Identifying energy and carbon footprint optimization potentials of a sludge treatment line with Life Cycle Assessment

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.

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.


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 99 (Supplement_1) ◽  
pp. 24-25
Author(s):  
Agbee L Kpogo ◽  
Jismol Jose ◽  
Josiane Panisson ◽  
Bernardo Predicala ◽  
Alvin Alvarado ◽  
...  

Abstract The impact of feeding growing pigs with high wheat millrun diets on the global warming potential (GWP) of pork production was investigated. In study 1, a 2 × 2 factorial arrangement of wheat millrun (0 or 30%) and multi-carbohydrase enzyme (0 or 1 mg kg-1) as main effects was utilized. For each of 16 reps, 6 pigs (60.2±2.2 kg BW) were housed in environmental chambers for 14d. Air samples were collected and analyzed for carbon dioxide (CO2); nitrous oxide (N2O); and methane (CH4). In study 2, data from study 1 and performance data obtained from a previous feeding trial were utilized in a life cycle assessment (LCA) framework that included feed production. The Holos farm model (Agriculture and Agri-Food Canada, Lethbridge. AB) was used to estimate emissions from feed production. In study 1, total manure output from pigs fed 30% wheat millrun diets was 30% greater than pigs on the 0% wheat millrun diets (P < 0.05), however, Feeding diets with 30% millrun did not affect greenhouse gas (GHG) output (CH4, 4.7, 4.9; N2O, 0.45, 0.42; CO2, 1610, 1711; mg s-1 without or with millrun inclusion, respectively; P > 0.78). Enzyme supplementation had no effect on GHG production (CH4, 4.5, 5.1; N2O, 0.46, 0.42; CO2, 1808, 1513; mg s-1 without or with enzymes, respectively; P > 0.51). In study 2, the LCA indicated that the inclusion of 30% wheat millrun in diets for growing pigs resulted in approximately a 25% reduction in GWP when compared to the no wheat millrun diets. Our results demonstrate that 30% wheat millrun did not increase GHG output from the pigs, and thus the inclusion of wheat millrun in diets of growing pigs can reduce the GWP of pork production.


Author(s):  
Bayu Sukmana ◽  
Isti Surjandari ◽  
Muryanto . ◽  
Arief A. R. Setiawan ◽  
Edi Iswanto Wiloso

Firstly global warming issue caused by greenhouse gas emissions (CO2) which comes from human activities. Along with increasing of daily need, that humans of activities food produce is also increase, include of tofu. Tofu is a traditional Indonesian specialty made from soybeans and used as a side dish. The purpose of this study was to determine the impact of global warming from tofu products on Mampang Prapatan's Small Tofu and Medium Enterprises. The method used in this study is the Life Cycle Assessment (LCA) method with the help of Simapro 8.4 software with a 1 kg tofu functional unit. The data collected in this study is the average data of tofu production for 3 months, namely January - March 2018. The LCA data in this study include the process of soybean cultivation, transportation processes for shipping soybeans, water, fuel wood, and electricity use. The limitations of this study are from cradle (soybean cultivation) to gate (tofu products).The results showed that UKM Mampang Prapatan has the potential impact of global warming with a value of 3.84 kg CO2-eq, while the value of global warming in the production process knows the scenario of wastewater treatment and the use of Liquefied Petroleum Gas (LPG) as fuel for boiling pulp 4.49 kg CO2-eq soybeans. Based on the results of this study, greenhouse gas (CO2) emissions are issued; the intervention that can be done is to optimize the use of raw materials for production to reduce the impact of CO2-eq kg global warming.


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.


2003 ◽  
Vol 47 (12) ◽  
pp. 43-48 ◽  
Author(s):  
J. Keller ◽  
K. Hartley

Many practical design and operating decisions on wastewater treatment plants can have significant impacts on the overall environmental performance, in particular the greenhouse gas (GHG) emissions. The main factor in this regard is the use of aerobic or anaerobic treatment technology. This paper compares the GHG production of a number of case studies with aerobic or anaerobic main and sludge treatment of domestic wastewater and also looks at the energy balances and economics. This comparison demonstrates that major advantages can be gained by using primarily anaerobic processes as it is possible to largely eliminate any net energy input to the process, and therefore the production of GHG from fossil fuels. This is achieved by converting the energy of the incoming wastewater pollutants to methane which is then used to generate electricity. This is sufficient to power the aerobic processes as well as the mixing etc. of the anaerobic stages. In terms of GHG production, the total output (in CO2 equivalents) can be reduced from 2.4 kg CO2/kg CODremoved for fully aerobic treatment to 1.0 kg CO2/kg CODremoved for primarily anaerobic processes. All of the CO2 produced in the anaerobic processes comes from the wastewater pollutants and is therefore greenhouse gas neutral, whereas up to 1.4 kg CO2/kg CODremoved originates from power generation for the fully aerobic process. This means that considerably more CO2 is produced in power generation than in the actual treatment process, and all of this is typically from fossil fuels, whereas the energy from the wastewater pollutants comes primarily from renewable energy sources, namely agricultural products. Even a change from anaerobic to aerobic sludge treatment processes (for the same aerobic main process) has a massive impact on the CO2 production from fossil fuels. An additional 0.8 kg CO2/kg CODremoved is produced by changing to aerobic sludge digestion, which equates for a typical 100,000 EP plant to an additional production of over 10 t CO2 per day. Preliminary cost estimates confirm that the largely anaerobic process option is a fully competitive alternative to the mainly aerobic processes used, while achieving the same effluent quality.


