scholarly journals Synthesis, Characterization, and Synergistic Effects of Modified Biochar in Combination with α-Fe2O3 NPs on Biogas Production from Red Algae Pterocladia capillacea

2021 ◽  
Vol 13 (16) ◽  
pp. 9275 ◽  
Author(s):  
Mohamed A. Hassaan ◽  
Ahmed El Nemr ◽  
Marwa R. Elkatory ◽  
Safaa Ragab ◽  
Mohamed A. El-Nemr ◽  
...  

This study is the first work that evaluated the effectiveness of unmodified (SD) and modified biochar with ammonium hydroxide (SD-NH2) derived from sawdust waste biomass as an additive for biogas production from red algae Pterocladia capillacea either individually or in combination with hematite α-Fe2O3 NPs. Brunauer, Emmett, and Teller, Fourier transform infrared, thermal gravimetric analysis, X-ray diffraction, transmission electron microscopy, Raman, and a particle size analyzer were used to characterize the generated biochars and the synthesized α-Fe2O3. Fourier transform infrared (FTIR) measurements confirmed the formation of amino groups on the modified biochar surface. The kinetic research demonstrated that both the modified Gompertz and logistic function models fit the experimental data satisfactorily except for 150 SD-NH2 alone or in combination with α-Fe2O3 at a concentration of 10 mg/L. The data suggested that adding unmodified biochar at doses of 50 and 100 mg significantly increased biogas yield compared to untreated algae. The maximum biogas generation (219 mL/g VS) was obtained when 100 mg of unmodified biochar was mixed with 10 mg of α-Fe2O3 in the inoculum.

Author(s):  
Christian C. Opurum

This research paper aimed to evaluate the kinetics of anaerobic digestion (AD) of mixtures of cabbage waste (CW) with (Poultry dropping (PD) and Cow dung (CD). The study was conducted in 10L bio-digesters for 35 days under mesophilic conditions (25 - 35OC). Logistic function equation was used to simulate the experimental data to test for its goodness of fit and kinetic parameters namely: maximum biogas potential (Pb), the maximum biogas production rate (Rm), and the lag phase duration (λ) were estimated in each treatment. Chemical analysis showed that individual substrates possess characteristics that could support microbial activities in biogas production. The biogas yield in terms of added  volatile solids (VS) in decreasing order was as follows: 0.022, 0.018, 0.017, 0.014, 0.014 and 0.013 dm3/g VS for CW/CD 2:1, CW/PD3:1, CW/CD 1:1, CW alone, CW/PD1:1 and  CW/PD 2:1, respectively. A significant difference (P ≤ 0.05) in biogas yield was recorded in CW/CD 2:1 with 7.19 dm3 (53.29% increase). The kinetic parameters (Pb, Rm, and λ) for CW/CD 2:1 was 7.01 dm3, 1.58 dm3.d, and 2.29 days, respectively. This was followed by CW/PD 3:1 (5.84 dm3); with 24.92% increase in gas production and CW/CD 1:1 (5.42 dm3) with 15.53% increase relative to CW alone, 4.69 dm3. The digesters fed with CW/PD 1:1 and CW/PD 2:1 exhibited inhibitory effects on biogas production, with 7.51 and 2.05% decrease in gas yield, respectively. The logistic function model demonstrated a strong relationship between the experimental and model-predicted data. The high correlation coefficient (R2) ranging between 0.978 - 0.993 is evident. The model proved to be a useful tool in predicting anaerobic digestion and biogas production process.


Author(s):  
Christian C. Opurum ◽  
Christian O. Nweke ◽  
Christopher E. Nwanyanwu ◽  
Nkemakolam A. Nwogu

This study evaluated the kinetics of diauxic-like pattern of biogas production from energy crops, Sunflower (SF) and Napier grass (NG) with cow dung (CD). The tests were performed in a batch reactor (R) operation for 60 days in R1 - R4 and 53 days in R5 - R8 under mesophilic conditions (24 - 36OC). The characteristics of the tested energy crops suggest that they hold prospects for bioenergy production. The cumulative biogas yield/gVS showed that the best performance was R1 with a biogas yield of 15.17 dm3 (0.046 dm3/gVS) followed by R3, 13.90 dm3 (0.041 dm3/gVS) and R2, 11.01dm3 (0.032 dm3/gVS). A significant difference (P ≤ 0.05) in biogas yield was found in the reactors charged with SF/CD as against SF only. In the reactors that exhibited biphasic biogas production profile, two (2) kinetic parameters, K1 and K2 were determined by the bi-logistic function model. It was observed that the predicted values in the second phase (K2) of biogas production were considerably higher than the first phase (K1) in R2 - R5 as opposed to R6 - R8, which implies more biogas yield in phase 2 than phase 1. The results indicate that anaerobic digestion of SF and NG had a strong positive influence on biogas yield, BP, PR and λ1 but not for λ2. The bi-logistic function model suitably fitted the experimental data with a high correlation coefficient (R2) in the range of 0.986 - 0.997. Based on the kinetic parameters, the bi-logistic function model is well suited for the simulation of diauxic-like biogas production process.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5001
Author(s):  
Mohamed A. Hassaan ◽  
Antonio Pantaleo ◽  
Francesco Santoro ◽  
Marwa R. Elkatory ◽  
Giuseppe De Mastro ◽  
...  

