From PET waste to biomaterials: life cycle analysis of PHB synthesis and enriched biomass strategies for PET upcycling
Abstract Plastic pollution is a complex global challenge that demands both creative solutions and thorough environmental evaluation. This study evaluates the environmental impacts of two novel approaches for producing poly(3-hydroxybutyrate) (PHB) and polyhydroxyalkanoate (PHA)-enriched biomass, respectively, utilising terephthalic acid recovered from waste PET through reactive extrusion depolymerisation. Life cycle assessment revealed that for PHB production, the highest environmental impacts are associated with the use of sodium hypochlorite and the high energy consumed during processing, resulting in significant effects on climate change, freshwater eutrophication, and photochemical ozone formation. On the other hand, the production of PHA-enriched biomass, which omits the PHA extraction step, derives that its main impacts from the electrical energy consumption, primarily affecting climate change and fossil resource use. When compared to conventional PET mechanical recycling, both processes exhibit lower impacts on climate change and fossil resource depletion footprints, but they still present greater burdens in terms of photochemical ozone formation and freshwater eutrophication. According to the results, improving sustainability will require higher fermentation yields, the adoption of renewable energy, greener extraction methods, and effective wastewater treatment. The findings suggest that innovative PET repurposing routes can reduce reliance on fossil resources and lower CO2 emissions but also highlight the need for further process improvements to reduce harm to freshwater ecosystems and air quality. Overall, this work adds to the conversation around sustainable plastics and emphasises the trade-offs involved in biopolymer production. Graphical Abstract
- Research Article
98
- 10.1016/j.jclepro.2019.117966
- Aug 8, 2019
- Journal of Cleaner Production
The environmental impacts generated by household consumption are generally calculated through footprints, allocating the supply-chain impacts to the final consumers. This study compares the result of the Consumer Footprint indicator, aimed at assessing the impacts of household consumption in Europe, calculated with the two standard approaches usually implemented for footprint calculations: (i) a bottom-up approach, based on process-Life cycle assessment of a set of products and services representing household consumption, and (ii) a top-down approach, based on environmentally extended input-output tables (EXIOBASE 3). Environmental impacts are calculated considering 14 environmental impact categories out of the 16 included in the EF2017 impact assessment method. Both footprints show similar total values regarding climate change, freshwater eutrophication and fossil resource use, but in the meantime very large differences (more than a factor 2) regarding particulate matter, photochemical ozone formation, land use and mineral resource use. The exclusion of services in the bottom-up approach can explain only to some extent these differences. However, the two approaches converge in identifying food as the main driver of impact in most of the impact categories considered (with a generally lower contribution in top-down compared to bottom-up). Housing and mobility are relevant as well for some impact categories (e.g. particulate matter and fossil resource depletion). Some substances are identified as hotspot by both approaches, e.g. the emission of NH3 to air (for acidification and terrestrial eutrophication), of NOx to air (for acidification, marine and terrestrial eutrophication, and, to some extent, photochemical ozone formation), of P to water and to soil (for freshwater eutrophication) and of fossil CO2 to air (for climate change). Significant differences at the inventory side are key drivers for the differences in total impacts. These include: (i) differences in the intensity of emissions, (ii) differences in the coverage of elementary flows, (iii) differences in the level of detail relative to elementary flows. Overall, the key converging results from both approaches (in particular regarding most contributing areas of consumption and substances) can be considered as a robust basis to support the definition of policies aimed at reducing the environmental footprint of household consumption in Europe.
