Search results for: methane mitigation

Authors: K. M. Kim, S. J. Lee, D. S. Oh, Sadohara Satoru

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The climate change poses a serious challenge to urban sustainability. To alleviate the environmental risk, urban planning has been concentrated on climate adaptation and mitigation, and the sustainable urban model, smart city, has been suggested. However, with regard to sustainable smart city development, a majority of researchers have focused mainly on the aspect of adaptation, which causes the lack of the approaches for mitigation. Therefore, the objective was to identify the planning elements of smart city with integrative reviews about mitigation and adaptation. Moreover, the concepts of smart cities in Sweden, Japan, and Korea were analyzed to find out the country-specific characteristics and strategies for achieving smart city.

Keywords: sustainable urban planning, climate change, mitigating and adaptation, smart city

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Authors: Amriana Hifizah, Philip Edward Vercoe, Graeme Bruce Martin, Teuku Reza Ferasy, Muhammad Hambal

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Many native forage plant species have been used in Indonesia as feed for ruminants. However, less information is available about how these plants affect productivity, let alone methane emissions. In the province of Aceh, where the traditional practice is to feed local forages to small ruminants, the farmers are not satisfied with the productivity of their livestock, and they attribute this problem to poor availability and too few options for good quality forages. Forage quality is reduced by high environmental temperatures which increase the amount of lignification. In addition to reducing productivity, these factors also increase enteric methane production. A preliminary survey about potential forage species was completed in three different districts, two of low elevation and one of high elevation: Syiah Kuala (05°30’5.08” N to 095°24’7.35” E), elevation 29 m MSL; Kajhu (05°32’34.6” N to 095°21’17.7” E), elevation 30 m MSL; Lembah Seulawah (05°28'06.4" N to 095°43' 14.2" E), elevation 254 m MSL. Information about local plants was collected in a semi-structured interview with scientists, government field officers and local farmers, in the city of Banda Aceh and in those three districts. The outcome was a list 40 species that could be useful, of which 21 were selected for further study. The selection process was based on several criteria: high availability, high protein content, low toxicity, and evidence of secondary metabolites (eg, history of medicinal plants for both human and animals). For some of the selected medicinal plants, there is experimental evidence of effects on methane production during rumen fermentation. Subsequently, the selected forages were tested for their effects on rumen fermentation in vitro, using batch culture. The data produced will be used to identify forages with the potential to reduce CH4 emissions. These candidates will then be assessed for their benefits (fermentability and productivity) and potential deleterious side-effects.

Keywords: batch culture, forage, methane, rumen

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Authors: Hassan Gana Abdullahi, Michael A. Fullen, David Oloke

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Drought poses an enormous global threat to sustainable development and is expected to increase with global climate change. Drought and desertification are major problems in Yobe State (north-east Nigeria). This investigation aims to develop a workable framework and management tool for drought mitigation in Yobe State. Mixed methods were employed during the study and additional qualitative information was gathered through Focus Group Discussions (FGD). Data on socio-economic impacts of drought were thus collected via both questionnaire surveys and FGD. In all, 1,040 questionnaires were distributed to farmers in the State and 721 were completed, representing a return rate of 69.3%. Data analysis showed that 97.9% of respondents considered themselves to be drought victims, whilst 69.3% of the respondents were unemployed and had no other means of income, except through rain-fed farming. Developing a viable and holistic approach to drought mitigation is crucial, to arrest and hopefully reverse environment degradation. Analysed data will be used to develop an integrated framework for drought mitigation and management in Yobe State. This paper introduces the socio-economic and environmental effects of drought in Yobe State.

Keywords: drought, climate change, mitigation, management, Yobe State

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Authors: Mahmoud Hassan Onsa, Saadelnour Abdueljabbar Adam

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Wastes from slaughterhouses in most towns in Sudan are often poorly managed and sometimes discharged into adjoining streams due to poor implementation of standards, thus causing environmental and public health hazards and also there is a large amount of manure from dairy farms. This paper presents solution of organic waste from cow dairy farms and slaughterhouse the anaerobic digestion and biogas production. The paper presents the findings of experimental investigation of biogas production with and without pasteurization using cow manure, blood and rumen content were mixed at two proportions, 72.3% manure, 21.7%, rumen content and 6% blood for bio digester1with 62% dry matter at the beginning and without pasteurization and 72.3% manure, 21.7%, rumen content and 6% blood for bio-digester2 with 10% dry matter and pasteurization. The paper analyses the quantitative and qualitative composition of biogas: gas content, the concentration of methane. The highest biogas output 2.9 mL/g dry matter/day (from bio-digester2) together with a high quality biogas of 87.4% methane content which is useful for combustion and energy production and healthy bio-fertilizer but biodigester1 gave 1.68 mL/g dry matter/day with methane content 85% which is useful for combustion, energy production and can be considered as new technology of dryer bio-digesters.

