Solar-powered jet fuel (and diesel, and...)

Sounds kind of backwards, I suppose, but there is in fact research happening on creating jet fuel, and other liquid fuels, using solar energy. One of the big advantages of liquid fuels like gasoline, diesel, or jet fuel is the large amount of energy contained in a small mass—much more energy per gram than batteries. Just recently, in fact, one such research group announced that they had produced a jar of jet fuel, starting from sunlight and CO₂.

Taking out the quotes and the hyperbole about revolutionizing anything, what they've done is still pretty neat: turned CO₂, the low energy end state of carbon-based fuel combustion, back into usable fuel.

Because CO₂ is the low energy end state, to get it back into a high energy form such as kerosene (jet fuel) or diesel, a whole lot of energy has to be put into it. In this case, the energy is solar.

Well, the energy is intended to be solar.

Edible education

One subject I've had in my list to write about (once I spent the time to find some good sources) was why some leaves are edible while others aren't—completely aside from the question of toxicity, there are lots of plants that we simply can't digest. I hadn't yet got around to digging into the subject when I ran across the answer recently, along with loads of other interesting information about food chemistry.

A few weeks ago I discovered a free, online course offered by McGill University via edX, on the subject of food and nutrition. Despite being offered by the chemistry department there, it doesn't require more than high school chemistry and the ability to use a 4-function calculator as prerequisites, and I'm not even sure if it needs high school chemistry. You should probably know the difference between an atom and a molecule, and at least recognize the Periodic Table of the Elements.

I was too late to sign up for the credit version, where the assignment deadlines are enforced, but there is a non-credit, audit version (which I'm doing) where you still have access to all the video lectures, discussions, and mini-quizzes.

So back to edible vs. non-edible leaves.

In the lesson on carbohydrates, (week 4, lesson 1) they showed the chemical structure of starch vs. cellulose (video 8). Both are long strings of glucose connected by oxygen atoms, but the way they're strung together is different—and that's it. That's the difference between plants we can digest and plants we can't. (Plants we can digest still have cellulose in them and we pass that through our system no problem—but we don't get any nutrition out of it.)

(Screenshot from Food for Thought, week 4/lesson 1/video 8. Requires free course registration to view.)

They look very similar at first glance, but if you look closely, they have an important difference: every second glucose segment is upside down in the cellulose chain.

We have the enzymes necessary to digest starch. We don't, but cows and other ruminants do, have the enzymes necessary to digest cellulose.

Enzymes are complicated things which have a very specific shape, and can fit around molecules of a very specific shape. So, an enzyme that fits the shape of starch in order to cut it down to its component glucose molecules will simply not fit the different shape of cellulose, even though the components are all the same.

So that was short and sweet. Also, check out the course, it's fascinating. (Keep in mind you can adjust the playback speed of the videos. I found my attention wandering because the instructors speak kind of slowly; running them at 1.5x speed makes it easier for me to keep from wandering. You can also back up and repeat sections if you don't catch it the first time through, or pause to look at the diagrams, because it's a video.)

Unnatural or Natural

Something I've been thinking about for a while, even since before I did the greenwashing article series, is: what makes a thing "natural" or "unnatural"?

Many people would say that "natural" things are things which come from nature with minimal processing. It sounds like a reasonable definition at first glance, but when I try to get specific, I start running into trouble with the definitions of the words used to define "natural". They seem to be a bit fuzzy themselves, which makes the term "natural" hard to pin down.

So my first question is, what is meant, exactly, by "from nature"?

Oily algae

Algae, as well as other biologically sourced feed stocks, has been the subject of a lot of research in oil production, for what should be obvious reasons. There are several things about using some bio-sources that concern me, however. Using food cropland to grow corn or soy intended for conversion to fuel, for one, resulting in less food production (and contributing to higher food prices).

The bio-sources that don't bother me in this way are things like manure or other waste to bio-fuel. Even wood waste and scrap paper can be turned into either oil or syngas (which can be turned into oil, among other things).

But, an interesting comment in a recent press release about oil from algae caught my eye: "byproduct stream of material containing phosphorus that can be recycled to grow more algae."

