Download to read offline
More Related Content
Plastic eaters
- 1. Plastic Eaters Patrick Cusack,Elena Miyasato & Parker Raymond
- 2. Introduction ▪ Unprecedented levelsof plastic waste ▪ Polyethylene terephthalate (PET, PETE, recyclable plastic #1) used in majority of single use bottles and food packagings ▪ Purpose: reduce amount of waste PET ▪ Goal: Create a method of PET reduction by the bacteria Ideonella sakaiensis that can be utilized worldwide https://sputniknews.com/environment/201803221062811738-Great-Pacific-Garbage-Patch-Now-Bigger-Than-Texas/
- 3. Introduction ▪ Constraints: ▫ Insignificantinformation on microbe ▫ Lack of SuperPro experience ▪ Considerations ▫ Environmental impact of elements ▫ Characteristics of microbial growth ▫ Replicable design
- 4. Options for Reduction ▪Reduce, Reuse, and Recycle ▪ Produce biodegradable plastic ▪ Mechanically remove plastic pollutants ▪ Use microbial growth to increase rate of decomposition ▫ Decreases plastic overall quantity
- 5. Literature Review: Powerful Bacteria ▪I. sakaiensis discovered in 2016 in Sakai, Japan ▪ Adheres to PET surface ⇒ produces enzyme named PETase ▪ PET broken into two monomers by PETase: terephthalic acid (TPA) and ethylene glycol (EG) Above: SEM image of degraded PET film surface by I. sakaiensis after 60 hours. Below: Time course of the degradation of a PET film (60 mg, 20 × 15 × 0.2 mm) after 6 weeks Source: Yoshida et al.
- 6. Literature Review: Growing Characteristics ▪Mesophile (optimal temperature: 30-37℃) ▪ Neutrophile (optimal pH: 7.0-7.5) ▪ Aerobic ▪ Growth inhibited in presence of NaCl at 3% (w/v) ▪ Chemoorganotroph I. sakaiensis attached to PET film surface. Arrows indicate appendages between bacteria and surface. Source: Yoshida et al.
- 7. Governing Equations Catabolism ofPET C10H8O4 + 2H2O C2H6O2 + C8H6O4 Anabolism from TPA 2C8H6O4 + 5O2 + 2NH3 2C5H7O2N + 6CO2 + 2H2O Overall Equation for Growth 2C10H8O4 + 4H2O + 5O2 + 2NH3 2C2H6O2 + 2C5H7O2N + 6CO2 + 2H2O
- 8. Literature Review: PET, TPAand EG ▪ PET plastics ▫ strong, flexible, lightweight, cheap ▪ TPA (C8H6O4) ▫ used to make magnetic recording tapes and prescription drugs ▫ GHS classification: Skin and Eye Irritant ▪ EG (C2H6O2) ▫ used to make anti-adhesive agents, pen ink, agricultural chemicals, and antifreeze ▫ GHS classification: Acute Toxicity ▫ Deadly if ingested Sources: https://pubchem.ncbi.nlm.nih.gov/compound/ethyl ene_glycol#section=Safety-and-Hazards https://pubchem.ncbi.nlm.nih.gov/compound/terep hthalic_acid#section=NIOSH-Toxicity-Data
- 9. 3 Questions ofUser, Client and Designer ▪ User (humans) a. How does this design benefit me? b. Why is this design better than conventional recycling? c. Could this microorganism be dangerous if it escaped the facility? ▪ Client (United Nations) a. What is the annual operational cost for one system? b. How will you maximize PET degradation by growing I. sakaiensis? c. Will toxic byproducts be produced? ▪ Designer (Biosystems Engineers) a. What is the budget for the project? b. Where can this design be implemented? c. How can the process be made as sustainable as possible?
- 10. Design Methodology ▪ GrowI. sakaiensis in batch reactor, using PET plastic as carbon & energy source ▪ Separate byproducts of growth (carbon dioxide, biomass, ethylene glycol, water & residual ammonia) ▪ Utilize biomass, water, carbon dioxide and residual ammonia to grow plants in a greenhouse ▪ Recover polymer grade ethylene glycol for resale
- 11.
- 13. Sustainability Measures ▪ Reduceamount of PET plastic pollutants from the environment, specifically oceans ▪ Cradle to cradle: Greenhouse application ▪ Produce zero toxic waste ▪ Ethylene glycol produced sold to make biodegradable plastics
- 14.
- 15.
