scholarly journals Determination of the Concentration of Propionic Acid in an Aqueous Solution by POD-GP Model and Spectroscopy

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8288
Author(s):  
Mariusz Adamski ◽  
Mirosław Czechlowski ◽  
Karol Durczak ◽  
Tomasz Garbowski
Keyword(s):  
Aqueous Solution ◽  
Propionic Acid ◽  
Rural Areas ◽  
Acid Content ◽  
Control Method ◽  
Biogas Production ◽  
Estimation Error ◽  
Measurement Data ◽  
Calibration Model ◽  
Gp Model

Biorefining and biorefineries are the future of industry and energy. It is still a long way to complete its implementation, but small biorefineries focused mainly on the production of fuels and energy are more and more frequent in rural areas and large areas located near big cities in which, in addition to fuels and energy, various organic substances of high market value are also produced. In order to optimize biogas production and to control methane fermentation processes, fast and accurate identification of carboxylic acid concentrations, including propionic acid as a precursor to acetic acid, is needed. In this study, a process quality control method was developed to evaluate the propionic acid content of an aqueous solution from the fermentation mass. The proposed methodology is based on near infrared spectroscopy with multivariate analysis and stochastic metamodeling with a denoising procedure based on proper orthogonal decomposition (POD). The proposed methodology uses the Bayesian theory, which provides additional information on the magnitude of the correlation between state and control variables. The calibration model was, therefore, constructed by using Gaussian Processes (GP) to predict propionic acid content in the aqueous solution using an NIR-Vis spectrophotometer. The design of the calibration model was based on absorbance spectra and calculation data from selected wavelength ranges from 305 nm to 2210 nm. Measurement data were first denoised and truncated to build a fast and reliable metamodel for precise identification of the acid content of an aqueous solution at a concentration from 0 to 5.66%. The mean estimation error generated by the metamodel does not exceed 0.7%.

scholarly journals IMPROVEMENT OF BIOGAS PRODUCTION IN ANAEROBIC DIGESTION PROCESS

2021 ◽  
Vol 2021 (2/2021) ◽  
pp. 26-31
Author(s):  
Abdelhani Chaabna ◽  
Samia Semcheddine
Keyword(s):  
Anaerobic Digestion ◽  
Rural Areas ◽  
Control Method ◽  
Sliding Mode ◽  
Biogas Production ◽  
Control Design ◽  
Control Law ◽  
Renewable Energy Resources ◽  
Environmental Preservation ◽  
Linear Technique

The production of biogas enables environmental preservation and sustainable development of rural areas and landlocked regions, as well as diversification of renewable energy resources. This paper is a contribution to improving the production of biogas by Sliding Mode Control (SMC). In the literature there are many models describing the behaviour of reactions during anaerobic digestion and used for control design. The AM2 model is one of the simplest models and can be exploited easily for the control design purposes. In this paper, the reduced model AM2 was exploited to develop and testing by simulations the robust control law SMC. The results obtained have proved the effectiveness of the control method proposed in this paper. A study of the robustness for monitoring and disturbances rejection demonstrated the great interest of this method, which is a non-linear technique and gives very good results in terms of robustness but it presents the problem of chattering. In practice, the chattering of the control action can cause premature wear of the actuators or parts of the system due to heavy oscillations. The chattering phenomenon is caused by the discontinuous term which appears in the control signal. This paper presents a solution to the chattering problem by replacing the discontinuous term with a continuous one. Different Simulations and comparisons are presented and interpreted with satisfactory results.

scholarly journals Pilot Study of the Effects of Polyphenols from Chestnut Involucre on Methane Production, Volatile Fatty Acids, and Ammonia Concentration during In Vitro Rumen Fermentation

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Yichong Wang ◽  
Sijiong Yu ◽  
Yang Li ◽  
Shuang Zhang ◽  
Xiaolong Qi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Propionic Acid ◽  
Acid Content ◽  
Volatile Fatty Acids ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Quadratic Response ◽  
In Vitro Rumen Fermentation