Chlorinated hair

When I signed up for triathlon training, I had to buy a pair of swim goggles so I didn't crash into things like the lane markers, the other people swimming around me, and the wall at the end of the pool. (Ouch.) While buying that little necessity, the sales staff talked me into buying some special chlorine-removing shampoo. Naturally I was curious about whether it was actually significantly different from my normal shampoo or if it was just marketing, which is the majority of the difference between most normal shampoos, so I bought the little sample size bottle to test it out.

Using it in place of my normal shampoo after the swim didn't seem to make a difference that I could notice, but then I did make sure to pre-soak myself in the pool showers before jumping in. Hair absorbs a remarkable amount of water, so getting it to absorb low-chlorine tap water before it hits the high-chlorine pool water will provide some partial protection right there.

I remember my grandfather's white hair turning green when I was a kid and we'd go to the public pool (which I found out as an adult is due to copper from the pipes, not the chlorination). I also remember how the pool smell would cling even after that post-swim rinse.

Chilly chemical properties

Because it's the middle of winter here in Canada, I think today is a good day to talk about refrigeration.

Just kidding. Actually it's because the ISS had to replace a piece of its refrigeration system last week, and I thought that was a good excuse to talk about refrigeration.

Most modern refrigeration involves the chemical property \(\Delta H_{vap}\), or enthalpy (heat) of vaporization. Every substance has a heat of vaporization, and the amount of heat energy required to vaporize a substance is independent of what temperature the substance boils at. To choose a rather extreme contrast, water boils at 100C while lead boils at 1750C, but water requires 539cal/g to convert from liquid to gas while lead only needs 208cal/g, less than half that required by water. This amount of heat does not account for how much is required to get to the boiling point, and if you remember your high school chemistry, the temperature does not change with the additional heat input while it changes from liquid to gas.

The basic principle in use here is that when a substance evaporates, it draws heat energy from its surroundings (or the more familiar form: when you add heat to a substance, it will evaporate), and when a substance condenses, it releases heat energy back to its surroundings. Put an insulated barrier between these two sides of the process, and you have refrigerators, freezers, and air conditioners which get colder "inside" and warmer "outside".

Chemical telephones

The folks at UCLA have come up with a way to use cell phones to test for allergens in food. And we're not talking looking it up in a database somewhere, we're talking an actual lab test, which tests the actual piece of food in front of you.

Potentially useful if you have a life-threatening allergy, such as to peanuts, the example used in their paper.

While this does use the camera built into the phone, as a lab test, it is more than just taking a picture. Specifically, it uses a colorimetric process to measure how much allergen is in the sample.

I've used colorimeters before, and they are generally quick and handy (and portable, if you buy the portable version of the reader). However, that "generally" is important. While I've used some colorimetric kits that only take 5 minutes, I've used some that take over half an hour, and that's not counting sample preparation time.

And all of those kits require sample preparation of some sort, adding chemicals, and waiting for the reaction to finish before measuring. Most of the stuff I tested required dilution of a water sample to bring it into the testing range. The peanut test described requires the sample to be finely ground and dissolved first, and is described as taking 20 minutes, not including grinding time.

The good kits come with either pre-measured chemicals or easy quantities of liquid chemicals to measure, such as with a standard pipette or a supplied dropper, to minimize test error. The reaction of the compound of interest with the added reagents causes a colour change, which the sensor (or camera) measures. Generally, at least for the kits I've used, the darker the colour, the more of the compound of interest is present. From the paper, it looks like the peanut test turns red.

Realistically, now that the photo processing and colour measurement has been sorted out, any pre-existing colorimetric kit could be adapted for cel phone use. But then, most people who might get these things for personal use would be more interested in allergens than the stuff I have tested for at work. Most people don't care all that much how much calcium is in their water, because it isn't a health issue.

(Ok, technically this one is almost year old, but I don't restrict myself to only talking about new discoveries.)

