The redistribution and migration mechanism of chlorine during hydrothermal carbonization of waste biomass and fuel properties of hydrochars

Energy ◽  
2021 ◽  
pp. 122578
Author(s):  
Yousheng Lin ◽  
Ya Ge ◽  
Qing He ◽  
Pengwei Chen ◽  
Hanmin Xiao
Keyword(s):  
Hydrothermal Carbonization ◽  
Fuel Properties ◽  
Waste Biomass ◽  
Migration Mechanism ◽  
And Migration

scholarly journals Sewage Sludge Treatment by Hydrothermal Carbonization: Feasibility Study for Sustainable Nutrient Recovery and Fuel Production

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2697
Author(s):  
Gabriel Gerner ◽  
Luca Meyer ◽  
Rahel Wanner ◽  
Thomas Keller ◽  
Rolf Krebs
Keyword(s):  
Liquid Phase ◽  
Sewage Sludge ◽  
Hydrothermal Carbonization ◽  
Economic Feasibility ◽  
Phosphorus Recovery ◽  
High Yield ◽  
Nutrient Recovery ◽  
Waste Biomass ◽  
Sludge Treatment ◽  
Sewage Sludge Treatment

Phosphorus recovery from waste biomass is becoming increasingly important, given that phosphorus is an exhaustible non-renewable resource. For the recovery of plant nutrients and production of climate-neutral fuel from wet waste streams, hydrothermal carbonization (HTC) has been suggested as a promising technology. In this study, digested sewage sludge (DSS) was used as waste material for phosphorus and nitrogen recovery. HTC was conducted at 200 °C for 4 h, followed by phosphorus stripping (PS) or leaching (PL) at room temperature. The results showed that for PS and PL around 84% and 71% of phosphorus, as well as 53% and 54% of nitrogen, respectively, could be recovered in the liquid phase (process water and/or extract). Heavy metals were mainly transferred to the hydrochar and only <1 ppm of Cd and 21–43 ppm of Zn were found to be in the liquid phase of the acid treatments. According to the economic feasibility calculation, the HTC-treatment per dry ton DSS with an industrial-scale plant would cost around 608 USD. Between 349–406 kg of sulfuric acid are required per dry ton DSS to achieve a high yield in phosphorus recovery, which causes additional costs of 96–118 USD. Compared to current sewage sludge treatment costs in Switzerland, which range between 669 USD and 1173 USD, HTC can be an economically feasible process for DSS treatment and nutrient recovery.

scholarly journals Study on the removal and transport and migration mechanism for As with activated sludge system

AMB Express ◽  
2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jin Zhang ◽  
Wei Wei ◽  
Shuang Lin ◽  
Jie Lu ◽  
Qing Hu
Keyword(s):  
Activated Sludge ◽  
Activated Sludge System ◽  
Migration Mechanism ◽  
And Migration

scholarly journals Transformation of Sulfur during Co-Hydrothermal Carbonization of Coal Waste and Food Waste

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2271
Author(s):  
Pretom Saha ◽  
Nepu Saha ◽  
Shanta Mazumder ◽  
M. Toufiq Reza
Keyword(s):  
Food Waste ◽  
Hydrothermal Carbonization ◽  
Fuel Properties ◽  
Organic Sulfur ◽  
Coal Waste ◽  
Total Sulfur ◽  
Transformation Mechanism ◽  
Wet Chemical ◽  
The Difference ◽  
Sulfur Transformation

