Review
Agricultural Engineering
Wei Wang, Jo-Shu Chang, Duu-Jong Lee
Summary: The flourishing of anaerobic digestion (AD) in waste treatment highlights the importance of valorization of digestate, which determines the benefits of the AD process. The perception of digestate has shifted from waste to products to realize the concept of circular economy and maximize its benefits. This review provides an overview of the current status of digestate valorization, focusing on thermal-chemical methods, and summarizes novel valorization methods from recent research, highlighting prospects for digestate valorization.
BIORESOURCE TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Christian Aragon-Briceno, Artur Pozarlik, Eddy Bramer, Gerrit Brem, Shule Wang, Yuming Wen, Weihong Yang, Halina Pawlak-Kruczek, Lukasz Niedzwiecki, Agnieszka Urbanowska, Krzysztof Moscicki, Michal Ploszczyca
Summary: Anaerobic digestion is an efficient method for utilizing wet municipal solid waste (MSW) to produce biogas. This study focused on the determination of optimum hydrothermal carbonization (HTC) process conditions to recover water from MSW digestate. Results showed that HTC treatment increased water recovery during the dewatering process compared with the original feedstock. A process model was built, demonstrating a positive energy balance and electrical efficiency.
Article
Green & Sustainable Science & Technology
Noah Luciano Taufer, Vittoria Benedetti, Matteo Pecchi, Yukihiko Matsumura, Marco Baratieri
Summary: This study investigated a combined process of hydrothermal carbonization (HTC) and supercritical water gasification (SCWG) to fully utilize digestate from anaerobic digestion. The results showed that increasing SCWG temperature led to higher carbon yield and hydrogen content in the gas phase, while increasing residence time resulted in a decrease in carbon yield in the gas phase. Increasing feedstock concentration led to a higher gas generation rate.
Article
Agricultural Engineering
Wei Wang, Jo-Shu Chang, Duu-Jong Lee
Summary: The flourishing of anaerobic digestion highlights the importance of digestate valorization, which is crucial in determining the benefits of the process. Recently, digestate has gradually been perceived as a product rather than waste, in order to achieve the concept of a circular economy and maximize its benefits. Land application is the simplest way for valorization, but legislative restrictions and environmental concerns necessitate novel valorization methods. This review outlines the current methods for solid/liquid digestate valorization, nutrient recovery, microalgae cultivation, and integration with biological and thermochemical processes. The proposed novel valorization routes and their challenges and prospects are discussed, with the integration of anaerobic digestion and thermochemical methods showing potential market value for hydrochar/biochar-derived products.
BIORESOURCE TECHNOLOGY
(2023)
Article
Engineering, Environmental
Xudong Chen, Min Zheng, Xiang Cheng, Chengwen Wang, Kangning Xu
Summary: This study investigated the impact of organic and inorganic impurities in process water of kitchen waste hydrothermal carbonization (HTC) on the crystallization of vivianite, and explored approaches to reduce their negative effects.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Engineering, Environmental
Uttam K. Roy, Tanja Radu, Jonathan Wagner
Summary: This study explores the potential of using hydrothermal carbonisation (HTC) to fractionate anaerobic digestate of sewage sludge into hydrochar and aqueous phase (AP), which is then used to cultivate alkali halophilic microalgae. The results show that the AP obtained from HTC can serve as a suitable growth medium substitute, promoting microalgae growth and increasing biomass yield.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Thermodynamics
Niloufar Ghavami, Karhan Ozdenkci, Simeone Chianese, Dino Musmarra, Cataldo De Blasio
Summary: This study proposes the use of energetic yield as a performance indicator for selecting optimum conditions in hydrothermal carbonization. The study also investigates the required experimental data and simulation aspects for producing hydrochar. The findings provide insights into the energy and mass balances of the process.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Green & Sustainable Science & Technology
Jessica Chaparro-Garnica, Melanie Guiton, David Salinas-Torres, Emilia Morallon, Enrico Benetto, Diego Cazorla-Amoros
Summary: Life Cycle Assessment (LCA) is used to eco-design the H3PO4-assisted hydrothermal carbonization (HTC) process for converting biomass residue into high-value products. The study found that electricity consumption contributes the most to the environmental impacts, such as climate change and acidification, while the main chemical used in the functionalization stage contributes to human toxicity and marine eutrophication. Furthermore, potential improvements were identified through different scenarios, showing a reduction potential compared to the reference scenario.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Environmental
Zixuan Wang, Daran Anand, Zhen He
Summary: Two different environments in an electrochemical process enable simultaneous leaching and recovery of phosphorus from municipal whole digestate. The proposed electrochemical phosphorus recovery cell (EPRC) achieved a high leaching efficiency of 93.3% through acidification, and precipitated nearly 99% of the leached phosphorus using native metals in the cathode chamber. The EPRC demonstrated the feasibility of recovering phosphorus from phosphorus-rich solid wastes.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Review
Energy & Fuels
Joanna Mikusinska, Monika Kuznia, Klaudia Czerwinska, Malgorzata Wilk
Summary: In agricultural biogas plants, the by-product digestate is produced along with biogas. This paper examines the properties of agricultural digestate and its hydrothermal conversion into hydrochar and process water. The parameters of the hydrothermal carbonization process affect the characteristics of hydrochar, making it suitable for various applications such as biofuel, fertilizer, soil improver, adsorber, or catalyst. The properties of hydrochar derived from agricultural digestate are extensively discussed in this paper.
