Hydrothermal carbonisation products energy properties: The role of digested sludge type and operating conditions

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress Pub Date : 2025-03-13 DOI:10.1016/j.tsep.2025.103461

Nina Kossińska , Renata Krzyżyńska , Anna Grosser , Marzena Kwapińska , Heba Ghazal , Hussam Jouhara , Witold Kwapiński

{"title":"Hydrothermal carbonisation products energy properties: The role of digested sludge type and operating conditions","authors":"Nina Kossińska , Renata Krzyżyńska , Anna Grosser , Marzena Kwapińska , Heba Ghazal , Hussam Jouhara , Witold Kwapiński","doi":"10.1016/j.tsep.2025.103461","DOIUrl":null,"url":null,"abstract":"<div><div>Hydrothermal carbonization (HTC) is a promising alternative to conventional sludge drying, enhancing energy recovery in wastewater treatment plants (WWTPs). This study examines how temperature, residence time, and sludge collection point influence HTC product properties. Experiments were conducted at 200–250 °C for 30–120 min using digested sludge collected before filtration, after thickening, and after dewatering. Results show that sludge collection point strongly affects hydrochar’s higher heating value (HHV), while temperature and residence time influence the biomethane potential (BMP) of HTC liquids. The highest HHV (16.31 MJ/kg) was obtained from dewatered sludge (19.8 % TS) at 250 °C, 75 min, while the highest BMP (506 mlCH<sub>4</sub>/g NPOC) was observed from HTC liquids of thickened sludge (11.1 % TS) at 200 °C, 30 min. Findings highlight that sludge pre-treatment (thickening, dewatering) plays a crucial role in HTC efficiency, influencing both solid and liquid fractions. From a WWTP perspective, dewatered sludge processed under mild HTC conditions provides the best trade-off between hydrochar quality, HTC liquid valorization, and operational costs. These insights support the optimization of sludge-to-energy strategies, essential for implementing HTC in WWTPs.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"61 ","pages":"Article 103461"},"PeriodicalIF":5.1000,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thermal Science and Engineering Progress","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2451904925002513","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

Hydrothermal carbonization (HTC) is a promising alternative to conventional sludge drying, enhancing energy recovery in wastewater treatment plants (WWTPs). This study examines how temperature, residence time, and sludge collection point influence HTC product properties. Experiments were conducted at 200–250 °C for 30–120 min using digested sludge collected before filtration, after thickening, and after dewatering. Results show that sludge collection point strongly affects hydrochar’s higher heating value (HHV), while temperature and residence time influence the biomethane potential (BMP) of HTC liquids. The highest HHV (16.31 MJ/kg) was obtained from dewatered sludge (19.8 % TS) at 250 °C, 75 min, while the highest BMP (506 mlCH₄/g NPOC) was observed from HTC liquids of thickened sludge (11.1 % TS) at 200 °C, 30 min. Findings highlight that sludge pre-treatment (thickening, dewatering) plays a crucial role in HTC efficiency, influencing both solid and liquid fractions. From a WWTP perspective, dewatered sludge processed under mild HTC conditions provides the best trade-off between hydrochar quality, HTC liquid valorization, and operational costs. These insights support the optimization of sludge-to-energy strategies, essential for implementing HTC in WWTPs.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Thermal Science and Engineering Progress Chemical Engineering-Fluid Flow and Transfer Processes

CiteScore

7.20

自引率

10.40%

发文量

327

审稿时长

41 days

期刊介绍： Thermal Science and Engineering Progress (TSEP) publishes original, high-quality research articles that span activities ranging from fundamental scientific research and discussion of the more controversial thermodynamic theories, to developments in thermal engineering that are in many instances examples of the way scientists and engineers are addressing the challenges facing a growing population – smart cities and global warming – maximising thermodynamic efficiencies and minimising all heat losses. It is intended that these will be of current relevance and interest to industry, academia and other practitioners. It is evident that many specialised journals in thermal and, to some extent, in fluid disciplines tend to focus on topics that can be classified as fundamental in nature, or are ‘applied’ and near-market. Thermal Science and Engineering Progress will bridge the gap between these two areas, allowing authors to make an easy choice, should they or a journal editor feel that their papers are ‘out of scope’ when considering other journals. The range of topics covered by Thermal Science and Engineering Progress addresses the rapid rate of development being made in thermal transfer processes as they affect traditional fields, and important growth in the topical research areas of aerospace, thermal biological and medical systems, electronics and nano-technologies, renewable energy systems, food production (including agriculture), and the need to minimise man-made thermal impacts on climate change. Review articles on appropriate topics for TSEP are encouraged, although until TSEP is fully established, these will be limited in number. Before submitting such articles, please contact one of the Editors, or a member of the Editorial Advisory Board with an outline of your proposal and your expertise in the area of your review.