̽��ֱ�� of Cambridge - chemical engineering

Researchers unravel the complex reaction pathways in zero-carbon fuel synthesis

Anonymous — Fri, 20 Jan 2023 11:54:46 +0000

When the eCO2EP: A chemical energy storage technology project started in 2018, the objective was to develop ways of converting carbon dioxide emitted as part of industrial processes into useful compounds, a process known as electrochemical CO2 reduction (eCO2R)

While eCO2R is not a new technique, the challenge has always been the inability to control the end products. Now, researchers from the ̽��ֱ�� of Cambridge have outlined how carbon isotopes can be used to trace intermediates during the process, which will allow scientists to create more selective catalysts, control product selectivity, and promote eCO2R as a more promising production method for chemicals and fuels in the low-carbon economy. Their results are reported in the journal Nature Catalysis.

̽��ֱ��project was led by Professor Alexei Lapkin, from Cambridge’s Centre for Advanced Research and Education in Singapore (CARES Ltd) and Professor Joel Ager, from the Berkeley Education Alliance for Research in Singapore (BEARS Ltd). Both organisations are part of the Campus for Research Excellence and Technological Enterprise (CREATE) funded by Singapore’s National Research Foundation.

In the 1950s, Berkeley’s Melvin Calvin identified the elementary steps used in nature to fix carbon dioxide in photosynthesis. Calvin and his colleagues used a radioactive form of carbon as a tracer to learn the order in which intermediates appeared in the cycle now named after him, work which won him the Nobel Prize in Chemistry in 1961.

̽��ֱ��eCO2EP team found that with a sensitive enough mass spectrometer, they could use the small differences in reaction rates associated with the two stable isotopes of carbon, carbon-12 and carbon-13, to perform similar types of analyses.

First, a mixture of products such as methanol and ethylene were generated by a prototype reactor that was built to operate under industrial conditions. To detect both major and minor products in real time as the operating conditions were changed, high-sensitivity mass spectrometry was used.

Since high-sensitivity mass spectrometry is more commonly used in biological and atmospheric sciences, co-authors Dr Mikhail Kovalev and Dr Hangjuan Ren adapted the technique to their prototype system. They developed a method to directly sample the reaction environment with high sensitivity and time response.

̽��ֱ��researchers used the difference in reaction rates of carbon-12 and carbon-13 to group a product such as ethanol and its major intermediates sharing the same pathway, to deduce key relationships in the chemical network.

̽��ֱ��researchers found that there are substantial differences in the mechanisms at work in smaller reactors versus larger reactors, a finding which will enable them to better control product selectivity.

̽��ֱ��team also discovered that the reaction used less of the heavier carbon-13 isotope than carbon-12. This difference in usage was found to be five times greater than that observed in natural photosynthesis, where carbon-13 is fixed at a slower rate than carbon-12. This is inspiring efforts in Professor Ager’s lab to better understand fundamental physics and the chemical origins of this large and unanticipated effect. An international patent application has also been filed.

“ ̽��ֱ��set-up of the project within CREATE Campus allowed Joel and I to create an environment of creativity and ambition, to enable the researchers to excel and to target the really complex and interesting problems,” said Lapkin. “ ̽��ֱ��monitoring of multiple species in such a complex reaction is, by itself, a significant breakthrough by the team, but the ability to further dig into the mechanism by exploring the isotope enrichment effect has made all the difference.”

“This work required an interdisciplinary approach drawing on expertise from both Cambridge and Berkeley,” said Ager. “CREATE campus provided an ideal environment to realise this collaborative research with a skilled and motivated team.”

̽��ֱ��eCO2EP project was funded by the National Research Foundation, Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme.

Reference:
Hangjuan Ren et al. ‘Operando proton-transfer-reaction time-of-flight mass spectrometry of carbon dioxide reduction electrocatalysis.’ Nature Catalysis (2022). DOI: 10.1038/s41929-022-00891-3.