The aim of this study was to analyze the effect of ZnO nanoparticles (ZnO NPs) on the biogas production from mechanically treated barley straw and to perform a techno-economic analysis based on the costs assessment and on the results of biogas production. The structural changes of mechanically pretreated barley straw were observed using FTIR, XRD, TGA, and SEM. Additionally, both green ZnO NPs prepared from red alga (Antithamnion plumula) extract and chemically prepared ZnO NPs were characterized by FTIR, XRD, SEM, and TEM, surface area, and EDX. The results revealed that the biogas production was slightly improved by 14.9 and 13.2% when the barley straw of 0.4 mm was mechanically pretreated with 10 mg/L of both green and chemical ZnO NPs and produced 390.5 mL biogas/g VS and 385 mL biogas/g VS, respectively. On the other hand, the higher concentrations of ZnO NPs equal to 20 mg/L had an inhibitory effect on biogas production and decreased the biogas yield to 173 mL biogas/g VS, which was less than the half of previous values. It was also clear that the mechanically treated barley straw of 0.4 mm size presented a higher biogas yield of about 340 mL/g VS, in comparison to 279 mL biogas/g VS of untreated biomass. The kinetic study showed that the first order, modified Gompertz and logistic function models had the best fit with the experimental data. The results showed that the nanoparticles (NPs) of the mechanically treated barely straw are a suitable source of biomass for biogas production, and its yields are higher than the untreated barley straw. The results of the cost-benefit analysis showed that the average levelized cost of energy (LCOE), adopting the best treatments (0.4 mm + 10 mg/L ZnO), is 0.21 €/kWh, which is not competitive with the other renewable energy systems in the Egyptian energy market.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 781
Author(s):  
Xinli Yang ◽  
Nan Wu ◽  
Yongxia Miao ◽  
Haobo Li

Tungsten oxide (WO3) and boron oxide (B2O3) were irreversibly encapsulated into the nanocages of the Zr-based metal organic framework UiO-66, affording a hybrid material B2O3-WO3/UiO-66 by a simple microwave-assisted deposition method. The novel B2O3-WO3/UiO-66 material was systematically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption, ultraviolet–visible diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray phosphorescence, and Fourier transform infrared (FTIR)-CO adsorption methods. It was found that WO3 and B2O3 were highly dispersed in the nanocages of UiO-66, and the morphology and crystal structure of UiO-66 were well preserved. The B2O3 species are wrapped by WO3 species, thus increasing the polymeric degree of the WO3 species, which are mainly located in low-condensed oligomeric environments. Moreover, when compared with WO3/UiO-66, the B2O3-WO3/UiO-66 material has a little weaker acidity, which decreased by 10% upon the B2O3 introduction. The as-obtained novel material exhibits higher catalytic performance in the cyclopentene selective oxidation to glutaraldehyde than WO3/UiO-66. The high catalytic performance was attributed to a proper amount of B2O3 and WO3 with an appropriate acidity, their high dispersion, and the synergistic effects between them. In addition, these oxide species hardly leached in the reaction solution, endowing the catalyst with a good stability. The catalyst could be used for six reaction cycles without an obvious loss of catalytic activity.


2017 ◽  
Vol 71 (10) ◽  
pp. 2404-2410 ◽  
Author(s):  
Erik A. Taylor ◽  
Ashley A. Lloyd ◽  
Carolina Salazar-Lara ◽  
Eve Donnelly

