immiscible liquids? -Decanter 4. At what condition the distillation should be operated to avoid very high temperature? -Vacuum (low pressure) 5.How binary interaction parameters between components are estimated?

-By UNIFAC

Shyamal (2011CH70875)

Q1 Why is the Concentration of H2S in liquid phase increasing in the reactor to a maximum and then decreasing ?

Ans1 Concn of H2S in liquid phase is having a positive contribution from HDS reaction and negative contribution due to mass transfer from the liquid to gas phase. Initially the Reaction rate is high hence the concentration of H2S in the liquid phase increases. But gradually the reaction rate decreases hence mass transfer from liquid to gas dominates

Q2 Why is Length of bed kept higher than the Length for desired reaction?

Ans2 It is a overdesign factor( Also a safety factor). It done to increase the cycle of the DHDT reactor and prevent frequent shutdowns for cleaning the reactor.

Q3 Which is the best catalyst for HDS reaction?

Ans3: CoMo/ γ - Al 2 O 3

Q4 If Higher H2 gas pressure at inlet increases the rate of HDS and other reactions, what are the constraints on increasing the partial pressure of H2?

Ans4 : Constraints:

a)Process H2 feed cost

b)Max Pressure permissibility based on the Reactor Material

H2 Recycle Cost

Q5 What is the purpose of Dividing the reactor into separate reactor beds?

Ans5:

1) Adding Quench Section

2) Allowing space for redistributor for mixing of vapour and liquid stream and uniformly distributing over the cross section of the next bed

Mousumi Boro (2011CH70168) 1. What are the raw materials for Methanol Plant in RCF ? -Associated gas, steam and carbon dioxide. 2. Why is methanol required in Effluent Treatment Plant? -It is the source of carbon for micro-organisms. 3.Why is NaOH added to crude methanol? -To neutralize before it enters the distillation column. 4. How many wax filters are present at the methanol plant and why? -2; one in-line and another is stand-by 5. Which catalyst is used in Final Desulphurizer Reactor? -TK-250

Arpit Jain (2011CH70148)

Q.1 Why Vanadium Oxide catalyst is used for the production of 3 cyanopyridine?

Ans. Due to its high reactivity & low price.

Q. 2 Which process is used for the production of fine chemicals such as 4-DMAP – batch or continuous?

Ans. Batch Process

Q.3 Why we have connected all the reactors in parallel, not in series?

Ans. It provides us higher conversion & also the process is cheap.

Q.4 What is the full form & goal of TPM?

Ans. TPM – Total Productive Maintenance

Goal of TPM – Zero breakdown, Zero accidents & Zero defects.

Q.5 Which company is the largest manufacturer of Pyridine and its derivatives in India?

Ans. Jubilant Life Sciences Ltd, Gajraula

Kartik Chouhan (2011CH70160)

Q1. What is the basis of separation in agarose gel electrophoresis?

A. Charge and Size

Q2. Why are baffled flask used for fermentation?

A. For better mixing to maintain similar environment throughout the flask.

Q3. How is the activity of amylase variant checked?

A. By the clearing zones on the starch agar plates.

Q4. Which antibiotic is added to the starch agar plates?

A. Chloramphenicol

Q5. What is the use of SDS in SDS dye?

A. SDS induces a negative charge on protein and linearizes the protein.

YASHI AGRAWAL (2011CH70192) Q1. Why online detection at intermediate step preferred over offline detection at the end in pharmaceutical activities? -Time reduction in detection process; early detection reduces number of batch discards by changing relevant residual solvents during crystallization Q2. Why is water avoided as a solvent during NIR scanning? -It depresses the effect of compound absorption leading to increased noise in the spectra and inappropriate results. Q3. Why is smoothing algorithm applied before data processing? -To increase the signal to noise ratio Q4. What is the main aim of using Principal Component Analysis? -Used for data reduction; correlating data space into independent variables ranked according to decreasing variance in data Q5. The wavenumbers covered in NIR spectra? -3999cm-1 to 9999cm-1

MANISH KUMAR (2011CH70164)

Q1:Why do we remove acetylene from ethylene stream in gas cracking unit?

We remove acetylene from ethylene gas stream because acetylene exhaust the catalyst(ziegler natta) which is used in the polymerization reaction of ethylene.

Q2:Define green oil? How it get formed ?

Green oil is a mixture of C4 to C20 unsaturated and reactive components with about 90% aliphatic dienes and 10% olefins plus paraffins. Green oil polymer is formed by side reactions of the hydrogenation reaction itself like oligomerisation.