Nutritional strategies can be employed to mitigate greenhouse emissions from ruminants. This article investigates the effects of polyphenols extracted from the involucres of Castanea mollissima Blume (PICB) on in vitro rumen fermentation. Three healthy Angus bulls (350 ± 50 kg), with permanent rumen fistula, were used as the donors of rumen fluids. A basic diet was supplemented with five doses of PICB (0%–0.5% dry matter (DM)), replicated thrice for each dose. Volatile fatty acids (VFAs), ammonia nitrogen concentration (NH3-N), and methane (CH4) yield were measured after 24 h of in vitro fermentation, and gas production was monitored for 96 h. The trial was carried out over three runs. The results showed that the addition of PICB significantly reduced NH3-N (p < 0.05) compared to control. The 0.1%–0.4% PICB significantly decreased acetic acid content (p < 0.05). Addition of 0.2% and 0.3% PICB significantly increased the propionic acid content (p < 0.05) and reduced the acetic acid/propionic acid ratio, CH4 content, and yield (p < 0.05). A highly significant quadratic response was shown, with increasing PICB levels for all the parameters abovementioned (p < 0.01). The increases in PICB concentration resulted in a highly significant linear and quadratic response by 96-h dynamic fermentation parameters (p < 0.01). Our results indicate that 0.2% PICB had the best effect on in-vitro rumen fermentation efficiency and reduced greenhouse gas production.

Sensorless Control of Switched Reluctance Motors Based on Pulse Injection, Position Sectors Divided and Variable Thresholds

2014 ◽  
Vol 989-994 ◽  
pp. 3252-3257
Author(s):  
Zi Fei Jia ◽  
De An Zhao ◽  
Yu Yan Zhao
Keyword(s):  
Control Method ◽  
Estimation Error ◽  
Position Estimation ◽  
Switched Reluctance Motors ◽  
Switched Reluctance ◽  
Variable Threshold ◽  
Pulse Injection ◽  
Angle Section ◽  
Two Phases ◽  
Rotor Position Estimation

To realize starting operation and reduce position estimation error of switched reluctance motor (SRM) without position sensor, a novel control method based on pulse injection, divided angle section and variable threshold is presented. The starting operation of SRM can be accomplished by injecting high frequency pulse and judging position sectors. Variable threshold is used to reduce position estimation error. The value of threshold is obtained by looking up table prestored in controller. The method avoids complicated mathematical model and is suitable for starting operation with two phases. Besides, rotor position estimation error of this method is analyzed and the method which can decreased the error is proposed. At last, the experiment has been done to verify the performance of the control method.

scholarly journals Multi Objective for PMU Placement in Compressed Distribution Network Considering Cost and Accuracy of State Estimation

2019 ◽  
Vol 9 (7) ◽  
pp. 1515 ◽  
Author(s):  
Kong ◽  
Wang ◽  
Yuan ◽  
Yu
Keyword(s):  
State Estimation ◽  
Estimation Error ◽  
Distribution Network ◽  
Measurement Data ◽  
Optimal Solution ◽  
Pareto Set ◽  
Measurement Unit ◽  
Nsga Ii ◽  
Multi Objective ◽  
Pmu Placement

A phasor measurement unit (PMU) can provide phasor measurements to the distribution network to improve observability. Based on pre-configuration and existing measurements, a network compression method is proposed to reduce PMU candidate locations. Taking the minimum number of PMUs and the lowest state estimation error as the objective functions and taking full observability of distribution network as the constraint, a multi objective model of optimal PMU placement (OPP) is proposed. A hybrid state estimator based on supervisory control and data acquisition (SCADA) and PMU measurements is proposed. To reduce the number of PMUs required for full observability, SCADA measurement data are also considered into the constraint by update and equivalent. In addition, a non-dominated sorting genetic algorithm-II (NSGA-II) is applied to solve the model to get the Pareto set. Finally, the optimal solution is selected from the Pareto set by the technique for order preference by similarity to ideal solution (TOPSIS). The effectiveness of the proposed method is verified by IEEE standard bus systems.

scholarly journals The Review of Biomass Potential for Agricultural Biogas Production in Poland

