scholarly journals Energy and Resource Efficient Production of Fluoroalkenes in High Temperature Microreactors

2019 ◽  
Vol 3 (4) ◽  
pp. 77
Author(s):  
Konstantin Mierdel ◽  
Andreas Jess ◽  
Thorsten Gerdes ◽  
Achim Schmidt ◽  
Klaus Hintzer

Tetrafluoroethylene (TFE) and hexafluoropropylene (HFP) are the most common monomers for the synthesis of fluoropolymers at industrial scale. Currently, TFE is produced via multistep pyrolysis of chlorodifluoromethane (R22), resulting in a high energy demand and high amounts of waste acids, mainly HCl and HF. In this study, a new chlorine-free process for producing TFE and HFP in a microreactor is presented, starting from partially fluorinated alkanes obtained from electrochemical fluorination (ECF). In the microreactor, high conversion rates of CHF3, which is used as a surrogate of partly fluorinated ECF streams, and high yields of fluoromonomers could be achieved. The energy saving and the environmental impact are shown by a life cycle assessment (LCA). The LCA confirms that the developed process has economical as well as ecological benefits, and is thus an interesting option for future industrial production of fluoroalkenes.

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 356
Author(s):  
Paulina Szulc ◽  
Jędrzej Kasprzak ◽  
Zbysław Dymaczewski ◽  
Przemysław Kurczewski

The efficient and timely removal of organic matter and nutrients from water used in normal municipal functions is considered to be the main task of wastewater treatment plants (WWTPs). Therefore, these facilities are considered to be essential units that are required to avoid pollution of the water environment and decrease the possibility of triggering eutrophication. Even though these benefits are undeniable, they remain at odds with the high energy demand of wastewater treatment and sludge processes. As a consequence, WWTPs have various environmental impacts, which can be estimated and categorized using Life Cycle Assessment (LCA) analysis. In this study, a municipal WWTP based in Poznań, Poland, was examined using the method defined in ISO 14040. ReCiPe Endpoint and Midpoint (v1.11), in a hierarchical approach, were used to evaluate the environmental impacts regarding 18 different categories. All calculations were conducted using a detailed database from 2019, which describes each chosen facility. It was found that the energy component, related to the wastewater treatment process demand and electricity production, is the main determinant of the sum of the environmental impact indicators in light of the modelled energy mix. Therefore, it determines the entire process as an environmentally friendly activity.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3045 ◽  
Author(s):  
Roberta Di Bari ◽  
Rafael Horn ◽  
Björn Nienborg ◽  
Felix Klinker ◽  
Esther Kieseritzky ◽  
...  

New materials and technologies have become the main drivers for reducing energy demand in the building sector in recent years. Energy efficiency can be reached by utilization of materials with thermal storage potential; among them, phase change materials (PCMs) seem to be promising. If they are used in combination with solar collectors in heating applications or with water chillers or in chilled ceilings in cooling applications, PCMs can provide ecological benefits through energy savings during the building’s operational phase. However, their environmental value should be analyzed by taking into account their whole lifecycle. The purpose of this paper is the assessment of PCMs at the material level as well as at higher levels, namely the component and building levels. Life cycle assessment analyses are based on information from PCM manufacturers and building energy simulations. With the newly developed software “Storage LCA Tool” (Version 1.0, University of Stuttgart, IABP, Stuttgart, Germany), PCM storage systems can be compared with traditional systems that do not entail energy storage. Their benefits can be evaluated in order to support decision-making on energy concepts for buildings. The collection of several case studies shows that PCM energy concepts are not always advantageous. However, with conclusive concepts, suitable storage dimensioning and ecologically favorable PCMs, systems can be realized that have a lower environmental impact over the entire life cycle compared to traditional systems.


