The Staged Thermal Conversion of Sewage Sludge in the Presence of Oxygen

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Mateusz Wnukowski ◽  
Krystian Krochmalny ◽  
Mateusz Kowal ◽  
Marcin Baranowski ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Sewage Sludge ◽  
Thermal Processing ◽  
Thermal Conversion ◽  
Single Step ◽  
Energy Yield ◽  
Mass Yield ◽  
Optimal Conditions ◽  
Kinetics Of ◽  
By Products

This study compares a staged thermal processing of the sewage sludge, with single step, integrated thermal processing. The aim of this study is to find the optimal conditions for drying and subsequently for carbonization/torrefaction of sewage sludge, regarding the energy consumption. This study presents the results of the drying tests performed at laboratory scale convective dryer for different parameters of drying agent (air). The tests were focused on finding and developing a method of drying that allows to minimize the energy consumption. Subsequently, both dry and vapothermal torrefaction was performed in the presence of oxygen. The kinetics of drying, using low quality heat as well as the properties of products and by-products of torrefaction in both regimes were determined. The process was characterized by mass yield and energy yield in both of the cases. There has been only scarce amount of literature studies published on the torrefaction of sewage sludge so far, without a detailed study of the composition of the torgas and tars of such origin. Performed study enables a comparison of two distinct scenarios of the processing, i.e., drying followed by dry torrefaction with a single stage of vapothermal torrefaction.

scholarly journals Combustion Characteristics of Hydrochar and Pyrochar Derived from Digested Sewage Sludge

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4164 ◽  
Author(s):  
Pablo J. Arauzo ◽  
María Atienza-Martínez ◽  
Javier Ábrego ◽  
Maciej P. Olszewski ◽  
Zebin Cao ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Reaction Pathways ◽  
Energy Yield ◽  
Combustion Kinetics ◽  
Coal Blending ◽  
Carbon Recovery ◽  
And Storage ◽  
Kinetics Of ◽  
Digested Sewage Sludge ◽  
Lower Carbon

In this paper, hydrochars and pyrochars were produced at 260 °C under different residence times (2 and 4 h) using anaerobic digested sewage sludge (SSL) as initial feedstock. The effect of reaction time on the fuel properties of hydrochars and pyrochars was evaluated. Moreover, the combustion kinetics of raw SSL and the derived pyrochars and hydrochars without coal blending were determined at two different air flows (20 and 90 mL/min) and compared. In the same conditions, the yield of hydrochar was significantly lower than that of pyrochar, confirming the different reaction pathways followed in each process. The results showed hydrochars have lower carbon recovery and energy yield than pyrochars, making the latter more suitable for energy purposes. The thermogravimetric combustion study showed that both thermochemical treatments increased the ignition temperature but decreased the burnout temperature, which results in higher stability during handling and storage. However, raw SSL is better for combustion than hydrochar according to the combustibility index. In addition, the kinetic study showed that the activation energy of the combustion of biochars, especially pyrochar, is lower than that of raw SSL, which is advantageous for their combustion.

scholarly journals Analysis of Biohydrogen Production Potential from Organic Wastes Generated in Korea

2021 ◽  
Vol 43 (9) ◽  
pp. 591-600
Author(s):  
Jimin Kim ◽  
Seongwon Im ◽  
Alsayed Mostafa ◽  
Om Prakash ◽  
Dong-Hoon Kim
Keyword(s):  
Energy Consumption ◽  
Sewage Sludge ◽  
Food Waste ◽  
H2 Production ◽  
Biohydrogen Production ◽  
Energy Yield ◽  
Generation Process ◽  
Livestock Manure ◽  
H2 Generation ◽  
Reducing Potential

Objectives : To mitigate greenhouse gas (GHG) emissions, our country is trying to replace fossil fuel to hydrogen (H2). H2 has higher energy yield (122 MJ/kg) than other energy sources (natural gas, coal, etc.), and is considered a clean fuel that produces only water upon combustion. The water electrolysis using renewable energy is one of the green-H2 producing methods, but its unstable characteristics depending on weather condition impede its practical application. Therefore, to establish green-H2 society, the use of waste and biomass is essential to fulfil the demand.Methods : In this study, we estimated the biohydrogen potential of organic solid wastes: food waste, livestock manure, and sewage sludge, which are the main feedstock of domestic biogas plant. For the H2 generation process, dark fermentation (DF) and steam biogas reforming (SBR) were considered.Results and Discussion : The potential amount of H2 through DF and SBR was 44,000 ton/y and 675,000 ton/y, respectively. The GHG reducing potential was estimated to be 5 million tons CO2-eq/year, but it can be lowered down to 2 million tons CO2-eq/year, considering the energy consumption during H2 generation process. Among the energy potential of produced H2, 7% and 60% is required for H2 production in DF and SBR, respectively.Conclusion : The expected biohydrogen production was 718,000 ton/y which can account for about 14% of the domestic H2 production target in 2040 (526 million tons). The main source was livestock manure (86%), and minor fraction was from food waste (10%), and sewage sludge (4%). The GHG reducing potential was estimated to be 2 million tons CO2-eq/year, considering the energy consumption during H2 generation process.

