Hydrothermal processing, a thermochemical approach, is an excellent method of converting energy-rich biomass into useful products. This approach offers the advantage of handling biomass with relatively high moisture content by precluding an energy-intensive pretreatment step. Hydrothermal processing is of world-wide interest in view of depleting fossil-fuel reserves and increased environmental greenhouse gas emissions. There is potential to develop this novel technology at demonstration scale. This paper reviews the three hydrothermal technologies, namely hydrothermal liquefaction, gasification and carbonization, to provide insight into the likelihood of commercialization. The study discusses the role of different process parameters that have key impacts on the quality and yield of the desired products. This study also identifies the gaps in the literature including the need to establish a baseline to develop key process models and to perform a techno-economic assessment to get a better sense of the viability of the technology in future.

/pdf/a-review-on-the-current-status-of-various-hydrothermal-3lklcyrz7f.pdf

A review on the current status of various hydrothermal technologies on biomass feedstock

Electrospinning is the most facile and highly versatile approach to produce 1D polymeric, inorganic, and hybrid nanomaterials with a small diameter, controllable dimensions, and designed architectures In particular, with large surface area, high porosity, low density, good directionality, and tunable composition, electrospun nanofibers and mats are regarded as ideal candidates for various kinds of electrochemical energy storage devices such as supercapacitors (SCs) In this review, the recent progress in electrospun electrode materials for SCs is presented, covering the architecture design and their electrochemical performance After a brief introduction about SCs, the basic principles of the electrospinning technique are discussed Following, attention is paid to the discussion of various electrospun nanofibers and mats including 1D carbons, metal oxides, metal sulfides, metal nitrides, conducting polymers and composite nanomaterials with various types of architectures as electrodes for SCs The relationship between the composition, architecture, and the electrochemical performance is discussed in detail Finally, some challenges and perspectives of future research of the electrospun nanofibers and mats for high performance SCs are highlighted It is anticipated that this review would provide the researchers some inspiration for constructing new types of energy storage devices

Electrospun Nanomaterials for Supercapacitor Electrodes: Designed Architectures and Electrochemical Performance

Biomass derived carbon as binder-free electrode materials for supercapacitors

In the past three decades, many studies on the production of biofuels and other chemicals have been conducted using renewable sources such as lignocellulosic biomass. Lignocellulosic biomasses are abundantly available in most countries and furthermore they are carbon neutral. However, the main problem in utilizing lignocellulosic materials lies in the recalcitrance of its bonding. This review provides a comprehensive overview and a brief discussion on producing biofuel and valuable chemicals from lignocellulose biomass. Various aspects of the physical, chemical, thermophysical, thermochemical and biological pretreatment of lignocellulosic materials are discussed in this review. The success in biofuel and chemical production strongly depends on the pretreatment method used. Overall, pretreatment is the major step in the successful production of valuable products from lignocellulosic biomass.

/pdf/pretreatment-and-conversion-of-lignocellulose-biomass-into-gmcvcwpf63.pdf

Pretreatment and conversion of lignocellulose biomass into valuable chemicals

Phase change materials (PCMs) can alleviate concerns over energy to some extent by reversibly storing a tremendous amount of renewable and sustainable thermal energy. However, the low thermal conductivity, low electrical conductivity, and weak photoabsorption of pure PCMs hinder their wider applicability and development. To overcome these deficiencies and improve the utilization efficiency of thermal energy, versatile carbon materials have been increasingly considered as supporting materials to construct shape-stabilized composite PCMs. Despite some carbon-based composite PCMs reviews regarding thermal conductivity enhancement, a comprehensive review of carbon-based composite PCMs does not exist. Herein, a systematic overview of recent carbon-based composite PCMs for thermal storage, transfer, conversion (solar-to-thermal, electro-to-thermal and magnetic-to-thermal), and advanced multifunctional applications, including novel metal organic framework (MOF)-derived carbon materials are provided. The current challenges and future opportunities are also highlighted. The authors hope this review can provide in-depth insights and serve as a useful guide for the targeted design of high-performance carbon-based composite PCMs.

Carbon-Based Composite Phase Change Materials for Thermal Energy Storage, Transfer, and Conversion.

