Hydrothermal carbonisation of sewage sludge for char production with different waste biomass: Effects of reaction temperature and energy recycling

Zhai, Yunbo; Peng, Chuan; Xu, Bibo; Wang, Tengfei; Li, Caiting; Zeng, Guangming; Zhu, Yun

doi:10.1016/j.energy.2017.03.116

Cited by 138 publications

(43 citation statements)

References 38 publications

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“…The heating value analysis showed that the heating value of the HTC product increased from 4503 to 4960 kcal/kg on the basis of the raw material. Such a tendency is coincident with other findings [30]. For solid yield (i.e., percentage of HTC hydrochar compared to sewage sludge on dry solid weight) decreased from 65.75% to 51.07-55.28%.…”

Section: Comparison Of Htc Hydrochar Properties With Different Organisupporting

confidence: 90%

Upgrading Hydrothermal Carbonization (HTC) Hydrochar from Sewage Sludge

2019

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As a treatment method of sewage sludge, the hydrothermal carbonization (HTC) process was adopted in this work. HTC has a great advantage considering the economic efficiency of its process operation due to its reduced energy consumption and production of solid fuel upgraded through the increased fixed carbon and heating value. The ash of sewage sludge, however, contains up to 52.55% phosphate, which degrades the efficiency of the thermochemical conversion process such as pyrolysis, combustion, and gasification by causing slagging. In this study, three kinds of organic acids, i.e., oxalic, tartaric, and citric acid, were selected to eliminate phosphorus from hydrochars produced through the HTC of sewage sludge. The efficiency of the phosphorus removal and the properties of the corresponding HTC hydrochars were analyzed by adding 20 mmoles of organic acids per 1 g of phosphorus in the HTC sample. In addition, the phosphorus reduction effect and the applicability to an upgrading process were verified. Oxalic acid was selected as the most appropriate organic acid considering the economic efficiency of its process operation. Furthermore, the optimal conditions were selected by analyzing the efficiency of the phosphorus elimination and the characteristic property of the HTC hydrochars with the weight fraction of oxalic acid.

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Section: Comparison Of Htc Hydrochar Properties With Different Organisupporting

confidence: 90%

Upgrading Hydrothermal Carbonization (HTC) Hydrochar from Sewage Sludge

2019

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“…A feasibility study to compare hydrothermal carbonization (HTC) with conventional drying methods for sewage sludge found that HTC required less input energy and it is dependent on the dry mass content of the product [6]. Similar results were obtained for hydrothermal carbonization of sewage sludge with waste biomass as the energy balance shows low energy input as compared to the output energy [13]. There is thus a need for systematic study of this promising option for biosolid treatment.…”

Section: Introductionmentioning

confidence: 80%

Hydrothermal Carbonization of Biosolids from Waste Water Treatment Plant

et al. 2018

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The high moisture content of biosolid from a wastewater treatment plant limits its use for agriculture and energy applications. This limitation could be obviated by hydrothermal carbonization, which requires less energy compared to other thermochemical treatment processes, and results in stabilized solid hydrochar product. The present study examined this option by hydrothermally treating the biosolid at three temperatures (180, 200 and 220 °C) for 30 min, and at 200 °C for 15, 30 and 60 min. An increase of 50% in the heating value of the biosolid was obtained after this carbonization. A reduction in the nitrogen concentration in hydrochar was noted with an increase in phosphorus concentration, but potassium concentration remained largely unchanged. Additionally, the carbon to nitrogen ratio in the hydrochar product was higher than the biosolid that makes it suitable for agriculture applications. The chemical oxygen demand of the process water was in the range of 83,000 to 96,000 mg/L. The study thus provides insight into high-value products that can be generated by the hydrothermal carbonization of biosolids.

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“…Table 3. Analysis of the agro biomass feedstock used in this research [56]. Figure 4a presents the dependence of the Gibbs free energy on the operating temperature of the gasifier and the WGS reactor for the different reactions listed in Table 1.…”

Section: Feedstock Proximate Analysis Ultimate Analysis Biomassmentioning

confidence: 99%

High Quality Syngas Production with Supercritical Biomass Gasification Integrated with a Water–Gas Shift Reactor

et al. 2019

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A thermodynamic assessment is conducted for a new configuration of a supercritical water gasification plant with a water–gas shift reactor. The proposed configuration offers the potential for the production of syngas at different H2:CO ratios for various applications such as the Fischer–Tropsch process or fuel cells, and it is a path for addressing the common challenges associated with conventional gasification plants such as nitrogen dilution and ash separation. The proposed concept consists of two reactors, R1 and R2, where the carbon containing fuel is gasified (in reactor R1) and in reactor R2, the quality of the syngas (H2:CO ratio) is substantially improved. Reactor R1 is a supercritical water gasifier and reactor R2 is a water–gas shift reactor. The proposed concept was modelled using the Gibbs minimization method with HSC chemistry software. Our results show that the supercritical water to fuel ratio (SCW/C) is a key parameter for determining the quality of syngas (molar ratio of H2:CO) and the carbon conversion reaches 100%, when the SWC/C ratio ranges between two and 2.5 at 500–1000 °C.

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Hydrothermal carbonisation of sewage sludge for char production with different waste biomass: Effects of reaction temperature and energy recycling

Cited by 138 publications

References 38 publications

Upgrading Hydrothermal Carbonization (HTC) Hydrochar from Sewage Sludge

Upgrading Hydrothermal Carbonization (HTC) Hydrochar from Sewage Sludge

Hydrothermal Carbonization of Biosolids from Waste Water Treatment Plant

High Quality Syngas Production with Supercritical Biomass Gasification Integrated with a Water–Gas Shift Reactor

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