Blog

How-to-construct a composter

Posted by Chandler Slavin on Oct 16, 2012 4:40:00 PM

Greetings all!

After conversing, Phil thought that it would be cool if we had two compartments for our composter because, as alluded to yesterday, this allows us to have different batches of material based on how long the material has been “composting.” Also, in having two compartments for the composter, we can play mad scientist with the bio-based resins we have sampled and see how they do in fact break down, and if so, over what kind of time frame. As discussed in a previous post, we have some concern about bio-based resins breaking down completely i.e. being completely consumed by the microorganisms present in the disposal environment. If bio-based resins do not completely break down, then we walk the risk of introducing a ton of teeny tiny plastic particulates into the environment, which could travel into our waterways, be consumed by tiny things that get consumed by bigger things and on it goes until humans are ingesting tiny bits of plastic. Yuck! The fancy term is “bioaccumulation” and it is no good.

Where was I going…oh yea: so while we won’t be able to tell, obviously, if the bio-based material breaks down completely because we don’t have insane microscopic vision, we will be able to watch the degredation process in real time, which I think is pretty neato! In theory, the second compartment could be devoted entirely to watching different bio-based resins breakdown; the remaining compost, therefore, would not be used on our farm next spring because the risk that it may contain plastic particulates. Perhaps we could even send this compost to a “lab” to determine if the plastic particulates have in fact been entirely consumed…imagine the possibilities!

Please note, however, than most bio-based resins are certified to breakdown in an industrial composting facility, which is much more sophisticated than our composter. Therefore, I am unsure if most of these materials, certified with the ASTM D6400 Standard for Industrial Compostability, will break down at all, as our composter resembles more of a home composter than an industrial one. We did, on the other hand, just sample a new bio-based resin, which has received certification for “OK to home Compost.” This stuff is definitely going in our mighty composter to see how it breaks down!

And, how cool is this, but when we decide to start playing mad scientist, I will take pictures of the degredation process over time so you can see how a converted package morphs and breaks down in the disposal environment in which it is intended for. Splendid!

Alright, let’s continue with our how-to construct a composter:

So yeah, we decided on two compartments.

Then Phil suggested that we add some kind of mechanism, which would allow us to access the compost pile without having Go Go Gadget arms. After all, the composter is over 4 feet tall, which would make access to the material difficult as would it make “tending” to the compost problematic. Phil came up with another solution: why not add a tracked, wooden component to one side of the composter, which would then receive a thin piece of wood that you could move up and down along the track! Sort of like a curtain, this wood veil could be easily manipulated by the person tending to the compost, moving it up to access the mix and moving it down to conceal the pile from critters and excessive wind, rain, sun, etc.

So that was the approach Phil took toward constructing our compost: two compartments with a retractable side wall built out of post-industrial wood pallets.

Once we were all in agreement, Phil began working on “piratizing” our pallets. This consisted of him breaking down the pallets with a pry-bar in hopes of gathering enough material to carry out his vision.?



Basically, Phil intended on have two pallets per side of the composter, with a “divider” that cut the area of the composter in half, thereby creating two compartments. In order to accomplish this he began by attaching two skids together via a drill and nails. See:



After assembling one side of the composter, Phil repeated this process and created another side wall. He then attached these together, creating an “L” form.

Prior to calling it a day, Phil attached one pallet to the newly constructed “L,” which would serve as the divider between the other compartment, yet to be created. Check it out:



The next day, Phil finished the divider wall by attaching another skid, and created the entire second compartment. Check out the skid organization:



He also designed and constructed our “opening mechanism,” illustrated here:



And TA DA, we have a fully functioning and arguably adorable composter; I’m so proud:



I can't wait to paint it! I'm thinking polka dots!

Tune in tomorrow to learn about oxo-degradables and other biodedradable plastics.

Read More

Compost baby ya!

Posted by Chandler Slavin on Oct 16, 2012 4:38:00 PM

Helllooooooo everyone and happy day!

A quick mention before I get into the meat of today’s post, which discusses how to construct a home composter!

I am beginning a new research project on all things “oxo-degradable.” One of our customers expressed interest in these “magical little additives,” which supposedly render a resin biodegradable in a landfill? I am totally confused after my conference call with a rep from a company marketing this “innovative new technology” but I will keep you all posted with what I find. I didn’t even know things broke down in a landfill, really, let alone can receive certification for such a process, which according to this company rep, they have? Go figure!

If any of you, my diligent blog followers, know of the validity of these additives from a holistic, sustainability-based approach, please advise!!!

OK….drum roll please….

