Please help with this

A single-effect evaporator is concentrating a feed of 9072 kg/h of a 10 wt % solution of NaOH in water at temperature of 288.8 K

Aloiza [94]

Answer:

a) steam used = 8440 kg/hr

b) Because as per calculation done in a), Steam is sufficient to evaporate 7257.6 kg/hr water from feed. Since feed is less than this amount, therefore whole water will be evaporated and 100% solid product will be obtained in bottom collection

Explanation:

Saturated steam pressure = 42KPag=1.42 bar

From steam table, Steam temperature = 110 C

Latent heat of this steam = 2230 KJ/kg

Process side pressure = 20 Kpaa = .2 bar

Water latent heat at this Pressue = 2360 KJ/kg

Water boiling Point at this Pressure =60 C

Feed Inlet temperature = 15.6 C

Total Heat required = Heat required to rise feed temperature from 15.6 to 60 degree C + Evaporation of water to concentrate the feed

Total Water evaporation required = 9072*(100-10)/100-9072*.1/.5*.5=7257.6 Kg/hr

Specific heat of feed assumed = 4.2 KJ/kg/K

=> Total heat required = 9072*4.2*(60-15.6)+7257.6*2360=18819682 KJ/hr

LMTD = ((110-60)-(110-15.6))/LN((110-60)/(110-15.6))=69.8 C

U, Overall Heat transfer coefficient = 1988 W/m2/K

Total heat required = U*A*LMTD

=> Area required of evaporator, A=18819682 *1000/3600/1988/59.8=44 m2

Steam used = 18819682/2230=8440 kg/hr

Energy required to condense vaporised feed = 7257.6*2360=17127936 KJ/hr

=> Steam efficiency = (18819682-17127936)/18819682=9%

b) Because as per calculation done in a), Steam is sufficient to evaporate 7257.6 kg/hr water from feed. Since feed is less than this amount, therefore whole water will be evaporated and 100% solid product will be obtained in bottom collection

6 0

4 years ago

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Robert makes a glass of tea and takes it outside with him. While outside, the thermal energy within the glass of tea is transfer

lukranit [14]

Answer:

A

Explanation:

i had answer it and it was A

5 0

3 years ago

Can you draw the peptide structure at pH 7.0 (including peptide bonds)

ELEN [110]

Answer:

See image below

Explanation:

The image is labeled according to the sequence N'-Trp-Ser-Asg-Gly-Cys-His-COOH' which means that in the main chain of the peptide, the amino group of the Tryptophan and the carboxylic group of the Histidine are free and thus its charge depends on the pH; other groups that rely on the pH are the side groups of the Cysteine and the Histidine.

Overall, ionizable groups in this peptide are:

Amino Group of the Tryptophan (pKa = 9.39)

SH group of the Cysteine (pKa = 8.18)

Secondary amine of the Histidine (pKa = 6.00)

Carboxylic Group of the Histidine (pKa = 1.82)

Then, the amino group of Trp and SH group of Cys are protonated since the peptide is at a pH below the pKa. The secondary amine of the Histidine is deprotonated because the pH is greater than the pKa, as well with its carboxylic acid group.

7 0

3 years ago

Question 10<br> How many atoms are there in total in the following chemical formula: 7NHO3

sergey [27]

Answer:

7N + 7H + 21O

= 35

i think its like this

4 0

3 years ago

A solution of 34% nacl is separated by a semipermeable membrane to a solution of 22% glucose. the membrane is only permeable to

Katyanochek1 [597]

The net osmosis will occur in the direction of the NaCl solution. This is because the solute concentration on that side is greater than that of the glucose solution. Osmosis is the process by which liquids move through semi permeable membrane from the region of lower concentration to the region of higher concentration.
Thus the water is going to move from the glucose solution into the NaCl solution.<span />

7 0

4 years ago

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