Nickel is a common catalyst, and Abas Mohsenzadeh’s research shows what actually happens when different forms of nickel are used as catalysts in the gasification and combustion of hydrocarbon-based biomass.
There are two known processes in the production of hydrocarbon-based biofuel: hydrocarbon combustion and what is known as the Fischer-Tropsch process (also called indirect liquefaction). The results of Abas’ studies show that it is advantageous to use nickel as a catalyst in hydrocarbon combustion, but not in the Fischer-Tropsch process.
Thesis: Computational Studies of Nickel Catalysed Reactions Relevant for Hydrocarbon Gasification
By doctoral student: Abas Mohsenzadeh at the University of Borås
Main supervisor: Professor Tobias Richards, University of Borås
Thesis defence: 29 September 2015, University of Borås
In his research, Abas hopes to obtain more detailed knowledge about what actually happens at molecular level during the various stages of the gasification or combustion process when nickel is used as a catalyst.
“A catalyst is something that is added to speed up a reaction,” he says. “For example, this could be a metal that is added and that makes the other molecules react in one way or another.”
His research is mainly being carried out by computer. Abas explains how he sits or stands while the long runs are carried out by the super-efficient computer in his study, and is so fascinated by what is happening that he forgets to take breaks.
“I can see the events in three-dimensional models which twist and turn on the monitor. There, I can study things in detail and find out more about what happens to the water and carbon dioxide molecules when nickel is added in various forms. How the atoms move, and which form of nickel makes the reaction as fast as possible. These simulations can be used as a complement to laboratory experiments.”
The reactions he has chosen to look at are some of the most important reactions in the gasification process, where the hydrocarbon molecules are split and can be converted into gases. He calculates the speed of the reaction and notes the crucial difference made by the catalyst. Without a catalyst, the reaction would require much higher temperatures – several hundred degrees higher, in fact – in order to take place. This is not ideal if the end-product will be hydrogen gas, for example, as there will be less hydrogen gas at higher temperatures.
He has studied many different variants of nickel as a catalyst for both gasification and combustion, where the differences in the position of the atoms in the surface of the catalyst affect the reaction. Thanks to computer simulations, it is possible to see more quickly how the reaction will occur for the different variants. Better scientific support is thereby available when choosing a catalyst for each instance. Gasification can also be used to develop new catalysts. They are first tested using computer simulations, after which physical experiments are carried out.
“I want us to be able to achieve a significant reduction in greenhouse gases. I hope that my research will contribute towards this, by making it possible to produce biofuel more quickly.”