What do I do?

So, as you may or may not know, I currently work as an organic chemist in the field of carbon capture and storage (CCS). It has come to my attention that not many of you actually know what CCS is so I thought I would take this opportunity, in my jet lagged state, to explain it. There are plenty of other people who have explained it much better than me so do also check out the literature.^{1, 2}

“Carbon capture” refers to the capturing of carbon dioxide (CO₂), usually from power station flue gases and “storage” is the storing of this captured CO₂. So why do we want or need to capture and store carbon dioxide from places such as power stations? Fossil fuel combustion supplies more than 85% of energy for industrial activities and is therefore a huge greenhouse gas contributor. Coal will supply 28% of global energy by 2030, as part of a 57% increase in CO₂ emissions. CCS is a way of reducing emissions and is considered a provisional system to allow a transition away from the use of fossil fuels [“World energy outlook” (International Energy Agency, Paris, 2007), http://www.iea.org]. ²

There are many different methods for the capture of CO₂. My research is in post-combustion carbon capture (PCCS) which, as the name suggests, allows the capture of CO₂ after the combustion of the coal (or gas). There are also pre-combustion and oxy-fuel combustion processes which can be used (as shown in my very crude and simplified schemes below).³

Post-combustion CCS

Pre-combustion CCS

Oxy-Fuel CCS

Since it is what I research, I will only talk about PCCS, but the other CCS options are equally valid. The majority of PCCS research is in the use of amines to capture CO₂, as these can form stable carbamates or bicarbonates with CO₂. These salts can then be heated up to allow release of pure CO₂, which can be sent off for storage, and the free amine, which is recycled.

There are many amines that can be used in carbon capture processes but mostly they are alkanolamines such as monoethanolamine (MEA) and N-methyldiethanolamine (MDEA) or hindered amines such as piperazine (PZ).

          MEA                                               MDEA                                                     PZ

There are currently lots of pilot plant projects where amines are being used to capture carbon dioxide. Hopefully soon there will be a full-scale demonstration project, and then fingers crossed, it will be commercialised.

Right, now onto storage… ^{5, 6}

Storage (or sequestration) is very much a geologist’s problem and although I know more than the average person about it, I am in no way an expert. The theory is that the captured, pure CO₂ can be stored in underground geological formations such as oil fields, gas fields and saline aquifers. The current trend is to use CO₂ in enhanced oil recovery which allows previously unavailable oil to be retrieved. Similarly, CO₂ can be used to obtain coal from unmineable coal seams. Saline aquifers, of which there are many, offer a large potential storage volume but relatively little is known about the effects of storing CO₂ in them, particularly in relation to potential CO₂ leakage. There is a great deal of research into all areas of storage and I do recommend looking at further literature if you wish to learn more.

I hope I have managed to inform you further on CCS. Although it is not a fix-all process, I believe CCS is necessary as a short term measure to reduce our carbon emissions and I hope a full-scale CCS project does go ahead very soon.

 

1 J. Gibbins, Energy Policy, 2008, 36, 4317–4322.

2 H. J. Herzog, Environ. Sci. Technol., 2001, 35, 148A–153A.

3 R. S. Haszeldine, Science, 2009, 325, 1647–52.

4 J. D. Figueroa et al, Int. J. Greenh. Gas. Con., 2008, 2, 9–20.

5 K. Michael et al, Int. J. Greenh. Gas. Con., 2010, 4, 659–667.

6 K. S. Lackner, Science, 2003, 300, 1677–8.

 

Chemistry Careers – more than just research

A bit of a different post for me…

On Wednesday 14th November the Yorkshire and Humber regional group of the Society of Chemical Industry (SCI) hosted a careers options seminar at the University of York. The aim of the session was to show undergrads, postgrads and postdocs that there is a range of research and non-research careers paths that they can take, both in and out of the lab. As their newest communications officer, I thought I would share a summary of the evening with you ahead of the next session for the Uni of Leeds students and postdocs (message me for more info).

Matthew Thornton talked about his career in Knowledge Transfer. Not surprisingly, no one in the audience had even heard of knowledge transfer as a career option but Matthew explained it very well. Matthew has a degree in chemical engineering and a PhD in materials science. He showed that there are great opportunities to meet interesting people (e.g. Duke of Edinburgh) and to travel to many countries in his job. He gets to work with a wide variety of people from industry, academia and government.

Gareth Ensor works in process development and scale up at Astra Zeneca. He demonstrated, in his talk, that it is possible to have a great career in research without having a PhD. Gareth talked about the importance of the development of transferable skills such as acting decisively, strategic thinking and working collaboratively. He also showed pros and cons of his career, highlighting the learning that comes from scale up of processes.

Dan Woolaston is a trainee patent lawyer. He had a very entertaining talk on the intellectual challenge of patent law, and variety of work, switching from cutting edge science to lone inventors with simple ideas like bike locks. He described the required skills as excellent communication skills and the ability to understand the science behind the inventor’s idea quickly. He said the downside was the number (8+) of exams required.

Finally, Jason Lynham gave a talk on his academic career. He talked of the pleasure of working in something you really enjoy and the travel opportunities and collaborations abroad. He also described the pressure of constantly having to find funding, and the highs and lows of getting papers and funding bids accepted or rejected.

