scholarly journals The Effect of Ammonia Toxicity on Methane Production of a Full-Scale Biogas Plant—An Estimation Method

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5031
Author(s):  
Sotirios D. Kalamaras ◽  
Georgios Vitoulis ◽  
Maria Lida Christou ◽  
Themistoklis Sfetsas ◽  
Spiridon Tziakas ◽  
...  
Keyword(s):  
Reduction Rate ◽  
Estimation Method ◽  
Weight Ratio ◽  
Ammonium Nitrogen ◽  
Biogas Plant ◽  
Ammonia Toxicity ◽  
Ch4 Production ◽  
Ammonia Accumulation ◽  
Biogas Plants ◽  
The Individual

Ammonia accumulation in biogas plants reactors is becoming more frequently encountered, resulting in reduced methane (CH4) production. Ammonia toxicity occurs when N-rich substrates represent a significant part of the biogas plant’s feedstock. The aim of this study was to develop an estimation method for the effect of ammonia toxicity on the CH4 production of biogas plants. Two periods where a biogas plant operated at 3200 mg·L−1 (1st period) and 4400 mg·L−1 (2nd period) of ammonium nitrogen (NH4+–N) were examined. Biomethane potentials (BMPs) of the individual substrates collected during these periods and of the mixture of substrates with the weight ratio used by the biogas plant under different ammonia levels (2000–5200 mg·L−1 NH4+–N) were determined. CH4 production calculated from the substrates’ BMPs and the quantities used of each substrate by the biogas plant was compared with actual CH4 production on-site. Biogas plant’s CH4 production was 9.9% lower in the 1st and 20.3% in the 2nd period in comparison with the BMP calculated CH4 production, of which 3% and 14% was due to ammonia toxicity, respectively. BMPs of the mixtures showed that the actual CH4 reduction rate of the biogas plant could be approximately estimated by the ammonia concentrations levels.

Flare stacks on agricultural biogas plants – safety and operational requirements

2019 ◽  
Vol 65 (No. 3) ◽  
pp. 98-104
Author(s):  
Petr Trávníček ◽  
Luboš Kotek ◽  
Vlastimil Nejtek ◽  
Tomáš Koutný ◽  
Petr Junga ◽  
...  
Keyword(s):  
Biogas Plant ◽  
Explosive Mixture ◽  
Explosion Pressure ◽  
Biogas Plants ◽  
Vapour Cloud ◽  
The Individual ◽  
Gaseous Cloud

The flare stack is a piece of equipment, which is used as a safety element at a biogas plant. In the case of a cogeneration unit or gas boiler failure, the biogas is redirected to the flare stack where it is burned. When the flare stack fails, the biogas releases to the atmosphere and an explosive mixture can form. The paper is focused on the description of the causes, which can cause the failure of the equipment. For this purpose, the individual components are described and, subsequently, the possibilities of their failure are discussed. In the next part of the work, the following scenario is considered: failure of the cogeneration unit and flare stack, the subsequent leakage of the biogas to the atmosphere. The calculation for determining the consequences of the biogas leakage is carried out. The size of the gaseous cloud and the explosion pressure in the case of a vapour cloud explosion are determined. The calculations were carried out by the software ALOHA (version 5.4.7).

scholarly journals Design Approach for Reducing Cross-Axis Sensitivity in a Single-Drive Multi-Axis MEMS Gyroscope

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 902
Author(s):  
Hussamud Din ◽  
Faisal Iqbal ◽  
Byeungleul Lee
Keyword(s):  
Microelectromechanical Systems ◽  
Reduction Rate ◽  
Design Technique ◽  
Matching Method ◽  
Mems Gyroscope ◽  
Mode Split ◽  
The Cross ◽  
The Individual ◽  
Cross Axis ◽  
Ratio Matching

In this paper, a new design technique is presented to estimate and reduce the cross-axis sensitivity (CAS) in a single-drive multi-axis microelectromechanical systems (MEMS) gyroscope. A simplified single-drive multi-axis MEMS gyroscope, based on a mode-split approach, was analyzed for cross-axis sensitivity using COMSOL Multiphysics. A design technique named the “ratio-matching method” of drive displacement amplitudes and sense frequency differences ratios was proposed to reduce the cross-axis sensitivity. Initially, the cross-axis sensitivities in the designed gyroscope for x and y-axis were calculated to be 0.482% and 0.120%, respectively, having an average CAS of 0.301%. Using the proposed ratio-matching method and design technique, the individual cross-axis sensitivities in the designed gyroscope for x and y-axis were reduced to 0.018% and 0.073%, respectively. While the average CAS was reduced to 0.045%, showing a reduction rate of 85.1%. Moreover, the proposed ratio-matching method for cross-axis sensitivity reduction was successfully validated through simulations by varying the coupling spring position and sense frequency difference variation analyses. Furthermore, the proposed methodology was verified experimentally using fabricated single-drive multi-axis gyroscope.

