Hydrothermal Carbonization Research Articles

Proposal of a Pilot Plant (2T/day) for Solid Fuel Conversion of Cambodian Mango Waste Using Hybrid Hydrothermal Carbonization Technology

Proposal of a Pilot Plant (2T/day) for Solid Fuel Conversion of Cambodian Mango Waste Using Hybrid Hydrothermal Carbonization Technology

Enhancing the Fuel Properties of Spent Coffee Grounds through Hydrothermal Carbonization: Output Prediction and Post-Treatment Approaches

The reuse potential for the large annual production of spent coffee grounds (SCGs) is underexploited in most world regions. Hydrochars from SCGs produced via hydrothermal carbonization (HTC) have been recognized as a promising solid fuel alternative. To increase demand, optimization of the HTC and two post-treatment processes, washing and agglomeration, were studied to improve hydrochar in terms of energetic properties, minimizing unwanted substances, and better handling. HTC experiments at three scales (1–18.75 L) and varying process conditions (temperature T (160–250 °C), reaction time t (1–5 h), and solid content %So (6–20%) showed that the higher heating value (HHV) can be improved by up to 46%, and most potential emissions of trace elements from combustion reduced (up to 90%). The HTC outputs (solid yield—SY, HHV, energy yield—EY) were modeled and compared to published genetic programming (GP) models. Both model types predicted the three outputs with low error (<15%) and can be used for process optimization. The efficiency of water washing depended on the HTC process temperature and type of aromatics produced. The furanic compounds were removed (69–100%; 160 °C), while only 34% of the phenolic compounds (240 °C) were washed out. Agglomeration of both wet SCG and its hydrochar is feasible; however, the finer particles of washed hydrochar (240 °C) resulted in larger-sized spherical pellets (85% > 2000–4000 µm) compared to SCGs (only 4%).

A super magnetic porous biochar manufactured by potassium ferrate-accelerated hydrothermal carbonization for removal of tetracycline

Hydrothermal carbonization (HTC) is a promising and powerful technology for manufacturing magnetic biochar with abundant functional groups at relatively low temperature. Herein, K2FeO4-accelerated HTC of kelp was studied to manufacture high-performance magnetic biochar for eliminating tetracycline (TC) in aqueous solution. Nanoscale magnetic iron oxides were generated with abundant oxygen containing groups and porous structures as the HTC was performed at 300 °C. This magnetic biochar displayed 1245.43 mg/g adsorption capacity at 35 °C with 56.48 emu/g saturation magnetization. The adsorption was mostly ascribed to hydrogen bonding/coordination/cation exchange of oxygen functional groups and iron oxides. Moreover, K2FeO4-promoted HTC also exhibited good efficiency and generality for manufacturing potent magnetic biochars from different biowastes for eliminating TC in aqueous solution.

Graphene-like materials supported on sepiolite clay synthesized at relatively low temperature

The preparation of solids with graphitic structure usually requires synthesis procedures using very high temperatures. In this work, a comparative study involving different experimental strategies of synthesis at relatively low temperature was carried out to obtain graphene-like materials supported on microporous sepiolite (SEP) clay. The final objective was the optimization of the development of new clay-graphitic nanostructured materials to achieve porous solids while saving energy and time during the preparation stages. The pyrolysis of sucrose (SUC), used as carbon precursor, was accomplished by microwave (MW) pyrolysis or tube furnace (TF) pyrolysis at 200 or 500 °C followed by a hydrothermal carbonization (HTC) step. The resulting carbon-clay nanoarchitectures were characterized by Raman and Infrared spectroscopy, X-ray diffraction, elemental analysis, electron microscopy, and nitrogen adsorption-desorption isotherms. The MW200 and TF200 treatments caramelized SUC and the post-HTC step was fundamental to obtain porous carbonaceous materials. The TF500 pyrolysis produced predominantly crystalline carbon, while the MW500 pyrolysis formed an amorphous material. Moreover, the high-resolution transmission electron microscopy observations of TF500 sample revealed a crystalline material with a d-spacing of 0.33 nm, matching the graphitic lattice. All the treatment conditions performed at 500 °C i.e., MW or TF followed or not by HTC, resulted in mesoporous carbons with a specific surface area above 200 m2 g−1. The MW pyrolysis saved 100 min of the reaction time in comparison to TF pyrolysis to obtain the carbonaceous porous materials.