Food chemicals

I was tossing around the idea of doing some posts on the various food additives one sees (and which some people are frightened by, due to their long chemical names) when I ran across Science Fare's list of The Ingredients of Scientific Cooking. Some of these every cook has used (sodium bicarbonate aka baking soda; sodium chloride aka table salt; ethanol aka drinking alcohol, to name the three most instantly recognizable ones), and some are a bit more specialty (such as pectin to gel a jam - mmmmm, I remember my mom's jam) and some I didn't realize people used in home kitchens. Although in hindsight, the fact that I have seen a bag of MSG in the supermarket means that yeah, people do actually use them.

This list looks like an excellent resource, though I may branch out from it and look into some of the things used only in commercially produced food, because I am curious about some of these. Especially items such as preservatives, since without them, food (and even non-food items such as sunscreen) doesn't last very long and provides a potential base for bacteria and mould, some of it potentially harmful, to grow.

Chopping up pollution

Normally I just post whatever interesting bit of chemistry catches my interest on a given week, but today I'm posting about something of special interest to me. It's not about my work specifically, but it is about pollution remediation—and that, in a broad sense, is what I do.

This fascinating bit of cleanup chemistry targets some of the most difficult to remove pollutants. The unsightly colour of lignin stained water coming out of a pulp mill, pharmaceuticals passing through sewage plants (page 2), pesticide and herbicide runoff from farms, parks, golf courses, and lawns, and many others. Chemical warfare agents are even on the list of targets.

Gold, with or without cyanide

Some things are unavoidably toxic, and some things were unavoidably toxic until a new, less toxic process was discovered. Less toxic is always a good thing. Sometimes it's less expensive in terms of direct costs such as how much the reagents cost, sometimes less expensive in terms of indirect costs, such as safety precautions and environmental protection.

Sodium hydroxide is one such; the old industrial method of making it involved mercury, which is highly toxic. The new industrial method doesn't. (There are still toxic chemicals involved, but they're not mercury.)

One thing that will hopefully one day be added to the past-tense version of unavoidably toxic is gold mining. Currently, if gold can't be panned from a streambed (placer mining) where it's present as pieces of fairly pure gold, it has to be dissolved out of the rocks, often using cyanide. A newly discovered process is being described as possibly displacing the cyanide.

Chemophobia

I've been busy lately so I haven't had time to put together any good posts. In the interim, here's some interesting reading. The first sentence describes me perfectly, but then I'm one of the group named in it as well: "It’s the number one pet peeve of just about every chemical professional I talk to: why is ‘chemical’ such a dirty word in the minds of so many people?"

Even people who have some interest in chemistry can fall prey to this. I was talking to a friend (who does have an interest in chemistry) recently and this came up, and he pulled out a few of the classics about synthesized things not being tested "enough" (even though it's been my experience that for many chemophobes there is never a level that will be "enough") using "unnatural" or "chemical" as a loose synonym for dangerous—acknowledging immediately when I pointed out that there are plenty of natural poisons, because he does know more than a little about chemistry, BUT...

It's easier to argue with strangers about this, than with friends; at least I find it so. It sucks when friends hit your pet peeves, and it's easier to walk away from strangers who do the same.

Greenwashing and CBC: some final thoughts

Well, that ten-post greenwashing series was a bit more work than I had anticipated, but interesting. I learned a lot, so I think that makes it worthwhile. After all, that is the point of this site!

I noticed some common threads running through nearly every item on the Marketplace list, which I've also seen and heard elsewhere. The main one is a fundamental misunderstanding of chemistry. I've lost count of how many times I've heard people in other context using "chemicals" as a blanket term for something bad. It's as if they don't realize that water is a chemical, vitamin C is a chemical, every micro- and macro-nutrient in food are chemicals, everything made of matter—beneficial, harmful, or neutral—is made of chemicals.

And they probably truly don't realize it.

Being a chemical engineer I've been so immersed in chemistry I sometimes forget that after about grade ten general science class, chemistry of any kind becomes optional. A lot of people, probably most people, don't take chemistry and don't have anything more to do with chemistry after that—sometimes to the point of not knowing the difference between an atom and a molecule.

Unfortunately, this seems to lead to a fundamental misunderstanding of what is natural and what is healthy—and what is environmentally friendly. In turn, that makes it really challenging to make informed decisions on those subjects.