Author(s):  
M. von der Thannen ◽  
S. Hoerbinger ◽  
C. Muellebner ◽  
H. Biber ◽  
H. P. Rauch

AbstractRecently, applications of soil and water bioengineering constructions using living plants and supplementary materials have become increasingly popular. Besides technical effects, soil and water bioengineering has the advantage of additionally taking into consideration ecological values and the values of landscape aesthetics. When implementing soil and water bioengineering structures, suitable plants must be selected, and the structures must be given a dimension taking into account potential impact loads. A consideration of energy flows and the potential negative impact of construction in terms of energy and greenhouse gas balance has been neglected until now. The current study closes this gap of knowledge by introducing a method for detecting the possible negative effects of installing soil and water bioengineering measures. For this purpose, an environmental life cycle assessment model has been applied. The impact categories global warming potential and cumulative energy demand are used in this paper to describe the type of impacts which a bioengineering construction site causes. Additionally, the water bioengineering measure is contrasted with a conventional civil engineering structure. The results determine that the bioengineering alternative performs slightly better, in terms of energy demand and global warming potential, than the conventional measure. The most relevant factor is shown to be the impact of the running machines at the water bioengineering construction site. Finally, an integral ecological assessment model for applications of soil and water bioengineering structures should point out the potential negative effects caused during installation and, furthermore, integrate the assessment of potential positive effects due to the development of living plants in the use stage of the structures.


Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.


2021 ◽  
Vol 13 (12) ◽  
pp. 6894
Author(s):  
Shakira R. Hobbs ◽  
Tyler M. Harris ◽  
William J. Barr ◽  
Amy E. Landis

The environmental impacts of five waste management scenarios for polylactic acid (PLA)-based bioplastics and food waste were quantified using life cycle assessment. Laboratory experiments have demonstrated the potential for a pretreatment process to accelerate the degradation of bioplastics and were modeled in two of the five scenarios assessed. The five scenarios analyzed in this study were: (1a) Anaerobic digestion (1b) Anaerobic digestion with pretreatment; (2a) Compost; (2a) Compost with pretreatment; (3) Landfill. Results suggested that food waste and pretreated bioplastics disposed of with an anaerobic digester offers life cycle and environmental net total benefits (environmental advantages/offsets) in several areas: ecotoxicity (−81.38 CTUe), eutrophication (0 kg N eq), cumulative energy demand (−1.79 MJ), global warming potential (0.19 kg CO2), and human health non-carcinogenic (−2.52 CTuh). Normalized results across all impact categories show that anaerobically digesting food waste and bioplastics offer the most offsets for ecotoxicity, eutrophication, cumulative energy demand and non-carcinogenic. Implications from this study can lead to nutrient and energy recovery from an anaerobic digester that can diversify the types of fertilizers and decrease landfill waste while decreasing dependency on non-renewable technologies. Thus, using anaerobic digestion to manage bioplastics and food waste should be further explored as a viable and sustainable solution for waste management.


Author(s):  
Morten Gulbrant Sørensen ◽  
Stig Irving Olsen ◽  
Tracey Colley

Main purposes and research question: Wheat is the second largest grain crop by tonnage in the world and the largest in Denmark. Given the observed, adverse impacts on wheat yields of climate change and the importance of wheat in the human diet, the purpose of this study was to use life cycle assessment to compare conventional wheat farming with indoor vertical farming using hydroponics. Methods: Life Cycle Assessment was used to assess the base case systems up to the “farm gate” for 1 tonne of wheat grain. The processes contributing most of the impacts were identified, and scenarios were assessed to determine how much the impacts could be reduced. Results: The conventional system outperformed the base case vertical system in every impact category, due to the electricity consumption in the lighting system. The scenarios included increasing the efficiency of the LED lighting and using 100% wind energy, but the conventional system still outperformed the vertical system by significant margins in all impact categories. This was due to the low photosynthetic conversion efficiency and the high energy density of wheat. Conclusions: Until significant improvements are made to lighting efficiency, the photosynthesis conversion efficiency of wheat, new wheat variants designed for vertical gardens and the sustainability of electricity supply, conventional wheat production will be environmentally preferable and vertical gardens would be advised to focus on food products with low energy densities.