Article
Engineering, Environmental
W. M. L. K. Abeyratne, I. S. A. Abeysiriwardana-Arachchige, H. Bayat, Y. Zhang, C. E. Brewer, N. Nirmalakhandan
Summary: A new process is proposed to stabilize wastewater sludges and recover calcium phosphate from them. This process concentrates most of the phosphorus content of the sludges into a solid residue called HTL-char. Acid leaching and a 3-step precipitation process are used to recover high-quality calcium phosphate. The results show that this process can efficiently recover phosphorus and the recovered calcium phosphate meets environmental standards.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Agricultural Engineering
Zebin Cao, Benedikt Huelsemann, Dominik Wuest, Hans Oechsner, Armin Lautenbach, Andrea Kruse
Summary: The study shows that HTC treatment of biogas digestate can improve the slagging and fouling indices of hydrochar, with the specific methane yield of process water minimally affected by varying HTC residence time. Energy assessment reveals that HTC for 0.5 hours achieves the highest process efficiency and net energy gain, suggesting the use of 210 degrees C, 0.5 hours HTC condition for energy production.
BIORESOURCE TECHNOLOGY
(2021)
Article
Engineering, Environmental
Xiaochen Liu, Jun Lu, Minghao Fu, Hua Zheng, Quanyuan Chen
Summary: Powdered activated carbon (PAC) was used as a catalyst for hydrothermal carbonization (HTC) of cotton pulp black liquor (CPBL). The results showed that PAC-HTC could effectively decontaminate CPBL and had excellent reusability.
JOURNAL OF WATER PROCESS ENGINEERING
(2022)
Article
Engineering, Chemical
Chen Zhang, Shuzhuang Sun, Shaojun Xu, Chris Johnston, Chunfei Wu
Summary: This study investigates the treatment of phosphorus in dirty irrigation water using biochar samples derived from anaerobic digestate. The results show that the biochar exhibits remarkable adsorption efficiency for phosphorus, and the adsorption process is endothermic and spontaneous. Therefore, biochar may provide a promising solution to address phosphorus-related environmental challenges in industry and agriculture.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Environmental Sciences
L. Zaccariello, D. Battaglia, B. Morrone, M. L. Mastellone
Summary: The purpose of this paper is to illustrate the design basis of a pilot-scale reactor for converting putrescent and high-water content biowaste into a stabilized product using the Hydrothermal Carbonization process (HTC). The design process involved optimizing the process parameters in a bench-scale reactor and scaling up the reactor by 30 times. The new pilot-scale reactor, with a volume of 0.1 m(3), was designed and certified to operate at high temperature and pressure conditions. The process design focused on heat power, heating control, and reaction time, while the mechanical design focused on scalability, product extraction, and improving reliability and safety. The designed reactor was built, commissioned, and operated to validate the design criteria and hypotheses. The comparison between experimental results and design input confirmed the correctness of the design data but highlighted the need to enhance thermal efficiency.
WASTE AND BIOMASS VALORIZATION
(2022)
Article
Energy & Fuels
Katrin Stoekle, Benedikt Huelsemann, David Steinbach, Zebin Cao, Hans Oechsner, Andrea Kruse
Summary: Forced chicory roots can be utilized in a cascaded manner by extracting sugars, hydrothermal carbonization, and anaerobic digestion, achieving a complete utilization of the biomass. This cascaded utilization can elongate the value chain of chicory and enhance the efficiency of biomass usage, with a carbon efficiency of 96%.
BIOMASS CONVERSION AND BIOREFINERY
(2021)
Article
Energy & Fuels
Manuel C. Bauer, Philipp Konnerth, Andrea Kruse
Summary: Liquefied dimethyl ether (DME) is a promising, green solvent for biomass lipid extractions. This study examines its use with four microalgae and cyanobacteria species, and finds that cryo-milling increases oil yield and improves fatty acid composition.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Editorial Material
Energy & Fuels
David Chiaramonti, Andrea Kruse, Marco Klemm
Article
Agricultural Engineering
Konstantin Dinkler, Bowen Li, Jianbin Guo, Benedikt Huelsemann, Gero C. Becker, Joachim Mueller, Hans Oechsner
Summary: The study found that the majority of phosphate in biogas digestate is inorganic, and it is essential to analyze inorganic phosphate for optimal nutrient recovery. Phosphate concentration in extracts was found to be independent of extraction time, highlighting the importance of controlling parameters during different extraction stages to prevent phosphate losses.
BIORESOURCE TECHNOLOGY
(2021)
Article
Energy & Fuels
Ekaterina Ovsyannikova, Andrea Kruse, Gero C. Becker
Summary: HTL technology is a promising method to recover energy from sewage sludge and manure, producing bio-crude oil. This study focuses on recovering phosphate and ammoniacal nitrogen by producing struvite from the byproducts of HTL. The air-agitated system tested in the laboratory showed potential for enhancing the quality of the product, making it suitable for fertilizer use.