Co-hydrothermal carbonization (Co-HTC) is an emerging technology for processing multiple waste streams together to improve their fuel properties in the solid product, known as hydrochar, compared to the hydrothermal carbonization (HTC) of those individual streams. Sulfur is considered one of the most toxic contaminants in solid fuel and the combustion of this sulfur results in the emission of SOx. It was reported in the literature that, besides the fuel properties, Co-HTC reduced the total sulfur content in the hydrochar phase significantly. However, the transformation of different forms of sulfur has not yet been studied. Therefore, this study investigated the transformation of different forms of sulfur under the Co-HTC treatment. In the study, the Co-HTC of food waste (FW) and two types of coal wastes (middle bottom (CW1) and 4 top (CW2)) were conducted at 180 °C, 230 °C and 280 °C for 30 min. Different forms of sulfur were measured by using elemental analysis (total sulfur), and a wet chemical method (sulfate sulfur and pyritic sulfur). The organic sulfur was measured by the difference method. The results showed that a maximum of 49% and 65% decrease in total sulfur was achieved for CW1FW and CW2FW, respectively, at 230 °C. Similar to the total sulfur, the organic sulfur was also decreased about 85% and 75% for CW1FW and CW2FW, respectively. Based on these results, a sulfur transformation mechanism under Co-HTC treatment was proposed.

scholarly journals Influence of the Visitor Walking on Airflow and the Bioaerosol Particles in Typical Open Tomb Chambers: An Experimental and Case Study

Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 538
Author(s):  
Zhijian Liu ◽  
Minnan Wu ◽  
Hongwei Cao ◽  
Yongxin Wang ◽  
Rui Rong ◽  
...  
Keyword(s):  
Potential Risk ◽  
Deposition Time ◽  
Scientific Basis ◽  
Discrete Phase Model ◽  
Migration Mechanism ◽  
Discrete Phase ◽  
And Migration ◽  
The Impact ◽  
Experimental Sampling

Effective maintenance of ancient buildings is paid more and more attention worldwide. Many ancient buildings with high inheritance value were gradually destroyed, especially for murals in the open tombs. The bioaerosol particles (BPs) are the major source of contamination in murals and visitor walking could increase this hazard. In order to study the impact of visitors walking on the air flow and the distribution of BPs in the typical tomb chambers, the k-ε and Lagrangian discrete phase model were adopted. The walking visitor was described by the dynamic mesh, and the concentration of BPs in the simulation was verified by experimental sampling. The distribution and migration mechanism of contamination in the chamber were dynamically analyzed. The results indicate that the denser vortex generated when a visitor was walking, and the concentration of BPs changed obviously. Therefore, the number of BPs deposited on some precious murals increased and the contamination location shifted in the direction of visitor walking. In addition, the deposition time of BPs was lagging which would cause potential risk. This research can provide scientific basis for reducing murals contamination during visitor visiting and a reference for the maintenance of ancient buildings.

scholarly journals Energy Calculator for Solar Processing of Biomass with Application to Uganda

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1485 ◽  
Author(s):  
Toby Green ◽  
Opio Innocent Miria ◽  
Rolf Crook ◽  
Andrew Ross
Keyword(s):  
Developing Countries ◽  
Rural Areas ◽  
Energy Demand ◽  
Hydrothermal Carbonization ◽  
Resource Assessment ◽  
Animal Manure ◽  
Integrated System ◽  
Steam Treatment ◽  
Waste Biomass ◽  
Local Supply

Rural areas of developing countries often have poor energy infrastructure and so rely on a very local supply. A local energy supply in rural Uganda frequently has problems such as limited accessibility, unreliability, a high expense, harmful to health and deforestation. By carbonizing waste biomass streams, available to those in rural areas of developing countries through a solar resource, it would be possible to create stable, reliable fuels with more consistent calorific values. An energy demand calculator is reported to assess the different energy demands of various thermochemical processes that can be used to create biofuel. The energy demand calculator then relates the energy required to the area of solar collector required for an integrated system. Pyrolysis was shown to require the least amount of energy to process 1 kg of biomass when compared to steam treatment and hydrothermal carbonization (HTC). This was due to the large amount of water required for steam treatment and HTC. A resource assessment of Uganda is reported, to which the energy demand calculator has been applied. Quantitative data are presented for agricultural residues, forestry residues, animal manure and aquatic weeds found within Uganda. In application to rural areas of Uganda, a linear Fresnel HTC integration shows to be the most practical fit. Integration with a low temperature steam treatment would require more solar input for less carbonization due to the energy required to vaporize liquid water.

scholarly journals HTC of Wet Residues of the Brewing Process: Comprehensive Characterization of Produced Beer, Spent Grain and Valorized Residues

