scholarly journals Long-Term Assessment of Temperature Management in an Industrial Scale Biogas Plant

2022 ◽  
Vol 14 (2) ◽  
pp. 612
Author(s):  
Senem Onen Cinar ◽  
Abdullah Nsair ◽  
Nils Wieczorek ◽  
Kerstin Kuchta
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Plant ◽  
Hydrolysis Rate ◽  
Industrial Scale ◽  
Temperature Management ◽  
Temperature Changes ◽  
Biochemical Processes ◽  
Operation Temperature ◽  
The Impact

Temperature management is one of the primary considerations of biogas plant operation, and influences physical and biochemical processes. An increase in the temperature leads to an increase in the hydrolysis rate of the feedstock, while it can inhibit microorganisms taking part in different stages of anaerobic digestion. Because of the complexity of the biochemical processes within the anaerobic digestion process, there is a lack of knowledge about the effects of temperature and temperature change on efficiency. Moreover, the impact of stirring directly affects the temperature distribution in the anaerobic digestion reactors. In this study, the temperature management in an industrial-scale biogas plant was examined, and the effect of small temperature changes (from the operation temperature 42 °C) on the efficiency was studied in a laboratory under two different conditions: with stirring (at 40 and 44 °C) and without stirring (at 40 and 44 °C). The examination results from the biogas plant showed that heat transfer in the reactor was not sufficient at the bottom of the digester. Adaptation of the post-digester samples to the temperature changes was more challenging than that of the digester samples. From digestate samples, higher biomethane generation could be obtained, resulting from sufficient contact between microorganisms, enzymes, and substrates. Overall, differences between these changing conditions (approx. 6 NmL CH4 g VS−1) were not significant and could be adapted by the process.

scholarly journals Innovations in anaerobic digestion: a model-based study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Karol Postawa ◽  
Jerzy Szczygieł ◽  
Marek Kułażyński
Keyword(s):  
Mathematical Model ◽  
Anaerobic Digestion ◽  
Production Efficiency ◽  
Biogas Production ◽  
Biogas Plant ◽  
Methane Content ◽  
Pig Manure ◽  
Pig Slurry ◽  
Production Chain ◽  
The Impact

Abstract Background Increasing the efficiency of the biogas production process is possible by modifying the technological installations of the biogas plant. In this study, specific solutions based on a mathematical model that lead to favorable results were proposed. Three configurations were considered: classical anaerobic digestion (AD) and its two modifications, two-phase AD (TPAD) and autogenerative high-pressure digestion (AHPD). The model has been validated based on measurements from a biogas plant located in Poland. Afterward, the TPAD and AHPD concepts were numerically tested for the same volume and feeding conditions. Results The TPAD system increased the overall biogas production from 9.06 to 9.59%, depending on the feedstock composition, while the content of methane was slightly lower in the whole production chain. On the other hand, the AHPD provided the best purity of the produced fuel, in which a methane content value of 82.13% was reached. At the same time, the overpressure leads to a decrease of around 7.5% in the volumetric production efficiency. The study indicated that the dilution of maize silage with pig manure, instead of water, can have significant benefits in the selected configurations. The content of pig slurry strengthens the impact of the selected process modifications—in the first case, by increasing the production efficiency, and in the second, by improving the methane content in the biogas. Conclusions The proposed mathematical model of the AD process proved to be a valuable tool for the description and design of biogas plant. The analysis shows that the overall impact of the presented process modifications is mutually opposite. The feedstock composition has a moderate and unsteady impact on the production profile, in the tested modifications. The dilution with pig manure, instead of water, leads to a slightly better efficiency in the classical configuration. For the TPAD process, the trend is very similar, but the AHPD biogas plant indicates a reverse tendency. Overall, the recommendation from this article is to use the AHPD concept if the composition of the biogas is the most important. In the case in which the performance is the most important factor, it is favorable to use the TPAD configuration.

DOES HARMFUL CLIMATE INCREASE OR DECREASE MIGRATION? EVIDENCE FROM RURAL HOUSEHOLDS IN NIGERIA

2019 ◽  
Vol 10 (04) ◽  
pp. 1950013
Author(s):  
CRISTINA CATTANEO ◽  
EMANUELE MASSETTI
Keyword(s):  
Climate Change ◽  
Adaptation Strategy ◽  
Climatic Conditions ◽  
Marginal Effect ◽  
Cross Sectional ◽  
Temperature Changes ◽  
And Migration ◽  
Migrant Households ◽  
The Impact

This paper analyzes whether migration is an adaptation strategy that households employ to cope with climate in Nigeria. We estimate our model using the cross-sectional variation in climate and long-term migration decisions because we are interested in the average response to long-term climatic conditions. For households that operate farms, we find that the relationship between climate and migration is nonlinear. In particular, climates closer to ideal farming conditions are associated with a higher propensity to migrate, whereas in the least favorable climatic conditions, the propensity to migrate declines. The marginal effect of rainfall and temperature changes on migration varies by season. We estimate the impact of climate change on the number of migrant households in 2031–2060 and 2071–2100, ceteris paribus. With current population levels, climate change generates between 3.6 and 6.3 million additional migrants, most of them being internal. However, these estimates are not statistically significant.

