Monthly Archives:   February 2016

CO2 capture with less energy consumption
  24 February, 2016

MyPhD_100x30_v2In order to stall the climate changes, more CO2 emitting industries must install technology for carbon capture and storage. To make this type of technology more available, I work on a way to make CO2 capture technology less energy demandig.

Since the start of the industrial revolution, the concentration of CO2 in the atmosphere has dramatically increased due to human activity. As CO2 is largely the reason for global warming, it is causing global temperatures and sea level to raise and it is changing weather patterns and climate. Fortunately, there are several measures we can do to prevent damaging consequences of climate change as they are in fact caused by human activity. One solution is carbon capture and storage (CCS).

Chemical absorption of the CO2
In my PhD I will focus on CO2 capture by means of chemical absorption. It is the most mature technology to capture CO2 and has already reached commercial stage at Boundary Dam in Canada. A chemical absorption process capture CO2 from CO2 emitting industries such as combustion of coal and cement production.

How the absorption process works
The flue gas containing CO2 enters an absorption column and reacts counter current with a solvent. After the solvent has captured CO2 it is led to a desorption column where the CO2 is released and the solvent is returned to the absorption column. Unfortunately, the energy demand related to solvent regeneration is high and more research is needed.
My goal is therefore to identify and characterize a solvent system that enable low energy requirement.

An pilot scale system for C02-removal at NTNU. The flue gas enters an absorption column and reacts counter current with a solvent. After the solvent has captured CO2 it is led to a desorption column where the CO2 is released and the solvent is returned to the absorption column.  Unfortunately, the energy demand related to solvent regeneration is high and more research is needed. Photo: Per Henning / NTNU

A pilot scale system for CO2-removal at NTNU. Absorption column to the left and desorption column to the right. Photo: Per Henning / NTNU

Systematic experimental work
A solvent system that has already shown potential to reduce the energy demand is blended amine systems, which consist of a primary or a secondary amine and a tertiary amine. Through targeted experimental work and systematically vary molecular properties of the amines, we hope to find a solvent that will lead to a real break-through in solvent technology. It can then be more economically feasible to implement a CO2 capture technology.


How many moose and deer can a modern forest hold?
  24 February, 2016


As a part of my doctoral degree, I study the interaction between large herbivores like moose and deer, and the forests they live in.

Moose and deer populations have increased drastically in Norway the last decades resulting in a high browsing pressure that is having an effect on forest tree regeneration.

This affects the functioning of forests in terms of timber production, but may also influence other important aspects such as biodiversity, soil fertility, and carbon storage.


Photo: Per Harald Olsen / NTNU

Inside and outside the fence

To study some of the complicated interactions between large herbivores, vegetation, and climate, I compare field measurements made inside and outside large exclosure fences that have been erected on recent logging sites.

By using long-term ecological data collected in several different forest types with known herbivore densities, we hope to be able to explain the observed differences in forest development.

Moose and deer population sizes
Learning about the effects of large herbivores on the forest vegetation will help us identify appropriate moose and deer population sizes to ensure sustainable management of our natural resources, as well as identifying potential conflict between management goals, such as forestry and biological conservation.

The connection between space and Earth weather
  24 February, 2016

MyPhD_100x30_v2As a part of my doctoral degree I will learn more about what happens 90 kilometers over our heads. What happens up there today will influence the weather and climate here at Earth in the weeks to come.

The atmosphere is really more than just air to breath and rain and snow. It warms us – without it we would be about 30 degrees cooler here, it protects us from incoming meteoroids and builds the scene for the fabulous light-show we call northern lights. Yet, many things “up there” are still a mystery to us.

To learn more about all this, we have to become creative. For us, that means looking with a telescope to the darkest spots of the night sky, to listen to burning meteors or to look at the warmth of the ozone, high up in the atmosphere. Because, if we want to know the weather of tomorrow, we have to understand the atmosphere today.

Christoph Franzen with the all-sky-camera on top of the natural science building in Gløshaugen. This camera detects nights with northern lights to separate between effects from the aurora and from the light from the hydroxyl. Photo: Per Henning / NTNU

Looking at the darkest spot of the night sky
I’m specializing in the warmth of the hydroxyl molecule (OH) – which is mostly contained in a thin layer at about 90 km altitude, where northern lights have a strong influence as well. This altitude is already too high for weather balloons, so I’m using a Telescope, actually pointing it towards the darkest spots in the sky, and not towards stars, which seems rather pointless in the classical usage of telescopes.

But there we can see the very dim light that lies outside the visible range, which comes from the hydroxyl and changes with the temperature of the surrounding atmosphere. We are observing these differences via spectroscopy.This can give us new measurements of the temperature, and with a little computational effort, the density of the atmosphere at a height of about 90km.

Space weather and Earth weather
We find that the weather in this part of the atmosphere can influence long term weather and climate down here. Measurements like the ones we are doing, provide important input for future climate models and weather forecasts. With the research results from the research group I am a part of, we hope to better understand the Earth’s whole atmosphere and its natural variability.

Multitasking: a highway to self-deception
  18 February, 2016


Asserting to ourselves that we work efficiently is something we strive for – it’s hard to beat the feeling of having been really productive after a long day at work. To accomplish this, it seems incredibly inefficient to just do one thing at a time while you’re working, doesn’t it. Why should you, when you can check your email or social media, eat your lunch, while writing a report and planning the important meeting you have tomorrow all at once.

Let’s pause for a second. How certain are you that juggling all kinds of activities throughout the day is the most efficient way to work?

It does seem impressive. Getting a lot of stuff done, more or less at the same time, has to be a remarkable feat. However, the research you’re about to get acquainted with might prompt you to reconsider.

Multitaskers worse at multitasking

Researchers at Stanford [1] and Ohio [2] university published a few years ago studies where they, among other things, compared the following two groups:

  1. Persons who multitasked heavily and who believed that doing so made them more efficient than others
  2. Persons who preferred to focus on one task at a time

As you might suspect by now, the second group accomplished to get more work done. But here’s the kicker: the researchers found that the persons in the first group, the self-confessed multitaskers, were actually worse at multitasking than those in group two! That’s gotta hurt.

It turns out our brains aren’t really built for multitasking. In fact, they are pretty terrible at it. The studies in [1] and [2] found that we become less productive and work more slowly when multitasking.


So why do we do it? The reason is that it makes us feel great: we think we’re being super efficient while in reality we’d be much better off focusing on one thing at a time.

Of course, there are plenty of activities outside of work that leaves us little choice but to multitask if we want to be successful. If you’re a professional e-gamer competing in real-time strategy games such as Starcraft or League of Legends or a chef preparing a complex dish for a dinner party of ten, you will never excel unless you can multitask like a hero.

But when it comes to doing scientific research or teaching, the studies in [1] and [2] suggest that there is little reason to multitask and that you are tricking yourself into thinking you are more efficient than what is really the case. I encourage you to have a look at these studies – they certainly made me repent and change my multitasking ways.

[1] E. Ophira, C. Nass, and A. D. Wagner. Cognitive control in media multitaskers. PNAS 106, 15583 (2009)

[2] Z. Wang and J. M. Tchernev. The “Myth” of Media Multitasking: Reciprocal Dynamics of Media Multitasking, Personal Needs, and Gratifications.
Journal of Communication 62, 493–513 (2012)