2019 ◽  
Vol 11 (22) ◽  
pp. 6515 ◽  
Author(s):  
Katarzyna Anna Koryś ◽  
Agnieszka Ewa Latawiec ◽  
Katarzyna Grotkiewicz ◽  
Maciej Kuboń
Keyword(s):  
Rural Areas ◽  
Food Industry ◽  
Biogas Production ◽  
Agricultural Waste ◽  
Storage Conditions ◽  
Waste Products ◽  
Biomass Residues ◽  
Biogas Plants ◽  
Biomass Potential ◽  
Food Residues

Adequate management of biomass residues generated by agricultural and food industry can reduce their negative impacts on the environment. The alternative use for agricultural waste is production of biogas. Biomass feedstock intended as a substrate for the agricultural biogas plants may include energy crops, bio-waste, products of animal and plant origin and organic residues from food production. This study reviews the potential of selected biomass residues from the agri-food industry in terms of use for agricultural biogas production in Poland. The most common agri-food residues used as substrates for biogas plants in Poland are maize silage, slurry, and distillery waste. It is important that the input for the agricultural biogas installations can be based on local wastes and co-products that require appropriate disposal or storage conditions and might be burdensome for the environment. The study also discusses several limitations that might have an unfavourable impact regarding biogas plants development in Poland. Given the estimated biomass potential, the assumptions defining the scope of use of agricultural biogas and the undeniable benefits provided by biogas production, agricultural biogas plants should be considered as a promising branch of sustainable electricity and thermal energy production in Poland, especially in rural areas.

scholarly journals Treatment of milk wastewater using up-flow anaerobic packed bed reactor

2015 ◽  
Vol 17 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Kiran D. Bhuyar ◽  
Sanvidhan G. Suke ◽  
S.D. Dawande
Keyword(s):  
Rural Areas ◽  
Biogas Production ◽  
Packed Bed ◽  
Dairy Wastewater ◽  
Packed Bed Reactor ◽  
Reactor Performance ◽  
Reactor Model ◽  
Loading Rates ◽  
Empirical Relations ◽  
Low Costs

Abstract An up-flow anaerobic packed bed (UAPB) bioreactor has been designed on a laboratory-scale and used for treatment of domestic milk wastewater (MWW). The UAPB bioreactor was operated under mesophilic temperature (37-45°C) and reactor performance evaluated at various organic loading rates of MWW effluent at hydraulic retention times (HRT) of 1, 2, and 3 d based on the removal of organic matter COD, BOD, SS, pH changes and biogas production. The kinetic parameters were estimated using the experimental data to develop a reactor model. Empirical relations were generated for the characteristics like COD, BOD, and SS using modeling equations. This study proved that the UAPB reactor performance is excellent for treating domestic MWW and easily biodegradable dairy wastewater influent. Hence, this system can operate at low costs, making it suited for use in the developing countries and rural areas.

scholarly journals Modelling of anaerobic digester biogas production: case study of a pilot project in Morocco

2013 ◽  
Vol 3 (4) ◽  
pp. 381-391 ◽  
Author(s):  
Youssef Abarghaz ◽  
Khiyati Mohammed El Ghali ◽  
Mustapha Mahi ◽  
Christine Werner ◽  
Najib Bendaou ◽  
...  
Keyword(s):  
Rural Areas ◽  
Environmental Science ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Principal Component ◽  
Pilot Project ◽  
Gas Production ◽  
Input Material ◽  
Demand Reduction ◽  
Volume Measurements

An anaerobic digestion pilot system was implemented in June 2010 in the Moroccan village of Dayet Ifrah. The input material consists of toilet wastewater and cattle manure. Biogas is produced under anaerobic conditions. It is used for heating and cooking. This biogas system could be an useful sanitation technology due to its ability to treat wastewater. The biogas system was monitored over 86 days in summer 2012 to measure gas production. The average gas production recorded was about 1,870 l per day. This amount is sufficient for a farming family composed of 17 people. Our work seeks to find the most appropriate formula to predict biogas production under Moroccan conditions. We compared and ranked different formulas by applying principal component analysis and the ELECTRE III method. The variables studied were the chemical oxygen demand reduction and biogas volume measurements. The results show that the formula of Vedrenne is the most appropriate equation to predict biogas production in Moroccan rural areas (see Vedrenne (2007) ‘Study of Anaerobic Degradation Processes and Methane Production During Storage of Manure’. Environmental Science Thesis. ENSA, Rennes).

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