Keywords: anaerobic digestion, bio-digester, blood, cow manure, rumen content

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Authors: Piyaphan Changwatchai

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Global value chain is important for current world economy through foreign direct investment. Multinational enterprises' efficient location seeking for each stage of production lead to global production network and more global value chain participation of several countries. Global value chain participation has several effects on participating countries in several aspects including the environment. The effect of global value chain participation on the environment is ambiguous. As a result, this research aims to study the effect of global value chain participation on countries' CO₂ emission and methane emission by using quantitative analysis with secondary panel data of sixty countries. The analysis is divided into two types of global value chain participation, which are forward global value chain participation and backward global value chain participation. The results show that, for forward global value chain participation, GDP per capita affects two types of pollutants in downward bell curve shape. Forward global value chain participation negatively affects CO₂ emission and methane emission. As for backward global value chain participation, GDP per capita affects two types of pollutants in downward bell curve shape. Backward global value chain participation negatively affects methane emission only. However, when considering Asian countries, forward global value chain participation positively affects CO₂ emission. The recommendations of this research are that countries participating in global value chain should promote production with effective environmental management in each stage of value chain. The examples of policies are providing incentives to private sectors, including domestic producers and MNEs, for green production technology and efficient environment management and engaging in international agreements in terms of green production. Furthermore, government should regulate each stage of production in value chain toward green production, especially for Asia countries.

Keywords: CO₂ emission, environment, global value chain participation, methane emission

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Authors: Cynthia E. Nwobodo, A. E. Agwu

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The study was carried out in Benue State, Nigeria. Multi-stage sampling technique was used to select 120 respondents from two agricultural zones in the State. Data was collected using interview schedule. Descriptive statistics was used in data analysis. Findings showed that youth farmers in the area had positive attitude to climate change adaptation and mitigation as shown by their response to a set of positive and negative statement including: the youth are very important stakeholders in climate change issues (M= 2.91), youths should be encouraged to be climate change conscious (2.90), everybody should be involved in planting trees not just the government (M= 2.89), I will be glad to participate in climate change seminars (M= 2.89) among others. Findings on information seeking behavior indicate that majority (80.8 %) of the respondents sought climate change information from radio at an average of 19.78 times per month, 53.3 % sought from friends and neighbours at an average of 12.55 times per month and 42.5 % sought from family members at an average of 12.55 times per month among others. It was recommended that Youth farmers should be made important stakeholders in climate change policies and programmes since they have a very positive attitude to climate change adaptation and mitigation.

Keywords: adaptation, mitigation, attitude, climate change, youth farmers

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Authors: Sushil Kumar Saraswat, K. K. Pant

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Co metal supported on SiO2 and Al2O3 catalysts with a metal loading varied from 30 of 70 wt.% were evaluated for decomposition of methane to CO/CO2 free hydrogen and carbon nano materials. The catalytic runs were carried out from 550-800 oC under atmospheric pressure using fixed bed vertical flow reactor. The fresh and spent catalysts were characterized by BET surface area analyzer, TPR, XRD, SEM, TEM, and TG analysis. The data showed that 50% Co/Al2O3 catalyst exhibited remarkable higher activity and stability up to 10 h time-on-stream at 750 oC with respect to H2 production compared to rest of the catalysts. However, the catalytic activity and durability was greatly declined at a higher temperature. The main reason for the catalytic inhibition of Co containing SiO2 catalysts is the higher reduction temperature of Co2SiO4. TEM images illustrate that the carbon materials with various morphologies, carbon nanofibers (CNFs), helical-shaped CNFs, and branched CNFs depending on the catalyst composition and reaction temperature, were obtained. The TG data showed that a higher yield of MWCNTs was achieved over 50% Co/Al2O3 catalyst compared to other catalysts.

Keywords: carbon nanotubes, cobalt, hydrogen production, methane decomposition

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Authors: Isaac Samuel

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A study was conducted to determine the in-vitro degradation of selected Nigerian browse plants consumed by small ruminants on free range in northern guinea savannah region of Nigeria using in vitro gas production, proximate composition, fibre components, methane gas production and dry matter degradation as tools. The leaves samples of the selected browse plants were collected, processed and incubated using in vitro gas dry matter degradation techniques. Results obtained showed variation in the rate of degradation. The result obtained from chemical analysis showed that the CP content of A. occidentale (26.49%) was higher than F. thonningi (23.58%), M. indica (20.58%) and T. catappa (18.61%). Both ADF and NDF of A. occidentale (40.00 and 50.00) were as well higher than F. thonningi (20.00 and 40.00), M. indica (20.00 and 40.00) and T.catappa (20.00 and 42.00). Results from in vitro gas production however showed that T. catappa (23.67ml/DM) has a significantly higher (p<0.05) value than F.thonningi (20.67ml/DM), A. occidentale (16.67ml/DM), and M. indica(14.00ml/DM) at 72 hours of incubation. Methane gas production and in vitro gas production can be used to predict dry matter degradation and nutritive value of feedstuff for small ruminants. A. occidentale with the least methane gas production and highest crude protein (CP) content might have the most nutritive value among the browse plants investigated.