Author(s):  
N. Lourenço ◽  
L. M. Nunes

Abstract This study benchmarks vermifiltration (VF) as secondary wastewater treatment in three nature-based decentralized treatment plants using life-cycle assessment. The comparison is justified by the comparatively easier and cheaper operation of VF when compared to more traditional technologies, including small rate infiltration (SRI), constructed wetlands (CW), and activated sludge (AS). Standard life cycle assessment was used and applied to three case studies located in southern Europe. Material intensity during construction was highest for VF, but impacts during operation were lower, compensating those of the other phases. Impacts during the construction phase far outweigh those of operation and dismantling for facilities using constructed wetlands and activated sludge, when the number of served inhabitants is small, and due to lack of economies of scale. VF used as secondary treatment was shown to contribute to reducing the environmental impacts, mainly in constructed wetlands and activated sludge. The replacement of CW by VF seems to bring important environmental benefits in most impact categories, in particular in the construction phase. The replacement by VF in facilities with SRI seems to result in the improvement of some of the impact categories, in particular in the operation phase. As for dismantling, no conclusive results were obtained.


HortScience ◽  
2016 ◽  
Vol 51 (8) ◽  
pp. 989-994 ◽  
Author(s):  
Dewayne L. Ingram ◽  
Charles R. Hall ◽  
Joshua Knight

The production components of an evergreen shrub (Ilex crenata ‘Bennett’s Compacta’) grown in a no. 3 container in an east coast U.S. nursery were analyzed for their costs and contributions to carbon footprint, as well as the product impact in the landscape throughout its life cycle. A life cycle inventory was conducted of input materials, equipment use, and all cultural practices and other processes used in a model production system for this evergreen shrub. A life cycle assessment (LCA) of the model numerated the associated greenhouse gas emissions (GHG), carbon footprint, and variable cost of each component. The LCA also included the transportation and transplanting of the final product in the landscape as well as its removal after a 40-year useful life. GHG from input products and processes during the production (cutting-to-gate) of the evergreen shrub were estimated to be 2.918 kg CO2e. When considering carbon sequestration during production weighted over a 100-year assessment period, the carbon footprint for this model system at the nursery gate was 2.144 kg CO2e. Operations, combining the impact of material and equipment use, that contributed most of GHG during production included fertilization (0.707 kg CO2e), the liner and transplanting (0.461 kg CO2e), the container (0.468 kg CO2e), gravel and ground cloth installation (0.222 kg CO2e), substrate materials and preparation (0.227 kg CO2e), and weed control (0.122 kg CO2e). The major contributors to global warming potential (GWP) were also major contributors to the cutting-to-gate variable costs ($3.224) except for processes that required significant labor investments. Transporting the shrub to the landscaper, transporting it to the landscape site, and transplanting it would result in GHG of 0.376, 0.458, and 0 kg CO2e, respectively. Variable costs for postharvest activities were $6.409 and were dominated by labor costs (90%).


1993 ◽  
Vol 28 (1) ◽  
pp. 273-281 ◽  
Author(s):  
P. Grulois ◽  
A. Bousseau ◽  
E. Blin ◽  
C. Fayoux

A systemic analysis of a wastewater treatment plant quickly reveals that return flows from the sludge treatment line affect the water treatment process. These return flows have a maximum value that is characteristic of a steady state of plant operation and the effects are detectable at several levels. It can, for example, influence the operation of the clarifier indicated by changes in the Sludge Volume Index, induce anaerobiosis in the separation works that stems from excess sludge production or decrease the dewatering of sludges. All these observations lead to the conclusion that the sludge treatment line should be designed that it could take up production overloads. It was also found that it is indispensible to monitor the water treatment line operation step by step in order to detect rapidly any drift of the operating parameters from their normal values.


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