scholarly journals Hydrothermal Carbonization (HTC) of Seaweed (Macroalgae) for Producing Hydrochar

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1805
Author(s):  
Neel Patel ◽  
Bishnu Acharya ◽  
Prabir Basu
Keyword(s):  
Batch Reactor ◽  
Reaction Times ◽  
Hydrothermal Carbonization ◽  
Process Conditions ◽  
Maritime Provinces ◽  
Heating Value ◽  
Direct Combustion ◽  
Ecological Problems ◽  
Liquid Slurry ◽  
Work Done

Waste seaweed that is collected at coastal regions of maritime provinces in Canada is creating ecological problems as it promotes an anoxic event, which produces nearly zero dissolved oxygen in water along with hydrogen sulfide emission. The work done in this study attempts to address this issue by producing a coal-like solid hydrochar and nutritious liquid slurry (processed water) by employing a rather recent thermo-chemical process called hydrothermal carbonization (HTC) on the seaweed. The HTC was carried out in a batch reactor system for three different reaction temperatures, 180 °C, 200 °C, 220 °C, and three different reaction times, 30, 60, and 120 min. Each of the produced hydrochars was characterized by different analytical methods. The effects of the process conditions on the yield and the properties of the hydrochar and process water were examined. The hydrochar produced at 220 °C and 120 min showed the highest carbon content (48.5%) and heating value (18.93 MJ/kg). The energy density and carbon to nitrogen (C/N) ratio in the hydrochar increased significantly as compared to raw seaweed. Moreover, HTC reduced the ash yield and volatile compounds of the seaweed. Thus, hydrochar can be used as a fuel for direct combustion, in soil remediation, or in carbon sequestration applications.

scholarly journals Hydrothermal Carbonization Brewer’s Spent Grains with the Focus on Improving the Degradation of the Feedstock

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3226 ◽  
Author(s):  
Pablo Arauzo ◽  
Maciej Olszewski ◽  
Andrea Kruse
Keyword(s):  
Water Content ◽  
Liquid Product ◽  
Reaction Times ◽  
Hydrothermal Carbonization ◽  
Heating Value ◽  
High Heating Value ◽  
Acid Addition ◽  
Spent Grains ◽  
Different Temperatures ◽  
Higher Temperature

Hydrochar is a very interesting product from agricultural and food production residues. Unfortunately, severe conditions for complete conversion of lignocellulosic biomass is necessary, especially compared to the conversion of sugar compounds. The goal of this work is to improve the conversion of internal carbohydrates by application of a two-steps process, by acid addition and slightly higher water content. A set of experiments at different temperatures (180, 200, and 220 °C), reaction times (2 and 4 h), and moisture contents (80% and 90%) was performed to characterize the solid (high heating value (HHV), elemental) and liquid product phase. Afterwards, acid addition for a catalyzed hydrolysis reaction during hydrothermal carbonization (HTC) and a two-steps reaction (180 and 220 °C) were tested. As expected, a higher temperature leads to higher C content of the hydrochar and a higher fixed carbon (FC) content. The same effect was found with the addition of acids at lower temperatures. In the two-steps reaction, a primary hydrolysis step increases the conversion of internal carbohydrates. Higher water content has no significant effect, except for increasing the solubility of ash components.

scholarly journals Conversion of organic fraction of municipal solid waste into solid fuel via hydrothermal carbonization

2019 ◽  
Author(s):  
Herlian Eriska ◽  
Kania Dewi ◽  
Enri Damanhuri ◽  
Ari Darmawan Pasek
Keyword(s):  
Municipal Solid Waste ◽  
Process Condition ◽  
Hydrothermal Carbonization ◽  
Mixture Component ◽  
Process Conditions ◽  
Organic Fraction ◽  
Heating Value ◽  
High Heating Value ◽  
High Heating ◽  
Solid Load

Hydrothermal carbonization (HTC) is thermochemical process that can convert wet biomass into coal-like material. In this study, a series of HTC experiments was done. In the first stage targeted to obtain the process condition for mixture component. The process conditions comprised temperature, solid load, and holding time. Five typical components were used as representative pseudo-components of organic fraction of municipal solid waste. Each of substrates was carried out on the prototype HTC reactor. Process condition took place tempera- ture at 190, 210 and 230 oC, with a holding time (30 and 60 minutes) and feed to water ratio (0.1, 0,2, 0.3). The result from first stage showed that the optimum process condition for mixture component were temperature 215 oC, 55 minutes, and solid load 0.16. The process conditions were applied for next stage. In the second stage, mixture component comprised 15% fruit peel, 10% food waste, 10% of office paper, 30% leaves, and 35% sawdust were used as feedstock. Model to determine process condition for mixture component and also to predict high heating value have been developed. The fuel characteristics and combustion behavior of HTC-derived hydrochars were eval- uated. Hydro-thermal carbonization of waste gave high heating value (HHV) with value of 20.24 MJ/kg higher than its raw 16.42 MJ/kg.