Keywords: in vitro, degradation, browse, gas production

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Authors: Maria Altamirano, Alfonso Duran

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Biostimulation has recently become important in order to improve the stability and performance of the anaerobic digestion (AD) process. This strategy involves the addition of nutrients or supplements to improve the rate of degradation of a native microbial consortium. With the aim of biostimulate sytrophism between secondary fermenting bacteria and methanogenic archaea, improving metabolite degradation and efficient conversion to methane, the addition of conductive materials, mainly carbon based have been studied. This research seeks to highlight the effect that coconut biochar (CBC) has on the metanogenic conversion of the organic fraction of municipal solid waste (OFMSW), analyzing the surface chemistry properties that give biochar its capacity to serve as a redox mediator in the anaerobic digestion process. The biochar characterization techniques were electrical conductivity (EC) scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier Transform Infrared Transmission Spectroscopy (FTIR) and Cyclic Voltammetry (CV). Effect of coconut biochar addition was studied using Authomatic Methane Potential Test System (AMPTS II) applying a one-way variance analysis to determine the dose that leads to higher methane performance. The surface chemistry of the CBC could confer properties that enhance the AD process, such as the presence of alkaline and alkaline earth metals and their hydrophobicity that may be related to their buffering capacity and the adsorption of polar and non-polar compounds, such as NH4+ and CO2. It also has aromatic functional groups, just as quinones, whose potential as a redox mediator has been demonstrated and its morphology allows it to form an immobilizing matrix that favors a closer activity among the syntrophic microorganisms, which directly contributed in the oxidation of secondary metabolites and the final reduction to methane, whose yield is increased by 39% compared to controls, with a CBC dose of 1 g/L.

Keywords: anaerobic digestion, biochar, biostimulation, syntrophic metabolism

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Authors: Robin Anderson, David Nisbet

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Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) are biologically active chemicals that can accumulate naturally in rangeland grasses forages consumed by grazing cattle, sheep and goats. While toxic to livestock if accumulations and amounts consumed are high enough, particularly in animals having no recent exposure to the forages, these chemicals are known to be potent inhibitors of methane-producing bacteria inhabiting the rumen. Consequently, there is interest in examining their potential use as anti-methanogenic compounds to decrease methane emissions by grazing ruminants. Presently, rumen microbes, collected freshly from a cannulated Holstein cow maintained on 50:50 corn based concentrate:alfalfa diet were mixed (10 mL fluid) in 18 x 150 mm crimp top tubes with 0.5 of high nitrate-containing barley (Hordeum vulgare; containing 272 µmol nitrate per g forage dry matter), and NPA- or NPOH- containing milkvetch forages (Astragalus canadensis and Astragalus miser containing 80 and 174 soluble µmol NPA or NPOH/g forage dry matter respectively). Incubations containing 0.5 g alfalfa (Medicago sativa) were used as controls. Tubes (3 per each respective forage) were capped and incubated anaerobically (using oxygen free carbon dioxide) for 24 h at 39oC after which time amounts of total gas produced were measured via volume displacement and headspace samples were analyzed by gas chromatography to determine concentrations of hydrogen and methane. Fluid samples were analyzed by gas chromatography to measure accumulations of fermentation acids. A completely randomized analysis of variance revealed that the nitrate-containing barley and both the NPA- and the NPOH-containing milkvetches significantly decreased methane production, by > 50%, when compared to methane produced by populations incubated similarly with alfalfa (70.4 ± 3.6 µmol/ml incubation fluid). Accumulations of hydrogen, which are typically increased when methane production is inhibited, by incubations with the nitrate-containing barley and the NPA- and NPOH-containing milkvetches did not differ from accumulations observed in the alfalfa controls (0.09 ± 0.04 µmol/mL incubation fluid). Accumulations of fermentation acids produced in the incubations containing the high-nitrate barley and the NPA- and NPOH-containing milkvetches likewise did not differ from accumulations observed in incubations containing alfalfa (123.5 ± 10.8, 36.0 ± 3.0, 17.1 ± 1.5, 3.5 ± 0.3, 2.3 ± 0.2, 2.2 ± 0.2 µmol/mL incubation fluid for acetate, propionate, butyrate, valerate, isobutyrate, and isovalerate, respectively). This finding indicates the microbial populations did not compensate for the decreased methane production via compensatory changes in production of fermentative acids. Stoichiometric estimation of fermentation balance revealed that > 77% of reducing equivalents generated during fermentation of the forages were recovered in fermentation products and the recoveries did not differ between the alfalfa incubations and those with the high-nitrate barley or the NPA- or NPOH-containing milkvetches. Stoichiometric estimates of amounts of hexose fermented similarly did not differ between the nitrate-, NPA and NPOH-containing incubations and those with the alfalfa, averaging 99.6 ± 37.2 µmol hexose consumed/mL of incubation fluid. These results suggest that forages containing nitrate, NPA or NPOH may be useful to reduce methane emissions of grazing ruminants provided risks of toxicity can be effectively managed.

Keywords: nitrate, nitropropanol, nitropropionic acid, rumen methane emissions

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Authors: D. De-León-Escobedo, D. J. Delgado-Hernández, S. Pérez

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A probabilistic formulation to assess the slopes safety under the hazard of strong storms is presented and illustrated through a slope in Mexico. The formulation is based on the classical safety factor (SF) used in practice to appraise the slope stability, but it is introduced the treatment of uncertainties, and the slope failure probability is calculated as the probability that SF<1. As the main hazard is the rainfall on the area, statistics of rainfall intensity and duration are considered and modeled with an exponential distribution. The expected life-cycle cost is assessed by considering a monetary value on the slope failure consequences. Alternative mitigation measures are simulated, and the formulation is used to get the measures driving to the optimal one (minimum life-cycle costs). For the example, the optimal mitigation measure is the reduction on the slope inclination angle.