Q3:List differences between front end catalytic hydrogenation unit and back end catalytic hydrogenation unit?

Front-end unit •Acetylene reactors precede the demethanizer . •Large excess of hydrogen—typically 10 to 35 mol percent. •Formation of green oil is minimized.

Backend reactor unit •The reactors are located at the overhead of the de-ethanizer. •The catalyst gets exhausted more rapidly as compared with front-end hydrogenation •Precise control over hydrogen concentration.

Q4:Why do we need a inter-cooler between the lead and the guard reactor during hydrogenation of acetylene?

As conversion of acetylene to ethylene is highly exothermic in nature, so stream coming out from lead reactor has to be cooled before it enters the guard reactor inorder to increase our selectivity and yield.

Q5:Why Pd-Al203 based catalyst is suitable for hydrogenation of acetylene?

Acetylene has a greater affinity towards adsorption on the palladium surface which is reflected by higher heat of adsorption

Siddharth Dwivedi (2011CH70183)

Q.1 What are the main sections of Ammonia plant?

A.1 An ammonia has four basic sections-

Ø Hydrodesulphurization section

Ø Reforming Section

Ø CO2 Removal and Methanation Section

Ø Ammonia Conversion section

Q.2 What are the thermodynamic models most suitable for simulating reforming and CO2 removal sections in Aspen Plus?

A.2 i) Reforming Section - Soave - Redlich – Kwong equation of state with the Kabadi – Damer modification for water - hydrocarbon systems (SRK-KD)

ii) CO2 Removal – Electrolyte Non-Random Two Liquid (ELEC-NRTL)

Q.3 What can be major sources of errors while taking plant data?

A.3 Error can creep in through following sources-

i. Malfunctioning Flowmeters due to old –age fatigue, improper calibration, unsuitable range of operation

ii. Thermo-couples – placed far from point of which temp has to be measured, malfunctioning, etc.

iii. Improperly functioning Pressure Gauges

iv. Improper composition analysis i.e. GC not carried out properly, inaccurate sampling, etc.

Q.4 What catalyst(s) are used in Reforming Section?

A.4 Reduced Nickel

Q.5 Which transition metal’s salts are added to CO2 removal section to prevent corrosion?

A.5 Vanadium. V2O5 formed inside Absorber-Regenerator system helps controlling corrosion.

Praduman Arora (2011CH70175)

1.What is the importance of zero order release in drug delivery vehicles?

● Release takes place at a constant rate independent of drug concentration involved and hence led to constant in-situ drug concentration over time

2.What’s the difference between in-vivo and in-vitro system?

● In Vitro means the experiment was done in a controlled environment and In Vivo means a non-controlled environment (inside the body)

3.What does occlusion in drug delivery system signifies?

● Occlusion are the region occupied by dissolved or solid drug, marked by the absence of polymer matrix

4.What is degradation front for a polymer?

● It reflects the average position of polymer degradation at any point in time

5.What does therapeutic window for a drug mean?

● It’s the difference between minimum effective concentration and minimum toxic concentration

SUPRATIM DAS (2011CH70186)

•How can market clustering help in increasing turnover of HUL in Laundry?

Enhance speed to market, decrease reaction time to competitor moves and implement winning formulations

•How do Transition metal ions affect the bleaching process?

TMI disrupt the working of activator on peroxide precursor

•What is the role of activator in a bleach system?

Role of activator is to enable peroxide to function in wash temperature and pH

•What is AD in a detergent?

AD is Active Detergency - percentage of surfactant in formulation, depends on cleaning requirements and sensorial aspects also

•How is detergent performance over multi-wash measured for a cloth?

By using a spectrophotometer to measure the Reflectivity of the cloth at 460nm of light (most sensitive to the human eye) and a shift of 2 units is considered ‘detectable by consumer’

Gaurav Kathuria (2011CH70158)

What is Granular Flow?

The particulate flow, in which the particles can be considered as hard spheres, flowing freely with the carrying fluid and thus imitates the flow behavior of gases and can be modelled on the same ground as Kinetic Theory of Gases.

What is the difference between EULER-EULER and EULER-LAGRANGIAN schemes to study granular flows?

Euler-Euler – This scheme assumes the two phases to be two separate continuum and model the flow equations for each phase separately. The interaction between the two phases is quantified via friction models such drag force.

Euler-Lagrangian – This scheme considers flow equations on each particle separately and the interaction of each particle with the fluid phase is modelled separately.

What is Granular Temperature ?