- Research Article
20
- 10.1016/j.scitotenv.2023.162169
- Feb 11, 2023
- Science of The Total Environment
Environmental and economic sustainability of fresh-cut and pre-cooked vegetables
- Research Article
87
- 10.1016/j.ijhydene.2022.07.199
- Sep 1, 2022
- International Journal of Hydrogen Energy
Life cycle assessment of a renewable energy system with hydrogen-battery storage for a remote off-grid community
- Research Article
13
- 10.1093/jas/skad188
- Jan 3, 2023
- Journal of Animal Science
Traditionally, swine diets have been formulated to meet nutrient requirements at the lowest cost with little regard toward minimizing environmental impacts. The overall objective of this study was to evaluate the relative differences among four grower-finisher feeding programs, using precision diet formulation practices, on growth performance, carcass composition, nitrogen utilization efficiency, and environmental impacts. In experiment 1, four 4-phase growing-finishing feeding programs consisting of diets containing corn and soybean meal (CSBM), low protein CSBM supplemented with crystalline amino acids (LP), CSBM with 30% distillers dried grains with solubles (DDGS), and DDGS supplemented with crystalline Ile, Val, and Trp (DDGS + IVT) were fed to 288 mixed sex pigs (initial body weight [BW] = 36.9 ± 4.2 kg) for 12 wk to determine effects on growth performance and carcass characteristics. Pigs fed with CSBM had greater (P < 0.05) final BW than those fed with LP and DDGS, and greater gain efficiency than pigs fed with LP. Pigs fed with DDGS + IVT tended to have greater (P = 0.06) backfat depth than pigs fed with DDGS, and less (P < 0.05) loin muscle area than pigs fed with CSBM. In experiment 2, nitrogen (N) and phosphorus (P) balance of barrows (n = 32; initial BW = 59.9 ± 5.1 kg) fed with each of the phase-2 diets from experiment 1 was determined in a 12-d metabolism study (7 d adaptation and 5 d collection). Pigs fed with CSBM had a greater (P < 0.05) amount of N retained than pigs fed with other diets, but also had a greater (P < 0.05) amount of urinary N excretion and blood urea N than pigs fed with LP and DDGS + IVT diets. Pigs fed with LP tended (P = 0.07) to have the greatest N utilization efficiency but the least (P < 0.05) P retained as a percentage of P intake among dietary treatments. Diet composition and data collected from experiments 1 and 2 were used to calculate life cycle assessment environmental impacts using Opteinics software (BASF, Lampertheim, Germany). The CSBM feeding program had the least impact on climate change, marine and freshwater eutrophication, and fossil resource use. The LP feeding program had the least impact on acidification, terrestrial eutrophication, and water use, while the DDGS feeding programs had the least impact on land use. These results indicate that feeding CSBM diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with the other feeding programs evaluated.
- Preprint Article
- 10.5194/egusphere-egu2020-10478
- Mar 23, 2020
&lt;p&gt;Electricity production from biomass has the potential to significantly contribute to the share of renewable energy in the global power mix with lesser environmental impact than non-renewable resources. The production of bioenergy from forest biomass residues is currently increasing in Portugal, mainly as a consequence of concerns related to climate change and forest fires. &amp;#160;In Portugal, the annual production of residual biomass from forest logging is estimated at 0.8-1.2 million dry tons per year, and about 47-58% of these residues come from eucalypt.&amp;#160;&lt;/p&gt;&lt;p&gt;This study evaluates the environmental impacts resulting from electricity production in Portugal using eucalypt logging residues (composed of branches, foliage and tops) and considering two types of technologies: grate furnaces and fluidised bed furnaces. This assessment was performed using life cycle assessment (LCA) methodology, a methodology that evaluates the environmental impacts entire life cycle of a product or process (from the extraction of the raw materials until its end-of-life), allowing to identify the most significant stages and processes along the life cycle, and supporting by this way the decision and policy-making.&lt;/p&gt;&lt;p&gt;Two alternative scenarios for biomass-to-energy conversion technologies were simulated: grate furnace and fluidised bed furnace. The functional unit is the production of electricity from the combustion of eucalypt logging residues equivalent to 1 kWh delivered by the power plant to the Portuguese grid. System boundaries include the following stages: (1) forest management (including site preparation, planting, stand tending and logging); (2) residues collection; and (3) energy conversion (including forest biomass combustion as well as treatment and final destination of wastes). Seven impact categories from the International Reference Life Cycle Data System (ILCD) are considered: climate change, particulate matter, photochemical ozone formation, acidification, freshwater eutrophication, marine eutrophication and mineral and fossil resource depletion.&lt;/p&gt;&lt;p&gt;The results show that the forest management stage had a low contribution to the total impact in all impact categories for both technologies under analysis. The only exception is the impact category of mineral and fossil depletion, in which forest management is mainly responsible and which accounts for 92-94% of the total impact for both technologies analysed. The energy conversion is the hotspot in most of the impacts studied (climate change &amp;#8212;49-63%, particulate matter &amp;#8212;94-95%, photochemical ozone formation &amp;#8212;85-88% of, acidification &amp;#8212;76-79%, freshwater eutrophication &amp;#8212;56-58% and marine eutrophication &amp;#8212;70-71% of the total impact) and therefore, this is the stage for which improvements should be primarily establishedestablished for both technologies analysed. In addition, for all impact categories analysed, the fluidised bed presented the smallest environmental impact. Even when the grate furnace efficiency increases and the fluidised bed efficiency decreases in a sensitivity analysis, the fluidised bed has lower impacts than the grate furnace and is a good alternative for implementing new power plants. Further research is needed to analyse the effects of converting the grate technology in Portugal to fluidised bed technology.&lt;/p&gt;
- Supplementary Content
26
- 10.1016/j.oneear.2023.05.022
- Jun 1, 2023
