What is calorimetry?

Calorimetry measures how much heat is used or released in a chemical process. The instruments, called calorimeters, track changes in heat that occur during a chemical reaction as a function of time. This can help researchers determine what conditions can be modified to make reactions more efficient. Calorimetry is a useful tool for understanding hydrogen storage and the chemical conversions central to energy sciences.

What is inside the Energy Sciences Center calorimetry laboratory?

The thermal analysis and reaction calorimetry lab, or calorimetry lab, in the Energy Sciences Center houses six calorimeters. Each instrument analyzes different combinations of temperature and pressure, allowing researchers to obtain more detailed insight into reactivity suited to probing a range of reactions in a mix of gas, liquid and solid phases. One instrument, known as the “flipper,” physically rotates to mix systems that have all three phases. Another instrument is connected to a mass spectrometer and uses a combined auto sampler and robot that can perform up to 20 experiments without direct supervision.  Calorimetry experiments enable researchers to directly study both the energetics and composition of a reaction mixture as it changes over time or a range of temperatures. Many of these experiments require long reaction times. However, once set up, the time dependent data is collected for hours in automated processes that do not require additional oversight.

The instruments represent unique capabilities that help scientists at Pacific Northwest National Laboratory study how chemical reactions proceed. This specialized technique allows researchers to develop a rich picture of what is happening during a chemical process. Scientists use calorimeters to explore how catalysts, substances that speed up chemical reactions, change the rates of a process. Using this knowledge, researchers can then better control the environment of a reaction or a catalyst to make it more efficient.

Researchers in this lab also use calorimetry to study how hydrogen behaves in different energy storage systems. They can quantify the amount of energy it takes for hydrogen to add to and detach from the storage molecule or material. Combined with computational studies, these experiments allow us to understand these steps, which are critical for creating practical, reversible storage of green hydrogen.

Publications

1. Kumar, R., A. Karkamkar, M. Bowden and T. Autrey (2019). "Solid-state hydrogen rich boron-nitrogen compounds for energy storage." Chemical Society Reviews. 48(21): 5350-5380.
2. Yu, Y., T. He, A. A. Wu, Q. J. Pei, A. Karkamkar, T. Autrey and P. Chen (2019). "Reversible Hydrogen Uptake/Release over a Sodium Phenoxide-Cyclohexanolate Pair." Angewandte Chemie-International Edition. 58(10): 3102-3107.
3. Karkamkar, A., K. Parab; D. M. Camaioni, D. Neiner, H. Cho, T. K. Nielsen, T.  Autrey (2013). “Thermodynamic and Kinetic Study of the Heterolytic Activation of Hydrogen by Frustrated Borane-Amine Lewis Pairs.” Dalton Trans. 42: 615–619.