Keywords: expected life-cycle cost, failure probability, slopes failure, storms

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Authors: D. Lepe-Cervantes, E. Leon-Becerril, J. Gomez-Romero, O. Garcia-Depraect, A. Lopez-Lopez

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In this study, raw coffee wastewater (CWW) was used as a complex substrate for anaerobic digestion. The inoculum adaptation stage, microbial diversity analysis and biomethane potential (BMP) tests were performed. A fast inoculum adaptation stage was used by the replacement of vinasse to CWW in an anaerobic sequential batch reactor (AnSBR) operated at mesophilic conditions. Illumina MiSeq sequencing was used to analyze the microbial diversity. While, BMP tests using inoculum adapted to CWW were carried out at different inoculum to substrate (I/S) ratios (2:1, 3:1 and 4:1, on a VS basis). Results show that the adaptability percentage was increased gradually until it reaches the highest theoretical value in a short time of 10 d; with a methane yield of 359.10 NmL CH₄/g COD-removed; Methanobacterium beijingense was the most abundant microbial (75%) and the greatest specific methane production was achieved at I/S ratio 4:1, whereas the lowest was obtained at 2:1, with BMP values of 320 NmL CH₄/g VS and 151 NmL CH₄/g VS, respectively. In conclusion, gradual replacement of substrate was a feasible method to adapt the inoculum in a short time even using complex raw substrates, whereas in the BMP tests, the specific methane production was proportional to the initial amount of inoculum.

Keywords: anaerobic digestion, biomethane potential test, coffee wastewater, fast inoculum adaptation

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Authors: Farah Lazzali, Yamina Ait Meziane

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Recent earthquakes in Algeria have demonstrated the need for seismic risk reduction. In fact, the latest major earthquake that affected the Algiers-Boumerdes region in 2003 caused excessive levels of loss of life and property. Economic, social and environmental damage were also experienced. During the three days following the event, a relatively weak coordination of public authority was noted. Many localities did not receive any relief due to lack of information from concerned authorities and delay in connecting damaged roads. Following this event, Algerian government and civil society has recognized the urgent need for an appropriate and immediate seismic risk mitigation strategy. This paper describes procedures for emergency response following past earthquakes in Algeria and provides a brief review of risk mitigation activities since 1980. The paper also aims to provide measures to reduce earthquake risk through general strategy and practical implementation of the mitigation actions.

Keywords: earthquake, hazard, prevention, strategy, risk reduction

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Authors: Hossein Lotfizadeh, André McDonald, Amit Kumar

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Renewable energy resources, which can supplement space and water heating for residential buildings, can have a noticeable impact on natural gas consumption and air pollution. This study considers a technical analysis of a combined solar water heating system with evacuated tube solar collectors for different solar coverage, ranging from 20% to 100% of the total roof area of a typical residential building located in Edmonton, Alberta, Canada. The alternative heating systems were conventional (non-condensing) and condensing tankless water heaters and condensing boilers that were coupled to solar water heating systems. The performance of the alternative heating systems was compared to a traditional heating system, consisting of a conventional boiler, applied to houses of various gross floor areas. A comparison among the annual natural gas consumption, carbon dioxide (CO₂) mitigation, and emissions for the various house sizes indicated that the combined solar heating system can reduce the natural gas consumption and CO₂ emissions, and increase CO₂ mitigation for all the systems that were studied. The results suggest that solar water heating systems are potentially beneficial for residential heating system applications in terms of energy savings and CO₂ mitigation.

Keywords: CO2 emissions, CO2 mitigation, natural gas consumption, solar water heating system

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Authors: Bismina Akbar, Smitha M. V.

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Flooding is a global phenomenon that causes widespread devastation, economic damage, and loss of human lives. In the past twenty years, the number of reported flood events has increased significantly. Millions of people around the globe are at risk of flooding from coastal, dam breaks, groundwater, and urban surface water and wastewater sources. Climate change is one of the important causes for them since it affects, directly and indirectly, the river network. Although the contribution of climate change is undeniable, human contributions are there to increase the frequency of floods. There are different types of floods, such as Flash floods, Coastal floods, Urban floods, River (or fluvial) floods, and Ponding (or pluvial flooding). This study focuses on formulating mitigation strategies for urban flood risk reduction through analysis of different best practice case studies, including China, Japan, Indonesia, and Brazil. The mitigation measures suggest that apart from the structural and non-structural measures, environmental considerations like blue-green solutions are beneficial for flood risk reduction. And also, Risk-Informed Master plans are essential nowadays to take risk-based decision processes that enable more sustainability and resilience.

Keywords: hazard, mitigation, risk reduction, urban flood

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Authors: Pui Yong Leo, Normy Maziah Mohd Said

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Change of global economy landscape and business environment has led to companies’ decision to go global and enter international markets. As the companies go beyond the comfort zone (i.e. investing in the home country), it is important to ensure a comprehensive risk assessment is carried out. This paper describes a standardized approach for international investment, ensuring identification of risk, risk appetite, risk rating, risk treatment and mitigation plans for respective international investment proposal. The standardized approach is divided into three (3) stages as follows: Stage 1 – Preliminary Risk profiling; with the objective to gauge exposure to countries and high level risk factors as first level assessment. Stage 2 – Risk Parameters; with the objective to define risk appetite for the international investment from the perspective of likelihood and impact. Stage 3 – Detailed Risk Assessments; with the objectives to assess in detail any triggered elements from Stage 1, and project specific risks. The final output will include the mitigation plans for the identified risks for the total investment. Example will be given in this paper to show how comprehensive risk assessment is carried out for an international investment in power energy sector.