Adapted from a story posted on the CARES website.

Researchers have used isotopes of carbon to trace how carbon dioxide emissions could be converted into low-carbon fuels and chemicals. ̽��ֱ��result could help the chemical industry, which is the third largest subsector in terms of direct CO2 emissions, recycle its own waste using current manufacturing processes.

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Chemical plant drone view

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Soft solids and the science of cake

sc604 — Wed, 24 Feb 2016 11:26:08 +0000

What do cake batter and a massive, offshore oil drilling rig have in common? ̽��ֱ��answer lies in a type of material known as a soft solid, which can behave either like a solid or like a liquid, depending upon the stress it is subjected to. Cake batter, molten chocolate, Marmite®, custard and the foamed concrete used in oil wells are all examples of these ‘dual personality’ materials.

Soft solids are non-Newtonian fluids, which don’t adhere to the same rules as ‘normal’ liquids. Newtonian fluids – such as water or cooking oil – don’t change their behaviour as a result of how they have been handled, such as having been mixed or being left stagnant for days. For example, if a bowl of water is mixed for an hour at high speed, it will flow in exactly the same way at the end of the hour as at the beginning.

Non-Newtonian fluids – such as custard, cake batter or foamed concrete – are different. Sometimes they behave like a solid, and sometimes they behave like a liquid. For example, move quickly and firmly enough and it’s possible to walk on custard. But stop moving, and you will start to sink. This is because custard gets thicker or thinner depending on the rate at which you try to move it. This is one way in which non-Newtonian fluids differ.

However, the mechanisms that make soft solids distinctive in this way are complex and still not well understood, making it difficult for engineers to control their properties precisely. Being able to do so would open up a range of new opportunities, whether the goal is a fluffier cake or safer drilling for oil.

There are a wide range of soft solid materials, many of which are present in your kitchen. Researchers in Cambridge’s Department of Chemical Engineering and Biotechnology are attempting to unravel how the structure of one type of soft solid – bubbly liquids – affects their properties, which may enable a far greater degree of control than is currently possible.

“Non-Newtonian fluids are mysterious things, and being able to accurately control their properties has all kinds of practical implications,” says Professor Ian Wilson, who leads the research. “ ̽��ֱ��connections between cake and concrete may not seem obvious at first, but the link is bubbles. It’s amazing how widely this type of soft solid is found – we also see them in the natural world, in things like magma. What we’re trying to do is to develop a simple method to describe a complex phenomenon, in order to get to the point where we can design these materials to do exactly what we want them to do.”

When trying to lighten either a cake or cement, one answer is simple: fill it with air bubbles. In cake batters, this leads to a fluffier cake. In oil wells, it makes for lightweight cement which is used to fill in the gaps between the pipe and the rock to prevent oil and gas from escaping.

̽��ֱ��fact that this approach is far from perfect was proven in disastrous terms when, in April 2010, an explosion at the giant offshore oil rig Deepwater Horizon in the Gulf of Mexico killed several workers and precipitated the largest accidental oil spill in the history of the oil industry. ̽��ֱ��subsequent enquiry highlighted that something went wrong with the foamed concrete used, and its failure was one of a series of events that led to the explosion of the rig and the massive oil spill in the Gulf of Mexico which followed.

For foamed concrete to work well, the bubbles have to be well distributed throughout the material, and they must remain stable so that they don’t collapse or combine into giant holes.

Wilson and his colleague Dr Bart Hallmark have been working on a closely related, but slightly different, type of soft solid. In foamed concrete the base liquid is viscoplastic, whereas in many food products the base liquid is viscoelastic. Viscoelastic materials display both viscosity and elasticity when undergoing deformation. Adding bubbles increases the elasticity enormously – this is why cake batter climbs up your whisk when you are beating it. Much of the research in this area has focused on Newtonian base liquids, but in the food and other industries the base liquids are often viscoelastic.