Scalable synthesis of N, O co-doped hierarchical porous carbon for high energy density supercapacitors

Rational design of hierarchical porous architecture with abundant pseudocapacitive sites is highly desirable for carbon electrode materials. However, the lengthy production process and high economic input limit its broader application. Herein, we successfully prepared N, O co-doped hierarchical porous carbon (NOHC) through hydrothermal carbonization (HTC) of chitin biomass with the assist of NH4Cl and subsequent carbonization with NaNH2. The optimal NOHC600 exhibits a remarkable hierarchical porous structure and an ultrahigh specific surface area (SSA) of 2555 m2 g−1. Furthermore, it showcases a significant content of N, O co-doping, thereby providing abundant defects and additional active sites for ion adsorption. The aforementioned characteristics ensure outstanding capacitance performance of NOHC600. In the three-electrode system, NOHC600 exhibits a remarkable specific capacitance of up to 455 F g−1 at a current density of 0.5 A g-1. The symmetric supercapacitors (SCs) based on NOHC600 achieve an impressive energy density of 30.4 Wh kg−1 at a power density of 180 W kg−1. Moreover, the all-solid-state NOHC600 microsupercapacitors (MSCs) demonstrate an exceptional areal capacitance of 78.2 mF cm−2 and an areal energy density of up to 10.8 μWh cm−2. Accordingly, this facile and scalable strategy shows a great potential for producing high-heteroatom-doped porous carbon materials from chitin biomass, which can be applied in practical energy-related applications.

Swine manure management by hydrothermal carbonization: Comparative study of batch and continuous operation

Hydrothermal carbonization (HTC) is considered a promising technology for biomass waste management without pre-drying. This study explores the potential for swine manure management by comparing batch and continuous processes, emphasizing the benefits of the continuous mode, particularly for its potential full-scale application. The continuous process at low temperature (180 °C) resulted in a hydrochar with a lower degree of carbonization compared to the batch process, but similar characteristics were found in both hydrochars at higher operating temperatures (230–250 °C), such as C content (∼ 52 wt%), fixed carbon (∼ 24 wt%) and higher calorific value (21 MJ kg−1). Thermogravimetric and combustion analyses showed that hydrochars exhibited characteristics suitable as solid biofuels for industrial use. The process water showed a high content of organic matter as soluble chemical oxygen demand (7–22 g L−1) and total organic carbon (4–10 g L−1), although a high amount of refractory species such as N- and O-containing long aromatic compounds were detected in the process water from the batch process, while the process water from the continuous process presented more easily biodegradable compounds such as acids and alcohols, among others. The longer time required to reach operating temperature in the case of the batch system (longer heating time to reach operating temperature) resulted in lower H/C and O/C ratios compared to hydrochar from the continuous process. This indicates that the dehydration and decarboxylation reactions of the feedstock play a more important role in the batch process. This study shows the efficiency of the continuous process to obtain carbonaceous materials suitable for use as biofuel, providing a solution for swine manure management.

Hydrothermal carbonization carbon induced synthesis of flower-like C/Bi/BiOI heterojunction with heightened photocatalytic Cr(VI) reduction

Modification with metallic Bi and formation heterojunction with carbon material are considered as the compelling strategies to address the shortcoming of bismuth oxyhalide in photocatalytic Cr(VI) reduction. However, the simultaneous and in-situ synthesis of metallic Bi and hydrothermal carbonization carbon (HC) on BiOI to fabricate a ternary heterojunction photocatalyst remains a challenge yet, and the synergistic mechanism between the localized surface plasmon resonance (LSPR) effect and HC is still indistinct. Herein, a ternary heterojunction photocatalyst comprising metallic Bi, HC, and flower-like BiOI was designed and synthesized through the in-situ induction of HC. During the solvothermal synthesis, a portion of Bi3+ was reduced to metallic Bi nanoparticles, and simultaneously gauzy HC was formed. In the ternary heterojunction, the metallic Bi nanoparticles displayed strong LSPR effect, and the coated HC was conducive to transferring photogenerated electrons and enriching Cr(VI). Due to the synergistic effect of metallic Bi and HC, multiple channels for photogenerated carrier transfer were constructed. Deriving from the excellent light-harvesting, accelerated transfer/separation, and restrained recombination of photogenerated carriers, the ternary heterojunction of flower-like C/Bi/BiOI showed superior photocatalytic Cr(VI) reduction. The reaction rate constant of photocatalytic Cr(VI) reduction was about 26 times higher than that of BiOI.