Keywords: international investment, mitigation plans, risk appetite, risk assessment

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Authors: Kumaresh Selvakumar, Man Young Kim

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In order to elaborate the main idea of investigating the flow physics inside the catalytic combustor, the characteristics of the catalytic surface reactions are analyzed by employing the CHEMKIN methodology with detailed gas and surface chemistries. The presence of a catalyst inside an engine enables complete combustion at lower temperatures which promotes desired chemical reactions. A single channel from the honeycomb monolith catalytic combustor is preferred to analyze the gas and surface reactions in the catalyst bed considering the fact that every channel in the honeycomb monolith behaves in similar fashion. The simplified approach with single catalyst channel using plug flow reactor can be used to predict the flow behavior inside the catalytic combustor. The hydrogen addition to the combustion reactants offers a way to light-off catalytic combustion of methane on platinum catalyst and aids to reduce the surface ignition temperature. Indeed, the hydrogen adsorption is higher on the uncovered Pt(s) surface sites because the sticking coefficient of hydrogen is larger than that of methane. The location of flame position in the catalyst bed is validated by igniting the methane fuel with the presence of hydrogen for corresponding multistep surface reactions.

Keywords: catalytic combustor, hydrogen adsorption, plug flow reactor, surface ignition temperature

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Authors: Maryam Zarabian, Hector Guzman, Pedro Pereira-Almao, Abraham Fapojuwo

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Dry reforming of methane (DRM) has sparked significant industrial and scientific interest not only as a viable alternative for addressing the environmental concerns of two main contributors of the greenhouse effect, i.e., carbon dioxide (CO₂) and methane (CH₄), but also produces syngas, i.e., a mixture of hydrogen (H₂) and carbon monoxide (CO) utilized by a wide range of downstream processes as a feedstock for other chemical productions. In this study, we develop an AI-enable syngas production model to tackle the problem of achieving an equivalent H₂/CO ratio [1:1] with respect to the most efficient conversion. Firstly, the unsupervised density-based spatial clustering of applications with noise (DBSAN) algorithm removes outlier data points from the original experimental dataset. Then, random forest (RF) and deep neural network (DNN) models employ the error-free dataset to predict the DRM results. DNN models inherently would not be able to obtain accurate predictions without a huge dataset. To cope with this limitation, we employ reusing pre-trained layers’ approaches such as transfer learning and greedy layer-wise pretraining. Compared to the other deep models (i.e., pure deep model and transferred deep model), the greedy layer-wise pre-trained deep model provides the most accurate prediction as well as similar accuracy to the RF model with R² values 1.00, 0.999, 0.999, 0.999, 0.999, and 0.999 for the total outlet flow, H₂/CO ratio, H₂ yield, CO yield, CH₄ conversion, and CO₂ conversion outputs, respectively.

Keywords: artificial intelligence, dry reforming of methane, artificial neural network, deep learning, machine learning, transfer learning, greedy layer-wise pretraining

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Authors: Mengying Wang, Xiaohui Wang, Chun Deng, Bei Liu, Changyu Sun, Guangjin Chen, Mahmoud El-Halwagi

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Significant amounts of natural gas hydrates (NGHs) are considered potential new sustainable energy resources in the future. However, common used methods for methane gas recovery from hydrate sediments require high investment but with low gas production efficiency, and may cause potential environment and security problems. Therefore, there is a need for effective gas production from hydrates. The natural gas hydrate production method by CO₂/H₂ replacement coupling steam methane reforming can improve the replacement effect and reduce the cost of gas separation. This paper develops a simulation model of the gas production process integrated with steam reforming and membrane separation. The process parameters (i.e., reactor temperature, pressure, H₂O/CH₄ ratio) and the composition of CO₂ and H₂ in the feed gas are analyzed. Energy analysis is also conducted. Two design scenarios with different composition of CO₂ and H₂ in the feed gas are proposed and evaluated to assess the energy efficiency of the novel system. Results show that when the composition of CO₂ in the feed gas is between 43 % and 72 %, there is a certain composition that can meet the requirement that the flow rate of recycled gas is equal to that of feed gas, so as to ensure that the subsequent production process does not need to add feed gas or discharge recycled gas. The energy efficiency of the CO₂ in feed gas at 43 % and 72 % is greater than 1, and the energy efficiency is relatively higher when the CO₂ mole fraction in feed gas is 72 %.

Keywords: Gas production, hydrate, process integration, steam reforming

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Authors: D. Bianco, A. Sollazzo, M. Barbarino, G. Elia, A. Smoraldi, N. Favaloro