Advanced sludge thermal processes in Japan

1994 ◽  
Vol 30 (8) ◽  
pp. 139-148 ◽  
Author(s):  
M. Hiraoka
Keyword(s):  
Sewage Sludge ◽  
Thermal Processing ◽  
Thermal Processes ◽  
Recycling Process ◽  
Sludge Management ◽  
Processing Technologies ◽  
Process Systems ◽  
Incineration Process ◽  
Treatment And Disposal ◽  
Melting Slag

As a result of the spread of sewerage systems, the management of growing quantities of sewage sludge is becoming an urgent need. As the method of sludge management, thermal processes have mostly been applied to the treatment and disposal of sewage sludge in Japan, because of the difficulty of finding final disposal sites. This paper describes the progress of thermal processing technologies, especially focusing on drying-incineration process systems and melting-slag recycling process systems.

scholarly journals Optimization of banana crop by-products solvent extraction for the production of bioactive compounds

2021 ◽  
Author(s):  
Sara Díaz ◽  
Antonio N. Benítez ◽  
Sara Ramírez-Bolaños ◽  
Lidia Robaina ◽  
Zaida Ortega
Keyword(s):  
Antioxidant Activity ◽  
Aqueous Ethanol ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Total Phenol Content ◽  
Optimal Conditions ◽  
Satisfactory Description ◽  
Optimized Conditions ◽  
By Products ◽  
Banana Crops

AbstractThe aim of this work is the optimization of phenolic compound extraction from three by-products of banana crops (rachis, discarded banana, and banana’s pseudostem pulp), as a way to valorize them through a green extraction process. The influence of the temperature and aqueous ethanol concentration (Et-OH) on extract properties (total phenol content (TPC) and antioxidant activity) was firstly analyzed. 78 ℃ and ethanol concentrations close to 50% yielded the best results for the three materials. The equations obtained by the response surface methodology gave a satisfactory description of the experimental data, allowing optimizing the extraction conditions. Under optimized conditions, time influence was then assessed, although this parameter seemed not influence results. Among the three by-products, rachis extract (60% Et-OH, 78 ℃, and 30 min) presented the highest TPC (796 mg gallic acid/100 g of dried material) and antioxidant activity (6.51 mg Trolox equivalents/g of dried material), followed by discarded banana, and pseudostem pulp. Under the optimal conditions, experiments were performed at a larger scale, allowing to determine the extraction yields (EY) and to characterize the extracts. The highest EY was obtained for the rachis (26%), but the extract with the highest activity was obtained for discarded banana (50% Et-OH, 78 ℃, and 60 min), which presented a TPC of 27.26 mg/g extract corresponding to 54.59 mg Trolox equivalents/g extract. This study contributes to the valorization of banana crops residues as a source of polyphenolic compounds with bioactive functions that can be extracted under economic extraction conditions. Graphical abstract

scholarly journals Synthesis and Polymerization Kinetics of Rigid Tricyanate Ester

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Single Step ◽  
Polymerization Kinetics ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Diffusion Controlled ◽  
Polymerization Product ◽  
The One ◽  
Kinetics Of

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.

scholarly journals Kinetics of Microcystin-LR Removal in a Real Lake Water by UV/H2O2 Treatment and Analysis of Specific Energy Consumption

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 810
Author(s):  
Sabrina Sorlini ◽  
Carlo Collivignarelli ◽  
Marco Carnevale Miino ◽  
Francesca Maria Caccamo ◽  
Maria Cristina Collivignarelli
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Lake Water ◽  
Harmful Effect ◽  
Specific Energy Consumption ◽  
World Health ◽  
Oh Radicals ◽  
H2o2 Treatment ◽  
Initial Concentration ◽  
Kinetics Of

The hepatotoxin microcystin-LR (MC-LR) represents one of the most toxic cyanotoxins for human health. Considering its harmful effect, the World Health Organization recommended a limit in drinking water (DW) of 1 µg L−1. Due to the ineffectiveness of conventional treatments present in DW treatment plants against MC-LR, advanced oxidation processes (AOPs) are gaining interest due to the high redox potential of the OH• radicals. In this work UV/H2O2 was applied to a real lake water to remove MC-LR. The kinetics of the UV/H2O2 were compared with those of UV and H2O2 showing the following result: UV/H2O2 > UV > H2O2. Within the range of H2O2 tested (0–0.9 mM), the results showed that H2O2 concentration and the removal kinetics followed an increasing quadratic relation. By increasing the initial concentration of H2O2, the consumption of oxidant also increased but, in terms of MC-LR degraded for H2O2 dosed, the removal efficiency decreased. As the initial MC-LR initial concentration increased, the removal kinetics increased up to a limit concentration (80 µg L−1) in which the presence of high amounts of the toxin slowed down the process. Operating with UV fluence lower than 950 mJ cm−2, UV alone minimized the specific energy consumption required. UV/H2O2 (0.3 mM) and UV/H2O2 (0.9 mM) were the most advantageous combination when operating with UV fluence of 950–1400 mJ cm−2 and higher than 1400 mJ cm−2, respectively.

Effect of Diethylstilbestrol on Utilization of Energy by the Growing Chick

1958 ◽  
Vol 195 (3) ◽  
pp. 654-658 ◽  
Author(s):  
F. W. Hill ◽  
L. B. Carew ◽  
A. van Tienhoven
Keyword(s):  
Energy Consumption ◽  
Linear Function ◽  
Heat Production ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Yield ◽  
Net Energy ◽  
Lower Protein ◽  
Energy Gains ◽  
Total Tissue

Increased fat production in diethylstilbestrol-treated chicks was found to be due primarily to increased energy consumption and to a lesser extent to preferential synthesis of fat at the expense of protein tissue. This was shown in experiments comparing normal and estrogen-treated male chicks with respect to gains in live weight, fat and protein at two planes of nutrition, and the yield of metabolizable and productive (net) energy which they obtained from the diet. It was found that the fattening effect could not be due to increased digestibility, increased net energy yield from absorbed nutrients, or lowered heat production. Under the influence of estrogen, total tissue gain expressed in Calories was increased, and was composed of greater fat gain and lower protein gain. Tissue energy gains were a linear function of metabolizable energy consumption. This relationship predicted equal tissue energy gains under pair-feeding conditions, which was confirmed experimentally.

Sign in / Sign up

Export Citation Format

Share Document