Secondments

All MINSC fellows spend at least one month on secondment at a partner institute. Below is the table of planned secondments for each fellow.

ESR /ER	Primary Host	Secondment
Daniela MEIER	University of Leeds	Reykjavik Energy
Tomasz STAWSKI	University of Leeds	Uni Copenhagen
Taher RABIZADEH	University of Leeds	University of Oslo
Nik BERNINGER	CNRS Toulouse	University of Munich
Thomas RINDER	CNRS Toulouse
Giulia MONTANARI	University of Copenhagen	West Systems
Stan JELAVIC	University of Copenhagen	UCL
Diwaker JHA	University of Copenhagen	Uni Iceland
Christopher HAWKINS	University of Oslo	Uni Leeds
Biyun Zhen Wu	Maersk Oil and Gas	CNRS Toulouse
Cristina Ruiz Agudo	University of Münster	Maersk Oil and Gas
Fernando Berro Jimenez	West Systems	Reykjavik Energy
Jan Prikryl	University of Iceland	Reykjavik Energy + Uni Copenhagen
Prathap Moola	Reykjavik Energy	University of Iceland

Feedback on secondments:

Daniela Meier (Uni Leeds -> Reykjavik Energy):

In my PhD I combine laboratory and synchrotron experiments with field studies from geothermal power stations in Iceland in order to better understand the processes involved in the precipitation of amorphous silica. One of the questions I am working on is: What can microstructures and compositions of silica-rich precipitates tell us about the precipitation of amorphous silica in a power plant (in pipes and heat exchangers) and how is the precipitation affected by temperature, fluid composition, fluid flow regime and time? For this part of my research I work closely with Reykjavik Energy. I have been to Iceland twice, first time in June 2013 and the second time in July 2014, to visit the Hellisheiði geothermal power station. During the first visit, we collected silica precipitates deposited onto so-called scaling plates and studied their microstructures and composition. We could show that the formation of silica scales at Hellisheiði is not a simple precipitation process but that several factors such as temperature and fluid composition and flow regime control the modes of precipitation. In order to better constrain these factors, we have since, in close collaboration with Einar Gunnlaugsson and Ingvi Gunnarsson at Reykjavik Energy, deployed new sets of scaling plates for different immersion times (5 sets of experiments, 1 week up to 6 months). This set of time-resolved experiments is currently running and there is at least one more visit to Iceland planned, most likely next year, so I can obtain further silica scaling samples from the Hellisheiði power station. The collaboration with Reykjavik Energy has greatly affected the course my PhD is taking. Due to the possibilities to obtain fluid and solid samples from Hellisheiði, my PhD project has become a very applied study of silica precipitation which is supplemented by laboratory studies and synchrotron experiments, rather than just fundamental research of mechanisms and precipitation rates.

We are also collaborating with the team at the University of Oslo (potential visit in 2015), Christopher Hawkins and Bjorn Jamtveit, who work on hydrodynamic models simulating a range of precipitation regimes. This interdisciplinary collaboration allows me to see a field that is very different from what I have done so far. I highly appreciate this glimpse of a very complex topic that I would not understand if I had only books and journal articles to learn from. We hope that, by combining the data from "real-life" precipitates we collect at Hellisheiði and study in detail in our laboratories at Leeds and the flow modelling done at Oslo, we can generate a unique dataset that will greatly advance the understanding of how silica precipitates in a geothermal power station."

Biyun Zhen Wu (Maersk Oil and Gas -> CNRS Toulouse):

During my secondment at Geosciences Environment Toulouse (GET), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, France, for two periods of two months, Sep-Oct 2014 and Feb-Mar 2015, many solubility and kinetic experiments on barite were conducted. Many sets of experiments using low and high temperature reactors from both undersaturation and supersaturation approaches were carried out. In addition, effects of salinity and three different ions at three different temperatures were done with the closed system for precipitation and dissolution of barite. All the samples were analysed using the ICP-AES at GET. I received training on operating high temperature reactors. Guidance and supervision have been acheived from Dr. Eric H. Oelkers; support from the fellows from different networks: Ulf-Niklas Berninger from MINSC, Martin Voigt and Christian Grimm from CO2-REACT and Andrea Pérez from MetTrans; help and encouragement from experienced researches, such as Thomas Rinder, Aridane González González and Giuseppe Saldi; specialised training for operating the high temperature reactors and analytical equipment from Alain Castillo and Philippe Besson; and assistance from Clare Desplats. This opportunity was a great chance for exchanging knowledge and gaining experience within the applied geochemistry environment. I had a really great, helpful team during my stay.

