Source: This blog was written by Suresh Mulmi, PhD Candidate at University of Calgary. Suresh was funded by CMC Canada and the UK Carbon Capture and Storage Research Centre (UKCCSRC) to visit the School of Chemistry at the University of Birmingham.
The growing level of CO2 in our environment and drastic change in climate has forced us to develop new renewable sources of energy in order to lower the amount of fossil fuel consumption. Scientists have taken one further step to remove the carbon footprints by capturing it and literally hiding it underground, which is known as Carbon Capture and Storage (CCS). CCS technology has been developed to prevent the emission of CO2. UKCCS Research in UK and CMC (Carbon Management Canada) in Canada are working together for the technical and economical feasibility of the CCS process.
In CCS technology, it is very important to continuously monitor the concentration of gaseous species, particularly CO2, in real-time. Long term safety and integrity of the gas storage systems are of more concern, so that no CO2 leaks from the reservoirs. The potential risk of leakage could cause severe damage in our environment regarding pollution and climate change. Therefore, most of the projects for gas sensors under CMC are focused on fiber optics and seismic sensing techniques. They are well-established technologies and monitor the gases at harsh environmental conditions (e.g., high pressure, high temperature). However, the lack of sensitivity at parts per million (ppm) level, poor selectivity and long term stability still persist in these sensors. Therefore, solid-state electrochemical sensors, as an alternative, have been widely investigated due to their high selectivity, high sensitivity, reliability, and most of all low cost. For example, Swedish company Acreo in collaboration with Fibertronix and SenseAir has already started developing new electrochemical sensors for CCS since 2013.
Solid-state electrochemical sensors have further advantages such as ease in miniaturization, large scale production and low maintenance cost comparing to traditional NDIR and fiber optics gas monitoring technologies. My PhD study is based on the development of mixed ion electron conducting materials for gas sensing applications. So far, we have successfully developed CO2 sensors for high temperature (500-700 oC) applications in our lab based on Fe-doped metal oxides. However, we require sensors operating at lower temperatures (25-100 oC) mainly for the CCS application purpose. For this, we need to synthesize the nano-structured materials to reduce the operating temperature. Therefore, I had a great opportunity to visit University of Birmingham (UB) on this summer (June 1-19) to carry out new synthetic route for the preparation of nano-structured materials. In addition, further characterization techniques unavailable at University of Calgary (UofC) such as Raman Spectroscopy were utilized to understand the sensing mechanism.
The travel grant for my visit to School of Chemistry at UB was awarded by CMC and UKCSCRC. I am very grateful to Prof. Peter R. Slater, my host supervisor at UB, and his students who helped me throughout my stay in his lab. I would like to thank them all through this blog for their great support.
I had discussions with Prof. Slater to prepare new materials and the available instrumental techniques in his lab for further characterization of my materials. Prof. Slater guided me through the lab and Laura, his student, helped me filling the safety form. I spent most of my time learning sol-gel synthesis, which is employed to obtain nano-structured materials. It took a while to get acquainted with people. My accommodation was arranged at Birmingham International Student Homes, which was 20 mins walk away from UB and it was convenient to commute by bus.
Second and Third Week
I began to use the XRD instrument after I got trained from one of the staffs at School of Chemistry. I started collecting the data for Raman Spectroscopy as well for my sample that I prepared at UofC. To understand the sensing mechanism of our mixed conducting CO2 sensors is very critical in relation to further optimize sensor’s fabrication and design. Therefore, I learned TGA and iodometric tritraion techniques to calculate the oxidation state of transition metal(s) involved in the sample that induced the high CO2 sensitivity. The results obtained at UB were discussed with Prof. Slater. His suggestions and ideas were very useful for my studies. His guidance will certainly help me to organize my future experiments.