Author Archive

From coffee shop to biodiesel source in one step

Spent coffee grounds have been turned into biodiesel by researchers from Portugal and Spain, who combined two separate processes to produce the biodiesel in one step.

Spent coffee grounds contain up to 20 weight per cent lipids, most of which are triglycerides that can be extracted and converted by transesterification into the fatty acid methyl esters that make up biodiesel. Pedro Simões from the New University of Lisbon and colleagues produced the esters in a 93 per cent yield, combining the extraction and transesterification processes in one step. 

The process combines extraction and transesterification in one step

Current commercial biodiesel production consists of an alkali-catalysed method to produce a mixture of fatty acid alkyl esters and glycerol. But, several purification processes are needed to remove the catalyst and by-products. Reactions in supercritical methanol without a catalyst have also been used – vegetable oils are more soluble in supercritical methanol than in normal methanol, leading to greater yields – but scientists need expensive equipment to produce the high temperatures and pressures required.

Simões’ team performed the reaction in supercritical methanol at 603K and 30MPa to obtain a fatty acid methyl ester in a yield of 85 per cent. To increase the yield further, they had to increase the temperature and pressure. But then they found that adding carbon dioxide to the mixture gave a higher yield – 93 per cent – at a reduced temperature of 573K and pressure of 10MPa.

The researchers explain that CO2 may play a dual role in the reaction by increasing the extraction rate of oil from the spent coffee grounds and recovering the methyl esters from the reaction mixture. 

This work should pave the way for developing methods for new ways of processing waste food rather than composting and anaerobic digestion, says Rafael Luque, an expert on biofuels from the University of Cordoba, Spain. He adds that ‘there is a need to change the perception of waste as a problem – it should be perceived as a resource to produce valuable chemicals and biofuels.’

Reproduced from a Chemistry World story written by Anna Watson

Read the full article here:

Synthesis of fatty acid methyl esters via direct transesterification with methanol/carbon dioxide mixtures from spent coffee grounds feedstock
Filipe Calixto, João Fernandes, Ricardo Couto, Elvis J. Hernández, Vesna Najdanovic-Visak and Pedro C. Simões, Green Chem., 2011, DOI: 10.1039/c1gc15101k

 

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Read the best ionic liquid research from the Asia-Pacific region

Green Chemistry has collated a number of ionic liquid research presented at the recent 2nd Asia Pacific Conference on Ionic Liquids and Green Processes held in Dalian, China, on 7-10 September 2010. The selection of articles below represents some of the best ionic liquid research from the Asia-Pacific region. You can access the web-themed issue online.

Fangmin Jin and co-workers demonstrate the reduction of NaHCO3 to formate using isopropanol as a reducing agent. Yields of about 70% were acheived.

Read more about Fangmin Jin’s work:

From NaHCO3 into formate and from isopropanol into acetone: Hydrogen-transfer reduction of NaHCO3 with isopropanol in high-temperature water
Zheng Shen, Yalei Zhang and Fangming Jin
Green Chem., 2011, DOI:10.1039/C0GC00627K , Advanced Article

A fruitful collaboration between the teams led by Changping Li and Urs Welz-Biermann resulted in the development of a microwave-assisted extraction of bioactive lactones from chinese herbal medicines using protic ionic liquids.  The Dalian scientists concluded that the extraction mechanism of microwave-assisted ionic liquid extraction is the similar to traditional organic solvent extraction.

Read the full paper:

Microwave-assisted extraction of lactones from Ligusticum chuanxiong Hort. using protic ionic liquids
Chi Yansheng, Zhang Zhida, Li Changping, Liu Qingshan, Yan Peifang and Urs Welz-Biermann
Green Chem., 2011, 13, 666-670

In this web-themed issue, Li and Welz-Biermann also report a room-temperature method to desulfurise fuels employing an oxidation method combined with extraction using acidic ionic liquids. The method shows some promise level of sulfur removal from the model oil reached 99% in 180 min.

Interested in finding out more? Read the full article here:

Desulfurization by oxidation combined with extraction using acidic room-temperature ionic liquids

Chi Yansheng, Li Changping, Jiao Qingzhu, Liu Qingshan, Yan Peifang, Liu Xiumei and Urs Welz-Biermann
Green Chem., 2011, DOI: 10.1039/C0GC00745E, Advanced Article

 Liu et al. showed that double SO3H-functionalized ionic liquids exhibited better catalytic activity for the esterification of glycerol compared to non-functionalizeds ionic liquids. Glycerol conversion was achieved in 95% within 30 min by using catalytic amounts of ionic liquids (only 0.1 mol% based on glycerol).