Author(s):  
H. Harter ◽  
B. Willenborg ◽  
W. Lang ◽  
T. H. Kolbe

Abstract. Reducing the demand for non-renewable resources and the resulting environmental impact is an objective of sustainable development, to which buildings contribute significantly. In order to realize the goal of reaching a climate-neutral building stock, it must first be analyzed and evaluated in order to develop optimization strategies. The life cycle based consideration and assessment of buildings plays a key role in this process. Approaches and tools already exist for this purpose, but they mainly take the operational energy demand of buildings and not a life cycle based approach into account, especially when assessing technical building services (TBS). Therefore, this paper presents and applies a methodical approach for the life cycle based assessment of the TBS of large residential building stocks, based on semantic 3D city models (CityGML). The methodical approach developed for this purpose describes the procedure for calculating the operational energy demand (already validated) and the heating load of the building, the dimensioning of the TBS components and the calculation of the life cycle assessment. The application of the methodology is illustrated in a case study with over 115,000 residential buildings from Munich, Germany. The study shows that the methodology calculates reliable results and that a significant reduction of the life cycle based energy demand can be achieved by refurbishment measures/scenarios. Nevertheless, the goal of achieving a climate-neutral building stock is a challenge from a life cycle perspective.


Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 60 ◽  
Author(s):  
Mattias Gaglio ◽  
Elena Tamburini ◽  
Francesco Lucchesi ◽  
Vassilis Aschonitis ◽  
Anna Atti ◽  
...  

The need to reduce the environmental impacts of the food industry is increasing together with the dramatic increment of global food demand. Circulation strategies such as the exploitation of self-produced renewable energy sources can improve ecological performances of industrial processes. However, evidence is needed to demonstrate and characterize such environmental benefits. This study assessed the environmental performances of industrial processing of maize edible oil, whose energy provision is guaranteed by residues biomasses. A gate-to-gate Life Cycle Assessment (LCA) approach was applied for a large-size factory of Northern Italy to describe: (i) the environmental impacts related to industrial processing and (ii) the contribution of residue-based bioenergy to their mitigation, through the comparison with a reference system based on conventional energy. The results showed that oil refinement is the most impacting phase for almost all the considered impact categories. The use of residue-based bioenergy was found to drastically reduce the emissions for all the impact categories. Moreover, Cumulative Energy Demand analysis revealed that the use of biomass residues increased energy efficiency through a reduction of the total energy demand of the industrial process. The study demonstrates that the exploitation of residue-based bioenergy can be a sustainable solution to improve environmental performances of the food industry, while supporting circular economy.


Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 252 ◽  
Author(s):  
Vincenzo Muteri ◽  
Maurizio Cellura ◽  
Domenico Curto ◽  
Vincenzo Franzitta ◽  
Sonia Longo ◽  
...  

The photovoltaic (PV) sector has undergone both major expansion and evolution over the last decades, and currently, the technologies already marketed or still in the laboratory/research phase are numerous and very different. Likewise, in order to assess the energy and environmental impacts of these devices, life cycle assessment (LCA) studies related to these systems are always increasing. The objective of this paper is to summarize and update the current literature of LCA applied to different types of grid-connected PV, as well as to critically analyze the results related to energy and environmental impacts generated during the life cycle of PV technologies, from 1st generation (traditional silicon based) up to the third generation (innovative non-silicon based). Most of the results regarded energy indices like energy payback time, cumulative energy demand, and primary energy demand, while environmental indices were variable based on different scopes and impact assessment methods. Moreover, the review work allowed to highlight and compare key parameters (PV type and system, geographical location, efficiency), methodological insights (functional unit, system boundaries, etc.), and energy/environmental hotspots of 39 LCA studies relating to different PV systems, in order to underline the importance of these aspects, and to provide information and a basis of comparison for future analyses.


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