scholarly journals Conversion of biomass to biofuels and life cycle assessment: a review

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.

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2916
Author(s):  
Jérôme Payet ◽  
Titouan Greffe

Worldwide electricity consumption increases by 2.6% each year. Greenhouse gas emissions due to electricity production raise by 2.1% per year on average. The development of efficient low-carbon-footprint renewable energy systems is urgently needed. CPVMatch investigates the feasibility of mirror or lens-based High Concentration Photovoltaic (HCPV) systems. Thanks to innovative four junction solar cells, new glass coatings, Position Sensitive Detectors (PSD), and DC/DC converters, it is possible to reach concentration levels higher than 800× and a module efficiency between 36.7% and 41.6%. From a circular economy’s standpoint, the use of concentration technologies lowers the need in active material, increases recyclability, and reduces the risk of material contamination. By using the Life Cycle Assessment method, it is demonstrated that HCPV presents a carbon footprint ranking between 16.4 and 18.4 g CO2-eq/kWh. A comparison with other energy means for 16 impact categories including primary energy demand and particle emissions points out that the environmental footprint of HCPV is typically 50 to 100 times lower than fossil fuels footprint. HCPV’s footprint is also three times lower than that of crystalline photovoltaic solutions and is close to the environmental performance of wind power and hydropower.


2013 ◽  
Vol 67 (1) ◽  
pp. 63-73 ◽  
Author(s):  
C. Remy ◽  
B. Lesjean ◽  
J. Waschnewski

This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO2, CH4, N2O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (–162 MJ/PECOD * a) and carbon footprint (–11.6 kg CO2-eq/PECOD * a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general.


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.


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):  
Soumith Kumar Oduru ◽  
Pasi Lautala

Transportation industry at large is a major consumer of fossil fuels and contributes heavily to the global greenhouse gas emissions. A significant portion of these emissions come from freight transportation and decisions on mode/route may affect the overall scale of emissions from a specific movement. It is common to consider several alternatives for a new freight activity and compare the alternatives from economic perspective. However, there is a growing emphasis for adding emissions to this evaluation process. One of the approaches to do this is through Life Cycle Assessment (LCA); a method for estimating the emissions, energy consumption and environmental impacts of the project throughout its life cycle. Since modal/route selections are often investigated early in the planning stage of the project, availability of data and resources for analysis may become a challenge for completing a detailed LCA on alternatives. This research builds on such detailed LCA comparison performed on a previous case study by Kalluri et al. (2016), but it also investigates whether a simplified LCA process that only includes emissions from operations phase could be used as a less resource intensive option for the analysis while still providing relevant outcomes. The detailed LCA is performed using SimaPro software and simplified LCA is performed using GREET 2016 model. The results are obtained in terms of Kg CO2 equivalents of GHG emissions. This paper introduces both detailed and simplified methodologies and applies them to a case study of a nickel and copper mine in the Upper Peninsula of Michigan. The analysis’ are done for three modal alternatives (two truck routes and one rail route) and for multiple mine lives.


2013 ◽  
Vol 04 (09) ◽  
pp. 1018-1033 ◽  
Author(s):  
Monica C. Rothermel ◽  
Amy E. Landis ◽  
William J. Barr ◽  
Kullapa Soratana ◽  
Kayla M. Reddington ◽  
...  

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.


Author(s):  
Amit Kumar Chaurasia ◽  
Prasenjit Mondal

Increasing population and rapid urbanization lead to degradation of the natural environment while waste generation and energy crisis are major challenges in the most developing country. Hydrogen is considered one of the most promising energy carriers and capable to replace fossil fuels and meet the world's energy demand and concomitantly reduce toxic emissions. Currently, the world produces around 50 million tonnes/year from the process (i.e., electrolysis of water, steam reforming of hydrocarbons, and auto-thermal processes), but these processes are not sustainable and economical due to energy requirements and waste/pollutants generation. These challenges required growing interest in renewable energy resources such as hydrogen as an energy carrier. Hydrogen production from renewable sources attracted recent research attention because of its potential for sustainability and diversity. Hydrogen can be produced by various thermal, chemical, and biological technologies that include steam reforming, electrolysis, biomass conversion, solar conversion, and biological conversion.


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.


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