5 replies to this topic

[matrix_2005]

Hey guys!

Forgive me if this is the incorrect place to ask this.

I've been spending the last few weeks on trying to simulate a ground up simulation for the mass production of paracetamol in a PFR (with the help of AI ). spent the last few days hunting research papers, patents for reaction conditions, kinetics and materials required. There could be a fair bit of hallucinatory thinking from my part knowing that I am using AI for understanding what is required and which data to get from these papers

- Is what I'm doing possible to do comprehensively? I'm talking utilities, pumps, and the like. I keep hearing 'design data book' and 'this data is great' from AI, I just want a reality check.

- If it is, how do people decide utilities, pump configurations or at least good kinetics for all possible reactions? Do I have to reference books like Perrys? My college program didn't use it that much, and I am unfamiliar with other literature outside of what was used to teach our courses.

 

TLDR - attempting to design a paracetamol production plant, not sure if it's feasible

[latexman]

Since its for school, what you are doing is fine. The paracetamol process is very mature, and information is plentiful. Just reference what you use.

[breizh]

Hi,

I know a little bit about paracetamol. I was working in facilities producing paracetamol using CSTR. From memories it's a difficult process to get the right product due to side reactions and impurities in raw material (PAP). 

Which route did you take to get paracetamol, and which raw materials are you using? PAP + acetic acid and Acetic anhydride?

PFR should give you a better control of the reaction and should generate less impurities, I don't know whether this is used industrially. 

My understanding is that you are producing paracetamol powder and PFR will be used during the acetylation step.

About Kinetic reactions I don't know if you can get them from literature. In the real life, the data are coming from tests performed at lab scale, using Uni lab or experienced third party to generate them. Probably data you have on hands will suffice for your work.

The process I'm aware of has different steps:

a) Acetylation 

Discoloration to remove the impurities (adsorption on black carbon)

c) Crystallization

d) separation solid/liquid using centrifuges

c) Drying (flash dryer)

d) Classification using sifters

e) Packing (big bags or drums)

 

note: other step is the partial recovery of paracetamol from mother liquor (evaporation, crystallization, filtration) blend with the mainstream of paracetamol.

 

This process is managed under cGMP meaning strict control of manufacturing steps.

 

Last point, this process requires a lot of energy to recover material from mother liquor. I've been implementing multiple effects evaporators, probably MVR is a better option. Cooling is also key for Crystallization step (atmospheric refrigerant + chilled water) to adjust the morphology and the shape of the crystals.

 

Kinetics Study of Paracetamol Production from Para-Aminophenol and Acetic Anhydride

 

Good luck

Breizh

[matrix_2005]

Hi,

I know a little bit about paracetamol. I was working in facilities producing paracetamol using CSTR. From memories it's a difficult process to get the right product due to side reactions and impurities in raw material (PAP). 

Which route did you take to get paracetamol, and which raw materials are you using? PAP + acetic acid and Acetic anhydride?

PFR should give you a better control of the reaction and should generate less impurities, I don't know whether this is used industrially. 

My understanding is that you are producing paracetamol powder and PFR will be used during the acetylation step.

About Kinetic reactions I don't know if you can get them from literature. In the real life, the data are coming from tests performed at lab scale, using Uni lab or experienced third party to generate them. Probably data you have on hands will suffice for your work.

The process I'm aware of has different steps:

a) Acetylation 

Discoloration to remove the impurities (adsorption on black carbon)

c) Crystallization

d) separation solid/liquid using centrifuges

c) Drying (flash dryer)

d) Classification using sifters

e) Packing (big bags or drums)

 

note: other step is the partial recovery of paracetamol from mother liquor (evaporation, crystallization, filtration) blend with the mainstream of paracetamol.

 

This process is managed under cGMP meaning strict control of manufacturing steps.

 

Last point, this process requires a lot of energy to recover material from mother liquor. I've been implementing multiple effects evaporators, probably MVR is a better option. Cooling is also key for Crystallization step (atmospheric refrigerant + chilled water) to adjust the morphology and the shape of the crystals.

 

Kinetics Study of Paracetamol Production from Para-Aminophenol and Acetic Anhydride

 

Good luck

Breizh

 

Thank you to all those who replied!

and @breizh, the paper you shared is one of the resources I'm using

And yes, I'm using p-aminophenol and Acetic Anhydride in the presence of acetic acid to synthesize it. I also came about the use of water to prevent over-acetylation, found this.

I also found papers studying concentrations of PAP in different solvents (Water-Ethanol or Water-Propylene glycol). Why would we choose that if we can just dissolve both in Acetic Acid, and then add water during the reaction using side streams to prevent over-acetylation?
If there is no reliable way to get kinetic data from any 'usual' methods practiced, how does one go about it? Do they have to pull a Tennessee Eastman and generate the data using AI? or calculate from NIST or other data banks?

[matrix_2005]

Also, some people in the place I'm interning at pointed towards potentially using the Linde process. Why would that be a consideration for utilities, especially if we're liquefying air? Does this depend more on economics and energy available or is this really a requirement?

[breizh]

Hi,

To me PAP should be dissolved in Acetic acid prior to acetylation, based on my experience. 

Note: Excess of CH3COOH could be sold after distillation.

Good luck

Breizh