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The activities, described in the present paper, have been conducted in the framework of the HYPROB-New Program, carried out by the Italian Aerospace Research Centre (CIRA) promoted and funded by the Italian Ministry of University and Research (MIUR) in order to improve the National background on rocket engine systems for space applications. The Program has the strategic objective to improve National system and technology capabilities in the field of liquid rocket engines (LRE) for future Space Propulsion Systems applications, with specific regard to LOX/LCH4 technology. The main purpose of the HYPROB program is to design and build a Propulsion Test Facility (HIMP) allowing test activities on Liquid Thrusters. The development of skills in liquid rocket propulsion can only pass through extensive test campaign. Following its mission, CIRA has planned the development of new testing facilities and infrastructures for space propulsion characterized by adequate sizes and instrumentation. The IMP test cell is devoted to testing articles representative of small combustion chambers, fed with oxygen and methane, both in liquid and gaseous phase. This article describes the activities that have been carried out for the evaluation of the acoustic impact, and its consequent mitigation. The impact of the simulated acoustic disturbance has been evaluated, first, using an approximated method based on experimental data by Baumann and Coney, included in “Noise and Vibration Control Engineering” edited by Vér and Beranek. This methodology, used to evaluate the free-field radiation of jet in ideal acoustical medium, analyzes in details the jet noise and assumes sources acting at the same time. It considers as principal radiation sources the jet mixing noise, caused by the turbulent mixing of jet gas and the ambient medium. Empirical models, allowing a direct calculation of the Sound Pressure Level, are commonly used for rocket noise simulation. The model named after K. Eldred is probably one of the most exploited in this area. In this paper, an improvement of the Eldred Standard model has been used for a detailed investigation of the acoustical impact of the Hyprob facility. This new formulation contains an explicit expression for the acoustic pressure of each equivalent noise source, in terms of amplitude and phase, allowing the investigation of the sources correlation effects and their propagation through wave equations. In order to enhance the evaluation of the facility acoustic impact, including an assessment of the mitigation strategies to be set in place, a more advanced simulation campaign has been conducted using both an in-house code for noise propagation and scattering, and a commercial code for industrial noise environmental impact, CadnaA. The noise prediction obtained with the revised Eldred-based model has then been used for formulating an empirical/BEM (Boundary Element Method) hybrid approach allowing the evaluation of the barrier mitigation effect, at the design. This approach has been compared with the analogous empirical/ray-acoustics approach, implemented within CadnaA using a customized definition of sources and directivity factor. The resulting impact evaluation study is reported here, along with the design-level barrier optimization for noise mitigation.

Keywords: acoustic impact, industrial noise, mitigation, rocket noise

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Authors: Fatima M. Kabbashi, Abdalla M. Abdalla, Hussam K. Hamad, Elias S. Hassan

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This study investigates the production of renewable energy (biogas) from biomedical hazard waste (blood) and eco-friendly disposal. Biogas is produced by the bacterial anaerobic digestion of biomaterial (blood). During digestion process bacterial feeding result in breaking down chemical bonds of the biomaterial and changing its features, by the end of the digestion (biogas production) the remains become manure as known. That has led to the economic and eco-friendly disposal of hazard biomedical waste (blood). The samples (Whole blood, Red blood cells 'RBCs', Blood platelet and Fresh Frozen Plasma ‘FFP’) are collected and measured in terms of carbon to nitrogen C/N ratio and total solid, then filled in connected flasks (three flasks) using water displacement method. The results of trails showed that the platelet and FFP failed to produce flammable gas, but via a gas analyzer, it showed the presence of the following gases: CO, HC, CO₂, and NOX. Otherwise, the blood and RBCs produced flammable gases: Methane-nitrous CH₃NO (99.45%), which has a blue color flame and carbon dioxide CO₂ (0.55%), which has red/yellow color flame. Methane-nitrous is sometimes used as fuel for rockets, some aircraft and racing cars.

Keywords: renewable energy, biogas, biomedical waste, blood, anaerobic digestion, eco-friendly disposal

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Authors: Ehsan Arabian, Thomas Sattelmayer

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The formation of nitrogen dioxide NO2 in the exhaust duct of a MAN dual fuel test engine has been investigated numerically. The dual fuel engine concept with premixed lean methane combustion ignited through diesel pilot flames reveals high potential for the abatement of the NOx formation. The drawback of this combustion method, however, is the high NO2 formation due to the increasing concentration of unburned hydrocarbons. This promotes the conversion of NO to NO2, which is toxic and characterized through its yellow color. The results presented in this paper cover a wide range of engine operation points from full load to part load for different air to fuel ratios. The effects of temperature, pressure and concentrations of unburned methane and nitric oxide on NO2 formation in the exhaust duct has been investigated on the basis of a zero-dimensional well stirred reactor model implemented in Cantera, which calculates the steady state of a uniform composition for a certain residence time. It can be shown that the simulated conversion of NO to NO2 match the experimental results fairly well. The partial oxidation of methane followed by CO production can be predicted as well. It can also be concluded that the lower temperature limit for which no conversion takes place, depends mainly on the concentration of the unburned hydrocarbons in the exhaust.

Keywords: cantera, dual fuel engines, exhaust tract, numerical modeling of NO2 formation, well stirred reactor

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Authors: A. Al-Yaqout, A. Al-Alawi, T. Al-Said, E. Al-Enezi, M. Al-Roumi

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Kuwait’s marine environment suffers from increased organic pollution. Sea cucumbers play an important role in the marine environment. They create a healthier environment for many types of benthic micro-organisms through their slow movement and feeding mechanism on micro-organisms and organic material. A preliminary study has been conducted in Kuwait Institute for Scientific Research to assess the possibility of using sea cucumbers for mitigation of the coastal pollution. Sediments were collected from locations identified to be heavily loaded with organic pollutants. Ten aquaria glass tanks, 65x 40x 30cm will be supplied with 10 cm height (14 kg) of the sediments added in each tank and filled with 70 L of filtered seawater. Two species were used in this study, Stichopus hermanni, and Holothuria atra. Water and sediment samples were analyzed weekly. The results showed promising possibility for using sea cucumber to lower the organic load in sediments.