- 16. Conclusions ▪ User (humans) ▫Reduced PET plastic pollutants through accelerated decomposition ▪ Client (United Nations) ▫ The annual operational cost is $22,887,000. ▫ Additional research would need to be conducted to learn how to maximize PET degradation by I. sakaiensis ▫ Toxic material used as resource ▪ Designer (Biosystems Engineers) ▫ Budget: $200 Million ▫ Implemented in any industrialized country ▫ Cradle to cradle design is possible
- 17. References/Patents 1. Al-Sabagh, A.M., Yehia, F. Z., Eshaq, G., Rabie, A. M., ElMetwally, A. E. (2016). Greener routes for recycling of polyethylene terephthalate. Egyptian Journal of Petroleum, 25(1), 53-64. https://doi.org/10.1016/j.ejpe.2015.03.001 2. Arnott, J., Crawford, R. J., Ivanova, E. P., Webb, H. K. (2013). Plastic degradation and its environmental implications with special reference to poly(ethylene terephthalate). Polymers, 5, 1-18. doi:10.3390/polym5010001 3. Chen, C., Han, X., Ko, T., Liu, W., Guo, R. (2018). Structural studies reveal the molecular mechanism of PETase. The FEBS Journal, 285(20) https://doi.org/10.1111/febs.14612 4. Diebel, K., Fong, R., Heng, M.H., Rozeboom, G. (2014). Tangential flow filtration apparatuses, systems, and processes for the separation of compounds. European Patent No. EP 2 007 506 B1. 5. Drapcho, C., Nhuan, N.P., Walker, T. (2008). Biofuels Engineering Process Technology. New York, The McGraw-Hill Companies, inc. 6. Harrison, R., Todd P., Rudge S., Petridges D. (2015). Bioseparations Science and Engineering. New York: Oxford University Press. 7. Liu, B., He, L., Wang, L., Li, T., Li, C., Liu, H., Luo, Y., Bao, R. (2018). Protein crystallography and site-direct mutagenesis analysis of the poly(ethylene terephthalate) hydrolase PETase from Ideonella sakaiensis. ChemBioChem. 19, 1471-1475. https://doi.org/10.1002/cbic.201800097 8. Kondratowicz, F. L. and Ukielski, R. (2009). Synthesis and hydrolytic degradation of poly(ethylene succinate) and poly(ethylene terephthalate) copolymers. Polymer Degradation and Stability. 94(3), 375-382. https://doi.org/10.1016/j.polymdegradstab.2008.12.001 9. Tanasupawat, S., Takehana, T. Yoshida, S., Hiraga, K., and Oda, K. (2016). Ideonella sakaiensis sp. nov., isolated from a microbial consortium that degrades poly(ethylene terephthalate). International Journal of Systematic and Evolutionary Microbiology, 66, 2813-2818. DOI 10.1099/ijsem.0.001058 10. Tustin, G. C., Pell, T. M., Jenkins, D. A., Jernigan, M. T. (1993). Process for the recovery of terephthalic acid and ethylene glycol from poly(ethylene terephthalate). U.S. Patent No. US5413681A 11. Witt, U., Muller, R. J., and Deckwer W. D. (1995). New Biodegradable polyester-copolymers from commodity chemicals with favorable use properties. Journal of Environmental Polymer Degradation, 3(4), 215-223. 12. Yoshida, S., Hiraga, K., Takehana, T., Taniguchi, I., Yamaji, H., Maeda, Y., Toyohara, K., Miyamoto, K., Kimura, Y., and Oda, K. (2016). A bacterium that degrades and assimilates poly(ethylene terephthalate): Science, 351(6278), 1196-1199. DOI 10.1126/science.aad6359
Editor's Notes
- #3 Massive cluster of plastics and other garbage that makes up the Great pacific garbage patch (larger than size of Texas) Whales and other marine wildlife are washing up dead, stomachs full of plastics
- #4 Need optimal growing conditions so bacteria can thrive!
- #5 Use ours voices: support tax/ban, write manufacturing officials Reduce our plastic consumption/opt for reusable items instead of disposable Recycle plastics Companies like 4Ocean are mechanically removing pollutants from oceans All of these are good options, but they don’t actually reduce the volume of plastics in the world
- #6 SEM = scanning electron microscope
- #7 Can survive in 15-42 degC and 5.5-9 pH Chemo-> energy from chemical reactions (oxidation of TPA) Organotroph-> organic carbon source (TPA) If using plastics from oceans, would need to rinse off the salt since it would inhibit growth (3.5% salt
- #8 Anabolism from EG: 6C2H6O2 + 5O2 + 2NH3 2C5H7O2N + 2CO2 + 14H2O
- #10 How do we maximize PET degradation by growing I. sakaiensis?
- #12 Elena Our superpro design begins with a bioreactor, followed by a clarifier is which the flow is split between a centrifuge and microfiltration because of the differences of flow. The solid waste goes to our storage unit which is representative of a passive solar heater that would dry the solids further. Address the sustainability measures: the implementation of a greenhouse that would take the water and the biomass. Selling the ethylene glycol.
- #13 Elena Primary inputs are water and air and polyethylene. Primary outputs are biomass and ethylene glycol and carbon dioxide with residual air and water (which demonstrated a possible are of resource efficiency- if we can reduce the demand for water) The amount of polyethylene was based on the rough amount of plastic that could be decomposed in 40 days based on literature review
- #14 Elena Although we have some toxic biproducts- nothing is wasted because after purification the ethylene glycol is sold to external companies that can use it to produce biodegradable plastics.
- #15 Huge efficiency problems that mostly come down to the time it takes for the bacteria to decompose the plastic. The 40 day reaction time is long and demands many bioreactors in order to increase the efficiency of the other equiplent. And they cost more than a million dollars each and require their own labor as well. There are other ways that this process could be more effienct that were not modeled for this project but could give a more wholistic view of the economics behind this process. Such as the money made from the greenhouse, the money people would pay for us to dispose of their plastic. And passive energy
- #16 Elena