Loram Ipsum

Carbon Footprint Analysis

We are facing an huge increase in global population, from the current world population of f 7.6 billion to an expected 9.8 billion in 2050[1]. This projected increase in global population leads to an increase in both increased food and energy consumption, which in turn in is associated with the release of larger amounts of greenhouse gasses the atmosphere. Right now, we live in a plastic generation. The global production and consumption of plastics have been on the rise for over 50 years now, reaching a plastic consumption of 297.5 million tons by the end of 2015[2]. Plastic products from the petrochemical industries have a high carbon footprint (Boonniteewanich et al,. 2014). The combination of global population increase and a mass consumed non-eco-friendly product, in the form of petroleum-based plastics, could be disastrous. This is one of the reasons that the Groningen iGEM team’s project attempts to produce (bio)styrene, a building block for many plastics, from cellulose as an alternative to substitute the petroleum-based styrene. In this section we have carried out a partial Life Cycle Assessment (LCA) analysis to identify the environmental impact of both alternatives of petroleum-based styrene and bio-based styrene. The main purpose is to provide an insight of environmental burden that is caused by the worldwide styrene industry in terms of carbon dioxide equivalent emissions (CO2-e) and to showcase our greener alternative.

Analysis

For our LCA analysis , we have set the study boundary to what is called the ‘cradle to gate’ analysis instead of a full LCA which is called the ‘cradle to grave’ analysis (see figure 1). The reason for this is twofold. First of all, we discovered the LCA analysis in a late phase of the project. Therefore, so we did not have enough time to do the complete quantitative analysis because, in that case you have to look at all the inputs and outputs of equivalent CO2 of feedstock and energy, for each stage of our process, which is a complex task and in some cases that information is not even freely available. However, the main reason we choose to use the cradle to gate analysis over the cradle to grave is that fact that it is the only part that matters, since we will produce the exact same product, namely styrene. The second part of the life-cycle will be exactly the same. Therefore, the only part that matters is from the feedstock you use and the energy required to the product, in our case styrene.

Figure 1. Figure retrieved from: http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1021-20192013000200001

Contacts

In order to evaluate the environmental impact of the two ways of producing styrene, we met with multiple experts from the University of Groningen, and with experts from various start-ups and companies. First of all, Tjerk Douma, a master student whose specialized in sustainability and did a major part of the analysis. We also met with prof. dr. F. Francesco Picchioni, of the University of Groningen, head of the Product technology department - Engineering and Technology Institute Groningen. Moreover, we met with the start-up companies BioBTX and Zernike Advanced Processing and the companies CE Delft and Avantium.

Conclusions

1. Toilet paper waste is used as the primary raw material in the biorefinery to produce styrene.
2. Is it possible to take that percentage and use it in the biorefinery? The composition of cellulose is the determining factor which would need to be examined. If the raw materials were made up of pure biomass then the implications to the environment would be proportionally greater. Therefore locally sourced biomass, which does not impact on agricultural land, is the preferred option.
3. Currently the biorefinery is an energy and chemically intensive process. The amounts needed to convert x kg/h of raw materials into glucose is substantial.