Keywords: organic pollution, sea cucumbers, mitigation, Stichopus hermanni, Holothuria atra

Procedia PDF Downloads 276

Authors: Hao Liu, Lihui Zheng, Chinedu J. Okere, Chao Wang, Xiangchun Wang, Peng Zhang

Abstract:

The coalbed methane (CBM) extraction industry (an unconventional energy source) is yet to promulgated an established standard code of practice for the experimental evaluation of sensitivity damage of coal samples. The existing experimental process of previous researches mainly followed the industry standard for conventional oil and gas reservoirs (CIS). However, the existing evaluation method ignores certain critical differences between CBM reservoirs and conventional reservoirs, which could inevitably result in an inaccurate evaluation of sensitivity damage and, eventually, poor decisions regarding the formulation of formation damage prevention measures. In this study, we propose improved experimental guidelines for evaluating seepage sensitivity damage of CBM reservoirs by leveraging on the shortcomings of the existing methods. The proposed method was established via a theoretical analysis of the main drawbacks of the existing methods and validated through comparative experiments. The results show that the proposed evaluation technique provided reliable experimental results that can better reflect actual reservoir conditions and correctly guide future development of CBM reservoirs. This study is pioneering the research on the optimization of experimental parameters for efficient exploration and development of CBM reservoirs.

Keywords: coalbed methane, formation damage, permeability, unconventional energy source

Procedia PDF Downloads 102

Authors: Bedarnia Ishak

Abstract:

In the recent years, the dry reforming of methane has received considerable attention from an environmental view point because it consumes and eliminates two gases (CH4 and CO2) responsible for global warming by greenhouse effect. Many catalysts containing noble metal (Rh, Ru, Pd, Pt and Ir) or transition metal (Ni, Co and Fe) have been reported to be active in this reaction. Compared to noble metals, Ni-materials are cheap but very easily deactivated by coking. Ni-based mixed oxides structurally well-defined like perovskites and spinels are being studied because they possibly make solid solutions and allow to vary the composition and thus the performances properties. In this work, nano-sized nickel ferrite oxides are synthesized using three different methods: Co-precipitation (CP), hydrothermal (HT) and sol gel (SG) methods and characterized by XRD, Raman, XPS, BET, TPR, SEM-EDX and TEM-EDX. XRD patterns of all synthesized oxides showed the presence of NiFe2O4 spinel, confirmed by Raman spectroscopy. Hematite was present only in CP sample. Depending on the synthesis method, the surface area, particle size, as well as the surface Ni/Fe atomic ratio (XPS) and the behavior upon reduction varied. The materials were tested in methane dry reforming with CO2 at 1 atm and 650-800 °C. The catalytic activity of the spinel samples was not very high (XCH4 = 5-20 mol% and XCO2 = 25-40 mol %) when no pre-reduction step was carried out. A significant contribution of RWGS explained the low values of H2/CO ratio obtained. The reoxidation step of the catalyst carried out after reaction showed little amounts of coke deposition. The reducing pretreatment was particularly efficient in the case of SG (XCH4 = 80 mol% and XCO2 = 92 mol%, at 800 °C), with H2/CO > 1. In conclusion, the influence of preparation was strong for most samples and the catalytic behavior could be interpreted by considering the distribution of cations among octahedral (Oh) and tetrahedral (Td) sites as in (Ni2+1-xFe3+x) Td (Ni2+xFe3+2-x) OhO2-4 influenced the reducibility of materials and thus their catalytic performance.

Keywords: NiFe2O4, dry reforming of methane, spinel oxide, oxide zenc

Procedia PDF Downloads 255

Authors: Bouhenni Mohamed Saif El Islam

Abstract:

In the recent years, the dry reforming of methane has received considerable attention from an environmental view point because it consumes and eliminates two gases (CH4 and CO2) responsible for global warming by greenhouse effect. Many catalysts containing noble metal (Rh, Ru, Pd, Pt and Ir) or transition metal (Ni, Co and Fe) have been reported to be active in this reaction. Compared to noble metals, Ni-materials are cheap but very easily deactivated by coking. Ni-based mixed oxides structurally well-defined like perovskites and spinels are being studied because they possibly make solid solutions and allow to vary the composition and thus the performances properties. In this work, nano-sized nickel ferrite oxides are synthesized using three different methods: Co-precipitation (CP), hydrothermal (HT) and sol gel (SG) methods and characterized by XRD, Raman, XPS, BET, TPR, SEM-EDX and TEM-EDX. XRD patterns of all synthesized oxides showed the presence of NiFe2O4 spinel, confirmed by Raman spectroscopy. Hematite was present only in CP sample. Depending on the synthesis method, the surface area, particle size, as well as the surface Ni/Fe atomic ratio (XPS) and the behavior upon reduction varied. The materials were tested in methane dry reforming with CO2 at 1 atm and 650-800 °C. The catalytic activity of the spinel samples was not very high (XCH4 = 5-20 mol% and XCO2 = 25-40 mol %) when no pre-reduction step was carried out. A significant contribution of RWGS explained the low values of H2/CO ratio obtained. The reoxidation step of the catalyst carried out after reaction showed little amounts of coke deposition. The reducing pretreatment was particularly efficient in the case of SG (XCH4 = 80 mol% and XCO2 = 92 mol%, at 800 °C), with H2/CO > 1. In conclusion, the influence of preparation was strong for most samples and the catalytic behavior could be interpreted by considering the distribution of cations among octahedral (Oh) and tetrahedral (Td) sites as in (Ni2+1-xFe3+x)Td (Ni2+xFe3+2-x)OhO2-4 influenced the reducibility of materials and thus their catalytic performance.

