Biobased materials are gaining more and more attention; they are interesting options to consider, since they often come with a significantly lower environmental impact than traditional options. Our LCA-intern Conor Brennan wrote his thesis for the master Bio-inspired Innovation (University Utrecht) and adopted an LCA method to match his research-question. Conor assessed the environmental impact of a classic, clay brick and a brick made of fungal material, with attention to impacts on biodiversity. Read all about it in this article.
Conor, tell us; what were you researching?
I am referencing a previously done LCA study on fungal materials. I am converting the inputs of the German “Normalformat” brick and applying the Dutch clay brick dimensions 29.5 x 14 x 9cm.
Then I am applying a different life cycle assessment method, to better assess the specific impact of biodiversity. To assess the impact on biodiversity, I considered midpoint impact categories such as short and long term climate change, terrestrial acidification, ionising radiation, land use and water deprivation.To translate some of the impacts on biodiversity, I applied the Stepwise weighting approach to assign monetary values to each module of the life cycle.
Most LCA’s have spatial uncertainty and use general references to model their systems, but those references don't reflect each region or ecosystem. So the LCA assessment method I'm using, Impact World Plus, is more spatially resolved than those global references. It has more accurate data, that is specific to a country, a region or specific type of land based on regional data, indices and native data. Impact World Plus is an accumulation of assessment methods, and this way, it's more accurate regionally and it addresses that existing data gap.
This is the reason I'm doing this LCA; to learn more about fungal materials and mycelium as an industrial material, and to assess the environmental impact. Because in the future, fungal materials could be an alternative material to apply to a broad range of applications.
In the Netherlands, right now, clay bricks are the standard. This material is naturally around, and has been used for many, many years. This material is then extracted from the ground, depleting our natural resources. I am now looking at the environmental impact of this solid brick to see the impact on biodiversity categories.
At the moment, fungal bricks still lack the desired strength and material standards for building a house. They don't have the compressive strength, as more traditional materials like concrete do. These fungal bricks are grown in a mold, on a substrate like hemp-fibers. The brick is essentially a living organism that has similar material characteristics to expanded polystyrene. In some cases, they are used for packaging.
Another application that is currently emerging, is as insulation in the construction sector. The way the fungus grows leads to creation of air pockets within the material, creating excellent insulation properties.
And what was the topic of your thesis?
So I am assessing the life cycles of two different types of bricks for use in construction. A regular Dutch clay brick and a fungal brick for use in building walls. The construction industry contributes a significant amount of GHG to our atmosphere. Recently, biomaterials, versus traditional materials, like mineral based clay bricks, have become an attractive field to further explore.
And what results did you find?
In the results of the fungal brick itself, I found that the most of the impact is originating in the energy that is needed to produce the brick. The clay brick also uses an enormous amount of energy for treating and curing. In both cases, the bricks consume quite a lot of water and impact terrestrial and marine ecosystems.
Fungal production has many stages; starting from this one cell, that is placed on an agar plate, it grows. And then you add this to a starter feed;a substrate for the fungus to grow like a grain. And in order for this to grow, it takes temperature, water and air to grow. It’s a living organism, a biological system, and you have to create the right environment for it. The different processing stages take quite a lot of energy.
From the preliminary results, there are environmental impacts on terrestrial ecosystems and aquatic ecosystems seeming to originate from cultivation of the hemp substrate. If agricultural waste streams are used, this substrate can be seen as burden free. The substrate has already been produced, and we use those by-products such as the husks of the grain to grow the fungal material on.
When you place the two bricks next to each other, the fungal brick is significantly lighter than the traditional one. A finished fungal brick is less than a kilo and a finished clay brick is seven and a half kilos. So it's nearly seven and a half times heavier, so this is a major difference regarding transport!
At the end of its life, the material can be used as compost; the fungal bricks are biodegradable. They can improve soil conditions, after returning carbon to the soil, as well as maintain moisture. Using biogenic sources as feedstock for fungal growth makes the biomaterials attractive as carbon capturing materials, a nice alternative to fossil based materials.
Were the results kind of as you expected, or was there something that really surprised you?
With an LCA, you assess environmental impacts for a range of impact-categories, and the two different bricks were expected to have different impacts in different categories. I found that the brick do impact in some of the same categories, but overall the impacts of the two bricks are different.
With this new assessment method, we could gain insights into effects on biodiversity. I think the results were close to what I thought, but also surprising.
I figured that the fungal brick would be better for biodiversity and the terrestrial ecosystem. It influenced the categories of land use, water use and terrestrial acidification as expected. I did not expect the impact to be as big in the land use categories. The benefits of the material being biobased and potentially recyclable mitigates a lot of this impact.
Otherwise, land use for the production of crops for biomaterials or biobased solutions can indeed have greater impacts on biodiversity and ecosystem health.
In general, I would say that the cost on the environment is less with the fungal brick than it is with the traditional brick. This is the case if the material is recycled and kept in a sort of closed loop system.
It’s true you can reuse the clay, or recycle the clay, but the final material will again use more energy when you have to sort it, crush and grind it again to reuse it. This all costs' energy, whereas with the fungal brick you either re-cycle the brick, or just shred it and then spread it across the soil.
How was it for you to do the research?
The whole process was quite difficult; I had to do a lot of modelling in SimaPro (LCA software), a lot of reiterations of the model. And It was challenging, because you have to model something that’s a new and innovative technology. There were limited amounts of cradle-to-grave research done on these materials, so I had to create scenarios and model a lot of things myself.
But that made it also very interesting, because then you have to think about the whole life cycle and break it up into all components. It is sort of like problem-solving and sometimes takes a couple of heads to describe the system. I definitely learned a lot in the last 6 months about LCAs and full life cycle modelling!
Do you have any final advice or conclusion?
I would like to encourage more people to play around with mycelium, I believe this technology needs to be improved. And unfortunately, the material is not getting the attention it needs. But I have a lot of faith in it; I think it's really worth the investment and many great things can be done with mycelium, or fungi in general.