Raman and Fourier transform infrared (FT-IR) spectroscopic imaging techniques can be used to characterize bone composition. In this study, our objective was to validate the Raman mineral:matrix ratios (ν1 PO4:amide III, ν1 PO4:amide I, ν1 PO4:Proline + hydroxyproline, ν1 PO4:Phenylalanine, ν1 PO4:δ CH2 peak area ratios) by correlating them to ash fraction and the IR mineral:matrix ratio (ν3 PO4:amide I peak area ratio) in chemical standards and native bone tissue. Chemical standards consisting of varying ratios of synthetic hydroxyapatite (HA) and collagen, as well as bone tissue from humans, sheep, and mice, were characterized with confocal Raman spectroscopy and FT-IR spectroscopy and gravimetric analysis. Raman and IR mineral:matrix ratio values from chemical standards increased reciprocally with ash fraction (Raman ν1 PO4/Amide III: P < 0.01, R2 = 0.966; Raman ν1 PO4/Amide I: P < 0.01, R2 = 0.919; Raman ν1 PO4/Proline + Hydroxyproline: P < 0.01, R2 = 0.976; Raman ν1 PO4/Phenylalanine: P < 0.01, R2 = 0.911; Raman ν1 PO4/δ CH2: P < 0.01, R2 = 0.894; IR P < 0.01, R2 = 0.91). Fourier transform infrared mineral:matrix ratio values from native bone tissue were also similar to theoretical mineral:matrix ratio values for a given ash fraction. Raman and IR mineral:matrix ratio values were strongly correlated ( P < 0.01, R2 = 0.82). These results were confirmed by calculating the mineral:matrix ratio for theoretical IR spectra, developed by applying the Beer–Lambert law to calculate the relative extinction coefficients of HA and collagen over the same range of wavenumbers (800–1800 cm–1). The results confirm that the Raman mineral:matrix bone composition parameter correlates strongly to ash fraction and to its IR counterpart. Finally, the mineral:matrix ratio values of the native bone tissue are similar to those of both chemical standards and theoretical values, confirming the biological relevance of the chemical standards and the characterization techniques.


2013 ◽  
Vol 46 (4) ◽  
pp. 118-122
Author(s):  
Ondrej Cundr ◽  
Dagmar Haladova

Abstract The main objective of this work was to test the suitability of rice husk waste biomass for anaerobic digestion and to examine the energy potential of the co-digestion of rice husk with zebu dung. Rice husk and zebu dung were studied under batch anaerobic conditions as separate wastes as well as mixed in various proportions. All experiments were carried out at 5% of total solids. The methane yield achieved by single substrate digestion of rice husk and zebu dung was 13.9 l and 44.58 l CH4/kg volatile solids (VS), respectively. The co-digestion of 50% total solids (TS) rice straw with 50% total solids zebu dung gave the result of 38.42 l CH4/kg VS. According to these results, the degradation and methane production potential of rice husk were not sufficient and it was found that this residue material is less suitable for single substrate digestion without additional pretreatment than for co-digestion. Even if co-digestion of rice husk with zebu dung improved the digestibility of rice husk and hence increased the biogas production, the methane yield was lower in comparison with the result for zebu dung, due to the high lignin content in rice husk. Nevertheless, the proof of digestibility of rice husk showed the possibility of rational exploitation of this waste material.


2021 ◽  
Author(s):  
◽  
Edward Kwaku Armah

With the increasing demand for clean and affordable energy which is environmentally friendly, the use of renewable energy sources is a way for future energy generation. South Africa, like most countries in the world are over-dependent on the use of fossil fuels, prompting most current researchers to seek an affordable and reliable source of energy which is also,a focal point of the United Nations Sustainable Development Goal 7. In past decades, the process of anaerobic digestion (AD) also referred to as monodigestion, has proven to be efficient with positive environmental benefits for biogas production for the purpose of generating electricity, combined heat and power. However, due to regional shortages, process instability and lower biogas yield, the concept of anaerobic co-digestion (AcoD) emerged to account for these drawbacks. Given the considerable impact that industrial wastewater (WW) could provide nutrients in anaerobic biodigesters, the results of this study could apprise decisionmakers and the government to further implement biogas installations as an alternative energy source. The study aims at optimising the biogas production through AcoD of the agricultural biomasses: sugarcane bagasse (SCB) and corn silage (CS) with industrial WW sourced from Durban, KwaZulu-Natal, South Africa. The study commenced with the characterisation of the biomasses under this study with proximate and ultimate analysis using the Fourier transform infrared spectroscopy (FTIR), the thermo gravimetric analysis (TGA), the scanning electron microscopy (SEM) and the differential scanning calorimetry (DSC). The untreated biomass was subjected to biochemical methane potential (BMP) tests to optimise and predict the biogas potential for the selected biomass. A preliminary run was carried out with the agricultural biomass to determine which of the WW streams would yield the most biogas. Among the four WW streams sourced at this stage, two WW streams; sugar WW (SWW) and dairy WW (DWW) produced the highest volume of biogas in the increasing order; SWW ˃ DWW ˃ brewery WW > municipal WW. Therefore, both SWW and DWW were selected for further process optimisation with each biomass. Using the response surface methodology (RSM), the factors considered were temperature (25-55 °C) and organic loading rate (0.5-1.5 gVS/100mL); and the response was the biogas yield (m3 /kgVS). Maximum biogas yield and methane (CH4) content were found to be 5.0 m3 /kgVS and 79%, respectively, for the AcoD of CS with SWW. This established the association that existed among the set temperatures of the digestion process and the corresponding organic loading rate (OLR) of the AcoD process operating in batch mode. Both CS and SCB have been classified as lignocellulosic and thus, ionic liquid (IL) pretreatment was adapted in this study to ascertain their potential on the biogas yield. Results showed that the maximum biogas yield and CH4 content were found to be 3.9 m3 /kgVS and 87%, respectively, after IL pretreatment using 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) for CS with DWW at 55°C and 1.0 gVS/100mL. The IL pretreatment yielded lower biogas but of higher purity of CH4 than the untreated biomass. Data obtained from the BMP tests for the untreated and pretreated biomasses were tested with the existing kinetic models; first order, dual pooled first order, Chen and Hashimoto and the modified Gompertz. The results showed that for both untreated and pretreated biomass, the modified Gompertz had the best fit amongst the four models tested with coefficient of correlation, R 2 values of 0.997 and 0.979, respectively. Comparatively, the modified Gompertz model could be the preferred model for the study of industrial WW when used as co-substrate during AcoD for biogas production. The study showed that higher biogas production and CH4 contents were observed when CS was employed as a reliable feedstock with maximum volume of the untreated and pretreated feedstock reported at 31 L and 20 L respectively.