Dordan Manufacturing Company Incorporated is proud to announce completion of its composter construction! Dordan is now open for composting! Yehawww!

So this is what I learned: building a composter is just as easy, if not easier, then buying one. When I first received word from upper management that Dordan was considering getting a composter, I began researching what kinds and was quick to learn that there are a million different kinds, brands, styles, requirements, capacities, etc. For those of you who follow my blog, you will remember that this inspired me to conduct Dordan’s first waste audit, insofar as I was trying to quantify how much “compostables” Dordan generates via our employees and yard in order to determine what kind of composter to purchase. While I was never able to get a good reading of our compostables because I was too much of a sally and couldn’t separate our “wet waste” i.e. week old food, from our “dry waste” i.e. industrial scrap, I did intend on training our employees to separate the food waste from the other waste. In separating out the food waste, I assumed that we could get a much more accurate reading of how much compostables we generate per week, month, etc., therefore indicating what kind of composter to buy. Makes sense, right?

And enter Emily and Phil.

As some of you know, several weeks ago we had offered the use of Dordan’s land to a local farmer, Emily, for growing organics next summer as the land she is currently using is no longer available. Ironically, Emily also knows how to construct composters! When she and her father came out to access the land before committing to using it next summer, I indicated that I was researching composters and having a difficult time finding “the right one.” She explained how she and her father had just finished building a composter for one of the restaurants they provide organics to, and emphasized that it was super easy.

Awesome, I thought to myself; it certainly makes my job easier; and, it’s cheap!

After Emily and Phil agreed to help us construct a composter, it took literally 3 days for its completion!

What follows is a description of what I learned from observing Phil and Emily as they built our composter. Please note that the materials used for the construction of our composter are post-industrial, often times available at manufacturing facilities. Perhaps you can apply these insights to the construction of your own composter; after all, as Phil’s shirt said on day 1 of building our composter, “a rind is a terrible thing to waste!”

First, you need to find a material that will become the composter; Phil suggested wood or a combination of wood and chicken wire. The composter, in concept, should be open to the ground and the sky but have a retractable “roof” to keep rainwater and critters out. It should have at least one 4-walled compartment for the compost and preferably another for the compost that is farther along in the “process.” In other words, in having two compartments for compost, one can move a batch of compost to the compartment reserved for the more “mature” compost mix, while keeping the other compartment for the freshies. Make sense? It will!

As per Phil’s and Emily’s ingenious suggestion, we decided to use post-industrial wood pallets for our composter. We have a ton of wood pallets in-house, as that is what our material comes on when we receive it. While normally we recycle these pallets by selling them to wood re-processors, Dordan just so happened to have a bunch in-house waiting for shipment. Coincidence? I think not!

After inspecting our wood pallet selection (Dordan uses many different shapes and sizes of wood pallets and therefore we had several “types” to choose from), Phil determined that those of a more “narrow” disposition would be the best for conversion into a composter. These more narrow pallets measure roughly 4 ? feet by 2 feet, are made of solid pine wood, and have no iky additives added. Here is a picture of the skids selected, for your viewing pleasure:



We collected about a half a dozen of these wood pallets and Phil went on to “piratize” them into a very sophisticated composter, consisting of two compartments with a retractable “side.” This retractable side?will allow us to mix the concoction, add more materials without having to lift it the 4 ? feet required to access the compartments, and check in on the status of the compost.

But I am getting ahead of myself.

After we decided on what type of material to use in the construction of the skid, we selected a location. Dordan CEO Daniel Slavin suggested it be behind the future farm plot but close to a Dordan entrance/exit to make for easy maintenance. This is what we decided on:



The types of tools and amenities needed for a construction project of this character are:

Air gun



Extension cord

Electrical outlet?

Reciprocating saw



Circular saw and ear muffs



Hammer

Nails, screws

Measuring tape

Pry bar



And some handy-man know how!

After we gathered our composter materials and the needed tools and amenities, we started talking through the concept.

Tune in tomorrow to learn what Phil and Emily come up with!!!

Read More

Bio-based resin report!

Posted by Chandler Slavin on Oct 16, 2012 10:58:00 AM

Hello world! Today is officially the most beautiful day—the sun is shining and the weather is sweet. If I only I weren’t stuck in a cubicle…

Soooooo because I have had so many of Dordan's customers ask us about bio-based resins, I decided to compile a brief report, which details the various environmental ramifications one must consider when discussing bio-based plastics. Soon this report will be accessible on our website but because you are all so special, I have attached it below here. A sneak peak, per se. Wow I am a nerd.

Enjoy!

