Towards a more efficient Hydrothermal Carbonization: Processing water recirculation under different conditions

2021 ◽  
Vol 132 ◽  
pp. 115-123
Author(s):  
M. Boutaieb ◽  
S. Román ◽  
B. Ledesma ◽  
E. Sabio ◽  
M. Guiza ◽  
...  
Keyword(s):  
Hydrothermal Carbonization ◽  
Water Recirculation ◽  
Processing Water

Thermal behavior of hydrochar from co-hydrothermal carbonization of swine manure and sawdust: effect of process water recirculation

2019 ◽  
Vol 3 (9) ◽  
pp. 2329-2336 ◽  
Author(s):  
Qianqian Lang ◽  
Hainan Luo ◽  
Yi Li ◽  
Dong Li ◽  
Zhengang Liu ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Swine Manure ◽  
Hydrothermal Carbonization ◽  
Process Water ◽  
Combustion Behavior ◽  
Water Recirculation

Process water recirculation during co-HTC of swine manure and sawdust changed the combustion behavior of hydrochar.

scholarly journals Comparative Life Cycle Assessment of HTC Concepts Valorizing Sewage Sludge for Energetic and Agricultural Use

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 786 ◽  
Author(s):  
Kathleen Meisel ◽  
Andreas Clemens ◽  
Christoph Fühner ◽  
Marc Breulmann ◽  
Stefan Majer ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Ghg Emissions ◽  
Hydrothermal Carbonization ◽  
Additional Energy ◽  
Sludge Digestion ◽  
Water Recirculation ◽  
Agricultural Use ◽  
Agricultural Yields ◽  
Direct Use ◽  
Positive Effect

In many countries, sewage sludge is directly used for energy and agricultural purposes after dewatering or digestion and dewatering. In recent years, there has been a growing interest in additional upstream hydrothermal carbonization (HTC), which could lead to higher yields in the energetic and agricultural use. Twelve energetic and agricultural valorization concepts of sewage sludge are defined and assessed for Germany to investigate whether the integration of HTC will have a positive effect on the greenhouse gas (GHG) emissions. The study shows that the higher expenses within the HTC process cannot be compensated by additional energy production and agricultural yields. However, the optimization of the HTC process chain through integrated sewage sludge digestion and process water recirculation leads to significant reductions in GHG emissions of the HTC concepts. Subsequently, nearly the same results can be achieved when compared to the direct energetic use of sewage sludge; in the agricultural valorization, the optimized HTC concept would be even the best concept if the direct use of sewage sludge will no longer be permitted in Germany from 2029/2032. Nevertheless, the agricultural valorization concepts are not generally advantageous when compared to the energetic valorization concepts, as it is shown for two concepts.

Effects of process water recirculation on solid and liquid products from hydrothermal carbonization of Laminaria

2019 ◽  
Vol 292 ◽  
pp. 121996 ◽  
Author(s):  
Fengbo Wang ◽  
Jing Wang ◽  
Chen Gu ◽  
Ying Han ◽  
Shuaijun Zan ◽  
...  
Keyword(s):  
Hydrothermal Carbonization ◽  
Process Water ◽  
Liquid Products ◽  
Water Recirculation

scholarly journals Process Water Recirculation during Hydrothermal Carbonization of Waste Biomass: Current Knowledge and Challenges

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2962
Author(s):  
Antonio Picone ◽  
Maurizio Volpe ◽  
Antonio Messineo
Keyword(s):  
Current Knowledge ◽  
Hydrothermal Process ◽  
Hydrothermal Carbonization ◽  
Process Water ◽  
Residual Fraction ◽  
Waste Biomass ◽  
Carbon Recovery ◽  
Thermochemical Processing ◽  
Water Recirculation ◽  
Additional Water

Hydrothermal carbonization (HTC) is considered as an efficient and constantly expanding eco-friendly methodology for thermochemical processing of high moisture waste biomass into solid biofuels and valuable carbonaceous materials. However, during HTC, a considerable amount of organics, initially present in the feedstock, are found in the process water (PW). PW recirculation is attracting an increasing interest in the hydrothermal process field as it offers the potential to increase the carbon recovery yield while increasing hydrochar energy density. PW recirculation can be considered as a viable method for the valorization and reuse of the HTC aqueous phase, both by reducing the amount of additional water used for the process and maximizing energy recovery from the HTC liquid residual fraction. In this work, the effects of PW recirculation, for different starting waste biomasses, on the properties of hydrochars and liquid phase products are reviewed. The mechanism of production and evolution of hydrochar during recirculation steps are discussed, highlighting the possible pathways which could enhance energy and carbon recovery. Challenges of PW recirculation are presented and research opportunities proposed, showing how PW recirculation could increase the economic viability of the process while contributing in mitigating environmental impacts.

scholarly journals Process Water Recirculation During Hydrothermal Carbonization as a Promising Process Step Towards the Production of Nitrogen-Doped Carbonaceous Materials

2021 ◽  
Author(s):  
Wüst Dominik ◽  
Arauzo Pablo ◽  
Habicht Sonja ◽  
Cazaña Fernando ◽  
Fiori Luca ◽  
...  
Keyword(s):  
Hydrothermal Carbonization ◽  
Added Value ◽  
Process Water ◽  
Carbonaceous Materials ◽  
Process Step ◽  
Nitrogen Doped ◽  
Physico Chemical ◽  
Spent Grains ◽  
Liquid Products ◽  
Water Recirculation