- One Earth
Charting success for the Plastics Treaty
- Research Article
7
- 10.1007/s11367-017-1335-6
- Jun 1, 2017
- The International Journal of Life Cycle Assessment
PurposeLife cycle assessment aims to assess trade-offs between different impacts, including mineral and fossil resource use. The goals of this study were (1) to derive surplus cost potentials (SCPs) for a large number of fossil and mineral resources and (2) to derive surplus costs per megawatt hour of electricity produced for a range of both renewable and non-renewable technologies.MethodsThe SCP of a resource refers to the total cost increase over the full amount of resource expected to be extracted in the future, expressed as US dollar (USD) per unit of resource extracted. For the fossil resources oil, natural gas and hard coal, cost-cumulative production relationships were derived that were subsequently used as input to calculate SCPs for these three fossil resources. For mineral resources, SCPs were readily available for 12 resources and platinum-group metals as a separate group. SCPs for an additional number of 57 mineral resources and 4 mineral resource groups were derived on the basis of a statistical relationship between SCP and average price in year 2013. The SCPs of fossil and mineral resources were subsequently used to derive the surplus costs per megawatt hour of 10 electricity production technologies.Results and discussionThe surplus costs of electricity production ranged from 0.3 to 148 USD2013/MWh. The three fossil-based energy production technologies, based on coal, gas and oil, resulted in the highest overall surplus costs (23 to 148 USD2013/MWh), while nuclear, geothermal, photovoltaic, wind and hydropower technologies have the lowest surplus costs (0.3–6 USD2013/MWh). We found that the contribution of fossil resource use to the surplus costs was higher compared to mineral resource use, including the renewable energy technologies.ConclusionsSurplus costs of fossil and mineral resources can be used to compare renewable and non-renewable electricity production technologies. This case study shows that fossil fuel use drives the surplus costs of all energy technologies.
- Research Article
20
- 10.1016/j.jclepro.2022.135098
- Nov 9, 2022
- Journal of Cleaner Production
Life Cycle assessment of biorefinery technology producing activated carbon and levulinic acid
- Research Article
1
- 10.1093/jas/skac064.044
- Apr 12, 2022
- Journal of Animal Science
The objective of this study was to quantify and compare the environmental impact, using life-cycle assessment (LCA) analysis, of 4 different, 4-phase growing-finishing feeding programs consisting of diets containing corn and soybean meal (CSBM), low protein CSBM supplemented with crystalline amino acids (LP), CSBM with 30% distillers dried grains with solubles (DDGS), and DDGS supplemented with crystalline Ile, Val, and Trp (DDGS+IVT). The LCA analysis was performed using an online software application (Opteinics, BASF, Lampertheim, Germany) with calculations based on environmental impact factors from the Global Feed LCA Institute feed ingredient database. The specific model included impacts of feed production, animal farming, manure management, and meat processing. Environmental impacts were calculated at the farm gate and the functional unit was 1,000 kg of carcass weight. Diet composition, growth performance, and carcass data obtained from a feeding trial were used as inputs in the LCA calculations. Using CSBM as the reference feeding program (Table 1), the LP feeding program resulted in an overall decrease in impacts associated with acidification (10.9%), water use (7.6%), and land use (9.8%), but increased impacts associated with climate change (3.3%) and fossil resource use (3.7%). Both DDGS and DDGS+IVT feeding programs increased impact on climate change (18.4-18.7%), fossil resource use (42.7-47.3%), and water use (47.2-50.0%), but decreased impacts associated with acidification (3.0-3.4%) and land use (27.2-27.3%) compared with the CSBM feeding program. Overall, the LP feeding program resulted in the lowest total environmental footprint (1.0776 person years), followed by the CSBM (1.1081 person years), DDGS+IVT (1.1845 person years), and DDGS (1.1884 person years) feeding programs. These results indicate that feeding CSBM diets without and with crystalline amino acids have less impact on climate change, water use, fossil resource use, and total environmental footprint than DDGS feeding programs per 1,000 kg of pork carcass weight.
- Research Article
11
- 10.3389/fenrg.2024.1361720
- Feb 28, 2024
- Frontiers in Energy Research
The deployment of energy storage systems can play a role in peak and frequency regulation, solve the issue of limited flexibility in cleaner power systems in China, and ensure the stability and safety of the power grid. This paper presents a comprehensive environmental impact analysis of a lithium iron phosphate (LFP) battery system for the storage and delivery of 1 kW-hour of electricity. Quantities of copper, graphite, aluminum, lithium iron phosphate, and electricity consumption are set as uncertainty and sensitivity parameters with a variation of [90%, 110%]. The results show that global warming potential is 9.08E+01 kg CO2 eq. and fossil resource use is 1.21E+03 MJ, with uncertainty ranges of [8.54E+01, 9.23E+01] and [1.15E+03, 1.23E+03], respectively. Electricity consumption during the manufacture and installation process is the greatest contributor to climate change (CO2 eq. emissions), accounting for 39.71% and largely owing to non-renewable sources, followed by cathode materials at 27.85% and anode materials at 18.36%. The disposal and recycling process offers emission reductions but requires an additional 1.17% use of fossil resources. Sobol T indices for the quantity of electricity are the highest for acidification, climate change, fossil resource use, and ionizing radiation. By considering the pathway of China’s electricity mix from 2020 to 2050 under the Paris Agreement’s 2° target, the potential for environmental emission reduction in the system is evaluated. The results show that the greener electricity mix could lead to a 24.59% reduction in acidification impact, a 35.74% reduction in climate change impact, a 33.24% reduction in fossil resource use, and a 44.13% reduction in ionizing radiation impact. This study offers a comprehensive view of the environmental impact reductions associated with the lithium iron phosphate battery and its industry.
