Comparative life cycle assessment of first- and second-generation ethanol from sugarcane in Brazil

ABSTRACT: Purpose: The use of bagasse and trash from sugarcane fields in ethanol production is supposed to increase the ethanol yield per hectare, to reduce the energy demand, greenhouse gas emissions, and other environmental impacts. In this article, different technological options of ethanol production are investigated and quantified looking at potential environmental impacts. The first generation ethanol from sugarcane is compared to stand-alone second-generation ethanol as well as an integrated first- and second-generation ethanol production. Methods: The method applied for this life cycle assessment follows the ISO standards 14040/44. The data used in this life cycle assessment is mainly derived from process simulation, literature, and primary data collection. Background data was taken from databases such as GaBi and ecoinvent. The life cycle impact assessment follows the default methods at midpoint level recommended by the International Reference Life Cycle Data System. The calculations were performed using the GaBi 7 life cycle assessment software. It is assumed that 50% of sugarcane trash is recovered and used for second-generation ethanol production, whereas the other 50% remain in the field to maintain soil fertility and to prevent soil erosion. In the case of first-generation ethanol, the same amount of trash is used for energy generation. Results and discussion: The results of the life cycle impact assessment show that, compared to first-generation ethanol, secondgeneration ethanol from sugarcane in Brazil allows significant reductions in all investigated impact categories except resource depletion. Resource depletion, however, is strongly influenced by the demand for ammonium phosphate which is needed for inoculum preparation. Integrated first- and second-generation ethanol production also allows reductions in most of the environmental impacts except for global warming, photochemical ozone depletion, and resource depletion. The yield of ethanol per hectare increases since bagasse and trash are used for the production of second-generation ethanol. Consequently, the results show that agricultural land occupation is reduced for integrated first- and second-generation ethanol by approximately 11%, whereas second-generation ethanol allows reduction of land use by approximately a factor of 30. Conclusions: The use of bagasse and trash for ethanol production allows both the reduction of several environmental impacts and land use, in particular, because impacts caused by sugarcane cultivation are avoided. For the integrated first- and second generation ethanol scenario, it is important to further reduce the total energy demand in order to achieve self-sufficiency for the plant energy and to avoid additional emissions from burning fossil fuels.info:eu-repo/semantics/publishedVersio

Environmental assessment of emerging carbon capture and utilization technologies

Technologien zur Kohlenstoffabscheidung und -verwertung versprechen, die Treibhausgasemissionen und den Abbau abiotischer Ressourcen zu reduzieren und gleichzeitig zu einer Kreislaufwirtschaft beizutragen. Die ökologischen Vorteile von Technologien zur Kohlenstoffabscheidung und -verwertung müssen jedoch nachgewiesen werden. Die am häufigsten angewandte Methode zur Bewertung der Umweltwirkungen ist die Ökobilanzierung. Frühere Ökobilanzen weisen drei wesentliche Forschungslücken auf. Erstens sind frühere Studien zur Bewertung der Umweltwirkungen von Technologien zur Kohlenstoffabscheidung und -verwertung nicht harmonisiert. Zweitens war die bisherige Forschung nicht in der Lage, Entscheidungshilfen für die Einführung von Technologien zur Kohlenstoffabscheidung und -verwertung in der chemischen Industrie zu liefern. Drittens wurden neuartige Technologien zur Kohlenstoffabscheidung und -verwertung nicht prospektiv bewertet. Die vorliegende Dissertation schließt diese Forschungslücken

Comparison of global warming potential between conventionally produced and CO2-based natural gas used in transport versus chemical production

In the future, the capacities of renewable SNG (synthetic natural gas) will expand significantly. Pilot plants are underway to use surplus renewable power, mainly from wind, for electrolysis and the production of hydrogen, which is methanated and fed into the existing gas pipeline grid. Pilot projects aim at the energetic use of SNG for households and transport in particular for gas fueled cars. Another option could be the use of SNG as feedstock in chemical industry. The early stage of development raises the question of whether SNG should be better used for mobility or the production of chemicals. This study compares the global warming potential (GWP) of the production of fossil natural gas (NG) and carbon-dioxide (CO2)-based SNG and its use for car transport versus chemical use in the form of synthesis gas. Since the potential of wind energy for SNG production is mainly located in northern Germany, the consequences by a growing distance between production in the North and transport to the South of Germany are also examined. The results indicate that CO2-based SNG produced with wind power would lead to lower GWP when substituting NG for both uses in either transport or chemical production. Differences of the savings potential occur in short-distance pipeline transport. The critical factor is the energy required for compression along the process chain

Combining Life Cycle Assessment and Circularity Assessment to Analyze Environmental Impacts of the Medical Remanufacturing of Electrophysiology Catheters

Sustaining value after the end-of-life to improve products’ circularity and sustainability has attracted an increasing number of industrial actors, policymakers, and researchers. Medical products are considered to have great remanufacturing potential because they are often designated as single-use products and consist of various complex materials that cannot be reused and are not significant in municipal recycling infrastructure. The remanufacturing of electrophysiology catheters is a well-established process guaranteeing equivalent quality compared to virgin-produced catheters. In order to measure if using a remanufactured product is environmentally beneficial compared to using a virgin product, life cycle assessment (LCA) is often used. However, focusing on one life cycle to inform on the environmental-beneficial use fails to guide policymakers from a system perspective. This study analyzes the environmental consequences of electrophysiology catheters considering two modeling perspectives, the implementation of LCA, including a cut-off approach and combining LCA and a circularity indicator measuring multiple life cycles. Investigating the LCA results of using a remanufactured as an alternative to a newly-manufactured catheter shows that the global warming impact is reduced by 50.4% and the abiotic resource use by 28.8%. The findings from the system perspective suggest that the environmental savings increase with increasing collection rates of catheters

Handling of multi-functionality in life cycle assessments for steel mill gas based chemical production

Life cycle assessment is needed for quantifying potential greenhouse gas savings through material utilization of steel mill gases. However, methodological guidance for this purpose is lacking. Therefore, the article presents different approaches to handle multi-functionality. The investigation of steel mill gas based-methanol shows varying impacts on climate change due to handling multi-functionality differently. System expansion is recommended for assessing cross-sectoral cooperation and substitution as well as economic allocation for product-specific analyses