You can read the full paper online:

Esterification of glycerol with acetic acid using double SO3H-functionalized ionic liquids as recoverable catalysts

Xiumei Liu, Huiyuan Ma, Yue Wu, Chang Wang, Miao Yang, Peifang Yan and Urs Welz-Biermann
Green Chem., 2011, 13, 697-701

Kim et al. demonstrate an eco-friendly way of making polymers. The Korean scientists synthesized double metal cyanide (DMC) catalysts for the ring opening polymerization of propylene oxide, employing nontoxic lactate esters as complexing agents. “Highly pure polyol products that can be raw materials for high performance polymers like polyurethane are produced by using the resulting catalysts,” claim Kim and co-workers.

Double metal cyanide catalysts bearing lactate esters as eco-friendly complexing agents for the synthesis of highly pure polyols
Ji Hwan Yoon, In Kyu Lee, Hye Yoon Choi, Eun Ji Choi, Ju Ho Yoon, Sang Eun Shim and Il Kim
Green Chem., 2011, 13, 631-639

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Green Chemistry reviews some of the challenges

Green Chemistry has recently published a series of critical reviews that have been highly downloaded.  These reviews aim to cover the trends and progress in the fields and also set the scene for cutting-edge research and innovations for a greener and sustainable future. More importantly the reviews highlight the challenges that need to be urgently addressed in each of those research areas.

Use of carbon dioxide in chemical syntheses via a lactone intermediate
A. Behr and G. Henze
Green Chem., 2011, 13, 25-39
DOI: 10.1039/C0GC00394H

Converting carbohydrates to bulk chemicals and fine chemicals over heterogeneous catalysts
Maria J. Climent, Avelino Corma and Sara Iborra
Green Chem., 2011, 13, 520-540
DOI: 10.1039/C0GC00639D 

Processing of metals and metal oxides using ionic liquids
Andrew P. Abbott, Gero Frisch, Jennifer Hartley and Karl S. Ryder
Green Chem., 2011, 13, 471-481
DOI: 10.1039/C0GC00716A

Viable methodologies for the synthesis of high-quality nanostructures
Jonathan M. Patete, Xiaohui Peng, Christopher Koenigsmann, Yan Xu, Barbara Karn and Stanislaus S. Wong
Green Chem., 2011, 13, 482-519
DOI: 10.1039/C0GC00516A

Enzyme-mediated oxidations for the chemist
Frank Hollmann, Isabel W. C. E. Arends, Katja Buehler, Anett Schallmey and Bruno Bühler
Green Chem., 2011, 13, 226-265
DOI: 10.1039/C0GC00595A

5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications
Andreia A. Rosatella, Svilen P. Simeonov, Raquel F. M. Frade and Carlos A. M. Afonso
Green Chem., 2011, Advance Article
DOI: 10.1039/C0GC00401D

Greener solvents for ruthenium and palladium-catalysed aromatic C–H bond functionalisation
Cedric Fischmeister and Henri Doucet
Green Chem., 2011, Advance Article
DOI: 10.1039/C0GC00885K

The irruption of polymers from renewable resources on the scene of macromolecular science and technology
Alessandro Gandini
Green Chem., 2011, Advance Article
DOI: 10.1039/C0GC00789G

You  may also be interested in some of the review articles published in 2010:

Technology development for the production of biobased products from biorefinery carbohydrates—the US Department of Energy’s “Top 10” revisited
Joseph J. Bozell and Gene R. Petersen
Green Chem., 2010, 12, 539-554
DOI: 10.1039/B922014C

Catalytic conversion of biomass to biofuels
David Martin Alonso, Jesse Q. Bond and James A. Dumesic
Green Chem., 2010, 12, 1493-1513
DOI: 10.1039/C004654J

Vegetable oil-based polymeric materials: synthesis, properties, and applications
Ying Xia and Richard C. Larock
Green Chem., 2010, 12, 1893-1909
DOI: 10.1039/C0GC00264J

Glycerol as a sustainable solvent for green chemistry
Yanlong Gu and François Jérôme
Green Chem., 2010, 12, 1127-1138
DOI: 10.1039/C001628D

Synthesis of cyclic carbonates from epoxides and CO2
Michael North, Riccardo Pasquale and Carl Young
Green Chem., 2010, 12, 1514-1539
DOI: 10.1039/C0GC00065E

Enzymes in neoteric solvents: From one-phase to multiphase systems
Pedro Lozano
Green Chem., 2010, 12, 555-569
DOI: 10.1039/B919088K

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Are microwave reactions really green?