A green, efficient and stable platform based on hyperbranched quaternized hydrothermal magnetic chitosan nanospheres integrated cytomembranes for screening drug candidates from natural products

Compared with traditional tedious organic solvent-assisted separation process in natural medicinal chemistry, cytomembrane (CM) fishing technique became a more appealing and greener choice for screening bioactive components from natural products. However, its large-scale practical value was greatly weakened by the easy fall-off of CMs from magnetic supports, rooted in the instability of common Fe3O4 particles and their insufficient interaction with CMs. In this research, a new green biostable platform was developed for drug screening through the integration of hyperbranched quaternized hydrothermal magnetic carbon spheres (HQ-HMCSs) and CMs. The positive-charged HQ-HMCSs were constructed by chitosan-based hydrothermal carbonization onto Fe3O4 nanospheres and subsequent aqueous hyperbranching quaternization with 1,4-butanediol diglycidyl ether and methylamine. The strong interaction between HQ-HMCSs and CMs was formed via electrostatic attraction of HQ-HMCSs to negative-charged CMs and covalent linkage derived from the epoxy-amine addition reactions. The chemically stable HMCSs and its integration with CMs contributed to dramatically higher stability and recyclability of bionic nanocomposites. With the fishing of osteoblast CMs integrated HQ-HMCSs, two novel potential anti-osteoporosis compounds, narcissoside and beta-ionone, were discovered from Hippophae rhamnoides L. Enhanced osteoblast proliferation, alkaline phosphatase, and mineralization levels proved their positive osteogenesis effects. Preliminary pharmacological investigation demonstrated their potential action on membrane proteins of estrogen receptor alpha and insulin-like growth factor 1. Furthermore, beta-ionone showed apparent therapeutic effects on osteogenic lesions in zebrafish. These results provide a green, stable, cost-efficient, and reliable access to rapid discovery of drug leads, which verifiably benefits the design of nanocarbon-based biocomposites with increasingly advanced functionality.

Facile modification strategies on hydrochar-based carbon particles with hydrothermal carbonization from green pistachio hulls for the removal of cadmium ions from aqueous solutions

Facile modification strategies on hydrochar-based carbon particles with hydrothermal carbonization from green pistachio hulls for the removal of cadmium ions from aqueous solutions

Elaboration of cost-effective adsorbents derived from sewage sludge through hydrothermal carbonization: Influence of process parameters and feedstock components on the adsorption performance

Sewage sludge (SS)-derived hydrochar by hydrothermal carbonization (HTC) have demonstrated its potential as an adsorbent. This study investigated the effect of HTC parameters and feedstock components on the adsorption performance of hydrochar, with the aim of enhancing its adsorption performance without modification, thereby expanding applications of waste-derived adsorbent under cost constraints. Water, ash and five model compounds were used to adjust the typical components of SS, then hydrochar was prepared under various HTC parameters. The adsorption quantity of the model pollutants (tetracycline and methylene blue) on hydrochar decreased with an increase in HTC temperature, and there was a minor decrease with prolonged reaction times. Changes in the HTC parameters did not affect the adsorption mechanism of the hydrochar. Notably, humus and lignin emerged as key components affecting the adsorption performance of hydrochars. Compared with the blank control, the adsorption capacities of tetracycline and methylene blue by hydrochar after the addition of 30 wt% humic acid increased by 16.1% and 101.0%, respectively. Moreover, the adsorption capacity of methylene blue increased by 58.5% after adding 30 wt% alkali lignin. The underlying mechanism was elucidated based on hydrochar characterization. Changes in HTC parameters affected the properties of hydrochar and its adsorption performance. The effect of component adjustment on the adsorption performance of hydrochar was attributed to abundance of oxygen-containing functional groups formed by the model compounds during hydrolysis. Component adjustment facilitated the binding of groups to the hydrochar, thereby offering more adsorption sites. This study provides a valuable reference for utilizing SS in the preparation of efficient and low-cost adsorbents.