scholarly journals Empirical Validation of a Biogas Plant Simulation Model and Analysis of Biogas Upgrading Potentials

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2424
Author(s):  
Jan Martin Zepter ◽  
Jan Engelhardt ◽  
Tatiana Gabderakhmanova ◽  
Mattia Marinelli
Keyword(s):  
Simulation Model ◽  
Biogas Production ◽  
Biogas Plant ◽  
Raw Material ◽  
Biogas Upgrading ◽  
Integrated Energy Systems ◽  
First Order Kinetics ◽  
Biogas Plants ◽  
Plant Simulation ◽  
Kinetics Of

Biogas plants may support the transformation towards renewable-based and integrated energy systems by providing dispatchable co-generation as well as opportunities for biogas upgrading or power-to-X conversion. In this paper, a simulation model that comprises the main dynamics of the internal processes of a biogas plant is developed. Based on first-order kinetics of the anaerobic digestion process, the biogas production of an input feeding schedule of raw material can be estimated. The output of the plant in terms of electrical and thermal energy is validated against empirical data from a 3-MW biogas plant on the Danish island of Bornholm. The results show that the model provides an accurate representation of the processes within a biogas plant. The paper further provides insights on the functioning of the biogas plant on Bornholm as well as discusses upgrading potentials of biogas to biomethane at the plant from an energy perspective.

An Economic Alternative to Replacing Centralized Gas Supply with Autonomous Biogas Facilities in Russian Cities

2021 ◽  
Vol 20 (3) ◽  
pp. 582-612
Author(s):  
G. S. Chebotareva ◽  
◽  
A. A. Dvinayninov ◽  
Keyword(s):  
Economic Efficiency ◽  
Clean Energy ◽  
State Regulation ◽  
Biogas Plant ◽  
Main Trend ◽  
Effective Response ◽  
Biogas Plants ◽  
Gas Consumption ◽  
Gas Supply ◽  
Climatic Features

The main trend in energy development is to increase energy efficiency by reducing the use of limited natural resources, the spread of renewable energy, and reducing the negative impact on the environment. An effective response to these challenges is the use of biogas plants that produce clean energy and solve the environmental problems of waste disposal and recycling. The purpose of the article is to assess the economic efficiency of replacing district gas supply with autonomous biogas plants in public utilities. A hypothesis has been put forward that the feasibility of using such technologies depends on climatic features and the specific provisions of state regulation of prices and gas consumption rates. A cost approach was applied that assesses the overall structure of equipment costs, as well as a comparative assessment method according to the principle “with / without a biogas plant”, and a scenario analysis, the criterion of which is the size of the family owning the plant. An auxiliary method for forecasting retail and economically justified prices for natural gas for the population was used. The object of calculations is the “HomeBiogas” installation intended for home use. Three Russian cities were chosen as territorial subjects: Yekaterinburg, Irkutsk and Krasnodar. The cities which differ significantly in their natural characteristics and approaches to the formation of retail gas prices. It has been proved that although the average monthly temperatures differ significantly in the cities considered, none of them has a constant temperature exceeding the required standard value of 17°C. In each case, the initial capital investment is driven up by the cost of installing additional insulation and heating systems. This equalizes the costs of warmer and colder areas. Therefore, the climatic features of cities are not significant and do not affect the economic efficiency of using a biogas plant. In turn, state regulation of prices and norms of gas consumption by the population is of decisive importance. The findings are of theoretical and practical importance. The methodology can be applied to assess the efficiency of using biogas plants in industry and gasification projects in the remote areas of Russia.