scholarly journals Sewage Sludge Valorization via Hydrothermal Carbonization: Optimizing Dewaterability and Phosphorus Release

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4417
Author(s):  
Taina Lühmann ◽  
Benjamin Wirth
Keyword(s):  
Sewage Sludge ◽  
Scale Up ◽  
Reaction Times ◽  
Hydrothermal Carbonization ◽  
Phosphorus Release ◽  
Process Conditions ◽  
The European Union ◽  
Relevant Effect ◽  
Input Material ◽  
Initial Ph

As the use of sewage sludge as a fertilizer in agriculture is increasingly restricted in the European Union, other ways to utilize this waste stream need to be developed. Sewage sludge is an ideal input material for the process of hydrothermal carbonization, as it can convert wet biomass into a solid energy carrier with increased mechanical dewaterability. Digested sewage sludge was hydrothermally carbonized at 160–200 °C for 30–60 min with initial pH levels of 1.93–8.08 to determine optimal reaction conditions for enhanced dewaterability and phosphorus release into the liquid phase. Design of experiments was used to develop response surface models, which can be applied to optimize the process conditions. For optimal dewaterability and phosphorus release, low initial pH values (pH 1.93) and mild temperatures around 170 °C are favorable. Because holding time had no statistically relevant effect, a dependency of reaction time was investigated. Though it did not yield substantially different results, it could be included in investigations of short reaction times prospectively. Low reaction temperatures and short holding times are desirable considering economic reasons for scale-up, while the high acid consumption necessary to achieve these results is unfavorable.

scholarly journals Hydrothermal carbonization of stabilized sludge and meat and bone meal

2016 ◽  
Vol 61 (No. 1) ◽  
pp. 21-28 ◽  
Author(s):  
J. Malaťák ◽  
T. Dlabaja
Keyword(s):  
Energy Use ◽  
Batch Reactor ◽  
Hydrothermal Carbonization ◽  
Wastewater Sludge ◽  
Process Conditions ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Lower Heating Value ◽  
Increasing Temperature

Hydrothermal carbonization is one of suitable methods for energy recovery of sewage sludge and meat and bone meal. The task of the article is to determine appropriate hydrothermal carbonization process conditions and their impact on the quality of the final product – so called biochar or hydrochar. Parameters of the two main phases – initiation and polymerization – were monitored. The basic fuel properties of the final solid products of hydrothermal carbonization were determined. To produce biochar by hydrothermal carbonization, multifunctional pressure vessel with accessories was used – a batch reactor BR-300. Process parameters of hydrothermal carbonization confirm the effect of increasing temperature to increase the lower heating value (LHV). Neither calorific values of meat and bone meal (17.22 MJ/kg), nor calorific values of digested stabilized sludge (12.14 MJ/kg) showed a significant increase after undergoing processing. The effect of reaction temperature on the LHV of the final product is significantly higher than that of residence time. The results show that the main factor affecting LHV of the fuel sample is the final amount of ash. Unlike the meat and bone the hydrothermal carbonization of the stabilized wastewater sludge is one of the effective processing methods for subsequent energy use.

scholarly journals Greener Solution to Waste Corn Stalks and Shortage of Asphalt Resource: Hydrochar Produced by Hydrothermal Carbonization as a Novel Performance Enhancer for Asphalt Binder

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1427
Author(s):  
Xiaoming Wu ◽  
Chichun Hu
Keyword(s):  
High Temperature ◽  
Reaction Temperature ◽  
Storage Stability ◽  
Asphalt Binder ◽  
Aging Effect ◽  
Experimental Tests ◽  
Hydrothermal Carbonization ◽  
Modified Asphalt ◽  
Direct Combustion ◽  
Aging Property

