Cleaning of the reaction vessel

Check what the product being produced is; if it is water-soluble, simply rinse it with water using a hose； If it is oil-soluble, it will first be cleaned with a solvent, and then washed again with water and detergent ； However, we have some kettles dedicated to producing oil-soluble substances, so we only use solvents for cleaning.

Generally, we add water first and then raise the temperature; the mixture is boiled for two hours. If the reactor is corrosion-resistant, some acid or base can be added accordingly, depending on the properties of the materials inside the reactor, to accelerate the cleaning process

It mainly depends on what the reactants are when choosing a solvent; for example, acetic acid is used to remove scale. Additionally, it’s important to consider what type of reaction vessel you have, as different reactors require different washing procedures~~~

Generally, after washing with water, it is cleaned with alcohol

This depends on the specific products that have been manufactured; generally speaking, from a cost-safety perspective, it is advisable to opt for washing first

Generally, when conducting pilot tests, we first rinse with clean water, then use ethanol for reflux (in enamel reactors of 500L or less), while recovering the ethanol from the condenser. Then rinse with clean water, and finally dry it. For more stubborn organic substances, use ethyl acetate instead of ethanol for reflux.

A cleaning validation is required: the cleaning procedures, the requirements for residues after cleaning, and the methods for testing and sampling. . . . . .

The key is what the nature of the residues in the reactor is Water-soluble ones go without saying. For oil-soluble substances, cleaning agents can be considered; they are always cheaper than solvents and are also more environmentally friendly. If cleaning at room temperature does not work, then hot water, or even solvents, should be considered. Also, the cleaning efficiency isn’t clearly specified, and there are no requirements regarding hygiene indicators such as the presence of microorganisms in the reactor. Otherwise, the sterilization effect also needs to be considered.

What was mentioned above covers most of the aspects. The key is to consider the medium inside the reactor: if it’s water-soluble, water can be used directly; for oils, a detergent is needed for cleaning. Of course, if the medium is toxic, it must be detoxified before cleaning. In general, scaling requires cleaning with high-pressure water.

When designing process operation procedures nowadays, it is generally necessary to take the concept of cleaner production into account. The treatment concepts vary depending on the scale and system. For example, in the case of high-value-added products and large-scale systems, after the reaction is complete, try to use the reaction solvent to capture the residual products, considering their recovery and reuse.

Of course, it depends on what’s inside, that is, what needs to be cleaned. If it’s a new tank, water is usually used for leak testing as well as cleaning. :hug:

Some products have very strict requirements for reaction vessels, and cleaning them requires careful attention. Perhaps not many people are involved in production processes, but external inspections impose such requirements. Leaving aside the issue of sealing, we first wash the vessels with alkaline water, then with acidic water, followed by pure water; only after the resistance value meets the specified standards is it acceptable. There are specialized SOPs for this process

The landlord needs to come out and explain; the background needs to be made clear, so as to live up to everyone’s enthusiasm! ! ! ! :handshake

For cleaning our kettles, we generally: 1 First, neutralize it with acid (or alkali)； 2 Heat with clean water and stir for 3 hours (sometimes add a suitable amount of detergent), then drain and dry ； 3 Use a solvent or acid for penetration testing based on the actual conditions of the kettle ； 4 Rinse with purified water and dry ； 5 Before use, recycled solvent reflux may be employed depending on the specific project.

It depends on the type of reactor being used; for those used to process organic substances, organic solvents can generally be used for cleaning. If scaling is a problem, a small amount of weak acid can be added

We usually start by rinsing with water to remove contaminants that can be dissolved or washed away by water, and then proceed with reflux washing using methanol. Ethanol is generally not used, after all, methanol is cheaper than ethanol. In the case of stubborn stains, analyze their possible nature and use appropriate solutions such as ethyl acetate, dilute hydrochloric acid, or dilute sodium hydroxide to address the issue effectively. Foreigners like to use propylene to clean pots. For organic stains that are truly difficult to remove, our ultimate solution is DMF: it’s a bit expensive, but it’s very effective. If it really can’t be removed, the worst option is to clean it with the blank system used in the next reaction step. In other words, if the next step involves a reaction under basic conditions with methanol, I would use methanol along with sodium hydroxide for rinsing. If that still doesn’t work, well, maybe that contaminant won’t have much impact on your subsequent steps (but this isn’t 100% guaranteed)^^