12, 1. 16. ‘The major feedstock that is fed into a distillation tower i alled (a) Crude Oil (6) Coke (©) Diesel (4) Gasoline ‘Crude il can be classified by density and _(@) Amount of Hydrocarbons (b) Amount ‘of Metals in Crude Oil (c) Sulfur Content (@) Weiaht ‘The distillation process separates hydrocarbon mixtures by use of _(a) Catalyst (6) Boiling Points (b) Naphtha (4) Sulfur ‘Before crude ol ii put iL a distillation tower, the crude oil is__(a) Exposed to Benzee (b) Ran through a Catalyst (e) Heated (2) Physically Separated “The types of products taken fom the top of adstillation tower are _(a) Butane & light fuels (b) Asphalt & residuals (c) Gas oil (d) Diesel & heating ol “The types of products taken from the bottom of a disillaion tower are _(a) Butane & light fuels () Napa (c) Kerosene & jet fuel (2) Asphalt & residuals Sweet crude typically yields 33% ofthis product rom a bare! of ol _() Propane and butane (b) Alsphat & residuals (¢)Disillates(d) Gasoline products Heavy sour erude typically yields 19 of his product fom abael of ol (a) Propane and butane (6). Asphalt & residuals (=) Disillates (2) Gasoline products ‘The process of removing impurities sucha sul, nitrogen and metals) Alksltion (6) Hydrocracking (c) Hydroteating Desulfriation (@) Reforming What happens when crudr ol is fractional distilled? (a. Different factions are mbled together to form oi. (0) Sulfur s removed ftom the erie cil () The is seprated into teatons of different Boiling ranges by heating (d) Longer chain faction are broken down into shorter chain fractions. ‘Fhe It refining process separates cru oil into what? (a) Fractions (b) Polymers (¢) Residuals (€) Compounds ei one tific temperatacs whence ll i pt into 2 distillation column and heated. TRUE or FALSE ‘The basi refining process called distillation? TRUE or FALSE. Nut us that comes fom anol well ealled “No asoeated gas” TRUE or FALSE. Si Bee cllaon column isthe temperature the lowest?) At the Boom of the Sees cance the heat rises tothe top duc to natural convection ofthe hot gas flow. (b) serine feed potion, Because the seam has fo be cooled down before entering the Aiea iS there are no temperature differences over the whole column. (2) At the top of dae fect the more elatile components (lower boiling pont) are withdrawn at the top ofthe column, Teen eer the pressure inside the dsilation column’? (a) The pressure affects thr imernl low-rates of the column, Therefore in order to simplify the calculation, with Re CMO assurnpion @e. constant interalflow-rates) we assume also thatthe presse isConstant all over the column. (b) The pressure affects the vapour pressure of the feed mixture. Therefore the higher the pressure, the purer the distillate, (c) Pressure affects the ‘vaporliquid equilibrium, therefore also’ the .degree of separation obtained in the istllation process depend on the pressure set (d) No effect. Only the temperature isthe parameter to consider ina distillation process, Ifyou assume CMD and do au the calculations, but CMO is not tre, what happens? (a) ‘he efficiency of the column will be reduced (b) The Land V flow-rates he eolumn are different at every stage, The MeCabe-Thiele method cannot be applied anymore, A punctual design considering every single stage of the column must be done in ordet to caleulate the tisillatior products (c) No effect. The CMO is on an assumption o simplify the calculations durin the process design and has no influence on the functionality of the column, (d) Raoul’ law is also not void anymore. ‘Why the feed stage is never located atthe bottom of the column? (a) This i not true. The feed enters the column at that stage (whatever itis) where the concentration of the liquid and vapour phases are more similar to that one of the feed itself. (b) Since ‘the highest temperature is atthe bottom, the feed would evaporate all at once lowering dramatically the efficiency ofthe column (c) It depends on the quality bf the feed. The feed is typically located at the botiom of the column since it is a saturated liquid (d) It depends on the quality the fed. The lower the feed enthalpy, the lower the stage at which itis fed What is the optimum feed stage specification? (a) It says that in the MeCab-Thiele {graphical constuction, we have to use the working line ofthe stripping section when we pass the feed stage (b) The feed is located at the most convenient stage under the ‘economic point of view (optimum balance between investment and running costs). (c) ‘When this specification is used, the feed is positioned in that stage in order to have the ‘optimum design of the column, which means the fewest total number of stages. The feed Position is determined graphically with the McCabe-Thiele construction (d) The position Of the feed stage must be assumed atthe beginning in order to apply the MeCabe-Thiele construction. Then it must be verified through calculation after thatthe number of stages is determined. Which are the products of e distillation column which has an infinite reflux ratio? (a) There is no Distillate production: everythin is withdrawn atthe bottom, (b) There are no so feed rate is zero. The number of stages i the minimum in runs normally since the products are ony feed dependent. (d) The infinite reflux