Keywords: NiFe2O4, dry reforming of methane, spinel oxide, XCO2

Procedia PDF Downloads 347

Authors: Maria E. Hernnadez, Elizabeth Ramos, Claudia Ortiz

Abstract:

Pollutant removal (N-NH4, COD, S-SO4, N-NO3 and P-PO4) and greenhouse gases (methane and nitrous oxide) emissions were investigated in constructed wetlands CW mesocosms with four types of substrate (gravel (G) zeolite (Z), Gravel+Plastic (GP) and zeolite+plastic), all planted with the ornamental plant lily (Lilium sp). Significantly higher N-NH4 removal was found in the CW-Z (97%) and CW-ZP (85%) compared with CW-G (61%) and CW-GP (17%), also significantly lower emissions of nitrous oxide were found in CW-Z (2.2 µgm-2min-1) and CW-ZP (2.5 µgm-2min-1) compared with CW-G(7.4 µgm-2min-1 ) and CW-GP (6.30 µgm-2min-1).

Keywords: methane, nitrous oxide, lily, zeolite

Procedia PDF Downloads 371

Authors: Michael Graz, Andrew Shearer, Gareth Evans

Abstract:

Manipulation of rumen bacteria is receiving increasing attention as a way of controlling greenhouse gas (GHG) emissions that are generated by the agricultural sector. Feed supplementation in particular is one of the ways in which this drive is being addressed, in particular with reference to livestock-generated GHG emissions. A blend of naturally occurring chemical extracts obtained from garlic and bitter orange extracts has been identified as a natural, sustainable and non-antibiotic based way of reducing methane production by ruminant livestock. In the current study, the acceptability and impact of this blend of natural extracts on feed rations of beef cattle was trialed in vivo on a commercial farm in Europe. Initial findings have demonstrated acceptable palatability, with all animals accepting the feed supplement into their ration both when it was mixed into the total daily ration and when used as a part of their high energy rations. Measurement of the impact of this feed supplement on productivity weight gain and milk quality is ongoing. In conclusion, this field study confirmed the palatability of the combination of garlic and citrus extracts and hence pointed to possibility of the extract blend to improve digestion, enhance body energy retention and limit CH4 formation in relation to feed intake.

Keywords: citrus, garlic, methane reduction, palatability, ruminants

Procedia PDF Downloads 373

Authors: Umesh Kumar Singh, Abhishek Raghuvanshi, Suyash Kumar Singh

Abstract:

As IoT networks gain popularity, they are more susceptible to security breaches. As a result, it is crucial to analyze the IoT platform as a whole from the standpoint of core security concepts. The Internet of Things relies heavily on wireless networks, which are well-known for being susceptible to a wide variety of attacks. This article provides an analysis of many techniques that may be used to identify vulnerabilities in the software and hardware associated with the Internet of Things (IoT). In the current investigation, an experimental setup is built with the assistance of server computers, client PCs, Internet of Things development boards, sensors, and cloud subscriptions. Through the use of network host scanning methods and vulnerability scanning tools, raw data relating to IoT-based applications and devices may be collected. Shodan is a tool that is used for scanning, and it is also used for effective vulnerability discovery in IoT devices as well as penetration testing. This article presents an efficient mitigation plan for encountering vulnerabilities in the Internet of Things.

Keywords: internet of things, security, privacy, vulnerability identification, mitigation plan

Procedia PDF Downloads 7

Authors: Yitong Xie, Chaokui Qin, Zhiguang Chen, Shuangqian Guo

Abstract:

Injecting hydrogen, a competitive carbon-free energy carrier, into existing natural gas networks has become a promising step toward alleviating global warming. Considering the differences in properties of hydrogen and natural gas, there is very little evidence showing how many degrees of hydrogen admixture can be accepted and how to adjust appliances to adapt to gas constituents' variation. The lack of this type of analysis provides more uncertainty in injecting hydrogen into networks because of the short the basis of burner design and adjustment. First, the properties of methane and hydrogen were compared for a comprehensive analysis of the impact of hydrogen addition to methane. As the main determinant of flame stability, the burning velocity was adopted for hydrogen addition analysis. Burning velocities for hydrogen-enriched natural gas with different hydrogen percentages and equivalence ratios were calculated by the software CHEMKIN. Interchangeability methods, including single index methods, multi indices methods, and diagram methods, were adopted to determine the limit of hydrogen percentage. Cooktops and water heaters were experimentally tested in the laboratory. Flame structures of different hydrogen percentages and equivalence ratios were observed and photographed. Besides, the change in heat efficiency, burner temperature, emission by hydrogen percentage, and equivalence ratio was studied. The experiment methodologies and results in this paper provide an important basis for the introduction of hydrogen into gas pipelines and the adjustment of gas appliances.

Keywords: hydrogen, methane, combustion, appliances, interchangeability

Procedia PDF Downloads 58