Reactions

Letters to the editor

Ammonia synthesis

I enjoyed reading the detailed update on the Haber-Bosch process for ammonia synthesis by Leigh Krietsch Boerner (C&EN, June 17, 2019, page 18). Boerner writes that the process “could be one of the most important industrial chemical reactions ever developed.” Surely this is an understatement! In my opinion, the process is the most important ever developed. More than other innovations and industrial developments, the process has been single-handedly responsible for providing a quasi-sustainable environment for humankind to grow and survive at the exponential rate at which the growth has occurred over the past century. Vaclav Smil has emphasized this aspect in his seminal book on the process titled Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production.

I used excerpts from this book as required supplemental reading about the economic, environmental, and sociological impacts of chemistry and chemical engineering in an undergraduate physical chemistry course that I taught at Beloit College for many years. If I were to teach again, I would now add Boerner’s article to the readings, highlighting as it does the current efforts to make the process green. Fascinating stuff! And the article goes hand in hand with the brilliant Periodic Graphics, by Andy Brunning in the same issue, that highlights the environmental impact of the top industrial reactions (page 23).

Rama Viswanathan
Long Beach, California

PKU

Without a doubt I think the July 8, 2019, issue of C&EN was the finest I have ever read. The article by Ryan Cross on phenylketonuria (PKU) is simply great (page 24). I have to admit that I have rarely considered this disease, but I won’t forget it now. The topic of PKU brings to mind my first exposure to the disease. I was in my first year of graduate school at the University of Notre Dame in 1963. I was taking a course in analytical chemistry. My teacher was Rudolph S. Bottei (Rudy). On one occasion he wanted to emphasize the place of chemistry as related to the well-being of society. He spoke of the research on PKU that resulted in the method of detection of the disease via a blood sample from the heel of a newborn child. Now in the July 8 issue all is brought up to date. Rudy is no longer with us, but I feel certain he is well pleased.

Clarence G. Johnson
Memphis, Tennessee