Jonathan Moseley and Oliver Kappe provide some pertinent answers to the question: “Why should microwave chemistry be green?”.

There has been over 5000 microwave-assisted syntheses reported in the last 25 years and most of the scientific reports assume that microwave reactions are green, sustainable, environmentally friendly (“ecofriendly”), benign etc. A lot of the times, authors do not provide a clear rationalization and justification why the respective protocols are green because most researchers assume that microwave heating is more energy efficient than classical heating methods.

Here, Moseley and Kappe critically assess the energy efficiency of microwave-assisted transformations in the context of scaling-up this technology to production quantities, taking into account the twelve principles of green chemistry, with a focus on the 6th principle: design for energy efficiency. 

“Microwave heating process performed in laboratory-scale single-mode microwave reactors is appallingly energy inefficient,” claim Moseley and Kappe.

However, they agree that when moving from the lab scale to the kilogram scale, microwave technology is more efficient that conventional heating processes.

The full perspective can be freely downloaded until the 3rd April 2011.

A critical assessment of the greenness and energy efficiency of microwave-assisted organic synthesis
Jonathan D. Moseley and C. Oliver Kappe
Green Chem., 2011, Advance Article
DOI: 10.1039/C0GC00823K, Perspective

This perspective has also been highlighted in Chemistry World. It can be read here:

Microwave chemistry – green or not? 

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Finding the optimum conditions – screening solvents and catalysts

Scientists from the Netherlands and the UK have conducted a solvent screening study aimed at identifying greener alternatives for the commonly used solvent dichloromethane in N-oxy catalysed bleach oxidations of various alcohol substrates.

The team found that environmentally acceptable ester solvents, notably isopropyl acetate and methyl acetate, gave results comparable to or better than dichloromethane.

However, there was no apparent correlation between common solvent properties and performance.

A comparison of two co-catalysts, NaBr and borax, revealed that borax gave better results with cinnamyl alcohols whereas NaBr was generally better with the other alcohols.

The team also studied the effect of catalyst loading. In the oxidation of 3-phenyl-1-propanol the amount of N-oxy catalyst could be effectively reduced to a mere 0.1 mol%.

They concluded that due to the complex nature of these systems, there is not a single set of conditions that gives good results for all alcohols. However, by employing a simple screening approach to assess solvent, catalyst and co-catalyst combinations, similar or even better results can often be achieved in solvents other than dichloromethane.

Read more about this article:

Towards greener solvents for the bleach oxidation of alcohols catalysed by stable N-oxy radicals
M H A Janssen, J F Chesa Castellana, H Jackman, P J Dunn and R A Sheldon, Green Chem., 2011, DOI:10.1039/c0gc00684j

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A reversible CO2 carrier for the carboxylation of ketones at room temperature

Beckman and Munshi reports a reversible CO2 carrier (RCC) for the carboxylation of ketone to β-ketoester under ambient CO2 pressure and temperature.

RCC has been synthesized by immobilizing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) on methylhydrosiloxane support and reacting with CO2 with 100% degree of functionalisation. RCC is found to be recyclable and shows retention of activity in 5 recycles. CO2 absorption under ambient temperature and desorption at 120 °C renders the material suitable for carrying out carboxylation reactions at 25 °C with excellent yields. The yield of the reaction can reach up to 100% with TON 200 in 4 h. The extent of the reaction primarily depends upon enol content of the substrate. β-Ketoacid produced during the reaction can be isolated and converted to its corresponding methyl ester derivative by reacting with methyl iodide.

Access this article for free by clicking on the link below: 

Ambient carboxylation on a supported reversible CO2 carrier: ketone to β-keto ester, Eric J. Beckman and Pradip Munshi, Green Chem., 2011, DOI: 10.1039/C0GC00704H, Advanced Article, Paper

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Is cellulose dissolution process with ionic liquids really environmentally friendly?

Righi and co-workers here present the life cycle assessment (LCA) of cellulose dissolution with ionic liquids 1-butyl-3-methylimidazolium chloride (Bmim Cl). The authors compared the “greenness” of the process with the well established environmental friendly N-methyl-morpholine-N-oxide (NMMO)/H2O process. Results from the LCA suggest that both processes are comparable.

Specifically, the process with Bmim Cl generates a higher environmental load on abiotic resource depletion, emissions of volatile organic compounds and ecotoxicity than the NMMO/H2O process. Conversely it has some environmental advantages with regards to human toxicity. In both cellulose dissolution processes, the major contributions to the environmental impacts come from precursor syntheses.