Lab-scale engineered hydrochar production and techno-economic scaling-up analysis

Despite the extensive use of engineered hydrochar (EHC) for contaminants adsorption in water, little is known about the scaling-up of EHC production which has kept the technology at a low readiness level (TRL). Full-scale EHC production was simulated to help bridge this knowledge gap. A systematic analysis was performed where EHC was produced from rice straw using hydrothermal carbonization (HTC) at 200 °C with iron addition. A techno-economic evaluation model was employed to simulate the production process and to estimate energy requirements, configuration, and cost scenarios for the HTC process. The minimum selling price (MSP) analysis of the engineered hydrochar was found to be almost half compared to the market price for other similar sorbents ($ 76/t vs. $136/t) suggesting that EHC production is feasible for scaling up. Finally, as a trial, the resulting material was tested for its efficacy in the adsorption of an anionic organic contaminant (e.g., Congo Red, C32H22N6Na2O6S2) in water to identify its potential for water treatment. Experimental results showed that EHC adsorbed > 95% CR suggesting significant adsorption capability and feasibility for production scale-up.

New insights into the hydrothermal carbonization process of sewage sludge: A reactive molecular dynamics study

In this work, reactive molecular dynamics simulations using the ReaxFF force field were performed to investigate the hydrothermal carbonization (HTC) process of sewage sludge. The focus was on the reaction mechanism, the effect of water content and temperature on the formation of different products. The results showed that temperature was the most important factor controlling the HTC process, with higher temperatures leading to more rapid carbonization reactions and lower H/C and O/C ratios in the hydrochar product. The estimated activation energy of the HTC process was in the range of 126–169 kJ/mol, depending on the water content. The H/C and O/C ratios of the hydochar product obtained from the simulation were in excellent agreement with experimental data. Overall, this work provides valuable new insights into the reaction mechanism and key factors influencing the HTC process of sewage sludge.

Hydrothermal carbonization of Calotropis procera leaves as a biomass: Preparation and characterization

Hydrothermal carbonization (HTC) is a biowaste treatment process and a promising technology for many applications. The use of Calotropis procera (CP), found in the Egyptian desert, as a biosource feedstock for the HTC process. In the present work, different process conditions were applied during the HTC process. The influence of temperature, time, and particle size was studied to produce hydrochar using CP leaves as biomass. The hydrochar samples were characterized by many analytical techniques. The temperature and time controlled the severity of the reaction; they caused a significant decrease in the yield (wt.%) and caused an increase in the carbon content of the hydrochar product, with a value of 57.03 % at 240 °C and a time of 180 min. Although time in this case has a more significant effect than temperature, a long reaction time influences the hydrochar yield. FTIR showed the formation on hydrochar with high content of lignin at high temperature and longtime. The O/C decrease with increase the temperature and time as evidence of decarboxylation reaction occurs and the reaction move toward carbonization and increase the HHV of hydrochar than raw biomass that recorded 40.2 MJ/Kg at 240 °C, time 180 min and biomass particle size 150 μm. The hydrochars produced under all condition have negative surface charge in wide range of pH and all have negative charge over pH 4–5 and most suitable pH value is between 6 and 7. The best conditions recorded were temperature 200–240 °C and reaction time 120–180 min at this conditions hydrochar has a stable negative charge in slightly acidic and basic media which let it able to use in applications of removing the cationic pollutants from wastewater, and the high heating value give opportunity to use in energy production applications.

Altering the Interfacial Microenvironment of the Photocatalytic System for Boosted H2O2 Generation from Biomass Waste

The catalytic and environmentally friendly synthesis of H2O2 is crucial in green chemistry. Many researchers are dedicated to its study, and various methods have been proposed, but these methods usually require organic solvents or dissipative reagents. It has been reported recently that different biomass could be converted to hydrothermal carbonaceous carbon (HTCC) photocatalysts capable of producing H2O2 with high efficiency. Herein, we report a method to further increase the catalytic efficiency of HTCC, from 0.53 mmol gcat -1 h-1 to 1.35 mmol gcat -1 h-1 under air, by simply changing the neutral solution to basic (pH = 11) where the contact environment between HTCC and the solvent is changed. The radical trap experiment and electron paramagnetic resonance (EPR) spectroscopy confirmed a two-step oxygen reduction reaction as the primary catalytic pathway. The mechanism study indicates that OH- in the solution could react with the acidic terminal functional groups of HTCC originating from the synthesis and hole-induced oxidation within HTCC during photocatalysis, thus enhancing the generation of active species and electron transfer. This study paves a new way to improve the photocatalytic efficiency of HTCC by altering the microenvironment of solvent and photocatalysts.

