Upcycling biowaste into advanced carbon materials via low-temperature plasma hybrid system: applications, mechanisms, strategies and future prospects.

This review focuses on the recent advances in the sustainable conversion of biowaste to valuable carbonaceous materials. This study summarizes the significant progress in biowaste-derived carbon materials (BCMs) via a plasma hybrid system. This includes systematic studies like AI-based multi-coupling systems, promising synthesis strategies from an economic point of view, and their potential applications towards energy, environment, and biomedicine. Plasma modified BCM has a new transition lattice phase and exhibits high resilience, while fabrication and formation mechanisms of BCMs are reviewed in plasma hybrid system. A unique 2D structure can be designed and formulated from the biowaste with fascinating physicochemical properties like high surface area, unique defect sites, and excellent conductivity. The structure of BCMs offers various activated sites for element doping and it shows satisfactory adsorption capability, and dynamic performance in the field of electrochemistry. In recent years, many studies have been reported on the biowaste conversion into valuable materials for various applications. Synthesis methods are an indispensable factor that directly affects the structure and properties of BCMs. Therefore, it is imperative to review the facile synthesis methods and the mechanisms behind the formation of BCMs derived from the low-temperature plasma hybrid system, which is the necessity to obtain BCMs having desirable structure and properties by choosing a suitable synthesis process. Advanced carbon-neutral materials could be widely synthesized as catalysts for application in environmental remediation, energy conversion and storage, and biotechnology.

Catalytic hydrothermal carbonization of wet organic solid waste: A review.

Hydrothermal carbonization has gained attention in converting wet organic solid waste into hydrochar with many applications such as solid fuel, energy storage material precursor, fertilizer or soil conditioner. Recently, various catalysts such as organic and inorganic catalysts are employed to guide the properties of the hydrochar. This review presents a summarize and a critical discussion on types of catalysts, process parameters and catalytic mechanisms. The catalytic impact of carboxylic acids is related to their acidity level and the number of carboxylic groups. The catalysis level with strong mineral acids is likely related to the number of hydronium ions liberated from their hydrolysis. The impact of inorganic salts is determined by the Lewis acidity of the cation. The metallic ions in metallic salts may incorporate into the hydrochar and increase the ash of the hydrochar. The selection of catalysts for various applications of hydrochars and the environmental and the techno-economic aspects of the process are also presented. Although some catalysts might enhance the characteristics of hydrochar for various applications, these catalysts may also result in considerable carbon loss, particularly in the case of organic acid catalysts, which may potentially ruin the overall advantage of the process. Overall, depending on the expected application of the hydrochar, the type of catalyst and the amount of catalyst loading requires careful consideration. Some recommendations are made for future investigations to improve laboratory-scale process comprehension and understanding of pathways as well as to encourage widespread industrial adoption.

Process analysis of solar steam reforming of methane for producing low-carbon hydrogen.

Regarding the trend of hydrogen-powered fuel cell engine development, hydrogen fuel is undisputedly the next generation renewable and sustainable energy carrier. The steam reforming of methane (SRM) is a field-proven technology for efficient hydrogen production. However, producing low-carbon hydrogen is the most technical challenge related to available hydrogen production technologies. This paper investigated the process analysis of SRM for low-carbon hydrogen production using concentrated solar energy as a heat source. Analysis of the solar SRM is carried out considering the reformate gas and their influencing factors. The operating temperature of 200-1000 °C and the pressure of 1.02-30 bar were considered when the mass ratio of steam-to-methane in feed gas was varied from 1.0 to 4.0. It was found that the composition of reformate gas, hydrogen yield, methane and steam conversion rate, the thermal efficiency of reforming reactor, and volume flow of reformate gas are significantly affected by the operating parameters including temperature, pressure, and the mass ratio of feed gas. Carbon content in the yield of hydrogen produced can be limited by considering the water-gas shift reaction in the SRM process. Besides, the centralized tower type solar concentrating system is selected as the heat source of the SRM process. The effect of solar radiation on the operation performance of the solar SRM process was analyzed. Direct normal irradiation is a key factor affecting the operating performance of the solar SRM process.

Energy-Efficient Multi-Disjoint Path Opportunistic Node Connection Routing Protocol in Wireless Sensor Networks for Smart Grids.

The gradual increase in the maturity of sensor electronics has resulted in the increasing demand for wireless sensor networks for many industrial applications. One of the industrial platforms for efficient usage and deployment of sensor networks is smart grids. The critical network traffic in smart grids includes both delay-sensitive and delay-tolerant data for real-time and non-real-time usage. To facilitate these traffic requirements, the asynchronous working-sleeping cycle of sensor nodes can be used as an opportunity to create a node connection. Efficient use of wireless sensor network in smart grids depends on various parameters like working-sleeping cycle, energy consumption, network lifetime, routing protocol, and delay constraints. In this paper, we propose an energy-efficient multi-disjoint path opportunistic node connection routing protocol (abbreviated as EMOR) for sensor nodes deployed in neighborhood area network. EMOR utilizes residual energy, availability of sensor node's buffer size, working-sleeping cycle of the sensor node and link quality factor to calculate optimum path connectivity after opportunistic connection random graph and spanning tree formation. The multi-disjoint path selection in EMOR based on service differentiation of real-time and non-real-time traffic leads to an improvement in packet delivery rate, network lifetime, end-end delay and total energy consumption.