At this point, I should probably reiterate my disclaimer from the first post, lest somebody claim a conflict of interest in my interest here. I have no connection with any of the companies or products listed in this series. I don't work in household products at all, in fact. I spend my days doing industrial scale environmental cleanup type work—mostly prevention lately, but I have done remediation as well. I'll also add that if some new, quality research comes to light that contradicts any of my conclusions in the previous ten posts, I'll update the relevant post accordingly as soon as I learn about it.

I'm actually more disappointed in Marketplace than I am in most people who don't understand these things, for two reasons. First, Marketplace probably has the budget to find a good expert to help them and their viewers understand this stuff—and if they don't know where to look, then they should go ask their colleague Bob McDonald: that guy has a team that can find experts in fields you didn't even know existed, and he's really good at explaining things. Second and more importantly, Marketplace have a good reputation for exposing actual problems. I had expected a higher level of accuracy from them, as well as a lower level of gullibility.

Greenwashing and CBC #5: Vim PowerPro Naturals

Continuing from last week with #5 on the CBC Marketplace "Lousy Labels" greenwashing list is Vim PowerPro Naturals.

As I mentioned every week, Marketplace is a 22 minute show and they did a 10-product countdown, giving them an average of 2 minutes per product, so they had to leave a lot of information out.

Vim PowerPro is, according to the manufacturer's product page, "made with 98% naturally derived ingredients including fermented citric acid."

Marketplace says that the word "natural" is totally unregulated, and without an ingredients list, they can't know what that 98% natural claim actually means.

As usual, I went looking for the MSDS, but couldn't find one online. Marketplace says they asked for an ingredients list and got "only" an MSDS, which isn't an ingredients list. Funny, that's where I've been getting my ingredients lists for this series. Wish they'd posted it. It is possible that the Vim MSDS contains only the chemicals regulated as hazardous, which is what the law requires. Most companies (whose MSDS's I've seen) put all ingredients in the list, although I have seen some with only the regulated ingredients.

So, no MSDS for me, and no ingredients list either.

But—I did eventually find a candidate for an ingredients list.

Greenwashing and CBC #6: Eco Collection bath mitt

Continuing from the previous entry in this series with #6 on the CBC Marketplace "Lousy Labels" greenwashing list is the Eco Collection bath mitt.

As I have mentioned each time, Marketplace is a 22 minute show and they did a 10-product countdown, giving them an average of about 2 minutes per product, so they had to leave a lot of information out. This series is me looking to see what other information is out there.

The Eco Collection bath mitt is, according to the manufacturer's product page, a natural bamboo fiber and natural cotton product. They claim antibacterial properties for the natural bamboo fiber, and that it's made using rayon from bamboo.

Marketplace claims that bamboo can be grown sustainably but requires "funky chemical processing" to make a nice soft fiber, and the product package is unrecyclable vinyl.

This may well be the shortest segment they did of the ten—basically saying the above, then moving on. (I didn't time the segments.)

So, I'm going to look at exactly what's so "funky" about the chemical processing required to turn bamboo fiber into rayon.

Arsenate: love it or hate it?

Science makes yet another super-interesting discovery that started from a "wait, that's weird" moment. One which was initially misinterpreted, too.

So a while back there was a big splash in the news about some bacteria which had been isolated from a lake that was quite high in arsenic, where said bacteria—and other creatures—were thriving despite the arsenic.

It wasn't just that the bacteria could live in an environment containing arsenic, as there were already known bacteria which "breathe" arsenate; it was that the initial tests seemed to show that the bacteria could grow in the absence of phosphate, by substituting arsenate for phosphate.

This last conclusion turned out to be incorrect. However, the bacteria could still thrive in lab environments where the phosphate to arsenate ratio got completely absurd—as long as there was a trace of phosphate there. That in itself was pretty strange, because arsenate is a deadly poison.

Greenwashing and CBC #7: Simple Green All-Purpose Cleaner

Continuing from last week with #7 on the CBC Marketplace "Lousy Labels" greenwashing list is Simple Green All-Purpose Cleaner.