AbstractHydrothermal Carbonization (HTC) refers to the conversion of biogenic wastes into char-like solids with promising perspectives for application, but a process water (PW) results which is difficult to dispose untreated. Thus, a biorefinery approach including one or two recirculation steps with the additional objective of improving the physico-chemical characteristics of the solid was performed in this study. During HTC, constitutive molecules such as saccharides, proteins and lignin of Brewer’s Spent Grains decompose into hundreds of organic compounds, following complex reactions. To get deeper insights a combination of proximate, ultimate and structural analysis for solid products as well as liquid chromatography for liquid products were the choice. The main reactions could be identified by key compounds of low and high molecular weight resulting from hydrolysis, dehydration, decarboxylation, deamination as well as amide formation and condensation reactions. Their intensity was influenced by the feedwater pH and reaction temperature. Via reactions of Maillard character up to around 90% of the dissolved nitrogen of the recirculated process water at 200, 220 and 240 °C result in the formation of nitrogen containing heterocycles or rather Quartnernary nitrogen incorporated into the hydrochar (HC). Thus, already one recirculation step during HTC at 240 °C promises the fabrication of high added-value materials, i.e. nitrogen doped carbonaceous materials. Graphic Abstract

scholarly journals Process Water Recirculation During Hydrothermal Carbonization as a Promising Process Step Towards the Production of N-doped Carbonaceous Materials

2021 ◽  
Author(s):  
Dominik Wüst ◽  
Pablo Arauzo ◽  
Sonja Habicht ◽  
Fernando Cazana ◽  
Luca Fiori ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrothermal Carbonization ◽  
Added Value ◽  
Process Water ◽  
Chemical Characteristics ◽  
Carbonaceous Materials ◽  
Process Step ◽  
Physico Chemical ◽  
Liquid Products ◽  
Water Recirculation

Abstract Hydrothermal Carbonization (HTC) refers to the conversion of biogenic wastes into char-like solids with promising perspectives for application, but a process water (PW) results which is difficult to dispose untreated. Thus, a biorefinery approach including one or two recirculation steps with the additional objective of improving the physico-chemical characteristics of the solid was performed. During HTC, constitutive biomass molecules decompose into hundreds of organic compounds, following complex reactions. To get deeper insights a combination of proximate, ultimate and structural analysis for solid products as well as liquid chromatography for liquid products were the choice. The main reactions could be identified by key compounds of low and high molecular weight resulting from hydrolysis, dehydration, decarboxylation, deamination as well as amide formation and condensation reactions. Their intensity was influenced by the feedwater pH and reaction temperature. Reactions of Maillard character result in N-containing heterocycles incorporated into the hydrochar (HC), which promises the fabrication of high added-value materials, i.e. N-doped carbonaceous materials.

Features of system for water recirculation in thermal power plant ‘Morava’ on the right bank of River Velika Morava

2013 ◽  
Vol 8 (3-4) ◽  
pp. 342-349
Author(s):  
L. Andjelic ◽  
M. Pavlovic ◽  
B. Babovic
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Drainage System ◽  
Water Quantity ◽  
Hydraulic Transport ◽  
Productive Force ◽  
Recirculation System ◽  
Water Recirculation ◽  
The Right

The thermal power plant ‘Morava’, with a productive force of 125 MW, is located on the right bank of the River Velika Morava, near the city of Svilajnac, Serbia. This power plant uses coal for production. Ash and slag from the coal are burned and go to a landfill by hydraulic transport. The ratio of the liquid/solid mixture is 10:1. Towards the reduction of water quantity taken from the Velika Morava river for hydraulic transport, it's provided to build a water recirculation system for overflow and drainage water from landfill to power plant. In this paper, the results of the hydraulic study of water balance in landfill is shown. The goal of this study is to assess the water quantity in landfill, which can then be reused for hydraulic transport. For dimensioning of drainage system and overflow building on landfill, it was necessary to perform detailed analysis of rainfall and filtration throw landfill. With results of water quantity in drainage system, and overflow water, all parts of the recirculation system of water, from landfill to power plant, was performed. Also, in this paper are the data of hydraulic transport of mixture of water and ash/slag.

scholarly journals Transformation of Contaminants of Emerging Concern (CECs) during UV-Catalyzed Processes Assisted by Chlorine

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1432
Author(s):  
Edyta Kudlek
Keyword(s):  
Hydrogen Peroxide ◽  
Water Samples ◽  
Water Environment ◽  
Toxicity Assessment ◽  
Contaminants Of Emerging Concern ◽  
Post Processing ◽  
Processing Water ◽  
Living Organisms ◽  
Trace Concentrations ◽  
By Products

Every compound that potentially can be harmful to the environment is called a Contaminant of Emerging Concern (CEC). Compounds classified as CECs may undergo different transformations, especially in the water environment. The intermediates formed in this way are considered to be toxic against living organisms even in trace concentrations. We attempted to identify the intermediates formed during single chlorination and UV-catalyzed processes supported by the action of chlorine and hydrogen peroxide or ozone of selected contaminants of emerging concern. The analysis of post-processing water samples containing benzocaine indicated the formation of seven compound intermediates, while ibuprofen, acridine and β-estradiol samples contained 5, 5, and 3 compound decomposition by-products, respectively. The number and also the concentration of the intermediates decreased with the time of UV irradiation. The toxicity assessment indicated that the UV-catalyzed processes lead to decreased toxicity nature of post-processed water solutions.

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