Thanattha Chobsilp¹, Alongkot Treetong², Visittapong Yordsri³, Mattana Santasnachok^4,5, Pollawat Charoeythornkhajhornchai⁶, Jaruvit Sukkasem⁷, Winadda Wongwiriyapan⁸, Worawut Muangrat^1,5,*

Journal of Renewable Materials, Vol.13, No.11, pp. 2155-2168, 2025, DOI:10.32604/jrm.2025.02025-0111 - 24 November 2025

Abstract Nitrogen-doped activated carbon (N-AC) was successfully prepared by KOH-activation and nitrogen doping using ammonia (NH₃) heat treatment. Coconut shell-derived activated carbon (AC) was heat-treated under NH₃ gas in the temperature range of 700°C–900°C. Likewise, the mixture of potassium hydroxide (KOH) and AC was heated at 800°C, followed by heat treatment under NH₃ gas at 800°C (hereafter referred to as KOH-N-AC800). Scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) method were utilized to analyze morphology, crystallinity, chemical bonding, chemical composition and surface area. The surface area and porosity of N-AC increased with increasing… More >

Zihao Yang^1,*, Jiarui Cheng¹, Zefeng Li², Yirong Yang¹, Linghong Tang¹, Wenlan Wei¹

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.9, pp. 2149-2176, 2025, DOI:10.32604/fdmp.2025.067739 - 30 September 2025

Abstract This study presents a two-dimensional, transient model to simulate the flow and thermal behavior of CO₂ within a fracturing wellbore. The model accounts for high-velocity flow within the tubing and radial heat exchange between the wellbore and surrounding formation. It captures the temporal evolution of temperature, pressure, flow velocity, and fluid density, enabling detailed analysis of phase transitions along different tubing sections. The influence of key operational and geological parameters, including wellhead pressure, injection velocity, inlet temperature, and formation temperature gradient, on the wellbore’s thermal and pressure fields is systematically investigated. Results indicate that due to… More >

Jiangbo Wu¹, Siyi Sun¹, Xiaoze Du^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.8, pp. 1789-1807, 2025, DOI:10.32604/fdmp.2025.064254 - 12 September 2025

Abstract This study explores the aerodynamic performance and flow field characteristics of supercritical carbon dioxide (sCO₂) centrifugal compressors under varying operating conditions. In particular, the Sandia main compressor impeller model is used as a reference system. Through three-dimensional numerical simulations, we examine the Mach number distribution, temperature field, blade pressure pulsation spectra, and velocity field evolution, and identify accordingly the operating boundaries ensuring stability and the mechanisms responsible for performance degradation. Findings indicate a stable operating range for mass flow rate between 0.74 and 3.74 kg/s. At the lower limit (0.74 kg/s), the maximum Mach number within… More >

Senchun Miao^1,*, Wenkai Hu¹, Jiangbo Wu¹, Zhengjing Shen¹, Xiaoze Du^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.7, pp. 1711-1735, 2025, DOI:10.32604/fdmp.2025.062239 - 31 July 2025

Abstract In Brayton cycle energy storage systems powered by supercritical carbon dioxide (sCO₂), compressors are among the most critical components. Understanding their internal flow loss characteristics is, therefore, essential for enhancing the performance of such systems. This study examines the main sCO₂ compressor from Sandia Laboratory, utilizing entropy production theory to elucidate the sources and distribution of energy losses both across the entire machine and within its key flow components. The findings reveal that turbulent viscous dissipation is the predominant contributor to total entropy production. Interestingly, while the relative importance of the entropy produced by various sources More >

Jiahao Liu^1,#, Xinyu Zhang^1,#, Huiwei Wang¹, Yupeng Li¹, Shan Jin¹, Guanxian Qiu¹, Ce Sun^1,2,*, Haiyan Tan¹, Yanhua Zhang^1,2,*

Journal of Renewable Materials, Vol.13, No.4, pp. 669-685, 2025, DOI:10.32604/jrm.2025.02025-0042 - 21 April 2025