It is a measure of the fluctuations of velocity of the particles about a fixed mean in a granular flow.

What is the behavior of Granular Temperature with the coefficient of restitution of particle-particle collision in gas-solid fluidized bed?

Decreases with decrease in value of coefficient of restitution.

What is variation of interphase drag force with slip velocity for multiphase flows?

It is proportional to the slip velocity.

Ankur Tenguria (2011CH70146)

1). What are the different types of polymer produced in the Polypropylene Plant ?

Ans. Homopolymer, impact and random copolymer.

2). Why two reactors are used in series?

Ans. To increase the residence time.

3).What is the purpose of pre-poly reactor in pp unit?

Ans. To slowly encapsulate, or form shell of polypropylene around the catalyst particle. This shell protects the catalyst when it enters the loop reactors.

4). How is MFI controlled in the polypropylene loop reactor ?

Ans. MFI controlled by addition of H2

5). What is the chemical name of Donar?

Ans. Cyclohexyl methyl dimethoxy silane .

KRITAGYA KUMAR (2011CH70161)

1.What is the name of the intermediate formed in Urea Production?

Ammonium Carbamate

2.What is the percentage of Nitrogen in Urea (approx.) ?

46.64 %

3.How is Prilling different from Granulation?

•Prills are made directly in Prilling Tower by spraying molten Urea solution in counter-current air

•While Granules are formed by spraying molten urea onto seed granules

4.Write the two step process for the production of Urea?

•2 NH3 (l) + CO2 (g) = NH2COONH4 (aq)

• NH2COONH4(aq) = NH2CONH2(aq) + H2O (l)

5. How is Snamprogetti Technology Different from Stamicarbon Technology of Urea Production?

In Snamprogetti NH3 is used in excess while in Stamicarbon CO2 is used in excess.

BAKSHINDER PAL SINGH (2011CH70834)

•What is the essential modeling strategy followed for Bioreactor Simulations?

The strategy for modeling a Bioreactor is:

1. Power Number / Flow Number Calculation 2. Mixing / Blend Time Calculation 3. Gas Sparging with mono-dispersed bubbles 4. Gas Sparging with poly-dispersed bubbles 5. Mass Transfer Coefficient Calculation

•What is the most common Turbulence Model used in Bioreactor Simulations? What other Turbulence Model is used otherwise?

The most common Turbulence Model used in Bioreactor Simulations is K-epsilon (k-ε) turbulence Model for Bioreactor with Baffles or nearly flat liquid surface. Otherwise for parabolic vortex surface or Bioreactor without baffles we use Reynolds Stress Model (RSM).

•Where is Population Balance Model useful?

Population Balance Model is very useful in study of Multiphase flows in Dispersed Regime, Polymerisation, Biology, Crystallization, Precipitation, Comminution etc.

•Which Multiphase Model could be used to model Mixing Tank? What are the applications of Mixing Tank?

Mixing Tank could be modeled using Mixture Model or Eulerian Model Approach for Multiphase Flow Modeling. Mixing Tanks are used in many industries involving blending as pharmaceutical, chemical, food, plastic, metallurgical and mineral industries.

•What are the essential components in a Bioreactor?

Components include:

1. Mixing Tank 2. Sparger 3. Baffles 4. Shaft 5. Impellers 6. Measurement Devices

Mayank Mishra 1. What do you understand by norms of the raw materials in a process? A: Amount of raw material used per Kg production of desired product. 2. How can we avoid blast in the reactor undergoing uncontrolled reactions? A: By providing sufficient diameter rupture disc for instant reduction of the pressure. 3. Why do we need nitrogen blanketing in the feed drums? A: To avoid contact of feed with atmospheric components even after leakage in the tank.

4. How can we separate neutral oils from the mixture of products? A: By cutting the layers in the level control tank with output valve at the desired level. 5. Why is there need of condensers with the storage tank ? A: There is always possibility of evaporation of the liquids from the storage tanks, from the vent Surbhi soni (2011CH70187)

1.What is ITSOFC ? Ans. It is a Fuel cell with solid oxide as electrolyte that operates in 500-600 C. 2.How do we ensure the completion of reaction of cerium sulphate with ammonium carbonate? Ans. Since it is a acid base reaction so by checking pH again and again until it reaches pH=7. 3. What does the peak position in diffractogram signify? Ans. It signifies the phase (atomic arrangement and specific chemistry)of the material. 4. How does peak width is related to the grain size of material in diffractogram? Ans. It is inversely proportional to the grain size. 5. What do you mean by sintering ? Ans. It is a diffusion process occurs between ½ - ¾ th of the melting temperature of material that convert the pellets to strong dense ceramics.