scholarly journals Long-term study of the impact of temperature changes, material aging and service load on the strains of a reinforced concrete structure

2018 ◽  
Vol 66 ◽  
pp. 02006
Author(s):  
Adam Kanciruk
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Reinforced Concrete Structure ◽  
Reinforced Concrete Slab ◽  
Temperature Changes ◽  
Long Term Study ◽  
Monitoring Process ◽  
Service Load ◽  
The Impact

The article discusses five year long measurements of strains of a concrete floor of a hangar. That hangar, originally meant for servicing light military aircraft, was rebuilt with a view to making it fit for servicing larger and heavier passenger planes. As part of that redevelopment, a new floor - reinforced concrete slab, capable of withstanding the weight of the planes - was constructed. In the areas of the floor where the greatest loads occur, ie. in the areas of the concrete slab on which the wheels of the three undercarriage legs rest, three strain rosettes were installed so that the slab strains could be measured. The rosettes were connected to two meters - dataloggers. The latter were programmed in such a way as to register the measured strains and additionally temperatures many times during every 24 hours. The monitoring process, conducted in such an automatic way, demonstrated the occurrence of strains resulting from service load, aging of the reinforced concrete, as well as changes in its temperature.

scholarly journals VARIABLE RHYTHMS IN GROUNDWATER REGIME AND THEIR RELATIONSHIP WITH CLIMATE FACTORS

2021 ◽  
pp. 71-81
Author(s):  
O. Shevchenko ◽  
A. Skorbun ◽  
V. Osadchiy ◽  
D. Charny
Keyword(s):  
Solar Activity ◽  
Water Cycle ◽  
Main Method ◽  
Dominant Position ◽  
Temperature Changes ◽  
Multiple Correlation Analysis ◽  
Groundwater Regime ◽  
Long Term Prediction ◽  
The Impact

Due to the anomalous changes in the groundwater regime over the past 5 years, the question arose about the adequacy and effectiveness of existing methods for predicting their level. The data of monitoring observations from 1951 in the upper part of the Southern Bug river basin are analyzed. The specific underground runoff to the river in the site of Khmilnyk was calculated by the finite difference method. It is established that at the end of the 80s of the last century a 7-8 year cycle began to appear in the fluctuations of the groundwater level (GWT) and groundwater runoff. It correlates well with the cyclicity of the air temperature, and, to a lesser extent, with the cycles of the monthly amount of precipitation. Instead, such rhythms are not at all typical of solar activity, which is characterized by 11-year and 5-6-year cycles. It is in connection with them that the heliosynoptic method of long-term prediction of RGV is based. It is likely that temperature changes occurring on Earth may change the "sun-induced" cyclicity of GWT, so this method of forecasting becomes ineffective. As there is no clear link between temperature changes and solar activity, it is possible that temperature changes are caused by human activity.From 2013-2015, with the beginning of the low water cycle in the study area, the anomalous minima in the GWT mode became more frequent and the cycles were transformed in the direction of their reduction (up to 5-6 years), which may indicate sharp changes in the nature of groundwater storage recovery. Deviations from 8-year cycles and differences in their duration in different parts of the same catchment area are primarily related to differences of GWT. Wavelet analysis was used as the main method of cyclic selection. Using multiple correlation analysis, it was found that in recent decades the temperature has reached a dominant position in terms of the impact on the groundwater regime (at their levels from 1.5 to 4.0 m). As a result, it was noted that our 7-8 year cycles are well traced during the relatively multi-water period caused by increased infiltration of groundwater due to increasing winter thaws (one of the most significant manifestations of global warming), and 5-6 year cycles correspond to low water periods.

scholarly journals The Impact of Selected Atmospheric Conditions on the Process of Abrasive Wear of CFRP

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3965 ◽  
Author(s):  
Aneta Krzyzak ◽  
Damian Racinowski ◽  
Robert Szczepaniak ◽  
Mateusz Mucha ◽  
Ewelina Kosicka
Keyword(s):  
Abrasive Wear ◽  
Atmospheric Conditions ◽  
Carbon Fabric ◽  
Temperature Changes ◽  
Cyclic Temperature ◽  
Research Findings ◽  
Long Term Impact ◽  
The Impact ◽  
Thermal Shocks