Innovative mathematical approach for hydrothermal carbonization process using an inverse method: Experimental analysis, rheology behavior, and numerical comparative investigation

Hydrothermal carbonization (HTC) shows promise for converting biomass into carbon solids, but simulating it at high biomass-to-water ratios is difficult due to limited models. Existing numerical methods have not been sufficiently tested and validated under such conditions. An experimental approach and a novel non-Newtonian mixture model (NNM) were developed to improve simulation accuracy. This model incorporated rheological parameters using COMSOL Multiphysics software and an inverse method, especially the Levenberg-Marquardt algorithm. The results show that the proposed design achieved desired HTC conditions within 55–70 min, depending on the ratio. Besides, the innovative NNM model proved more effective for predicting thermal behavior and exhibited significantly reduced computation time than other CFD models in the literature, with a maximum 5 % relative deviation, indicating lower computational costs. Infrared camera measurements validated the heat behavior predicted by the NNM. Moreover, during HTC, the mixture behaves as a Newtonian fluid at a 1/6 ratio, and as a shear-thinning fluid at 1/3 and 1/2 ratios, with viscosity decreasing with increasing shear rate and temperature. This study presents innovative findings in the field of HTC, offering a reliable NNM model for simulating HTC under challenging conditions, addressing the mixture's rheology, and proposing a novel design.

Synthetic natural gas production using CO2-rich waste stream from hydrothermal carbonization of biomass: Effect of impurities on the catalytic activity

The utilization of biomass and bio-waste, particularly through hydrothermal processes, has shown promise as a technology for converting these materials into valuable products. While most research has traditionally focused on the solid and liquid byproducts of these hydrothermal treatments, the gaseous phase has often been overlooked. This study specifically investigates the conversion of off-gases produced during hydrothermal carbonation (HTC) into synthetic natural gas, offering a readily marketable product with economic potential. Although the methanation of conventional flue gases has been extensively studied, dealing with non-standard off-gases from processes like HTC presents challenges due to the presence of minor impurities like CO and CH4. This novel research seeks to experimentally evaluate the methanation of HTC off-gases using nickel-based catalysts and analyze how these impurities affect the catalytic performance. The studied catalysts include nickel supported by ceria and alumina, as well as alumina supported nickel-cobalt systems. The results demonstrate that these catalysts exhibit high CO2 conversion and CH4 selectivity under ideal gas conditions. However, when real gas compositions with impurities are considered, CO2 conversion decreases at lower temperatures (ca. 20% lower conversion for real gas vs. ideal), probably due to side reactions such as CH4 cracking. This difference becomes less pronounced at higher temperatures. Nevertheless, the catalysts perform satisfactorily, especially at temperatures exceeding 350 °C. In conclusion, this study sheds light on the methanation of HTC off-gases and underscores the significance of understanding how impurities in real gases impact the process, providing potential directions for future research.

Advancing Sustainable Biofuel Production from Agricultural Residues: A Comprehensive Mini-Review

Fossil fuels widely satisfy the world's energy demands; however, they are absolutely unsustainable. Rational energy management is therefore one of humanity's greatest challenges in the 21st century. The sustainable resources of energy are speculated to minimize the global environmental challenges and consequences concerning the air and water quality, greenhouse effect, acid rain, etc. Biofuels-widely regarded as "fuel of future"- are a type of sustainable fuel, extracted immediately from living matter that is most likely produced over and again. Biofuels are majorly categorized into four groups based on the types of biomasses utilized as their raw material that including food crops, agricultural and industrial wastes and algae. A significant portion of lignocellulosic biomass consists of agricultural residues, presenting an opportunity to use them as a feedstock for generating biofuels. Agricultural wastes encompass more than just residues from cultivation; they also comprise wastes generated during the processing of agricultural products, livestock management, and distribution of fruits and vegetables. This review highlights the use of agricultural residues for the production of various types of Biofuels. Agricultural residues can be pretreated and treated through a myriad number of methods, for instance, acid catalysis, anaerobic digestion, hydrothermal carbonization, simultaneous saccharification, transesterification and pyrolysis; for the production of biodiesel, biogas, hydro-char, syngas and bioethanol. Each of these methods has several benefits and drawbacks since they are all conditional on some factors. Furthermore, the following study also mentions the advantages and disadvantages of biofuel production and usage.

