These last months, I have been deep amine gas treatement systems. Enjoying playing with eNRTL, the right Henry constants, with all the MEA, DEA, MDEA, piperazine blends, the whole family of solvents that industry uses to strip CO₂ and H₂S (and more) out of process gas. And one reference kept coming back in every paper, every thesis, every validation dataset I was reading: Kohl & Nielsen.
Just "Kohl & Nielsen", like everyone in the field already knows what you mean, but of course, not me.
So I dug a bit. It turned out to be Gas Purification, the 5th edition, by Arthur L. Kohl and Richard B. Nielsen, published nearly 30 years ago, in 1997. The reference on the subject, like Thermodynamic Models: Fundamentals & Computational Aspects by Michelsen and Mollerup for fluid phase equilibria. In it, you get flow schemes, loading correlations, reaction mechanisms, degradation pathways, heats of absorption; all the numbers I need to check my simulations against real plants. On the desk, not on the shelf.
Off I went online looking to buy a used copy of it, I have a collection of used reference books, I am still very old school, still prefer the dead tree version of reference books, because I always put post-its to mark the pages of interest to quickly find them again. Prices looked reasonable, €80 to €150 depending on the seller.
And then I looked at the cover.
The dark blue cover, the "FIFTH EDITION" banner at the top, the not so good photograph of the gas treating plant at the bottom. I had seen this book before. Many times. Too many times. Yes, on my wife's bookshelf, in the office next to mine.
My wife is a chemical engineer and a specialist in gas treating processes. Of course she has the reference work in her field. Of course it is the 5th edition. Of course it was already three meters away from my desk the whole time I was hunting for a copy online.
I raided her bookshelf. A bookmark is now sitting in the MDEA chapter.
The lesson: before you buy the reference book for your domain, check if the domain expert you live with has not already bought it for you.