Abstract In recent years, degradable materials to replace petroleum-based materials in preparing high-performance foams have received much research attention. Degradable polymer foaming mostly uses supercritical fluids, especially carbon dioxide (Sc-CO₂). The main reason is that the foams obtained by Sc-CO₂ foaming have excellent performance, and the foaming agent is green and pollution-free. In current research, Poly (butylene adipate-co-terephthalate) (PBAT), poly (lactic acid) (PLA), and other degradable polymers are generally used as the main foaming materials, but the foaming performance of these degradable polyesters is poor and requires modification. In this work, 10% PLA was added to PBAT to… More > Graphic Abstract

Ikram Belmehdi^1,*, Boumedienne Beladjine¹, Mohamed Djermouni¹, Amina Sabeur¹, Mohammed El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.1, pp. 71-85, 2025, DOI:10.32604/fdmp.2024.058510 - 24 January 2025

Abstract The objective of this study is to propose an optimal plant design for blue hydrogen production aboard a liquefied natural gas (LNG) carrier. This investigation focuses on integrating two distinct processes—steam methane reforming (SMR) and ship-based carbon capture (SBCC). The first refers to the common practice used to obtain hydrogen from methane (often derived from natural gas), where steam reacts with methane to produce hydrogen and carbon dioxide (CO₂). The second refers to capturing the CO₂ generated during the SMR process on board ships. By capturing and storing the carbon emissions, the process significantly reduces its… More >

Yanbo Shao¹, Xuewen Cao^1,*, Wei You¹, Shan Zhao¹, Zilong Nan², Jiang Bian^1,3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.12, pp. 2867-2885, 2024, DOI:10.32604/fdmp.2024.053774 - 23 December 2024

Abstract Transporting massive quantities of carbon dioxide through a pipeline in its supercritical state is extremely convenient. Because of the unique properties of supercritical carbon dioxide, however, leakage occurring in such conditions can be extremely intricate, resulting in the dispersion area following leakage being influenced by numerous factors. In this study, this problem is addressed in the frame of the so-called Unified Dispersion Model (UDM), and various influential parameters are considered, namely, leakage pressure, leakage temperature, leakage aperture, leakage angle, atmospheric stability, wind speed, and surface roughness. The results show that the supercritical carbon dioxide dispersion More >

Huda Adel Hassan Ali, Ameer Abed Jaddoa^*, Jafaar Mohamme Daif

Frontiers in Heat and Mass Transfer, Vol.21, pp. 443-465, 2023, DOI:10.32604/fhmt.2023.042288 - 30 November 2023

Abstract This paper is twofold. First, the effect of non-linear thermophysical property variation was presented using supercritical carbon dioxide (SCO₂) around the thermodynamic pivotal point. The second part exhibits an experimental examination of the heat transfer (HT) behaviour of SCO₂ in a helical tube with a hydraulic diameter of 2 mm at different mass fluxes (MF), heat fluxes (HF), and pressures (P). The experiments were carried out based on various pressures, mass fluxes, and heat fluxes for both scenarios. CO₂ was cooled in a 2 mm diameter serpentine tube made of copper material. The experimental results showed that More > Graphic Abstract

Yun Lei^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.12, pp. 3021-3032, 2023, DOI:10.32604/fdmp.2023.029570 - 27 October 2023

Abstract The highly inefficient simultaneous extraction of coal and gas from low-permeability and high-gas coal seams in deep mines is a major problem often restricting the sustainable development of coal industry. A possible way to solve this problem under deep and complex geological conditions is represented by the technology based on the phase-change induced explosion of liquid carbon dioxide. In this work, the mechanism of formation of the coal mass fracture circle resulting from the gas cracking process is theoretically analyzed. Numerical simulations show that a blasting crushing zone with a radius of 1.0 m is More >

Qifen Li, Xiaoxiao Yan^*, Yongwen Yang, Liting Zhang, Yuanbo Hou

Journal of Renewable Materials, Vol.11, No.7, pp. 3177-3191, 2023, DOI:10.32604/jrm.2023.027749 - 05 June 2023

Abstract Microbial Electrolytic Cell (MEC) is an electrochemical reaction device that uses electrical energy as an energy input and microorganisms as catalysts to produce fuels and chemicals. The regenerative electrochemical system is a MEC improvement system for methane gas produced by biological carbon sequestration technology using renewable energy sources to provide a voltage environment. In response to the influence of fluctuating disturbances of renewable electricity and the long system start-up time, this paper analyzes the characteristics of two strategies, regulating voltage parameter changes and activated sludge pretreatment, on the methane production efficiency of the renewable gas… More >