Read more about this article here:

Comparative cradle-to-gate life cycle assessments of cellulose dissolution with 1-butyl-3-methylimidazolium chloride and N-methyl-morpholine-N-oxide

Serena Righi, Andrea Morfino, Paola Galletti, Chiara Samorì, Alessandro Tugnoli and Carlo Stramigioli
Green Chem., 2011, DOI: 10.1039/C0GC00647E, Paper

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New Associate Editor for Green Chemistry

Professor Chao-Jun Li

We are delighted to announce that Professor Chao-Jun Li (McGill University, Canada) is the new Associate Editor for Green Chemistry.

His main area of research is innovative and fundamentally new organic reactions that will defy conventional reactivities and possess high “atom-efficiency”.

Professor Li will handle manuscripts from the Americas and Canada and his editorial office is now open for submissions. We welcome Professor Li to this new role.

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African Green Chemistry congress makes the headlines

The first PACN Green Chemistry Congress took place in Addis Ababa, Ethiopia, on the 15th –17th November 2010. The international event was organised by the RSC Pan Africa Chemistry Network (www.rsc.org/pacn) with support from Green Chemistry. The congress received fantastic media coverage in countries across the African continent and the rest of the world.

The Green Chemistry Congress was opened by the Ethiopian Minister for Water and Energy, H.E. Ato Alemaghu Tegenu. During the event, Tegenu wrote an opinion piece that highlighted the need for science and innovation to improve African people’s lives sustainably, and the important role of the RSC and the Pan Africa Chemistry Network in supporting these scientific developments. This piece was published both in print and online in 13 different newspapers across Africa. To read the piece online, click here.

Green Chemistry Advisory Board member, Yonas Chebude, chaired the local organizing committee. In addition to a number of distinguished scientists from all around the world, both the Chair of the Editorial Board, Martyn Poliakoff, and the Scientific Editor, Walter Leitner, spoke at the Congress, as well as Editorial Board members Buxing Han, Paul Anastas and Tom Welton. The Congress was very well attended with delegates from 22 countries.

One of the main outcomes of the Congress is the writing of a report which will include recommendations. Once the report is finalised we will announce it on the Green Chemistry website.

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Lights, camera, action

Martyn Poliakoff, CBE, FRS, is research professor of chemistry at the University of Nottingham in the UK. His main research interest is the application of supercritical fluids with a focus on green and sustainable chemistry. He is one of the narrators of 'The Periodic Table of Videos', which are popular on YouTube. He is chair of the Green Chemistry editorial board.

Martyn Poliakoff talks to Kathleen Too about the periodic table of videos and passion for green chemistry

Can you tell us a little known fact about yourself? 

I’m an Honorary Professor at Moscow State University, something I share with Fidel Castro and Bill Clinton. 

Which of your academic achievements are you most proud of? 

To me, academic work is rather like journalism – journalists get excited about the story they are working on, but when they move on to the next story, that one is more exciting than the one before. So I think that the only way you can operate as an academic is to be excited about whatever you are doing at a particular time. When I was younger, I did a lot of work on the reactive molecule iron tetracarbonyl, which is completely useless in the green chemistry context because it only exists at room temperature for a millionth of a second or less , but I am still quite proud of my experiments. As a professor, I am proud of the little contributions I can make to the design of an experiment by my research group. Experiments are almost always done by my students or postdocs. Sometimes, as a supervisor, the contributions to the design of the experiments are not as big as one would like. Occasionally, I have a really good idea , which makes the experiments work and that always give me pleasure. 

You’re keen to promote science on YouTube. Could you tell us more? 

I began working with YouTube purely by accident. My university was collaborating with Brady Haran, a very talented video journalist, who wanted to make a periodic table of videos. I didn’t think there was enough to say about some of the more obscure elements but as it turned out, there was plenty to say, at least enough to make short videos. We wanted to show that we enjoy chemistry and how much fun it can be. 

We’re in the process of making videos about different molecules and reactions. There are also other videos that are rather difficult to define, for example, we made a video of gold dissolving in Aqua Regia – a mixture of nitric acid and hydrochloric acid – it’s not exactly a reaction or a molecule but we thought that people may be interested in seeing the gold dissolving. 

Which video was the most fun to make? 

They were all fun, but my favourite is about the element hassium. This is element 108 and I knew nothing about it. In fact, in the precredit sequence – the bit before the main title of the video – I was filmed saying ‘I don’t know anything about hassium, let’s make something up’. 

What is your favourite element? 

I’m very fond of sodium. The chemical symbol for sodium is Na, which was my mother’s nickname when she was a child. Each time I hear the word Na or see it written down, I get a warm feeling. I’m also fond of xenon, because it’s been an important element in my research. 

