An Edible Drink Bottle - No Thanks, I've Lost My Appetite

Plenty of people take issue with the existence of single-use water bottles and the related disposal issues, so the recent announcement of an "edible drink bottle" being developed by a Harvard professor may seem like a real winner. There is nothing to dispose of - you can just eat the bottle when you are done. No waste, no garbage, no nothing to end up in the environment.

But before we all go out and invest in this technology, we need to review everything that a drink bottle does:.

• It needs to seal the water in and all other contaminants out.
• It needs to be made from materials that will not leach unsafe levels of chemicals into the water, or react with the water.
• It needs to not have any structural failure:
  • during shipment from the bottles' manufacturer (who is often someone different than the company filling the bottle) to the filling plant
  • while it is in the filling equipment
  • while the bottle is put into
  • the secondary packaging (often shrinkwrap)
  • into the tertiary packaging (a cardboard box)
  • additional packaging (such as to secure it to a pallet)
  • or during shipment via (multiple) trucks or boats
  • while on the shelf or rack, particularly when multiple layers of filled bottles are stacked on top of it
  • during the "normal" lifespan that the consumer has it
  • Keep in mind that during shipment and in the hands of the consumer, the bottle can see temperature extremes from below freezing temperatures to 140 oF or more, as well as UV light which can degrade polymers. If there is structural failure, the water will leak from the bottle, requiring that at the very least, that bottle be thrown away or recycled. Keep in mind that that bottle's contents are then also wasted. Depending on the extent and location of the leaker, the cardboard packaging may be weakened so that handling the other bottles or even the pallet with a forklift may be a problem, and therefore many more bottles may end up being trashed.
• The bottle needs to cost as little as possible.


• The water can only diffuse very slowly through the bottle's walls. Once too much water has evaporated, the bottle no longer holds the volume stated on the label, say 500 ml. Now it's mislabeled, and cannot be sold, so into the wastestream it goes.

I think this list is a pretty daunting challenge for the new material. Nothing was mentioned about the strength of the new material nor the diffusivity of water and other liquids through it, but considering that it is described as a "membrane", it probably leaks like a sieve. I've done enough product development to know better than to expect detailed costs estimates at this point, but this new material will be expensive if for no other reason than it will have to be treated as a food item and that means a whole boatload of regulations need to be followed in the production of it that a simple PET bottle is exempt from. But the real limitation will be this: if the bottle is to be edible, then it will have to be kept clean and sanitary, just like all food is, and the only way to do that is to have additional packaging around the bottle and that pretty much defeats the whole purpose of the bottle, doesn't it? Unless a PET bottle is filthy, people give little regard to where it's been or who/what has touched it, but if you are going to be eating that bottle, then everything contacting it will be a concern. A coworker handing you a bottle would be just like that coworker handing you a donut - not the box of donuts, but a donut directly with their hands. Anybody still hungry for these bottles?

To Develop Biofuels or Not?

One aspect of photosynthesis that has always struck me as odd is the poor efficiency of that reaction: about 1%. This inefficiency is embarrassing enough, but when you consider that it is the result of 3.5 billion years of evolution, it becomes abominable. While research is being done to try and increase it, I think that the eons that nature has had to work on the problem pretty much guarantees us failure. For whatever reason, plants started out with an inherently poor reaction and have optimized it about as much as they can. Evolution can only build on what was there before. It is constantly working with legacy systems, and can never completely escape what was there before. What is really needed is a quantum leaps - the development on an entirely new photosynthetic mechanism, but that is far beyond our current capabilities and will be for the foreseeable future.

As a result, any efforts that we put into the development of biofuels will be limited by those same inefficiencies. Nobel Prize winner Hartmut Michel has a short editorial entitled "The Nonsense of Biofuels"(open access) which details the inefficiencies that I just described. He is not completely against the idea of only harvesting food from plants, but instead proposes that "[t]he best use of the biomass lies in its conversion into valuable building blocks
for chemical syntheses." This is the same idea that is indirectly echoed in another recent editorial entitled "Alternative feedstocks: a continuing trend in the polymer industry?" (open access). I say indirectly as this latter editorial advocates strongly that refineries for biofuels will be developed on a size and scale comparable to existing petroleum refineries, all the while recognizing that in the refineries, "[b]iomass...loses all of the chemical complexity that is inherent in bio-derived molecules."

I may have a biased perspective, but this does seem to be by-and-large the options that are being explored by industry. News of biobased chemical developments and investments in the corresponding plants seems to be dominating that of biobased fuels, so it seems that at least for now, we are moving in the right direction.

Recycling Wine Bottles

Today's post is inspired by the comment left by an anonymous poster on a different website. The website mentioned that Amcor is now supplying both natural and synthetic corks for their PET wine bottle. The anonymous poster had a one-line comment:"At the end of the day, I would rather recycle the glass".

While this is a nice thought, the reality is that wine glass bottles are difficult to recycle. They are green and the largest user of green glass is the wine industry, with imported beers following after that. Unfortunately, the wine industry is located in very small regions of the country, so while you can place a wine bottle into a recycling bin, the recycler who then takes that bottle will have a difficult time working with it. Shipping it to California is not a viable option for most of the country, as is re-exporting the beer bottle glass.

On the other hand, the marketplace across the country for recycled PET has never been better, and since a case of wine shipped in PET bottles is lighter the glass alternative, less fuel is needed to transport it in the first place, making it a much more green option overall.

A Green Polyethylene - Is It Worth the Effort?

Plastemart is reporting that "[a] method of converting plant matter into ethylene and propylene using a nanotechnology process that offers an alternative to oil-based production, has been developed by a team from Utrecht University and Dow Chemical Co, as per Reuters. This also means they will not be biodegradable [*], although they will be made from renewable resources."