The aim of this study was to examine the impact of weathering and thermal shocks on the abrasive wear of epoxy resin composites reinforced with carbon fabric that are commonly used in aviation. The composite was exposed to degradation in an apparatus simulating weathering and thermal shocks and then subjected to an abrasion process, with and without the presence of water. The abrasive wear was controlled by checking the weight loss as well as by visual inspection. The research findings indicated a significant effect of the presence of water in the process of friction upon the deterioration of composite resistance to abrasion with regard to dry friction. The long-term impact of rapid cyclic temperature changes (temperature difference: from −56.5 °C to +60 °C) and a combined effect of UV-A (0.83 W/m2), along with condensation of vapor and an increased ambient temperature (above 50 °C), influenced an improvement in resistance to abrasive wear. The environment of thermal shocks diminished abrasive wear to a much smaller extent than after exploitation in an environment of weathering but both environments contributed to the degradation of the surface layer. Additionally, the environment with UV-A radiation resulted in exposure of the composite reinforcement already after four months of environmental impact.

scholarly journals Cobalt Nanoparticles To Enhance Anaerobic Digestion of Cow Dung: Focusing On Kinetic Models For Biogas Yield And Effluent Utilization

2021 ◽  
Author(s):  
Taha Abdelfattah Mohammed Abdelwahab ◽  
Mahendra Kumar Mohanty ◽  
Pradeepta Kumar Sahoo ◽  
Debaraj Behera
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Models ◽  
Logistic Models ◽  
Informed Choice ◽  
Hydrolysis Rate ◽  
Cow Dung ◽  
Experimental Measurements ◽  
Biogas Yield ◽  
Co Nanoparticles ◽  
The Impact

Abstract The impacts of Co nanoparticles (NPs) on the anaerobic digestion (AD) of cow dung were investigated using kinetic models (modified Gompertze, logistic, and first-order) and experimental measurements. The deviation between the predicted and measured data for biogas yield with modified Gompertze and logistic models were (0.66%-2.26%) and (1.43%-4.19%), respectively. The addition of Co NPs (1-3 mg/L) improved the hydrolysis rate (K) value by (66.66%-144%) compared with the control. Furthermore, effluent with Co NPs showed remarkable fertility (4.63%-5.32%). The combination of kinetic models and experimental measurements can effectively quantify the impact of Co NPs on AD performance and provide an informed choice for industrial production.

scholarly journals Farmers’ perception and knowledge of climate change in Bangladesh – an empirical analysis

2016 ◽  
Vol 3 (1) ◽  
pp. 27-35
Author(s):  
Muntaha Rakib ◽  
Shah Mohammad Hamza Anwar
Keyword(s):  
Climate Change ◽  
Developing Countries ◽  
Climate Variability ◽  
Sustainable Agriculture ◽  
Agricultural Production ◽  
Climate Changes ◽  
Temperature Changes ◽  
The Impact ◽  
Area Data

The lack of sufficient knowledge about climate changes and the impact on agricultural production is an impediment to long term sustainable agriculture in most developing countries, including Bangladesh. This paper presents the results of an investigation to determine perception of farmers about changes in climate in Bangladesh. The study finds the determinants of farmers’ perception on climate variability in different specifications of household characteristics. The sample was adult farmers with at least 20 years of farming experience in the area. Data was collected on perceptions about temperature changes and variability in precipitation over a 20 year period. The results indicated that more than 80% of farmers believe that temperature in the district had become warmer and over 90% were of the opinion that rainfall timing had changed, resulting in increased frequency of drought.Res. Agric., Livest. Fish.3(1): 27-35, April 2016

scholarly journals An Incubation System to Enhance Biogas and Methane Production: A Case Study of an Existing Biogas Plant in Umbria, Italy

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 925 ◽  
Author(s):  
Federica Liberti ◽  
Valentina Pistolesi ◽  
Mawaheb Mouftahi ◽  
Nejib Hidouri ◽  
Pietro Bartocci ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Pilot Scale ◽  
Biogas Plant ◽  
Industrial Scale ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Incubation System ◽  
Continuously Stirred Tank Reactor

The pre-incubation of digestate and recycling of microbes inside a continuously stirred tank reactor (CSTR) are effective ways to optimize the anaerobic digestion process and improve the performance of biogas and methane production, also in existing biogas plants. In this study, a digestate incubation system using a nutrient mix to boost the activity of microbes was coupled to a CSTR to boost biogas and methane production. This system has been tested both on a lab scale and on an industrial scale. On a pilot scale, the system achieved an increase of +16.47 v% in biogas production with respect to the conventional anaerobic digestion process, and an increase of +2 v% in methane content (from 65.94 v% to 67.84 v%). On an industrial scale, the use of this incubation reactor with a capacity of 1 m3 has led to an increase in methane yield of 12 v%. This system allows to maintain the syntrophic relationship between acid-producing bacteria and methanogens and contemporary push the development of methanogens. Moreover, it is an economic system to be integrated into an existing biogas plant given the small volume and the simplicity of the incubation reactor.

Suppressed, but Not Forgotten

2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke
Keyword(s):  
Memory Trace ◽  
Thought Suppression ◽  
Test Phase ◽  
Indirect Test ◽  
Final Test ◽  
Test Experiment ◽  
And Control ◽  
Cue Words ◽  
The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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