Question a to g using the following picture Monosodium Glutamate $($MSG$)$ is a flavor enhancing ingredient in tomato, cheese

and meat and forms a basis of a roughly $$7\mathrm{.}2$ billion Industry producing in excess of

$3$ million metric tons annually. It is mostly produced by the bacterium

Corynebacterium glutamicum from glucose and ammonia. The following conceptual

plant produces about $50$ metric tons $($MT$)$ of monosodium glutamate monohydrate

crystals per batch. The process has been divided into three sections: $(1)$

Fermentation, $(2)$ Purification, $(3)$ Water Supply. We focus on $(1)$ and $(2).$

Fermentation

The fermentation section consists of a train of two seed fermentors and the main

production fermentors. All fermentors use the same medium: glucose syrup$/$nutrients

$(70\%$ dry solids, mixed with water in blending tank V$-101,$ duration $8hr),$ a separate

process water flow, and ammonia $($mixed with water in blending tank $V-102,$ duration

$8hr),$ that are all sterilised by heat or filtration $($ammonia$).$ A $5m{31}^{st}$ seed fermentor

$($SFR $101,$ duration $18hr)$ feeds into a $2^{nd},$ larger $50m3$ seed fermentor $($SFR $102,$

duration $18$hr$),$ that feeds into a $360m3$ fermentor $($FR$-101,55h$ incl sterilisation, fill,

inoculate, ferment and transfer out$).$

Separation and Purification.

Broth is stored in a $300m3$ storage vessel $($V$-104)$ and from there fed to a Rotary

Vacuum Filter $($duration $8hr,$ RVF$-101)$ to remove biomass. Filtrate containing

intermediate product glutamic acid, is deionised using lon Exchange columns $($INX$-$

$,$ neutralised with NaOH into MSG in a $22m3$ vessel NT$-101(8$ hr$),$ decolored

with activated carbon $(2x$ columns of $1\mathrm{.}26m3$;$1\mathrm{.}5hr,$ GAC$-101),$ transferred to

blending vessel V$103)$ with the return flow of mother liquor from crystalliser

step yield, R$-101),$ concentrated by multi$-$effect evaporation $(8$ hr$,$ EV$-101),$

crystalised into solid MSG $(3h$;$36m3,R-101$; yield is $56\%.$ The crystals are

recovered in centrifuges $(51\mathrm{.}5hr,BCF-101),$ and dried in a rotary drier $(8h,$ RDR$-$

and packaged. The mother liquor is returned to blending vessel V$-103$ for

increasing MSG recovery by crystallisation.

a$.$ Draft a block diagram, perform a Critical Path

Analysis, and construct a Gantt Chart of the processing steps. What is the batch time $?$

b$.$ Construct a Gantt chart of Equipment Use $($Occupancy$)$ Chart.

c$.$ Determine the cycle time, and what is the plant capacity in this configuration. Make plausible that the seed and $($especially$)$ main fermenters are the bottleneck.

The plant however operates for about $7920$ hours per year, processing $977$ batches per year or a total annual production of approximately $48,917$ MT$/$yr$.$

d$.$ What is cycle time under these conditions and thus how many main fermentors would that require if these operate in a staggered mode $?$

e$.$ How many lines of seed fermentors would be required for the number of main fermentors that you found under $($e $).$ If you could not determine the answer of $($e $),$ assume that the answer to $($e$)$ is $6.$

The separation$/$purification section of the process can operate continuously.

f$.($bonus$)$ Update the Gantt chart to reflect the increased number of $($staggered$)$ main fermenters and the continuous processing in the separation$/$purification section.

g$.($bonus$)$ What is the role of V$-104?$ Draw the holding volume of V$-104$ in time for consecutive batches of the main fermenters under $($e$)($again use the number $6$ if you could not determine the answer of $($e $).$