- Research Article
20
- 10.1016/j.scitotenv.2015.09.095
- Sep 25, 2015
- Science of The Total Environment
Environmental assessment of different harvesting solutions for Short Rotation Coppice plantations
- Research Article
14
- 10.1016/j.animal.2023.101059
- Dec 20, 2023
- animal
Assessing the environmental impacts of beef production chains integrating grazing and landless systems
- Research Article
- 10.1093/jas/skae102.206
- May 4, 2024
- Journal of Animal Science
Various types of soybean co-products are used in swine diets which have benefits and limitations related to protein quality, environmental impact, and feed safety. To address these concerns for sustainable pork production, methodologies have evolved. Soybean processing and storage methods affecting protein oxidation have been studied less than lipid oxidation. Protein carbonyl concentrations were measured and compared among diverse samples of soybeans and soybean meal from different regions of the US and processed by mechanical or solvent extraction. Mechanically extracted soybean meal had greater concentrations of protein carbonyls than solvent extracted soybean meal which were associated with a greater concentration of residual oil. Soybeans and their co-products also contain antioxidants that may protect against more extensive lipid and protein oxidation. Understanding the interactions between natural antioxidants and oxidation of lipid and proteins in soy co-products is important for optimizing nutritional efficiency and health in sustainable pork production systems. Because soybean meal is a major component of swine diets, its origin and environmental footprint affects the environmental impact of feed, manure, and pork production. Using a spatially explicit lifecycle assessment of feed ingredients and regional manure management programs, we compared the effect of using four feeding programs on greenhouse gas (GHG) emissions, land use, and embedded water consumption in 3 major U.S. pork production regions assuming they would provide equal growth performance and carcass composition. Although environmental impacts varied among regions, the corn-soybean meal feeding program resulted in the greatest land and water use of all grower-finisher feeding programs, and more GHG emissions than feeding low protein amino acid supplemented (LP) diets and diets containing 8% supermarket food waste, but less overall GHG emissions than the distiller’s dried grains with solubles (DDGS) feeding program. Results from a subsequent study showed that feeding corn-soybean meal diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with feeding DDGS and LP diets. Lastly, the extended survival of infectious agents such as African swine fever virus in feed ingredients has important implications for biosecurity and prevention of transboundary transmission of swine diseases. We developed a risk-free in situ surrogate non-animal assay (RISNA) to estimate survival of ASFV in various feed ingredients and conditions, and results indicate greater thermal stability than previously observed, and comparable extended survival among corn- and soybean-based ingredients. These new insights will be useful in revising feed biosecurity protocols to prevent introduction and transmission of ASFV in feed supply chains. In conclusion, holistic assessments of feed ingredients, like our evaluation of soybean co-products, are needed to achieve a more sustainable, One Health approach to pork production.
- Research Article
72
- 10.1016/j.jenvman.2013.10.023
- Nov 27, 2013
- Journal of Environmental Management
Life cycle assessment of pig slurry treatment technologies for nutrient redistribution in Denmark
- Research Article
22
- 10.3390/su11226233
- Nov 7, 2019
- Sustainability
Indian households connected to improved water sources still need to purify their water before drinking. In this study, environmental impacts of three purification options in urban India were compared: (a) boiling water, (b) bottled, purified water, and (c) purifying the water with a domestic reverse-osmosis (RO) device. Primary data for the manufacture, distribution, and the use of the RO device were obtained directly from the manufacturer. Standard, attributional Life Cycle Assessment was performed using a suite of impact assessment methods from ReCiPe v 1.8. In addition, blue and green water consumptions were quantified using the Quantis water database. Bottled water was found to be associated with the highest impacts for all impact categories considered, mainly due to the production and the transportation of bottles. The preference between the other two systems depends on the considered impact category. Water boiled using the liquefied petroleum gas (current practice of urban consumers in India) was found to have higher impacts on climate change and fossil resource use than water from a domestic RO device. The use of the device; however, was found to have higher impacts on water resources than boiling, both in terms of quality (freshwater eutrophication) and availability (water consumption).