ratio is only a “tick” for caleulation purposes. It has no physical meaning therefor it cannot be used with areal column, ‘What happens in distillation column if the reflux ratio i zero? (a) If no liquid is recycled, back tothe column, te internal liquid and vapour flow-rtes cannot be controlled andthe design ofthe column gets more dificult b) In this case a partial condenser should be used since we don’t need any liquid for the recycle (c). The entire product is withdrawn as Distillate and moreover we save the investment costs for reeyele piping and pump. This is the best configuration possible fora disllaton column (4) No liquid is recyeled back to the column. Step by step the only vapour phase will be present in the rectification sec ‘and no mass transfers possible anymore, Which isthe physical meaning ofthe minimum refux ratio%\a) L divided by D (b) There is no physical meaning. cis limiting condition useful for the column design: at the: ‘minimum reftux rato, the column ean “operate” only with an infinite numberof stages (c) ‘The recycle atthe top ofthe column is minimum, therefore the intemal flow-rates are the ‘minimum and an infinite number of stages is needed to reach the specification on the ‘products () It isthe value of Reflux for which the Distillate low-rate isthe maximum. ‘When a paral condenser instead of a total condenser is more conveniently used? (a) The use of a partial or a total condenser depends onthe amount of cooling liquid availabe. (8) ‘When the distillate stream is very large and cannat be cooled dow in just one step by total condense (c) The paral condenser acts asa further equilibrium stage therefore i is used when the specification cannot be reached with total condenser (d). When the distillate is needed in further production steps as a vapour. A distillation column is usualy divided into how many sections? (a) 1 (b) 4 (e)2 (d) 3ee 2. Fora five component distillation with wo light nowys, a ight hey. 3 henry Mey ad § heavy noney, which are the products tat are assed o be spurt te 79 of Se column? (a) The light hey upon specification. We canon say syn so te i 37, keys since we could not solve the extemal material balance de othe Bact mamta of unknowns in comparison to the availble equations (0) The fight ey md te Bit 2m \keys upon specification (¢) The light key component opm specification set ie mo) aie rnon-key components. This later is an aiumpton ia order to sve the extra sss balances ad simplify the column design (d) We cant ny he Sewieieg. Type & ‘wal and ero method is wed applying the Fenske ad Underwater wie 2 Se guess and verifying the validity ofthe resu Row does an extractive o an tzectopic iil coke ite fom smh one” (3) No difference. The coldms are always the some bt simpy Gitlin chan a ot able to completely separate miurs having azeore. These can be coapled wie ee Separation methods wo break the azetrope. (0) Al the cok pect a conics Sinilar othe Sect steam bl isead ofthe eam, 2 Proper solves i traced i re the arectope (No differcce inthe column tthe mxine a aero comets 5 fel right a the bonom Yor a minimum boiling mrope and sit = he wp He * Tarim boling azcotrope (6) For a minimum boing azeaeops. Steal of Se Condensr (or De rebar for a maxima azeatope) an ssrpion cohen Prot Shere a proper solvent is wed to break the azeorope and comple Se puricaton process. Fire faction of crade oil that is used in LPG (liquid petrokewm gas) & (2) gr apa (refinery wus (8) Residue The fmt of ei ol ted i pli (2) ft ot) gs i (6) rome (4) Sis gasoline Four ofthe liquid factions from the fractional distillation of cade oil sre Giese! ol. Sect Oil, gasoline (petrol) and Kerosine. The correct order fo increasing boiling points of tse Gackons is (2) Kerosine, gasoline, feel ol, diesel oil (b) fae! on. diesed of. Keron, ‘gsoline (=) gasoline krosine, fe! ol, ise! oil (6) gacline herosine, sel ol Fock Fer ofthe quid ractoel from the fractional disillation of crade oil re diese! of. ei Oi, gasoline and kerosine. The most viscous (cast runny) ofthese i (2) diesel ol () fact cil ©) gasoline (6) kerosene Fou of the lige factions from the fractional distillation of crade ol are diesel cil fet lL gasoline aad Kerosie. The most volatile of these is (3) Giese! oil (b) foe oil (©) gasoline (4) kesosine Refineries are classified based on process configuration and refinery complexities. Trae False. List the four major refinery classification scheme. In which type of disllation process i an container add. ‘Another name of the heat exchanger that supplics the heat used in 2 distillation system 3 ‘What isthe function of a downeomer. ‘When do overlaps cccurs ina distillation process. Define External Reflux. ‘State to methods used in achieving products parity in» distillation system Define temperature gradient as regards distillation process. ney of prema otal in iain ers reac oy Tree State the factors affecting distillation column operations. How is batch distillation process differet from a continaoes distation process? State any tree characcrstcs which determine 2 refinery configuration ant performance ‘What do you think isthe primary economic objective of erude ol refining With the aid of a diagram explain how the atmospheric dsillstion process works = Refinery (5 Marks)