Marking Criteria for GA$1$

$\backslash$table$[[$INDICATORS$,$Questions,Marks$],[\backslash$table$[[$Identify$/$Define$],[$Problem$]],1.$ List any $5$ causes for the column malfunctioning,$15],[\backslash$table$[[$Contextualise$],[$Problem$]],\backslash$table$[[2.$ What indicators do chemical engineers use to ensure the$],[$efficient operation of a distillation column in a plant$]],15],[\backslash$table$[[$Recognise and$],[$Consider$],[$Assumptions$]],\backslash$table$[[3.$ What assumptions will you consider for separation to$],[$occur in this distillation column.$]],15],[\backslash$table$[[$Propose$/],[$Create Multiple$],[$Solutions$]],\backslash$table$[[4.$ Determine the condenser duty and reboiler heat$-$duty.$],[5.$ Determine the efficiency for this distilation column.$],[6.$ Assuming $100mm$ water pressure drop per plate.$],[$Estimate the bottoms pressure for this column.$]],15],[\backslash$table$[[$Analyze$,],[$Evaluate$,$ and$],[$select$],[$Solutions$]],\backslash$table$[[7.$ Devise a troubleshooting strategy to find the root cause$],[$of the column malfunctioning.$],[8.$ After troubleshooting. you discover the following:$],[$The column was running smoothly but not well. Reflux rate was$],[$too low, so it precluded significant fractionation. The column$],[$pressure was $100$KPa below design. Whenever the pressure$],[$reached $130$KPa, the reboller pressure exceeded the hot$-$oil$],[$pressure$.$ The relatively low$-$boiling toluene then flowed into the$],[$hot oll and flashed. This generated a large volume of vapor that$],[$then backed hot oil out of the reboiler. The toluene vapors$],[$passed on into the main fractionator and flooded this tower. Only$],[$a small amount of vapor, but no liquid, was being produced from$],[$the reflux drum, which should have produced mainly liquid.$],[$Explain three possible cause for the errors you observed.$]],15],[\backslash$table$[[$Implement$],[$Solutions$]],$Assess how you will implement solutions to $8.,15],[\backslash$table$[[$Evaluate$],[$Solution$],[$Implementation$]],\backslash$table$[[$Develop a PowerPoint presentation you will give in the next$],[$management giving an overview of how you solved the problem$],[\text{'}$the gas plant is non$-$operational. In your presentation, include$],[$future recommendations to be considered.$],[$Attach your presentation slides to your GA Assignment$]],15],[,,]]$

You serve as a chemical engineer at the BP refinery, with responsibility for overseeing operations involving the fractionating column. The column receives an equimolar mixture of Benzene and Toluene and consists of $5$ plates, including a condenser and reboiler, with a total condenser. This system maintains a constant volume and integrates a heating coil to warm the crude oil, alongside a shaft for agitating the oil within the tank. Designed to yield a distillate of $95\%$ purity with a $10\%$ waste in the bottoms, the column operates with a relative volatility of $3\mathrm{.}2$ and a reflux ratio of $3\mathrm{.}5.$ The feed remains in liquid state at its boiling point, and reflux is reintroduced to the column at $100$ degrees Celsius. The maximum feed rate is set at $10,000k\frac{g}{h},$ with the minimum feed rate established at $70\%$ of this maximum. Sieve plates are employed in the column.

Upon receiving notification from the refinery manager that the gas plant is non$-$operational, you are tasked with troubleshooting the fractionating column. Subsequent inquiries with unit operating personnel reveal that the pumparound circulating pump is malfunctioning. Whenever the hot oil flow to the reboiler is increased, destabilization occurs within the gas plant. Reboiler heat$-$duty and reflux rates become erratic, and the discharge pressure of the hot$-$oil circulating pump exhibits significant fluctuations. The operating personnel suggest that a replacement pump with reduced net positive suction head may be necessary.

As an engineer, your approach to solving this problem and restoring plant operation involves thorough assessment of the pump malfunction and subsequent actions to address the issue. This includes evaluating the pump's and column's performance, considering replacement options, optimizing operating parameters, and collaborating closely with the operations team to ensure effective resolution and sustained stability in plant operations.