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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: blackcat on February 23, 2020, 09:55:16 AM

Title: About mass efficiency of a reaction
Post by: blackcat on February 23, 2020, 09:55:16 AM
Not just talking about yield of a reaction, but mass of product relative to the mass of all reactants. This is a Green Chemistry idea.

What is a good mass efficiency? Any idea?
Title: Re: About mass efficiency of a reaction
Post by: OrganicDan96 on February 23, 2020, 02:09:05 PM
i assume you are thinking along the lines of atom economy?
Title: Re: About mass efficiency of a reaction
Post by: blackcat on February 23, 2020, 11:42:57 PM
i assume you are thinking along the lines of atom economy?

Yes, please advise.
Title: Re: About mass efficiency of a reaction
Post by: OrganicDan96 on February 24, 2020, 11:41:16 AM
look up atom economy, it's a well known thing
Title: Re: About mass efficiency of a reaction
Post by: Babcock_Hall on February 24, 2020, 07:17:55 PM
http://www.rsc.org/suppdata/cs/c1/c1cs15219j/c1cs15219j.pdf
Mass efficiency is defined in a different way versus atom economy.  I don't feel well versed enough in this subject to compare one metric to another.
Title: Re: About mass efficiency of a reaction
Post by: Borek on February 25, 2020, 03:46:16 AM
What is a good mass efficiency?

Somehow I am not convinced there exists something like a "good value of mass efficiency". It is a relative thing that can be used to compare different processes yielding the same final product, but I doubt in sense of comparing processes yielding different products.

Producing one ton of steel uses 280 m3 of water, producing one ton of beef requires 4000 m3 of water*. Do you thin you can draw any conclusions from comparing these numbers?

*different sources give different numbers, exact values don't matter here.
Title: Re: About mass efficiency of a reaction
Post by: blackcat on February 25, 2020, 11:34:16 AM
What is a good mass efficiency?

Somehow I am not convinced there exists something like a "good value of mass efficiency". It is a relative thing that can be used to compare different processes yielding the same final product, but I doubt in sense of comparing processes yielding different products.

Producing one ton of steel uses 280 m3 of water, producing one ton of beef requires 4000 m3 of water*. Do you thin you can draw any conclusions from comparing these numbers?

*different sources give different numbers, exact values don't matter here.

I understand your point.
However, the original intent for my post is to ask if there is any general value of good mass efficiency, especially in industry. If there isn't such a thing, that's alright.