Starting with honey – a viscous liquid – the researchers investigated how the amount and size of the bubbles affected its behaviour, and then attempted to model that behaviour accurately. They then moved on to gum solutions, which are used to thicken sauces. ̽��ֱ��researchers showed how the mathematical model for the base liquid behaviour – in this case, the Giesekus fluid model – responds to bubble addition.

This gives researchers a tool to understand, predict and control the properties of these soft solids. For the food industry, this may make it easier to bake moist, fluffy cakes at an industrial scale, while the approach could also be used by the huge range of industries that use bubbly liquids in their processes and products.

“By using a Giesekus model and changing the bubble size, we may be able to fine-tune the behaviours of bubbly liquids,” explains Wilson. “For food production, this may help determine how a formulation or process needs to be changed to make a better cake batter: what speed to beat it at, or how best to scale the recipe up to industrial quantities so that the end product has the right structure.”

However, the ramifications of this research reach far beyond the world of cakes, due to the ubiquity of bubbly liquids and related soft solids. Although foamed concrete differs from honey – it starts off as viscoplastic rather than viscoelastic – the development of models that can accurately describe these soft solids will allow engineers to design and control them, and hopefully prevent them from going wrong.

This research was originally funded by Premier Foods and developed further by a visiting Fellow, Dr Loly Torres-Pérez, courtesy of the Galician Council of Education and Culture and the European Union, and is currently funded by Schlumberger Cambridge Research.

Researchers hope that working out the behaviours of soft solids, which can act like either solids or liquids, may make for tastier cakes – and safer oil wells.

It’s amazing how widely this type of soft solid is found – we also see them in the natural world, in things like magma.

Ian Wilson

Divulgação Petrobras, ABr - Agência Brasil

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̽��ֱ��hidden power of moss

amb206 — Thu, 22 Sep 2011 05:03:47 +0000

Moss is regarded as a menace by gardeners who seek to eradicate it from their lawns. Now researchers all over the world are exploring how moss, algae and plants could be used as a source of renewable energy in the future.

A team of designers and scientists at Cambridge ̽��ֱ�� will be exhibiting a novel moss table at the London Design Festival later this week. ̽��ֱ��prototype table will showcase an emerging technology called biophotovoltaics (BPV) which uses the natural process of photosynthesis to generate electrical energy.

Featuring biological fuel cells made from moss, the table has been created as a vision of the future by Alex Driver and Carlos Peralta from Cambridge’s Institute for Manufacturing and Paolo Bombelli from the ̽��ֱ��’s Chemical Engineering and Biotechnology Department.

Still at early stages, BPV has the potential to power small devices such as digital clocks. Low cost BPV devices may become competitive alternatives to conventional renewable technologies such as bio-fuels in the next ten years.

̽��ֱ��appeal of BPV lies in its ability to harness a natural process that takes place all around us. Photosynthesis occurs when plants convert carbon dioxide from the atmosphere into organic compounds using energy from sunlight. Plants use these organic compounds – carbohydrates, proteins and lipids – to grow.

When the moss photosynthesises it releases some of these organic compounds into the soil which contains symbiotic bacteria. ̽��ֱ��bacteria break down the compounds, which they need to survive, liberating by-products that include electrons. ̽��ֱ��table designed by the Cambridge ̽��ֱ�� team captures these electrons to produce an electrical current.

̽��ֱ��table is based on research into biophotovoltaics funded by the Engineering and Physical Sciences Research Council (EPSRC). This pioneering work involves collaboration between the Departments of Chemical Engineering and Biotechnology, Biochemistry and Plant Sciences at Cambridge ̽��ֱ��, and the Chemistry Department at Bath ̽��ֱ��. ̽��ֱ��research is led jointly byDr Adrain Fisher, Professor Christopher Howe and Professor Alison Smith at Cambridge, and Dr Petra Cameron at Bath.