As I mentioned last week, Marketplace is a 22 minute show and they did a 10-product countdown, giving them approximately 2 minutes per product, so they had to leave a lot of information out.

So, first things first: the Simple Green MSDS.

Greenwashing and CBC #8: Obusforme EcoLogic Countoured Pillow

Continuing from last week with #8 on the CBC Marketplace "Lousy Labels" greenwashing list is the ObusForme EcoLogic contoured pillow.

As I mentioned last week, Marketplace is a 22 minute show and they did a 10-product countdown, giving them approximately 2 minutes per product, so they had to leave a lot of information out.

Interestingly, when I went to the ObusForme website to see how they were promoting the EcoLogic pillow, I couldn't find it there. Looking a little closer, Marketplace contacted the manufacturer to see what they had to say about it, and it turns out the EcoLogic line is no longer being marketed in Canada.

Oh, Marketplace. Why would you pick a product that isn't even being made anymore? Surely there are products still being actively marketed that are deserving of your "lousy label" sticker.

Oh well. Might as well look at it anyway. I don't know much about memory foam, and why pass up a chance to learn something new?

Greenwashing and CBC #9: Sunlight Green Clean Laundry Detergent

Continuing from last week with #9 on the CBC Marketplace "Lousy Labels" greenwashing list is Sunlight Green Clean Laundry Detergent.

As I mentioned last week, Marketplace is a 22 minute show and they did a 10-product countdown, giving them approximately 2 minutes per product, so they had to leave a lot of information out. I am the CC so I am filling the (chemistry side) gaps, to satisfy my own curiosity.

As always, I start with the MSDS to get an ingredients list.

Greenwashing?

Just this past weekend, CBC Marketplace did another one of their consumer product reviews, digging into the reality behind the marketing claims. This one is of special interest to me, because I'm both a chemical engineer and and an environmentally conscious person, and it demonstrates pretty clearly why a lot of people believe that combination isn't possible.

This episode was titled Lousy Labels: Home Edition (video, 22 minutes; text summary of their findings) and tackled "greenwashing", or overblown claims of being environmentally friendly, specifically on household products.

Since it's a 22 minute show and they covered ten products, that leaves about 2 minutes per product. There's a lot they had to leave out to fit inside that time limit.

So, because I am interested in learning, interested in being environmentally friendly, chemically inclined, and perpetually looking for something interesting to write about, I decided to take a closer look at these products.

Oh, and since I'm a chemical engineer and some people will be suspicious of me because of that, I will state up front that I have no relationship with any of the chemical products or companies talked about in this show. I don't do consumer goods, I do industrial scale environmental cleanup type stuff.

I'll do them in the same order that Marketplace did, which means I will start with #10: Raid EarthBlends Multi-bug Killer.

Computer researcher

Looks like computers are opening up even more areas of chemistry!

Earlier this year I posted about some software that can predict crystal growth conditions.

Now, there's new software coming out that can predict organic chemistry reactions.

Organic chemistry isn't my field, so unlike the crystal software I probably won't be able to justify a purchase to my boss, but I can still think that this is pretty amazing. The researchers spent a good solid ten years putting the sum total of all organic chemistry knowledge from the past 250 years into a database.

Not only can the computer search possible reaction pathways to make whatever compound you want, you can also filter those results. For example, pathways that use only non-toxic ingredients, or pathways with fewer reaction steps.

In one excellent example, the software came up with what they're calling a "one-pot" reaction for an asthma drug, which is normally produced with four separate reaction and separation steps. The suggested one-pot reaction said that they could put all the ingredients in the same flask in a specific order with specific timing—but with no separation steps, which are often complicated and expensive—and get the asthma drug they wanted—so they tried it.

It worked.

This software sounds like it can lead to the truly ideal case that chemical engineers wish for: faster, cheaper, and safer all at the same time. There are a lot of reactions that use dangerous chemicals, because we don't know of alternate reactions to produce the same thing. Sometimes, research eventually reveals an alternate; for an inorganic example, the production of sodium hydroxide used to involve mercury, which is very toxic even in very small amounts. Now, the mercury process is rarely if ever used, because better and safer processes have been found.