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2058 ◽  
Author(s):  
Mateusz Jackowski ◽  
Lukasz Niedzwiecki ◽  
Magdalena Lech ◽  
Mateusz Wnukowski ◽  
Amit Arora ◽  
...  
Keyword(s):  
Main Product ◽  
Hydrothermal Carbonization ◽  
Fuel Properties ◽  
Mass Yield ◽  
Tracer Method ◽  
Brewing Process ◽  
Spent Grain ◽  
Potential Use ◽  
Comprehensive Characterization

Steady consumption of beer results in a steady output of residues, i.e., brewer’s spent grain (BSG). Its valorization, using hydrothermal carbonization (HTC) seems sensible. However, a significant knowledge gap regarding the variability of this residue and its influence on the valorization process and its potential use in biorefineries exists. This study attempted to fill this gap by characterization of BSG in conjunction with the main product (beer), taking into accounts details of the brewing process. Moreover, different methods to assess the performance of HTC were investigated. Overall, the differences in terms of the fuel properties of both types of spent grain were much less stark, in comparison to the differences between the respective beers. The use of HTC as a pretreatment of BSG for subsequent use as a biorefinery feedstock can be considered beneficial. HTC was helpful in uniformization and improvement of the fuel properties. A significant decrease in the oxygen content and O/C ratio and improved grindability was achieved. The Weber method proved to be feasible for HTC productivity assessment for commercial installations, giving satisfactory results for most of the cases, contrary to traditional ash tracer method, which resulted in significant overestimations of the mass yield.

scholarly journals Synthesis and characterization of rice husk biochar via hydrothermal carbonization for wastewater treatment and biofuel production

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nazia Hossain ◽  
Sabzoi Nizamuddin ◽  
Gregory Griffin ◽  
Periasamy Selvakannan ◽  
Nabisab Mujawar Mubarak ◽  
...  
Keyword(s):  
Rice Husk ◽  
Agricultural Waste ◽  
Value Added ◽  
Hydrothermal Carbonization ◽  
Catalytic Performance ◽  
Biofuel Production ◽  
Suspension Stability ◽  
Waste Biomass ◽  
Suitable Material ◽  
Rice Husk Biochar

Abstract The recent implication of circular economy in Australia spurred the demand for waste material utilization for value-added product generations on a commercial scale. Therefore, this experimental study emphasized on agricultural waste biomass, rice husk (RH) as potential feedstock to produce valuable products. Rice husk biochar (RB) was obtained at temperature: 180 °C, pressure: 70 bar, reaction time: 20 min with water via hydrothermal carbonization (HTC), and the obtained biochar yield was 57.9%. Enhancement of zeta potential value from − 30.1 to − 10.6 mV in RB presented the higher suspension stability, and improvement of surface area and porosity in RB demonstrated the wastewater adsorption capacity. Along with that, an increase of crystallinity in RB, 60.5%, also indicates the enhancement of the catalytic performance of the material significantly more favorable to improve the adsorption efficiency of transitional compounds. In contrast, an increase of the atomic O/C ratio in RB, 0.51 delineated high breakdown of the cellulosic component, which is favorable for biofuel purpose. 13.98% SiO2 reduction in RB confirmed ash content minimization and better quality of fuel properties. Therefore, the rice husk biochar through HTC can be considered a suitable material for further application to treat wastewater and generate bioenergy.

Tritium trapping and migration mechanisms in Li2O: a first-principles study

2019 ◽  
Vol 21 (10) ◽  
pp. 5474-5480
Author(s):  
Xin Xiang ◽  
Guikai Zhang ◽  
Feilong Yang ◽  
Tao Tang
Keyword(s):  
First Principles ◽  
Oxygen Vacancies ◽  
First Principles Study ◽  
Migration Mechanism ◽  
And Migration

The tritium migration mechanism in Li2O is that the bred tritium is firstly trapped by oxygen vacancies, the tritium detrapped from oxygen vacancies subsequently forms tritium substituents, which then migrate by hopping along the lithium lattice.

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