Author(s):  
Virginija SKORUPSKAITĖ ◽  
Eglė SENDŽIKIENĖ ◽  
Milda GUMBYTĖ

The secondary raw materials of fish can be used for various purposes in food industry, agriculture, etc. No less important way for usage of secondary raw fish, dead fish and fish farming sludge is the utilization of mentioned feedstocks for energy purposes, i.e. biofuels production. In this reearch, the possibilities of the consumption of dead fish and fish farming sludge for biodiesel and biogas production has been studied. The influence of the basic biodiesel production parameters, including the methanol to oil molar ratio, amount of catalyst, temperature and process duration on transesterification yield was determined. The guantitative and gualitative research of biogas production using different substrates such as fish waste, fish farming sludge and substrates composed of fish waste (de-oiled and non de-oiled biomass)+fish farming sludge and fish farming sludge+wastewater sludge was performed. The biodiesel yield higher than 96.5% could be achieved under the following process conditions: methanol/oil molar ratio – 4:1, amount of enzyme content – 7% from oil mass, temperature – 40 ° C, reaction time – 24 hours. The highest biogas yield (1224 ml/gVS) was determined using wet fish waste biomass and mixed substrates consisted of fish waste and fish farming sludge. The results of qualitative biogas research revealed, that biogas produced from both homogeneous and heterogeneous substrates contained more than 60% of methane. The highest calorific value (app. 70% of methane) had biogas gained from fish waste biomass.


Author(s):  
Christian C. Opurum ◽  
Christian O. Nweke ◽  
Christopher E. Nwanyanwu ◽  
Nkemakolam A. Nwogu

In this study, anaerobic digestion (AD) of three livestock manure: (poultry manure (PM), pig dung (PD), and cow dung (CD) was conducted at different mixed ratios under mesophilic (25-35°C) conditions. Two kinetic models, the modified Gompertz and bi-logistic function model were used to simulate the cumulative biogas yield from the experiments, and model parameters simultaneously obtained. The biogas production profile appeared diauxic-like or biphasic with multiple peaks, revealing the complexity and multi-component nature of the substrates. There was an increase in biogas yield from the treatments, PD/CD 1:1; 37.25 dm3 (3.47%), PD/CD 3:1; 38.41 dm3 (6.96%), CD/PM 1:1; 26.76 dm3 (16.80%) and CD/PM 3:1 24.31 dm3 (6.11%), whereas PD/CD 2:1 (15.41 dm3) and CD/PM 2:1 (22.57 dm3) exhibited inhibitory effect. However, statistical analysis (ANOVA) indicated a significant difference in biogas yield from PD alone (36 dm3) compared to CD alone (22.91 dm3). The two models showed good performance in the simulation of the AD process, with high correlation coefficients, an indication of a very strong relationship between experimental data and model parameters. However, the bi-logistic function model showed a better fit in the simulation of the experimental values, as it was able to capture the curves in the plots, with a higher correlation coefficient R2 (0.9920 - 0.9985) than the modified Gompertz model (0.9797 - 0.9968). This work has shown that the phenomenon of diauxic growth in the anaerobic digestion of complex organic substrates could be captured quantitatively in the kinetic model using bi-logistic function model.


Sign in / Sign up

Export Citation Format

Share Document