Tomasz Stawski (University of Leeds -> University of Copenhagen)

For my secondment I visited the University of Copenhagen, where I performed a series of state-of-the-art analyses using Cryo X-ray Photoelectron Spectroscopy (CryoXPS). XPS is an advanced method measuring the chemical composition, the stoichiometry, as well the chemical and electronic state of the investigated material. In my research, I am looking at more efficient ways of dealing with calcium carbonate scale formation I pipes (also known as lime scale). My work is to understand the ways this compound forms through different pathways in natural and industrial environments. By understanding those nucleation and growth processes, one can control the exact moment of formation of calcium carbonate, and may be able to inhibit undesirable calcium carbonate precipitation. In particular, I am interested in the first moment of formation of CaCO3, which can determine the ultimate form and ultimate fate of the mineral. The early-stages of growth of calcium carbonate in solution are notoriously difficult to investigate due to the very small size of particles (< 100 nm) and their continuous ,very fast changes. One of the ways to investigate the process is to rapidly freeze the solution containing nanoparticles using liquid nitrogen, and then perform the analysis on that sample kept in a frozen form (i.e. by performing cryovitrification), and hence preserving the transient morphology. That in conjunction with the XPS technique allows us to obtain information about the chemical state of the sample for instance if particular bonds are formed, or if it is amorphous or crystalline, and quantitatively evaluate those properties. By freezing the sample at various stages of growth one can compare how its chemical state is changing as a function of time, and infer about the growth pathways. I had a great time in Copenhagen although days were a bit short.

Taher Rabizadeh (University of Leeds -> University of Oslo)

Visiting the Department of Geosciences at the University of Oslo for my secondment was a great opportunity for me to learn about the local geology and modelling the geological phenomena. I had the opportunity to attend a field trip on the Feragen region (full of amazing landscapes about 20 km east of the town Røros, near the Sweden border) where we collected samples of ultramafic rocks for further studies about mineral CO2 sequestration (ophicarbonates) and frost weathering – it was an amazing experience for me to see how geologists pay attention to various types of rocks and use different sampling methods. I attended GEO-PHYS-9200 course lectures and experienced a very nice team-working atmosphere with other students while preparing thin-sections. Further training was provided from the department in using optical and electron probe microscopes to investigate the microstructure and the elemental composition of the samples. A great part of my time in Oslo was dedicated to learn geological subject's modelling but also focused on understanding the fluid mechanics and computational fluid dynamics together to study the fluid flow in fractures and porous media. Overall, my secondment was a brilliant opportunity to meet other MINSC fellows and be familiar with the topics they are working on. Looking back, I realise I have learned lots of new things.

Nik Berninger (CNRS Toulouse -> University of Munich)

The overall goal of my project is to quantify in detail the dissolution and precipitation rates of Mg-carbonates like hydromagnesite, magnesite and dolomite as a function of temperature, fluid composition and saturation state using a suite of scale-spanning techniques. For this purpose I've spend my secondments at the University of Munich in 2012, 2013 and 2014 – each time for about three months. The collaboration between Toulouse and Munich brings together two internationally renowned complementary research teams to study in detail the reactivity of carbonate minerals. The complementary of these teams is that they are both expert in quantifying mineral reactivity but at different scales. The German team is expert in the use of hydrothermal atomic force microscopy. This technique allows direct measurement of reactions occurring at the mineral-fluid interface at the nano-scale as a function of time. The dynamic and microscopic evolution of crystal surfaces and their influence on growth and dissolution mechanisms are a key to the understanding of growth and dissolution kinetics on the macroscopic scale. The French team has vast experience quantifying rates of mineral-fluid reactions using macro-scale mixed flow and batch reactors and has successfully used results to develop rate equations describing natural processes. By combining both groups and their suite of scale-spanning techniques, it is possible to describe mineral-fluid reactions very detailed and providing insight into why some mineral precipitation reactions are inhibited at low temperatures. Results of my studies will then be used to develop robust rate equations to assess the role of carbonate-fluid reactivity in a variety of natural and socially relevant processes. To conclude, my secondments have been of great value for my research project but were great fun as well.

Cristina Ruiz Agudo (University of Münster -> Maersk Oil and Gas)

In September 2014 I had the opportunity to visit Maersk Olie og Gas A/S in Copenhagen. During my time there, II learnt about mineral scaling problems in the oil recovery industry. Since my research is focused at the atomic and nanoscale, the experience in Maersk Olie og Gas A/S provided me with another important perspective on barite formation problems on a larger scale in the North Sea in the oil recovery industry. I visited the Maersk Olie og Gas A/S core lab in Copenhagen and I have learnt about the different types of analyses (e.g. Chromatography, Spectrometry) that are carried out on injection and production waters and also about the mineral scales found in pipelines and equipment (e.g. Scanning electron microscopy, Energy Dispersive X-Ray analysis). I also had the opportunity of seeing the storage and organization of core samples from different oil fields. Thanks to Dr Pernille Josephine Raahauge, Senior Production Chemist at Maersk Olie og Gas A/S, I had the opportunity of going deeper into the scale formation problem and the strategies used for reducing scale formation. Dr. Raahauge spent a lot of time with me explaining how oil is extracted and which kind of problems Maersk Olie og Gas A/S faces in terms of scaling formation in pipelines and downhole completion equipment. Dr. Raahauge gave me several presentations with many details and interesting information I did not know before my visit. Dr. Raahauge and I have subsequently been collaborating throughout my PhD project. We have been exchanging information, results of my research and importantly Dr. Raahauge has provided me with all kinds of data and samples.