What excites you about chemistry and what does the future hold for green chemistry? 

Objects we use in everyday life, such as most of the clothes we wear, are made from synthetic chemicals. The jacket I’m wearing is actually leather but the inside is made of polyester – a synthetic material. We couldn’t enjoy any of these without the products of the chemical industry. Chemistry often has a bad image. People generally think about it polluting and destroying the planet but green chemistry allows young people to feel that they are helping both the planet and humanity at the same time. So it’s doubly good! 

With oil running out and the expanding world population leading to a greater demand for chemicals, we have got to do something. One of the greatest challenges is to get green chemistry to work. The future either holds success in delivering what people need or complete failure leading to society collapsing. We have to succeed. I hope that in the end the principles of green chemistry will be applied to most chemistry. You could argue that if green chemistry really succeeds, it will disappear because all chemistry will become green. 

What do you enjoy most about being the chair of Green Chemistry? 

I enjoy interacting with other chemists, inspiring young people and spreading the green chemistry message. I also enjoy promoting the subject in Ethiopia and encouraging people in economically developing countries to take up green chemistry so that they don’t make the same mistakes regarding pollution that we did in the past. 

What advice do you have for young scientists? 

Green chemistry offers terrific opportunities and there are different areas within the subject. It doesn’t matter that some people are using ionic liquids, others using new catalysts, the important message is that green chemistry is not about one area being better than another. We need all those areas and many more to solve our current problems. One of the attractions of green chemistry is that there are huge opportunities for new ideas. 

Which historical scientific figure would you most like to have dinner with and why? 

I have been fortunate to have met many fascinating famous scientists. One of the exciting things is actually finding out what they are like as people and not just learning about what they have discovered. However, historical figures come from a very different age. Possibly, they would strike us as being pompous or very formal compared to nowadays, not because they were famous scientists but because they lived 100 or 200 years ago. From my point of view, there are two quite exciting events that happened in 1869. One was Mendeleev propounding the Periodic Table for the first time. The other was that Thomas Andrews, a physical chemist in Belfast, described the critical point of carbon dioxide for the first time. Supercritical fluids have played a very important part in my research. It’s quite amusing that the two events took place in the same year. I would quite like to have dinner with Thomas Andrews and Mendeleev, though of course, they might not have been able to speak to each other because I am not sure whether Mendeleev could speak English. He definitely spoke German because he published some of his papers in German. It probably would be a rather strange triangular conversation. 

How would your family and friends describe you? 

Always doing chemistry.

When you got your CBE, how was your meeting with the Royal Family? 

A CBE is a British Award, which stands for Commander of the Order of the British Empire. It is presented at Buckingham Palace by a member of the Royal Family. I met with Prince Charles and he was very interested in my work. We had a 45 second discussion about recycling plastics, which was quite unexpected. He really had done his homework! 

You already have a number of fans; you even have a Martyn Poliakoff appreciation society on Facebook. How do you feel about being famous and how do you deal with fame? 

I’m not sure that I’m particularly famous. My brother is a well known playwright in the UK and much better known than me. Ten years ago I was walking through Helsinki with a friend of mine, who is very well known in Finland. I was with him and my postdoc who asked, ‘Have you noticed that everybody is looking at Neil?’ I replied ‘No’, because I am used to people staring at my hair anyway. So I didn’t notice anything different. 

Articles of interests:

Continuous heterogeneous catalytic oxidation of primary and secondary alcohols in scCO2
Adrian O. Chapman, Geoffrey R. Akien, Nicholas J. Arrowsmith, Peter Licence and Martyn Poliakoff, Green Chem., 2010, 12, 310
DOI:10.1039/b913434d

Solubilisation of -chymotrypsin by hydrophobic ion pairing in fluorous systems and supercritical carbon dioxide and demonstration of efficient enzyme recycling
Karima Benaissi, Martyn Poliakoff and Neil R. Thomas, Green Chem., 2010, 12, 54
DOI:10.1039/b904761a

Videos of interests:

Link icon The Periodic Table of Videos – Sodium
The Periodic Table of Videos – Sodium

Link icon The Periodic Table of Videos – Xenon
The Periodic Table of Videos – Xenon

Link icon The Periodic Table of Videos – Hassium
The Periodic Table of Videos – Hassium

Link icon Dissolving gold in aqua regia
Dissolving gold in aqua regia

Link icon Chemistry Christmas Tree
Chemistry Christmas Tree

Link icon Which element for Christmas?
Which element for Christmas?

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