Article
Environmental Sciences
Yi Wang, Xuelin Chen, Jingfan Yan, Tianyu Wang, Xiaomin Xie, Sen Yang
Summary: Ce3+-enriched Ce-BC exhibited high adsorption capacity for As(V), with adsorption fitting the Langmuir model and described by the pseudo-second-order kinetics model. Decreasing Ce3+ concentration significantly reduced As(V) adsorption, indicating a strong affinity between As(V) and Ce3+.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Biochemistry & Molecular Biology
Yun Li, Xiaomin Xie, Rongxiu Yin, Qingzhao Dong, Quanquan Wei, Bangxi Zhang
Summary: This study explores the application of forward osmosis (FO) membrane technology in the concentration of biogas slurry and evaluates the performance of FO membranes using three different draw solutions. The results indicate that MgCl2 is the most effective draw solution for the concentration of biogas slurry, but it is ineffective at retaining nitrogen. Furthermore, membrane fouling is primarily caused by organic fouling. This study provides a technical reference for the high-value utilization of biogas slurry.
Article
Engineering, Environmental
Xiaomin Xie, Jingfan Yan, Qiong Wu, Tianyu Wang, Fumin Chu, Sen Yang
Summary: Inspired by the Namib Desert beetle, we designed and fabricated hydrophobic porous polystyrene microspheres with different wetting properties. These microspheres, synthesized using a unique emulsion method, can separate different types of emulsions and efficiently remove pollutants. Additionally, they have a high recycling rate and can be used repeatedly.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Engineering, Environmental
Xingzu Gao, Feiyu Yang, Jingwen Cheng, Zhicheng Xu, Bing Zang, Guoxue Li, Xiaomin Xie, Wenhai Luo
Summary: This study aimed to identify the sources of volatile sulphur compounds (VSCs) during swine manure composting and evaluate their reduction by ferric oxide (Fe2O3). The results showed that the degradation of methionine and cysteine contributed to the majority of VSCs emissions, while the reduction of sulphite and sulphate also played a role. The addition of Fe2O3 significantly reduced the emission of VSCs and odour intensity, thereby reducing the non-carcinogenic risk.
Article
Environmental Sciences
Yun Li, Shuni Xu, Jiuzhou Li, Shanshan Li, Xiaohan Zhang, Xiaomin Xie
Summary: This review provides a comprehensive understanding of the properties and utilization of digested manure effluent, as well as the challenges and potential countermeasures in its high-value processing. Membrane concentration techniques for digested manure effluent are discussed, along with the potential approaches to address challenges such as high cost and membrane fouling.
CURRENT POLLUTION REPORTS
(2022)
Article
Environmental Sciences
Yun Li, Chengzhi Zhou, Shanshan Li, Xiaohan Zhang, Mengjie Pu, Xiaomin Xie
Summary: The effect of combined coagulation and membrane treatment on contaminant residuals and membrane fouling in anaerobically digested manure centrate was investigated. The combined treatment significantly improved water recovery rate, achieved better nutrient enrichment, reduced heavy metals and antibiotics, and reduced membrane fouling.
ENVIRONMENTAL RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Yun Li, Jiuzhou Li, Shanshan Li, Xiaohan Zhang, Xiaomin Xie
Summary: This study investigated the composting performance of Enteromorpha under different composting techniques and the effects of adding mushroom waste as an additive. The results showed that Enteromorpha had high compostability and low phytotoxicity, and the addition of mushroom waste improved the composting process. Forced ventilation was found to reduce the phytotoxicity of Enteromorpha composting better than windrow composting.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Chemistry, Multidisciplinary
Manuel C. Bauer, Gero C. Becker, Andrea Kruse
Summary: This study optimized the batch extraction of wet algae using dimethyl ether (DME) to avoid drying. The results showed that increasing the water content of the algae samples enhanced crude oil yields and fatty acid recoveries.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Energy & Fuels
Katrin Stoekle, Dennis Jung, Andrea Kruse
Summary: Chicory roots are a low-cost agricultural residue that can be used as a feedstock for producing 5-Hydroxymethylfurfural (HMF). In this study, two methods were investigated to increase the fructose content in the extracted inulin and fructose from chicory roots. The first method involved acid-assisted extraction, while the second method involved aqueous extraction followed by nitric acid hydrolysis. It was found that separating extraction and hydrolysis was more suitable for integrating this process into a biorefinery concept for HMF production.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Engineering, Environmental
Yun Li, Shuni Xu, Mingcan Zhao, Yuan Song, Zhiqi Wang, Xiaomin Xie
Summary: This study investigates the pre-treatment of biogas slurry using different densities of cornstalk filling and its impact on subsequent membrane processes. The results show that pre-treatment with cornstalks effectively controls membrane fouling, with the highest filtration effectiveness observed using high density filling. Membrane treatment after filtration with cornstalks is economically favorable compared to direct membrane treatment in practical applications.
ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY
(2022)