Bio-Based Resins: Environmental Considerations

Biodegradability is an end of life option that allows one to harness the power of microorganisms present in a selected disposal environment to completely remove plastic products designed for biodegradability from the environmental compartment via the microbial food chain in a timely, safe, and efficacious manner.[1]

Designing plastics that can be completely consumed by microorganisms present in the disposal environment in a short time frame can be a safe and environmentally responsible approach for the end-of-life management of single use, disposable packaging.[2] That being said, when considering any bio-based resin, there are some environmental considerations one must take into account. These include: end-of-life management; complete biodegradation,; its agriculturally-based feedstock; and, the energy required and the greenhouse gasses emitted during production.??

Before I expand on these concepts below, let us quickly discuss the biological processes that degradable plastics endure during biodegradation.

Microorganisms utilize carbon product to extract chemical energy for their life processes. They do so by:
    1. Breaking the material (carbohydrates, carbon product) into small molecules by secreting enzymes or the environment does it.
    2. Transporting the small molecules inside the microorganisms cell.
    3. Oxidizing the small molecules (again inside the cell) to CO2 and water, and releasing energy that is utilized by the microorganism for its life processes in a complex biochemical process involving participation of three metabolically interrelated processes. [3]
If bio-based plastic packaging harnesses microbes to completely utilize the carbon substrate and remove it from the environmental compartment, entering into the microbial food chain, then biodegradability is a good end of life option for single use disposable packaging.

End-of-life management considerations:

Because biodegradation is an end of life option that harnesses microorganisms present in the selected disposal environment, one must clearly identify the ‘disposal environment’ when discussing the biodegradability of a bio-based resin: examples include biodegradability under composting conditions, under soil conditions, under anaerobic conditions (anaerobic digestors, landfills), or marine conditions. Most bio-based resins used in packaging applications are designed to biodegrade in an industrial composting facility and one should require some type of certification or standard from material suppliers, ensuring compostability.

Unfortunately, little research has been done on how many industrial composting facilities exist in the United States and how bio-based plastic packaging impacts the integrity of the compost. However, the Sustainable Packaging Coalition did perform a survey of 40 composting facilities in the U.S., which provides some insight. According to their research, 36 of the 40 facilities surveyed accept compostable packaging. These facilities reported no negative impact of including bio-based plastic packaging in the compost. Of the 4 facilities that do not accept compostable packaging, 3 are taking certain packaging on a pilot basis and are considering accepting compostable packaging in the future. Of the facilities surveyed, 67.5% require some kind of certification of compostability i.e. ASTM, BPI, etc.

In addition, because value for composters is found in organic waste, I assume most facilities would not accept bio-based plastic packaging for non-food applications because the lack of associated food waste and therefore value. In other words, as Susan Thoman of Cedar Grove Composting articulated in her presentation at the spring SPC meeting, composters only want compostable food packaging because the associated food waste adds value to the compost whereas the compostable packaging has no value, positive or negative, to the integrity of the compost product.?

It is also important to note that because there are so few industrial composting facilities available, the likelihood that your bio-based plastic packaging will find its way to its intended end of life management environment is rare. While the idea of biodegradation and compostability for plastic packaging may resonate with consumers, the industrial composting infrastructure is in its infancy and requires a considerable amount of investment in order to develop to the point where it would be an effective and economical option to manage plastic packaging waste post consumer.

Complete biodegradability considerations:

A number of polymers in the market are designed to degradable i.e. they fragment into smaller pieces and may degrade to residues invisible to the naked eye. While it is assumed that the breakdown products will eventually biodegrade there is no data to document complete biodegradability within a reasonably short time period (e.g. a single growing season/one year). Hence hydrophobic, high surface area plastic residues may migrate into water and other compartments of the ecosystem.[4]

In a recent Science article Thompson et al. (2004) reported that plastic debris around the globe can erode (degrade) away and end up as microscopic granular or fiber-like fragments, and these fragments have been steadily accumulating in the oceans. Their experiments show that marine animals consume microscopic bits of plastic, as seen in the digestive tract of an amphipod.

The Algalita Marine Research Foundation[5] report that degraded plastic residues can attract and hold hydrophobic elements like PCB and DDT up to one million times background levels. The PCB’s and DDT’s are at background levels in soil and diluted our so as to not pose significant risk. However, degradable plastic residues with these high surface areas concentrate these chemicals, resulting in a toxic legacy in a form that may pose risks to the environment.

Therefore, designing degradable plastics without ensuring that the degraded fragments are completely assimilated by the microbial populations in the disposal infrastructure in a short time period has the potential to harm the environment more that if it was not made to degrade.