This strikes me as odd - not that it can't be done - but that anyone would try to undertake this. Polyethylene (PE) is the largest volume plastic in the world. It has been in that number one position for as long as I can recall and I don't see anything displacing it in the near future and possibly forever. Similarly, polypropylene (PP) is the second largest volume polymer produced in the world and again similarly, nothing is going to displace it anytime soon.

Given these large volumes of plastic, it may seem like making more would be a good idea since the demand is already so high. The problem with making more of these plastics however, is that the existing margins for these materials are very thin. They are made in highly specialized, extremely large (200,000 metrics tons or more) and expensive factories ($200 million or more), all in an effort to squeeze out costs. If you wanted to get into the polymer business, PE and PP are not the way to do it. This is not a "make a little, sell a little" business that you gradually scale up. You go all in or you go home. If you want to start small and grow, start with more exotic polymers that you can make and sell in very small quantities - medical grade plastics such as used in coatings are a terrific example. As the demand for your product slowly grows, you can slowly increase capacity. Plus you can sell them for a lot and make large margins.

But as we've discussed here many times, Dow works exclusively on a big scale. They have no interest in low volume polymers - the bigger the better, and so the idea of having a green source for polyethylene and polypropylene are going to catch their eye. While I think that this is potentially interesting to source these polymers from plants and not petroleum byproducts, unless the economics of this option are significantly different than existing option, I can't see this technology getting off the ground. It works in the lab, fine. It will be cheap enough to build a small pilot line, and see how the scale-up goes, although even that will be fraught with problems. The pilot plant will make such small amount of materials that no one other than a small-time operator would be able to use these novels materials, and Dow will be far more interested in the opinion of large consumers (Berry Plastics, or Bemis or Trex) and not 'Bubba John's Blow Molding, Insurance & Appliance Repair Shop'.
It the classic chicken-and-the-egg scenario: Dow needs to make a large quantity of material to decide if they want to make a large quantity of material.

I am far more optimistic about other bio-sourced polymers. Sources for various diols, diacids, etc. are begining to emerge for making polyamides, polyesters, etc. and all of these will have the potential to make gradual introductions into the marketplace since the volumes needed to make the decisions about the viability of the new materials are not so high. The investment needed is lower and so you don't need a massive bank statement to get into the game.

[*] I would hope that anyone regularly reading this blog would know that just because something - plastic or otherwise - is made from renewable resources, it is not necessarily biodegradable.

Reusing Old CD's - but for Artists Only

Like most people, I've plenty of old CD's that get pitched (microwaving them has lost all it's excitement), but if I were more skilled as an artist, something like this sculpture would be an incredible reuse for them:

This sculpture, and all the additional ones made by Sean Avery are tiny fragments of a CD. I have neither the patience, creativity or imagination to create something like this.

Hat tip to the ThisIsColossal webpage for the lead. A fascinating blog featuring visually impressive art from around the world. I highly recommend it.

Data Doesn't Lie

An editorial in the current issue of Nature magazine ($) is so poorly written and twisted in its logic that I am shocked a respected journal such as Nature would publish it. The editorial is about methane emissions from fracking operations. Methane is widely recognized as a greenhouse gas - even by climate change deniers. But all of this is beside the point. I'm not discussing fracking, greenhouse gases or climate change today. Instead I'm focusing on two aspects that every scientist and engineer deals with daily: data, and making conclusions from data. Here's how not to do it:

"How clean is natural gas? Although it is often lumped in with coal and oil, many in the energy industry are at pains to point out that burning gas to generate electricity produces fewer greenhouse-gas emissions than does burning other fossil fuels. Certainly, countries claim reductions in carbon emissions when they switch from coal to gas, as Britain did on a large scale in the 1990s...Industry maintains that the problem has been exaggerated, and many scientists agree. Sorting fact from fiction has been difficult, however, because nobody had any independent data — until now.

As discussed on page 139, a study led by scientists from the US National Oceanic and Atmospheric Administration (NOAA), headquartered in Washington DC, and the University of Colorado in Boulder looked at methane and other emissions from a natural-gas field north of Denver, where fracking methods are used to open up sand formations. They estimated cumulative emissions from the field using not industry reports or conceptual models, but concentrations of pollutants in air samples. This is important because the atmosphere does not misrepresent data or make mistakes; nor does it bend to ideology or political will.

The data suggest that methane emissions from natural-gas operations could be substantially higher — and so be worse for global warming — than was thought. At works in the Denver-Julesburg Basin, methane emissions were roughly double the official estimate.

This will by no means settle the debate. The NOAA scientists had to make assumptions to convert atmospheric data to cumulative emissions from a vast energy complex. They readily acknowledge substantial uncertainty in their calculations, and estimate that between 2% and 8% of the methane produced from wells in the Denver-Julesburg Basin is lost to the atmosphere, with a best guess of 4%."

(emphasis added)

Wasn't that a perfect setup? "This is important because the atmosphere does not misrepresent data or make mistakes; nor does it bend to ideology or political will." So then how come "this will by no means settle the debate"? We have ideologically/politically neutral data? What's the problem?

This is a perfect example of the Achilles Heel of science: making a conclusion from data. It is such a fragile endeavor because it involves human beings and their thoughts and their biases. That is when assumptions are made and logic is applied. Worse yet, there is no guarantee that any conclusion reached is correct. This is why we have climate change deniers - not because of data, but because of the conclusions made from it.

How can Nature publish an editorial like this that is so removed from an understanding of how science works?