The turnout and feedback from the session was really good, let’s hope the one at Leeds is just as successful!

Chemistry makes me cry

A recent discussion on Twitter about lachrymators (from lacrima meaning tear in Latin) has got me to wondering about chemicals that we use in the lab and the effect they can have on our “emotional” state.  Clearly, lachrymators don’t change our emotional state but when they are released they do make us look like immensely sad.

The most common culprit in our undergraduate labs is benzyl bromide. On contact with the eye, the chemical stimulates sensory neurons creating a stinging, painful sensation which causes tears to be released from the tear glands to dilute and flush out the irritant. When this gets released in a lab, everyone knows about it, especially when there are dozens of undergraduates using it.

Benzyl bromide

More commonly found lachrymators are onions, which release syn-propanethial S-oxide on slicing. The release is due to the breaking open of the onion cells and their releasing enzymes called alliinases, which then break down amino acid sulfoxides, generating sulfenic acids. A specific sulfenic acid, 1-propenesulfenic acid, is rapidly rearranged by a second enzyme, called the lachrymatory factor synthase (LFS), giving syn-propanethial S-oxide.  

Syn-propanethial S-oxide

1-propenesulfenic acid

Lachrymators were commonly used in World War I as “tear gas”.  Extremely low concentrations of lachrymators caused an intense irritant action on the eyes. This caused tears and pain which then resulted in reduced vision which meant that the soldier became impaired. Benzyl bromide, bromoacetone, dibrommethylethylketone (which could prove fatal), ethyl iodoacetate and xylyl bromide were the common culprits.

There are also many other lachrymators that are used today for crowd control purposes. In the past, phenacyl chloride was used but this has mostly been replaced by 2-chlorobenzalmalononitrile (CS gas), dibenzoxazepine (CR gas) and pepper spray (OC gas) due to the toxicity of phenacyl chloride. Pepper spray contains capsaicin which is a capsaicinoid which is produced as a secondary metabolite by chili peppers. It is why you may ‘cry’ when you are chopping up chillies…you may notice it more acutely when you accidentally rub your eyes after cooking with chillis.

I have explained that chemicals can make us ‘cry’ (probably not as much as our PhDs did) but chemicals can also have the opposite effect and make us giddy with laughter. I have never experienced this but I am told it is quite pleasant!

Nitrous oxide, or laughing gas, was discovered in 1799 by British chemist Humphry Davy, is an example of a chemical that makes us feel happy. Inhalation of nitrous oxide for recreational use, with the purpose of causing euphoria and possibly slight hallucinations, began in 1799 and was commonly used by the upper class at ‘laughing gas parties’. Nitrous oxide abuse has even been documented (Emergency Medicine Australasia (2010) 22, 88–90). It is also used as an analgesic, particularly in the dental profession although my dentist always chooses to use the unpleasant Lidocaine.

Nitrous oxide

Nitrous oxide quickly enters the bloodstream through the alveoli in the lungs and is distributed quickly through the whole body, including to synapses in the brain. Nitrous oxide is an uncompetitive NMDA channel blocker which blocks the ion channel by binding to a site within it. The NMDA receptor is a receptor which allows for the transfer of electrical signals between neurons in the brain and in the spinal column. For electrical signals to pass, the NMDA receptor must be open but when nitrous oxide is used, it is blocked.

Obviously, the laughing gas is causing a change in the chemistry of our brains, unlike lachrymators, which just make us look like we are upset but I just wanted to show that chemistry can make us cry, but it can also make us happy.**

Interesting reads:

J. Carson, Food Reviews International, 1987, 3, 71-103

Nitrous Oxide: No Laughing Matter – D. Wuebbles, Science, 2009, 326, 56-57

** I am not condoning the use of laughing gas to make you happy. Eat some chocolate instead.

My lightning bolt moment

I have been neglecting this blog lately as lot has been going on. Sorry! I have been working on a blog about crying in the lab, but I had a sudden urge to write this post during my mid-afternoon Earl Grey tea break… Is there a person that you would call your chemistry idol? Or perhaps someone that inspired and propelled you to break boundaries in your subject area?

I remember the moment where I felt like chemistry was really for me and that I really could change the world. It sounds corny but it is true. It all started during the early years of my PhD. I was begrudgingly dragged away from the lab to attend a three day series of lectures by Dan Nocera from MIT. I had no idea what to expect (I hadn’t googled him before the lectures) but I didn’t expect to come out of those lectures feeling as inspired and up for the challenge as I did.

For those who don’t know, Dan Nocera‘s group pioneers studies of the basic mechanisms of energy conversion in biology and chemistry. He has, for example, accomplished a solar fuels process that captures many of the elements of photosynthesis outside of the leaf. He has hundreds of publications which are all on his website. As well as his really interesting and important work, it was his attitude and presentation style that grabbed me. He was very passionate about what he does but he was also relaxed and open to questions. He showed of all of us in the audience that we, as scientists, need to be working on the future energy problem, sooner rather than later.

Although Dan Nocera isn’t my idol as such, I can put my desire to remain in research down to those short three days. He showed me that we can try to answer the ‘big’ questions by working our guts out in the lab and that, one day, humans could potentially be smarter than plants!

So who or what was your inspiration to go in to research? I am really interested to find out.

Jess