Agriculturally-based feedstock considerations:

Most commercially available bio-based resins are produced from sugar or starch derived from food crops such as corn and sugarcane.[6]Over the past few years, the use of food crops to produce biofuels has become highly controversial; the same may happen with bio-based resins. However, this is only if the scale of bio-based polymer production grows. According to Telles VP Findlen, “If the bioplastics industry grows to be 10% of the traditional plastics industry, then around 100 billion pounds of starch will be necessary, and there is no question that that will have an effect on agricultural commodities.”[7]

This sentiment is echoed by Jason Clay of the World Wild Life Fund. Because sugar is the most productive food crop[8] Clay explained, it makes an ideal feedstock for bio-based resin production; however, if all Bio-PE and Bio-PET came from sugarcane, we would need 2.5 times as much land in sugarcane. Unfortunately, this can not be done sustainably because, according to the Living Planet Report,[9] our current demand for the Earth’s resources is 1.25 times what the planet can sustain.[10] Put another way, on September 25th of this year our resource use surpassed what is sustainable. What this would mean as a financial issue is that we are living off our principle.[11]

Therefore, when considering bio-based resins, one should take into consideration the feedstock from which it is derived and the various environmental requirements that go into procuring said feedstock. While the current production of bio-based resins is not to scale to compete with sugarcane production for food, it is important to understand the environmental and social ramifications of sourcing materials from agriculturally based products.

Energy requirements and fossil fuel consumption of production:

Obviously sourcing plastics from bio-based resources as opposed to fossil fuel is an intriguing option for those looking to reduce the burden of packaging on the environment. However, if the energy required to produce bio-based plastics exceeds the energy consumed in the production of traditional resins, then the sustainability profile of bio-based plastics can be compromised.

When bio-based plastics first became commercially available, the processing technologies were not developed to the point where producing plastics from bio-based sources consumed less energy than producing traditional, fossil-fuel based plastics. However, the bio plastics industry has dramatically evolved and is now able to produce certain bio-based resins with less energy when compared with traditional resins. Natureworks Ingeo PLA (2005), for instance, is processed in such a way that it actually consumes less energy and emits fewer greenhouse gas equivalents during production when compared with traditional, fossil-fuel based resins.[12]

The Institute for Energy and Environmental Research (IFEU), Heidelberg, Germany, conducted the head-to-head lifecycle comparison on more than 40 different combinations of clamshell packaging made from Ingeo PLA, PET and rPET. Both PLA and rPET clamshells outperformed PET packaging in terms of lower overall greenhouse gas emissions and lower overall energy consumed and PLA exceeded rPET in its environmental performance.

According to the study, clamshell packaging consisting of 100 percent rPET emitted 62.7 kilograms of C02 equivalents per 1,000 clamshells over its complete life cycle. PLA clamshells emitted even less, with 61.7 kilograms C02 equivalents per 1,000 clamshells. Energy consumed over the lifecycle for 100 percent rPET clamshells was 0.88 GJ. This compared to o.72 GJ for the Ingeo 2005 resin, which is an 18% reduction in energy consumed.

Taken together, one would assume that the 2005 Ingeo PLA is a more sustainable option than traditional plastics, as manifest through this study. However, it is important to take into account the other dimensions discussed above, such as end of life management, complete biodegradation, and sustainable sourcing. By understanding the advantages and disadvantages of bio-based resins from an environmental perspective, packaging professionals can make informed material selections and truly comprehend the ecological ramifications of their packaging selections and designs.


[1] Ramani Narayan, “Biodegradability…” Bioplastics Magazine, Jan. 2009. Narayan is a professor from the Department of Chemical Engineering and Materials Science at Michigan State University.

[2] Ibid.

[3] Ibid.

[4] Ibid.

[5] See www.algalita.org/pelagic_plastic.html.

[6] Jon Evans, “Bioplastics get Growing,” Plastics Engineering, Feb. 2010, www.4spe.org, p. 19.

[7] Ibid, p. 19.

[8] 1-2 orders of magnitude more calories per ha than any other food crop. Information taken from Jason Clay’s presentation, “Biomaterial Procurement: Selected Resources,” at the Sustainable Packaging Coalition’s spring meeting in Boston.

[9] The Living Plant Report is a biannual analysis of the carrying capacity of the globe compared with resource consumption: Population x consumption > planet.

[10] Clay, SPC spring meeting presentation.

[11] Ibid.

[12] M. Patel, R.Narayan in Natural Fibers, Biopolymers and Biocomposites.

Read More

SUBSCRIBE TO OUR BLOG:

LATEST POSTS: