Welcome to part 2 of our regular blog series, breaking down the key news events from the past month. Here we outline the key stories from trade news publications and academic journals that have caught our eye. This month we look at how IR sensors are being used to eliminate the production of greenhouse gases; to advance biofuel technologies and their analysis; to evaluate the effect of a root canal on the rest of your teeth; and to ensure you’re drinking the wine you paid for.
1) Mid-IR sensors mitigating climate change – eliminating N2O production in CO2 purification for reuse
The importance of molecular analysis via IR sensors in mitigating climate change was again raised in a new paper published at the end of last month, in the Journal of Quantitative Spectroscopy and Radiative Transfer.
As the paper points out, CO2 is responsible for a little over half of anthropogenic radiative forcing on global warming. One way to reduce the volume emitted into the atmosphere when burning fossil fuels (the principal source) is to capture it and reuse it for chemical industrial applications and power generation. And “for this purpose, CO2 should be as pure as possible.”
But this also creates a secondary problem. The impurities are mostly NO and CO, and while a catalytic reduction process can be undertaken to produce N2 and CO2 (using a Pt/SiO2 catalyst), it can also create N2O – a gas with a global warming potential 300-times that of CO2.
The French research team – mostly based at the Université du Littoral Côte d’Opale (ULCO) – investigated the effect of temperature on the catalysis process; measuring the concentration of N2O – which gives a tell-tale absorption signature at 1261.0598 cm⁻¹ – in real time during the reaction via a mid IR sensor.
The results: temperature has a significant effect on catalysis rate, and also on concentrations of N2O, with the greatest concentration (6.1ppm) produced at 190oC, this however drops to virtually zero as temperatures exceed 340oC.
2) IR spectroscopy imaging techniques used to analyse bamboo for biofuels
As Chinese energy consumption increases and their access to fossil fuels are depleting, China is turning to one of its most abundant (and fast-growing) plant sources – bamboo; specifically moso bamboo, which is the most widely cultivated variety in China and makes up two thirds (65%) of the total area of bamboo forest.
Bamboo stores carbon in three main forms, cellulose, hemicellulose and lignin – collectively known as lignocelluloses. These make up 90% of the dry mass of the plant but the concentrations and the microscopic distribution of these will greatly affect its utilisation efficiency and other physical properties as a biomass resource. The ability to undertake a quantitative visualisation of the distribution of the lignocellulose concentrations is therefore essential – but had previously not been possible.
This changed last month when a Chinese team of researchers (from Zhejiang and Jiaxing Universities) undertook trials using infrared macro and micro-spectroscopy to understand the technology’s effectiveness in achieving this goal.
In short, the techniques used were successful and you can read the full paper published in Biotechnology for Biofuels here.
3) Increasing yields in algal biofuels
And speaking of biofuels… in one of our September blogs, we highlighted figures showing that not all biofuels are equal. Some, most notably palm oil, were worse for the environment than crude oil. As such, monitoring the source is vitally important and using IR sensors to monitor for tell-tale chemical signatures is a cost-effective, easy to roll out method.
As per our blog, some of the basic arguments are: how much CO2 does the production process emit in their creation, and does it use valuable arable land that could be used to create food for humans or livestock?
This was again laid out in October in Azo Cleantech’s blog, highlighting opposition to Qantas’s use of biofuel from the mustard-seed Carinata. Notably one flight required the output of 150 acres of mustard plantations, and powering Qantas’s annual air miles would require an area the size of the Maldives.
Algal-based biofuels were seen as a key hope for next-generation fuels, being able to be grown using industrial land and on industrial scales. It’s worth reading Forbes’ analysis of why it didn’t take off, highlighting one of the biggest failings as being “The huge learning curve between what takes place in a lab and commercial production is something with which researchers have no experience.”
So, it was interesting to see companies like BP starting to take up the mantel. But more interesting still to see Michigan State University’s proof-of-concept research for a biofuel production platform that uses a multi-species process – a marine algae and soil fungi – to lower cultivation and harvesting costs and increase productivity.
4) IR shows sodium hypochlorite used in root canal operations changes the collagen structure of dentine
IR sensors have been used to great effect in healthcare. One of my favourite papers on this came earlier this year from researchers at the University of Valencia in Spain, who had used the technology for ion mobility spectrometry to detect cocaine use from saliva samples (abstract here – full paper behind a paywall).
Possibly because I’ve just been to the dentist, but last month my eye was caught by a paper outlining an FTIR spectroscopy method to understand how dentinal collagen changes following exposure to sodium hypochlorite used in root canal irrigation. Ex vivo experiments showed that the sodium hypochlorite exposure did indeed cause alterations in the chemistry and structure of collagen in dentine, with FTIR spectra obtained from dentine surfaces and dentine adjacent to root canals exposed to sodium hypochlorite, all consistently showing degradation and conformational change of the collagen structure.
Infrared spectroscopy data from the ex vivo model showed that the depth of effect of sodium hypochlorite extended to at least 0.5 mm from the canal wall.
The paper – published in the International Endodontic Journal – can be accessed for free until the end of the year – after that time the abstract will still be available – click here to access both.
5) Maintaining the value of wine
There have been dozens of food scandals in recent years – from China’s baby milk formula scandal that led to the deaths of several infants and the convictions (and even executions for some) of those involved; to here in the UK, the contamination of halal lamb burgers with pork meat.
The journal Beverages last month published a strategy by researchers from two Portuguese universities for maintaining authenticity in the wine making process.
As the paper opens with: “The wine sector is one of the most economically important agro-food businesses. The wine market value is largely associated to terroir, in some cases resulting in highly expensive wines that attract fraudulent practices.” This, over the years has culminated in mis-labelling or even adulteration using several chemicals – possibly most famously the addition of diethylene glycol (a major constituent of antifreeze) in 1985 by Austrian wine makers. This makes the wine appear sweeter and more full-bodied and it took decades for the country’s wine industry to recover. The scandal was so significant it even made it into a 1990 season 1 episode of The Simpsons.
Back to the strategy, and near and mid-infrared spectrometry (among other techniques) play a key role in the researchers’ recommendations, looking at chemical and isotopic compositions of the wine to understand (which will vary according to the terroir, and therefore location) and highlighting studies that have shown specific elements that were dependent on geo-climatic conditions – notably sodium, copper, barium, manganese, potassium, magnesium, phosphorus and the oxygen isotope 18O.
The full paper can be seen here.