Operational results of an agricultural biogas plant equipped with modern instrumentation and automation

2008 ◽  
Vol 57 (6) ◽  
pp. 803-808 ◽  
Author(s):  
J. Wiese ◽  
O. Kujawski
Keyword(s):  
Energy Crops ◽  
Full Scale ◽  
Biogas Plant ◽  
Biogas Plants ◽  
Technical Details ◽  
Modern Instrumentation

Agricultural biogas plants based on energy crops gain more and more importance because of numerous energetic, environmental and agricultural benefits. In contrast to older biogas plants, the newest generation of biogas plants is equipped with modern ICA equipment and reliable machines/engines. In this paper, the authors present technical details and operational results of a modern full-scale agricultural biogas plant using energy crops.

scholarly journals Revised Estimation Method for Emissions from Automated Plunger Lift Liquid Unloadings

Environments ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 25
Author(s):  
Adam Pacsi ◽  
David W. Sullivan ◽  
David T. Allen
Keyword(s):  
Direct Measurement ◽  
Oil And Gas ◽  
Measurement Data ◽  
Estimation Method ◽  
The United States ◽  
Gas Production ◽  
Small Subset ◽  
Emission Estimate ◽  
National Measurement ◽  
The Individual

A variety of liquid unloading techniques are used to clear accumulated liquids from the wellbore to increase production rates for oil and gas wells. Data from national measurement studies indicate that a small subset of wells with plunger lift assist, that vent with high frequency and short event duration, contribute a significant fraction of methane emissions from liquid unloading activities in the United States. Compared to direct measurement of emissions at 24 wells in a field campaign, the most commonly used engineering emission estimate for this source category, which is based on the volume of gas in the wellbore, does not accurately predict emissions at the individual well (R2 = 0.06). An alternative emission estimate is proposed that relies on the duration of the venting activity and the gas production rate of the well, which has promising statistical performance characteristics when compared to direct measurement data. This work recommends well parameters that should be collected from future field measurement campaigns that are focused on this emission source.

scholarly journals Evaluation of Eco-Efficiency of Two Alternative Agricultural Biogas Plants

2018 ◽  
Vol 8 (11) ◽  
pp. 2083 ◽  
Author(s):  
Magdalena Muradin ◽  
Katarzyna Joachimiak-Lechman ◽  
Zenon Foltynowicz
Keyword(s):  
Waste Heat ◽  
Negative Impact ◽  
Biogas Production ◽  
Biogas Plant ◽  
Waste To Energy ◽  
Cost Calculation ◽  
Processing Plant ◽  
The European Union ◽  
Levelized Cost Of Electricity ◽  
Biogas Plants

Implementation of the circular economy is one of the priorities of the European Union, and energy efficiency is one of its pillars. This article discusses an effective use of agri-food industry waste for the purposes of waste-to-energy in biogas plants. Its basic objective is the comparative assessment of the eco-efficiency of biogas production depending on the type of feedstock used, its transport and possibility to use generated heat. The environmental impact of the analysed installations was assessed with the application of the Life Cycle Assessment (LCA) methodology. Cost calculation was performed using the Levelized Cost of Electricity (LCOE) method. The LCA analysis indicated that a biogas plant with a lower level of waste heat use where substrates were delivered by wheeled transport has a negative impact on the environment. The structure of distributed energy production cost indicates a substantial share of feedstock supply costs in the total value of the LCOE ratio. Thus, the factor affecting the achievement of high eco-efficiency is the location of a biogas plant in the vicinity of an agri-food processing plant, from which the basic feedstock for biogas production is supplied with the transmission pipeline, whereas heat is transferred for the needs of production processes in a processing plant or farm.

scholarly journals Operational Parameters of Biogas Plants: A Review and Evaluation Study

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3761 ◽  
Author(s):  
Abdullah Nsair ◽  
Senem Onen Cinar ◽  
Ayah Alassali ◽  
Hani Abu Qdais ◽  
Kerstin Kuchta
Keyword(s):  
Anaerobic Digestion ◽  
Review Paper ◽  
Biogas Production ◽  
Evaluation Study ◽  
Biogas Plant ◽  
Operational Parameters ◽  
Digestion Process ◽  
Design Considerations ◽  
Biogas Plants ◽  
Main Factors