Effect of Acid-Assisted Hydrothermal Carbonization Temperatures on the Hydrochar Properties for Supercapacitor Application

The investigation of biomass-based, cost-effective, efficient, and environmentally materials with high power density and fast ion/electron transfer is intensively carried out for the development of renewable energy storage devices. Pyrolysis and hydrothermal carbonization (HTC) are two common methods of thermochemical conversion to synthesize biomass-derived based carbon. Compared to the pyrolysis method, HTC is a more promising strategy because it can be carried out without a pre-drying process, has a high yield, low ash content, and requires a relatively low temperature (180-250 °C). The carbon produced from the HTC process is known as hydrochar. This study reports the acid-assisted hydrothermal carbonization temperature on the hydrochar properties and its application for supercapacitor electrodes. Hydrochar was synthesized from extracted avocado seed waste with potassium permanganate and sulfuric acid catalyst solution at 200 °C for 12 h. The effect of one- and two-stage HTC temperature on the hydrochar properties were compared. The hydrochar characterization includes yield, SEM, XRD, FTIR, and cyclic voltammetry analysis. According to the characterization and analysis results, hydrochar produced has the 3D porous network morphology and the highest specific capacitance of 73.54 F/g. In conclusion, hydrochar derived from avocado seed through the acid-assisted HTC can be a potential way for supercapacitor electrodes.

Synthesis of Al-modified hydrochar from corn stover for efficient phosphate removal

The development of a simple and feasible process for preparing adsorbent materials to recover phosphorus resources would have significant environmental and social benefits. In this study, the Al-modified hydrochar was synthesized for phosphate adsorption by hydrothermal carbonization in one pot using corn stover as raw material. The results showed that phosphate adsorption mainly depended on the precipitation reaction between Al element and phosphate, in which the hydrochar carrier played a synergistic role. Al element through the hydrothermal treatment loaded on hydrochar expressed a much higher phosphate adsorption performance than that on pyrochar. When the concentration of AlCl3 solution added in the hydrothermal process was 2 mol·L−1 and the hydrothermal temperature exceeded 180 ℃, Al element could transform from the amorphous state, which was less effective for phosphate adsorption, to Al24O11(OH)44Cl6 crystal with high adsorption performance and could be more stably loaded onto the hydrochar. Although the preparation process was simple, the adsorption performance of hydrochar is good. The phosphate adsorption capacity and removal efficiency by the hydrochar prepared at 260 °C reached to 114.40 mg·g−1 and 76.27%, which could be further increased by adjusting the dosage of adsorbent and pH of water. The pseudo-second-order kinetic model and Langmuir isotherm model could better describe the phosphate adsorption process on Al-loaded hydrochar. Phosphate was rapidly adsorbed on the surface of the hydrochar rich in mesoporous structure and bound to the surface-active sites. This study could transform agricultural waste into a functional hydrochar-based adsorbent and provide a low-cost, simple operation and efficient phosphate removal technology.

A first-of-its-kind study on founding concatenated trio fuels production platform: Biodiesel from lipids, biomethane by anaerobic digestion of defatted biomass, and hydrochar by hydrothermal carbonization of Oscillatoria willei biogas slurry (OWBS)

Sustainable production of multiple biofuels from algae/spent algal biomass through a concatenated route imparts a new energy and environmental sustainability platform. Thus, this is a first-of-its-kind study on establishing a novel and integrated trio fuels production platform using a cyanobacterium Oscillatoria willei (O. willei); - (i) production of biodiesel from O. willei (ii) Anaerobic digestion of defatted biomass for biomethane production (iii) Hydrothermal carbonization (HTC) of O. willei biogas slurry (OWBS) for hydrochar production. Initially, a maximum dry weight of 1.63 g/L was obtained from O. willei on the 18th day, and further, it contains 12.86 % lipids, 41.37 % proteins, and 34.21 % carbohydrates. Biodiesel (Bioenergy- I) produced from the test strain was 67.87 % and it contains preferable fatty acids such as C16:0, C16:1, C18:1, C18:2, and C18:3. The defatted biomass was used for anaerobic digestion (AD) for biomethane (Bioenergy- II) production for up to 45 days. The OWBS from the AD process was used as a feedstock in HTC for the production of hydrochar (Bioenergy- III) under different HTC temperatures (200, 220, 240, 260, and 280 °C) and time (60, 90, 120, 150 and 180 min). The highest hydrochar yield from OWBS was estimated to be 41.65 % at 200 °C and 60 min. Further, elemental analysis of hydrochar revealed 37.6, 4.8, 1.7, 0.1, and 28.3 % of C, H, N, S, and O, respectively with 27.5 % ash content. Based on the results, it is concluded that this novel sequence of strategy delivering trio biofuels along with biogas slurry nutrient removal has not been investigated till now to the best of our knowledge, which will lay a road map for the production of multiple bioenergies along with waste management.