Carlos Peralta said: “ ̽��ֱ��moss table provides us with a vision of the future. It suggests a world in which self-sustaining organic-synthetic hybrid objects surround us, and supply us with our daily needs in a clean and environmentally friendly manner.”

Looking into the future, possible applications for BPV include solar panels, power stations and generators. Currently at concept stage, these are envisaged as sustainable solutions to pressing problems across the world – including the growing need for energy and fresh water from vulnerable communities.

“A modular system of biological solar panels would be mounted on to the roof of a building to supply it with a portion of its energy requirements,” explained Alex Driver “A biophotovoltaic power station would comprise giant algae-coated lily-pads floating on the surface of the ocean near the coastline, generating energy for local communities. A biophotovoltaic generator would feature algae solar collectors mounted on floating buoys and anchored just offshore to generate energy and harvest desalinated water, which is a waste product of one of the chemical reactions occurring in the device.”

̽��ֱ��Cambridge team emphasised that the technology was at very early stages. “It will be a long time before a product powered by this technology will be commercially available,” said Dr James Moutrie, Head of the Design Management Group at the Institute for Manufacturing. “ ̽��ֱ��table we are exhibiting this week demonstrates the ways in which designers can play a valuable role in early stage scientific research by identifying commercial potential and is one of the outcomes from our Design in Science research project.”

Scientists at Cambridge ̽��ֱ�� are exhibiting a prototype table that demonstrates how biological fuel cells can harness energy from plants.

̽��ֱ��moss table provides us with a vision of the future. It suggests a world in which self-sustaining organic-synthetic hybrid objects surround us, and supply us with our daily needs in a clean and environmentally friendly manner.

Carlos Peralta

Institute for Manufacturing, ̽��ֱ�� of Cambridge

Close-up of the moss pots incorporated into a novel table developed at Cambridge ̽��ֱ��.

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Single component biology is past; bioengineering has begun

bjb42 — Wed, 01 Oct 2008 15:36:26 +0000

̽��ֱ�� ̽��ֱ�� of Cambridge has become increasingly aware of the major importance of recent advances at the interface between the life sciences, physical sciences and engineering. A key challenge is to assist the evolution of the established reductionist ‘molecular’ view of biology into a more quantitative, data-rich and predictive science, with an holistic and integrative understanding of its principles.

Research activities are crossing disciplines in efforts to address complex biological systems and provide technical solutions to current and emerging global concerns. Researchers are using new tools in predictive biology and synthetic biology for bio-product design – seeking to go beyond the analysis of enzymes, metabolic networks and cells to consider functionality and delivery as intimately linked elements of the design process. Developments in Cambridge are breaking new ground in biomechanics, tissue engineering and biomimetics: from strategies for restoring function to the damaged nervous system, to next-generation medical implants that interact therapeutically with the body, to the development of mechanically robust bone-like materials for engineering purposes.

̽��ֱ��need to integrate expertise in multidisciplinary research environments is well recognised in Cambridge, and 2008 sees the launch of two new research complexes. ̽��ֱ��Centre for the Physics of Medicine at the West Cambridge Site brings together researchers from the medical, biological and physical sciences to solve problems in healthcare and cell biology; and the Laboratory for Regenerative Medicine at the Cambridge Biomedical Campus provides a link between stem cell biologists, tissue engineers and clinicians for translating fundamental stem cell research to clinical benefits.

Systems biology also describes a multi-component approach, combining theoretical modelling with real data about the interaction between genes and their products. Arising from this is the need to interpret large datasets of complex biological information. ̽��ֱ��recently launched Cambridge Systems Biology Centre is enabling research groups from different disciplines to interact closely and develop a long-lasting multidisciplinary research environment.

Professor Nigel Slater, from the Department of Chemical Engineering and Biotechnology, describes how the influx of ideas and principles from non-biological disciplines is shaping a new biology.

Research activities are crossing disciplines in efforts to address complex biological systems and provide technical solutions to current and emerging global concerns.

Amy Loves Yah from Flickr

Bio Lab

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