The biogas production technology has improved over the last years for the aim of reducing the costs of the process, increasing the biogas yields, and minimizing the greenhouse gas emissions. To obtain a stable and efficient biogas production, there are several design considerations and operational parameters to be taken into account. Besides, adapting the process to unanticipated conditions can be achieved by adequate monitoring of various operational parameters. This paper reviews the research that has been conducted over the last years. This review paper summarizes the developments in biogas design and operation, while highlighting the main factors that affect the efficiency of the anaerobic digestion process. The study’s outcomes revealed that the optimum operational values of the main parameters may vary from one biogas plant to another. Additionally, the negative conditions that should be avoided while operating a biogas plant were identified.

scholarly journals The generation of a mathematical model of the biogas production process from organic municipal solid waste

2020 ◽  
Vol 180 ◽  
pp. 02019 ◽  
Author(s):  
Marzhan Temirbekova ◽  
Madina Aliyarova ◽  
Iliya Iliev ◽  
Aliya Yelemanova ◽  
Saule Sagintayeva
Keyword(s):  
Mathematical Model ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Biogas Plant ◽  
Model Parameters ◽  
Biochemical Processes ◽  
Biogas Plants ◽  
The Mathematical Model

This paper justifies the efficiency of the biogas collection and utilization at the MSW (municipal solid waste) landfill in Almaty with the installation of several modern biogas plants. The optimal mode of processes occurring in a biogas plant is determined by computer generated simulations. Mathematical model parameters were identified to describe biochemical processes occurring in a biogas plant. Two approaches are used to resolve the mathematical model: the finite-difference method for solving the system of differential equations and simulation modeling by using the Any Logic package. A program is written in the algorithmic language C ++. Numerous calculations were carried out, the results of which are presented in curves and their qualitative picture is consistent with the ongoing processes. The created computer program allows to make a preliminary forecast of anaerobic fermentation occurring in the bioreactor depending on volume of the substrate, methane microorganisms and temperature conditions.

Morphological subclassification of follicular lymphoma: variability of diagnoses among hematopathologists, a collaborative study between the Repository Center and Pathology Panel for Lymphoma Clinical Studies.

1985 ◽  
Vol 3 (1) ◽  
pp. 25-38 ◽  
Author(s):  
G E Metter ◽  
B N Nathwani ◽  
J S Burke ◽  
C D Winberg ◽  
R B Mann ◽  
...  
Keyword(s):  
Follicular Lymphoma ◽  
Clinical Studies ◽  
Accurate Determination ◽  
Collaborative Study ◽  
Estimation Method ◽  
Great Variability ◽  
Mixed Cell ◽  
The Individual ◽  
Follicular Lymphomas ◽  
Consensus Diagnosis

A collaborative study between the Repository Center for Lymphoma Clinical Studies and the members of the lymphoma pathology subcommittee of the major cooperative oncology groups was undertaken in an effort to ascertain the reproducibility and the interobserver agreement for the cytologic diagnosis of follicular lymphomas. A group of 105 patients with follicular lymphomas were subclassified by seven hematopathologists according to two methods. In the first method, cases were subclassified according to the Rappaport, Lukes, and Collins, and Working Formulation systems. In these systems, follicular lymphomas are subclassified by estimation of the different cell populations without the actual counting of cells. With this method, great variability in diagnosis was noted. For example: (1) The consensus diagnosis was that of poorly differentiated lymphocytic lymphoma (PDL) in 39 cases, but among the individual pathologists the number of cases thus diagnosed ranged from 24 to 65; (2) In 40 cases, the consensus diagnosis was follicular lymphoma, mixed-cell type; however, all seven pathologists independently agreed on this subtype in only one case; (3) A major disagreement was noted in 39 cases (37%), in which both diagnostic extremes (small cleaved and large noncleaved) were expressed. In the second method, only precise counts of different cells were made, according to a modification of the method recommended by Berard. With this counting method, diagnoses were independently derived based on the counts provided by the seven pathologists for large cleaved, small noncleaved, and large noncleaved cells. The variability in the results was wide also with this second method. For example, the average number of large cells found by each pathologist was ascertained, and the ranges were determined. The average range was 28 cells, which was considered high. The same determinations were performed only for large noncleaved cells, and the range was found to be 15 cells, which was also considered high. When the diagnoses derived from counts of only large noncleaved cells were compared with the traditional, more subjective diagnoses, fairly close agreement was obtained. In summary, the great variability in diagnoses of follicular lymphomas among pathologists may be attributed to the difficulties inherent in accurate determination of cell size and of the precise percentages of different cells. Until solutions to these problems are developed, one can subclassify follicular lymphomas according to the Berard method or the estimation method.

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