Utilization of waste corn stalks (CS) has seized extensive attention due to high annual output and hazardous impact of piling aside or direct combustion on environment. However, previously there has been a lot of emphasis on improvement of its energy efficiency as solid fuel while limited investigations are available which explore the possibility of applying corn stalks as performance enhancer in asphalt binder. The purpose of this study is to examine the potential of employing hydrochar as modifiers in asphalt binder by a series of experimental tests. In this study, two hydrochar were produced from corn stalks by a novel process called hydrothermal carbonization at a different reaction temperature. The two hydrochar and their responding hydrochar-modified asphalt (HCMA) were tested by chemical and rheological tests. Chemical analysis detected the interaction between hydrochar and binder factions, resulting in poor compatibility but satisfying anti-aging property. Even though hydrochar increased the viscosity of bitumen, implying worse workability, and caused poor storage stability, ameliorated performance of asphalt binder at high temperature by incorporating hydrochar was verified by various criteria such as higher performance grade (PG) failure temperature and lower non-recoverable creep compliance (Jnr). Moreover, higher reaction temperature makes hydrochar’s particles smaller and more homogeneous, which results in slightly lower enhanced high temperature performance, more satisfying workability, better storage stability, and greater anti-aging effect of hydrochar-modified asphalt. Eventually, this study provided a promising win-win solution to environment problems concerning corn stalk treatment and shortage of asphalt binder. Further exploration of methods to improve HCMA’s storage stability, real-scale corroboration on trial section and life cycle assessment of asphalt pavement containing hydrochar modifiers will be followed in the future.

Introduction to natural gas: A comparative study of its storage, fuel costs and emissions for a harbor tug

2013 ◽  
Author(s):  
Arun Kishore Eswara ◽  
S. C. Misra ◽  
U. S. Ramesh
Keyword(s):  
Natural Gas ◽  
Chemical Properties ◽  
Heating Value ◽  
Load Profile ◽  
Emission Efficiency ◽  
Adsorbed Gas ◽  
Efficiency Parameter ◽  
Physical And Chemical ◽  
Work Done ◽  
Fuel Costs

This paper discusses the science of natural gas, its composition and ways to determine and coherently express its physical and chemical properties. Pricing of natural gas is shown with regard to weight and energy. A 60 Ton harbor tug employing either a set of constant rpm engines for CPP operation, or a set of variable rpm engines for FPP operation, with a standard load profile is made the basis for discussion. Advantage of evaluating thermal efficiency of gas engines relative to the higher heating value of natural gas, as against its lower heating value is explained. A compendium of storage options and the resulting endurance with the use of natural gas forms such as liquified gas (LNG), compressed gas (CNG) and adsorbed gas (ANG) is presented. Steps to ascertain fuel consumption of the gas engines operated according to the load profile and an approach to evaluate and relate the quantities of LNG, CNG and ANG is shown. Fuel costs and emissions from the tug operation using natural gas as fuel are evaluated per month and compared with diesel and residual fuels. Green House Gas emissions as a summation of emission constituents from the natural gas fuelled tug operation is detailed, and its need emphasized. The concepts of useful work done, emission efficiency parameter and energy efficiency parameter, which may be helpful in the design of harbor tugs and similar service vessels are proposed. The emission efficiency parameter is evaluated and analyzed for the 60 ton harbor tug.

scholarly journals Influence of Hydrothermal Carbonization on Composition, Formation and Elimination of Biphenyls, Dioxins and Furans in Sewage Sludge

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1582 ◽  
Author(s):  
Heiner Brookman ◽  
Fabian Gievers ◽  
Volker Zelinski ◽  
Jan Ohlert ◽  
Achim Loewen
Keyword(s):  
Sewage Sludge ◽  
Organic Pollutants ◽  
Total Concentration ◽  
Hydrothermal Carbonization ◽  
Process Conditions ◽  
Limit Values ◽  
Composition Formation ◽  
Input Material ◽  
Dioxins And Furans ◽  
Toxicity Equivalent

In many areas of application, the influence of hydrothermal carbonization (HTC) on the composition of organic pollutants is still unexplored. In this study, sewage sludge (SS) was carbonized and the input as well as the hydrochar were examined for the organic pollutants: polychlorinated biphenyls (PCB), polychlorinated dibenzo-dioxins (PCDDs), and polychlorinated dibenzo-furans (PCDFs). The process temperatures of carbonization were 200 °C, 220 °C, and 240 °C and the holding time was 5 h for all tests. The total concentration of PCBs was relatively stable for all temperatures, whereas the toxicity equivalent (WHO-TEQ) at 200 °C and 220 °C increases compared to the input material. The strongest impact on toxicity was observed for PCDDs where concentrations were reduced for higher temperatures, whereas the toxicity increases by more than 16 times for temperatures of 240 °C. The concentrations and toxicity of PCDFs were reduced for all carbonization temperatures. In hydrochar from HTC at 240 °C, the limit values for the application of SS in German agriculture have been exceeded. The results indicate that the process conditions for HTC should be controlled also for SS with average contamination if the hydrochar is to be used as material, especially in agriculture.