In this study, water hyacinth was hydrolyzed to sugars with dilute sulphuric acid (0.25 M) under subcritical water conditions (P = 20 bar, T = 130 °C) for 2 h. The sugar solution was then carbonized under subcritical conditions to produce carbon microsphere. The subcritical water carbonization was conducted at 40 bar and various temperatures (160–200 °C) and times (6–10 h). The highest yield of carbon microspheres was 0.1019 g/g dry water hyacinth at the temperature of 200 °C for 10 h. The carbon microsphere was activated using a combination of chemical (KOH solution) and physical (microwave) treatments to increase the specific surface area and porosity of carbon microsphere. Electrocapacitive study of carbon microspheres showed that the carbon microsphere activated at impregnation ratio of 1:1 and microwave power of 630 W has the highest specific capacitance and excellent electrochemical stability.

Carbon microsphere from water hyacinth for supercapacitor electrode

In this study, we demonstrate a simple and low cost method to synthesize N/P/K co-doped porous carbon microfibers (CMFs) from a sugar-rich byproduct (cane molasses) as the precursor material. A two-step method for the synthesis of N/P/K co-doped porous CMFs involving electrospinning of precursor material followed by simple carbonization at various temperatures (773.15–1173.15 K) was successfully applied. The N/P/K co-doped porous CMFs exhibited high specific surface area (∼580 m2 g−1) and hierarchical porous structure. The potential application of N/P/K co-doped porous CMFs as supercapacitor electrodes was investigated in a two-electrode configuration employing aqueous K2SO4 solution and ionic liquids/acetonitrile (ILs/ACN) mixtures as the electrolytes. A series of electrochemical measurements include cyclic voltammetry, galvanostatic charge–discharge and cycling durability all confirmed that the CMF-1073.15 supercapacitor exhibited good electrochemical performance with a specific capacitance of 171.8 F g−1 at a current load of 1 A g−1 measured in 1.5 M tetraethylammonium tetrafluoroborate (TEABF4)/ACN electrolyte, which can be charged and discharged up to a cell potential of 3.0 V. The specific energy density and power density of 53.7 W h kg−1 and 0.84 kW kg−1 were achieved. Furthermore, the CMF-1073.15 supercapacitor showed excellent cycling performance with capacitance retention of nearly 91% after 2500 charge–discharge cycles, characterizing its electrochemical robustness and stable capacitive performance.

/pdf/easy-approach-to-synthesize-n-p-k-co-doped-porous-carbon-13r5dsrflj.pdf

Easy approach to synthesize N/P/K co-doped porous carbon microfibers from cane molasses as a high performance supercapacitor electrode material

Preparation of nanoporous carbon microspheres by subcritical water carbonization and electrocapacitive study

Model of Corncob Biochar Modified Carbon Paste Electrode for Nitrite Detection

Electrochemical response of ascorbic acid (AA) has been studied using a screen-printed carbon elec- trode (SPCE). The electrochemical response was measured using cyclic voltammetry (CV) in 0.1 M phosphate buffer solution at various pH. The measurement was carried out at a potential of – 0.75 V to + 1.0 V at room temperature. The effect of scan rate was observed from 25 to 125 mV/s. The presence of interference compounds, i.e., glucose, uric acid and urea during AA measurement was also investigated. The elec- trochemical response of AA using SPCE was observed at around + 0.45 V in all pH variations without reduction peak. This indicated that AA can be detected by SPCE from its oxidation peak. It is in good agree- ment with the natural properties of AA, which is easily oxidized, tuning into dehydroascorbic acid (DHAA). No interference signal was found from interfering compounds during AA measurement at pH 7.0. The scan rate effect implied that the occurred process in SPCE was diffusion controlled. It was also shown that the anodic current peaks are linearly proportional to the scan rate, which means the electrocatalytic behavior of AA associated with the surface electron transfer. The results of this study proved that SPCE has good potential as a sensor for detecting AA. phosphate buffer solutions with various pH (pH  5.0, 7.0, and 9.0). The interference study of SPCE for AA detection by measuring 10 mM of AA, glucose, UA, and urea solutions. All experiments were performed at room temperature. трафаретним друком Електрохімічну вимірювали використанням циклічної Вплив швидкості

https://essuir.sumdu.edu.ua/bitstream/123456789/88370/1/Illiya_jnep_3_2022.pdf

Fredi Kurniawan

Papers

Carbon microsphere from water hyacinth for supercapacitor electrode

Easy approach to synthesize N/P/K co-doped porous carbon microfibers from cane molasses as a high performance supercapacitor electrode material

Preparation of nanoporous carbon microspheres by subcritical water carbonization and electrocapacitive study

Model of Corncob Biochar Modified Carbon Paste Electrode for Nitrite Detection

Electrochemical Response of Ascorbic Acid Using Screen-Printed Carbon Electrode