Prathap Moola (Reykjavk Energy -> Uni Iceland)

I have performed my secondment with the Geysir research group at University of Iceland. I started tracer tests at laboratory scale at the university; flow through column experiments were performed at different conditions i.e. pH and rock. During my secondment, I had the opportunity to do courses in geochemistry and to learn analytical techniques that involve sampling and characterization techniques such as Ion chromatography, UV-Vis absorption spectroscopy and gas chromatography. During my stay at the university, I also attended a course on fluid geochemistry with the aim of creating models and comparing them with data by using PHREEQC geochemical modeling software that helped a lot for my research work.

Fernando Berro Jimenez (West Systems -> Reykjavik Energy)

My project is focused on the development of an automatic silica analyzer that can continuously measure the silica concentration through the yellow colorimetric method. The instrument had been already tested in the laboratory under favorable conditions but, in order to be sure that the device had been correctly designed, the purpose of the secondment was to test it in geothermal fields. Thus I had the opportunity to visit the Hellisheidi Power Plant (Reykjavik Energy) where very high silica concentrations are present in the geothermal water, causing the loss of energetic efficiency and clogging problems. I had already visited this facility two years ago to take samples and to know where the instrument was going to be placed. This first visit was very important to foresee and to avoid problems with vibrations, high temperatures and the presence of interferences.

The device was set up during the first week of June 2015 and it has been working for several weeks with different samples. The high presence of sulfide interfered with the measurement due to the development of a yellow-green color. However, the instrument was prepared to resolve this issue by acidification and air stripping with an air pump. Finally we were able to check how the monomeric silica concentration varies with time in every experiment. Under the same conditions the silica must have the same behavior. In addition, further experiments were made in the laboratory to get the confirmation that the monomeric silica polymerized in exactly the way the instrument had foreseen. My stay in Reykjavik Energy facilities also provided me with the opportunity to sample in geothermal areas with high pressures and temperatures and to work in the laboratory to analyze silica concentration. For these measurements the spectrophotometric method was used, analyzing monomeric and total silica. All these measurements are being studied for a better understanding of silica polymerization and precipitation.

Giulia Montanari (Uni Copenhagen -> West Systems)

I spent my secondment at West Systems, in Pontedera, Italy. When I first visited the company during the last MINSC Network meeting, I became very interested in the technologies they are developing for environmental to geothermal monitoring of gas emissions. In particular, I was very interested in learning about CO2 monitoring because it is closely linked to my research field at Copenhagen University. The aim of the study was to measure and map CO2 emissions of an area where there are natural thermal events: Rapolano Terme – Castelnuovo Berardenga (Siena). Quantitative and spatial understanding of natural CO2 emissions is important to ensure safety for local residents and workers. Furthermore, this information is useful for potential industrial applications like supply of natural CO2 for food and beverage processes, gas mixtures for healthcare, paper industry, welding processes and metalworking. The flux meter developed by West Systems, which is based on the accumulation chamber method, is an efficient and simple device to measure gaseous CO2 concentration.

After being instructed on how to operate and calibrate the instrument, I spent five days measuring CO2 emission rates in the field, under the guidance of Matteo Lelli from IGG - CNR of Pisa. Back in the office, I performed statistical and geostatistical data processing to produce isoflux maps and estimate the diffuse flux of CO2 of the surveyed area. This was made possible through to the excellent support I received from Luigi Marini, Ilaria Minardi and Elisabetta Giovenali. I also had the chance to observe travertine deposits, which frequently occur in areas with enhanced CO2 emissions. Travertine is a carbonate rock that usually forms in hot springs, where the depressurization combined with CO2 degassing permits a fast precipitation. This mineral can however also form in industrial settings that deal with water treatment and processing (food and beverage companies, breweries, paper industries, etc), when depressurization and loss of CO2 leads to the formation of scales in pipes and boreholes. This is somehow similar to what happens along pipelines, where high concentrations of calcium and carbonate lead to the formation of scale.

I am very grateful for this experience, where I have learned so many new techniques and experienced a multidisciplinary working life in the industrial sector. I would like to thank Giorgio Virgili for having made this visit possible and all the West Systems staff for sharing their knowledge, providing endless support and their great welcoming, especially my MINSC and CO2-React fellows, Fernando Berro Jimenez and Ana Hernandez Rodriguez.