Characterization of Silver Loaded Activated Carbon Prepared under Supercritical Water Condition

2019 ◽  
Vol 288 ◽  
pp. 59-64
Author(s):  
Narandalai Byamba-Ochir ◽  
Battseveen Buyankhishig ◽  
Nyamsuren Byambasuren ◽  
Enkhtuul Surenjav
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Supercritical Water ◽  
Fine Particles ◽  
Batch Reactor ◽  
Reaction Times ◽  
Acetate Solution ◽  
Reaction Rate Increase ◽  
Water Condition ◽  
Low Dielectric

The synthesis of silver nanoparticles loaded on the activated carbon (AC) surface were performed under SCW condition at 673 K and 31.15 MPa in a batch reactor. In supercritical region, fine particles are rapidly synthesized due to reaction rate increase at low dielectric constant of supercritical water. Samples were prepared with different concentrations of silver acetate solution and various reaction times. The synthesized silver loaded on AC particles were characterized by the Fourier transform infrared spectroscopy (FTIR),X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). FTIR spectrum of primary activated carbon, activated carbon treated under supercritical water condition and synthesized AC-Ag was compared. The particles size and crystallite size of silver deposited on AC surface were analyzed by TEM and XRD, respectively.

scholarly journals A Novel Approach of Bioesters Synthesis through Different Technologies by Highlighting the Lowest Energetic Consumption One

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4190
Author(s):  
Simona Popa ◽  
Andra Tamas ◽  
Vasile Simulescu ◽  
Dorin Jurcau ◽  
Sorina Boran ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Energy Consumption ◽  
Bubble Column ◽  
Batch Reactor ◽  
Reaction Times ◽  
Fatty Acid Esters ◽  
Bubble Column Reactor ◽  
Batch Reactors ◽  
Novel Approach ◽  
Microwave Reactors

Fatty acids esters have a wide application as bioplasticizers and biolubricants in different industries, obtained mainly in classic batch reactors, through an equilibrium complex reaction, that involves high temperatures, long reaction times, vigorously stirring, and much energy consumption. To overcome these shortcomings, we synthesized a series of fatty acid esters (soybean oil fatty acids being the acid components with various hydroxyl compounds) through novel low energy consumption technologies using a bubble column reactor, a microwave field reactor and for comparison meaning, a classic batch reactor. The obtained bioesters physicochemical properties were similar to one another, a good concordance among their rheological properties was obtained, but the energetic consumption is lower when using the bubble column or the microwave reactors instead of the classical batch reactor.

Optimal experimental design and artificial neural networks applied to the photochemically enhanced Fenton reaction

2001 ◽  
Vol 44 (5) ◽  
pp. 339-345 ◽  
Author(s):  
S. Göb ◽  
E. Oliveros ◽  
S.H. Bossmann ◽  
A.M. Braun ◽  
C.A.O. Nascimento ◽  
...  
Keyword(s):  
Neural Networks ◽  
Hydrogen Peroxide ◽  
Artificial Neural Networks ◽  
Fenton Reaction ◽  
Irradiation Time ◽  
Batch Reactor ◽  
Reaction System ◽  
Process Conditions ◽  
Minor Effect ◽  
Artificial Neural

Among advanced oxidation processes (AOPs), the photochemically enhanced Fenton reaction may be considered as one of the most efficient for the degradation of contaminants in industrial wastewater. This process involves a series of complex reactions. Therefore, an empirical model based on artificial neural networks has been developed for fitting the experimental data obtained in a laboratory batch reactor for the degradation of 2,4-dimethyl aniline (2,4-xylidine), chosen as a model pollutant. The model describes the evolution of the pollutant concentration during irradiation time as a function of the process conditions. It has been used for simulating the behavior of the reaction system in sensitivity studies aimed at optimizing the amounts of reactants employed in the process, an iron(III) salt and hydrogen peroxide, as well as the temperature. The results show that the process is most sensitive to the concentration of iron(III) salt and temperature, whereas the concentration of hydrogen peroxide has a minor effect.

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