Prachi kumari (2011CH70174)

Q. Is the overall urea formation reaction exothermic or endothermic ?

Ans. Exothermic

Q. What is the use of weep holes in the urea synthesis reactor?

Ans. For detecting leakage

Q. What are the utilities in the high pressure section?

Ans. Urea reactor, stripper, carbamate condenser and ejector

Q. How does NH3/CO2 effect the urea formation reaction ?

Ans. Higher ammonia to carbon dioxide ratio favours the formation of urea.

Q. Suggest any one method to increase urea yield.

Ans. By adding an additional reactor

Dharampal Singh Meel (2011CH70154)

Q. Why is desulphurization done in ammonia manufacturing? A. Sulphur in feed stock to steam reforming units act as poison to all the catalysts. Q.. Why the solution of Potassium carbonate kept hot in CO2 removal section in ammonia process? A. To increase the rate of absorption and keeping the bi- carbonate in the solution. Q. What are favorable conditions for formation of ammonia ? A. High pressure and low temperature Q. Why is methanation is required in ammonia process? A. Oxides are harmful for Ammonia synthesis catalyst. Q. What are the benefits of using LTS in ammonia process? A. Reduction of steam requirement and greater yield of H2 per unit of hydrocarbon feed.

Vishvendra Singh Dhayal (2011CH70189)

1.What are the raw materials for ammonia production? Associated Gas, steam and air. 2.How is hydrogen obtained for ammonia producLon? Through steam reforming of associated gas.

3.What is the main function of PC Stripper? The condensate coming from LT shift converter is to be stripped off ammonia,

methanol and carbon dioxide in a PC stripper.

4.How is the overall efficiency of a tray tower calculated? Using O’Connell’s correlation.

5.What is the reason for difference in calculated theoretical stages and actual no. of stages in PC stripper?

The difference may be due to the assumptions that the tower is operating

isothermally and constant flow rates.

Salman Khan (2011CH10112) Q. Who was the founder of TATA Group?

A.Jamsetji Tata

Q. How much is the annual production of steel of TATA Jamshedpur plant?

A. Approximately 10 million tonnes

Q.What is the driving force for magnetic separation ?

A.Magnetic susceptibility(k)

Q. Which region in India has the highest reserves of chromite ore?

A.Sukinda valley ,Orissa (98% reserves of chromite)

Q.Which method is used to confirm the presence of oxide /hydroxide minerals in an ore?

A.Thermogravimetric analysis (TGA)

Aman Jain (2011CH70144) 1. Application of Regression Modelling 2. What are the different Multi-Regression Models? 3. How do you define capacity in a filtration method in terms of pressure and flux? 4. What are the different standard models used in the filtration modelling? 5. Explain the difference between the different standard models used in the filtration modelling?

1. Data Driven – No theoretical model is available. Therefore, the data is being fitted in different software

like JMP, MATLAB, and Minitab to find the best model suitable to the data. Final Model is data specific. Theoretical Driven – A theoretical model is available. The experimental data is then being fitted in the available model using different software like JMP, MATLAB, and Minitab to find the coefficients of that model. The model is very general and is theory driven.

2. PLS (Partial Least Square), PCA (Principal Component Analysis) and Factor Analysis. 3. At fixed trans-membrane pressure, capacity is defined as the amount of fluid per membrane area that

can be processed until the flux declines to a set fraction of the initial flow. At fixed flow rate, capacity is determined when the trans-membrane pressure increases to some set multiple of the initial value.

4. Standard, Complete, Intermediate and Cake Models. 5. Standard model assumes the deposition of particles on the side of the pore. Complete model assumes the

deposition of particles on the opening of the pore and blocking it completely. Intermediate model assumes the deposition of particles on the opening of the pore, but blocking it partially. Cake model assumes the deposition of particles on the entire membrane surface and not only on the pore. VINITA KUMARI(2011CH70188)

1.Why is methanation required in ammonia production process?

-To reduce the traces of CO and CO2 remaining after reforming so as to prevent the catalyst poisoning.

2.What is the composition of the GV solution used for CO2 absorption?

-Potassium Carbonate

3.Which catalyst is used for reforming?

-Nickel based catalyst

4.Why shift conversion is done in two stages?

-To achieve high conversion

5.In most cases finned tubes are used in air cooled heat exchanger.Why?

-To compensate for the low heat transfer coefficient on air side.