Answer / nk

the DILUTION STEAM ADDING IN THERMAL CRACKING TO DECREACE THE VAP.PRESSURE OF THE HYDROCARBON....and it also helps in decreasing the rate of coke formation.....

Answer / eugene

Thermal crackers to produce cracked gasoline from heavy gas
oils in petroleum refineries have largely gone out of
existence and been replaced by fluid catalytic crackers and
hydrocrackers.

However, when they were used back in the 1930's and 1940's,
steam was always injected into the process tubes of the
fired heaters that raised the temperature of the gas oils
to the point where they cracked into smaller molecules ...
and the purpose of the steam was to inhibit the rate of
coking in the heater's process tubes so that the heaters
could stay online continuously for some months.

Today's delayed coking units in petroleum refineries are
designed to produce and lay down saleable coke in very
large vertical drums. In those delayed cokers, steam is
again used in the feed heaters to inhibit and delay the
coking from occuring until the heated, vaporized feed
reaches the large vertical coke drums.

GENETIC ENGINEERING - EXAMPLE 27.2 : (a) Three genes, I, J and K are available. All these genes are linked with respect to one another. If the percent recombination between I and J is 8 %, that between J and K is 10 %, and that between K and I is 18 %, what is the order of the gene? (b) Twenty six genes, a, b, c, d, e, f, ... x, y and z are available. All these genes are linked with respect to one another. If the percent recombination between a and b is 3 %, between b and c is 3 %, between c and d is 3 %, ... between w and x is 3 %, between x and y is 3 %, between y and z is 3 %, then what is the percentage recombination between b and y?

1 Answers  

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Explain what types of metals are typically removed via chemical precipitation?

0 Answers  

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BIOCHEMICAL ENGINEERING INSTRUMENTATION - EXAMPLE 29.4 : The resolution of separation, Rs for chromatography is given by the formula Rs = (difference in retention time) / (average width at the base). In a chromatogram, 3 peaks a, b and c are found. Average widths W at the bases of the solutes are : Wa = 20 s, Wb = 40 s, Wc = 30 s. Resolutions of separation, Rs for solutes b and c in comparison to a are 2 and 4 respectively. The differences in retention times T for b and c in comparison to a are (Tb - Ta) and (Tc - Ta), Ta = Tc - Tb : (a) Form 2 equations involving Rs as a function of Wa, Wb, Wc, Ta, Tb and Tc. (b) Find the values of Ta, Tb and Tc.

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Explain why is post-weld heat treatment (stress relieving) sometimes necessary for welded vessels?

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QUANTUM COMPUTING - EXAMPLE 32.3 : A system of linear congruences consists of 3 equations : X ≡ 1 (mod 3), X ≡ 3 (mod 5), X ≡ 4 (mod 6). X has positive values. (a) List the values of these equations from 1 to 35. Then find the minimum value of X. (b)(i) Find the least common multiple (LCM) of b = 3, 5 and 6 where X ≡ a (mod b). (ii) If b - a has the same value of all equations above, then X + (b - a) is divisible by LCM. Find the value of minimum value of X via LCM division.

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.12 : You, as an engineer, buy a piece of biochemical instrument to start a servicing business. The instrument has a useful life of 3 years, that costs $60k. The instrumental business generates $100k per year. The labor costs $50k per year. The $60k new instrument depreciates in its value evenly up to 3 years, thereafter the old instrument needs to be replaced by another piece of new instrument. (i) In the first year of this engineering business : (a) what is its starting cash? (b) calculate the depreciation value of the instrument. (c) find the operating profit generated. (d) what is the capital expense of the business? (e) calculate the cash from operation. (f) calculate the ending cash. (ii) Based on the income statement of the business in the second year : (a) find the capital expense of the business. (b) what is its starting cash? (c) calculate the depreciation value of the instrument. (d) find the operating profit generated. (e) calculate the cash from operation. (f) calculate the ending cash.

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ELECTRICAL TECHNOLOGY - EXAMPLE 16.2 : In a selection of suitable heating equipment for drying of crystals of biochemical, the one of the lowest current consumption will be chosen for safety consideration. Selection is available : (A) 120 V microwave oven 1800 W. (B) 240 V conventional oven 11000 W. Which one should be chosen and why?

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What is a good relation to use for calculating tube bundle diameter?

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COMPUTER PROGRAMMING FOR ENGINEERS - EXAMPLE 17.2 : There are 5 simultaneous equations with 5 unknowns as follow : 16 V - 4 X - Z = 36, 4 X - 4 W - Y + Z = 3, 8 V + 4 W - X + Y = 10, X - W = 1, V + W = 0. Find the values of V, W, X, Y and Z accurately within 15 minutes. State the computer program that you use to get the answers.

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which thing is responsible for making petroleum?

6 Answers   OGDCL,

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PROCESS CONTROL - EXAMPLE 6.3 : The differential equation is 3 dy / dt + 2y = 1 with y(0) = 1. (a) The Laplace transformation, L for given terms are : L (dy / dt) = sY(s) - y(0), L(y) = Y(s), L(1) = 1 / s. Use such transformation to find Y(s). (b) The initial value theorem states that : When t approaches 0 for a function of y(t), it is equal to a function of sY(s) when s approaches infinity. Use the initial value theorem as a check to the answer found in part (a).

1 Answers  

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What are the effects of oils on the properties of Polyolefins?

0 Answers   IOCL,

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