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1.
Biomass gasification technology under microwave irradiation is a new and novel method, and the energy conversion performances during the process play a guiding role in improving the energy conversion efficiencies and developing the gasification simulation models. In order to improve the energy utilization efficiency of microwave biomass gasification system, this study investigated and presented the energy conversion performances during biomass gasification process under microwave irradiation, and these were materialized through detailing (a) the energy conversion performance in the microwave heating stage, and (b) the energy conversion performance in the microwave assisted biomass gasification stage. Different forms of energies in the biomass microwave gasification process were calculated by the method given in this study based on the experimental data. The results showed that the useful energy (energy in silicon carbide (SiC), 18.73 kJ) accounted for 31.22% of the total energy input (electrical energy, 60.00 kJ) in the heating stage, and the useful energy (energy in the products, 758.55 kJ) accounted for 63.41% of the total energy input (electrical and biomass energy, 1196.28 kJ) in the gasification stage. During the whole biomass gasification process under microwave irradiation, the useful energy output (energy in the products, 758.55 kJ) accounted for 60.38% of the total energy input (electrical and biomass energy, 1256.28 kJ), and the energy in the gas (523.40 kJ) product played a dominate role in product energy (758.55 kJ). The energy loss mainly included the heat loss in the gas flow (89.20 kJ), magnetron loss (191.80 kJ) and microwave dissipation loss (198.00 kJ), which accounted for 7.10%, 15.27% and 15.76% of the total energy, respectively. The contents detailed in this study not only presented the energy conversion performances during microwave assisted gasification process but also supplied important data for developing gasification simulation models.  相似文献   
2.
In the last few decades, global warming, environmental pollution, and an energy shortage of fossil fuel may cause a severe economic crisis and health threats. Storage, conversion, and application of regenerable and dispersive energy would be a promising solution to release this crisis. The development of porous carbon materials from regenerated biomass are competent methods to store energy with high performance and limited environmental damages. In this regard, bio-carbon with abundant surface functional groups and an easily tunable three-dimensional porous structure may be a potential candidate as a sustainable and green carbon material. Up to now, although some literature has screened the biomass source, reaction temperature, and activator dosage during thermochemical synthesis, a comprehensive evaluation and a detailed discussion of the relationship between raw materials, preparation methods, and the structural and chemical properties of carbon materials are still lacking. Hence, in this review, we first assess the recent advancements in carbonization and activation process of biomass with different compositions and the activity performance in various energy storage applications including supercapacitors, lithium-ion batteries, and hydrogen storage, highlighting the mechanisms and open questions in current energy society. After that, the connections between preparation methods and porous carbon properties including specific surface area, pore volume, and surface chemistry are reviewed in detail. Importantly, we discuss the relationship between the pore structure of prepared porous carbon with surface functional groups, and the energy storage performance in various energy storage fields for different biomass sources and thermal conversion methods. Finally, the conclusion and prospective are concluded to give an outlook for the development of biomass carbon materials, and energy storage applications technologies. This review demonstrates significant potentials for energy applications of biomass materials, and it is expected to inspire new discoveries to promote practical applications of biomass materials in more energy storage and conversion fields.  相似文献   
3.
The potential of using high metals containing coal gangue and lignite to prepare high-activity coal char-based catalysts is investigated for effective biomass tar decomposition. Loose structure and rough surface are formed for these char-based catalysts with heterogeneous distribution of a large number of inorganic particles. In the biomass tar decomposition, the performance of the coal char-based catalysts is significantly influenced by the content of the metals in the raw materials and coal gangue char (GC) with the ash content as high as 50.80% exhibits the highest activity in this work. A high biomass tar conversion efficiency of 93.5% is achieved at 800 °C along with a significant increase in the fuel gas product. During the five-time consecutive tests, the catalytic performance of GC increases a little at the second or third times reuse and remains relatively stable, showing the remarkable stability of the catalyst in biomass tar decomposition applications.  相似文献   
4.
The coupling between biomass gasification and Solid Oxide Fuel Cells can represent a sustainable and efficient system for electricity production. This work aims to develop a preliminary model for the operation of a tubular, electrolyte-supported fuel cell (SOFC) fed by a syngas mixture. The fuel required by the SOFC system is produced inside the energy generator box from an integrated biomass gasification system. This study stems from the European DB-SOFC project, that proposed the exploitation of the abundant biomasses deriving from agricultural residues for energetic purposes (as from olive oil and wine production). In this study, the main processes have been simulated to find a possible configuration to obtain a power value of 200 W. 25 cells were used in the model to produce the required power. The results showed that at 0.7 V it is possible to achieve 12.3 W, when the biomass gasification was integrated into the SOFC box, while it was possible to achieve 9.6 W when the system was fed by externally produced syngas.  相似文献   
5.
Fossil fuel combustion is one of the major means to meet the mounting global energy demand. However, the increasing NOx and N2O emissions arising from fossil fuel combustion process have hazardous effects. Thus, mitigating these gases is vital to attain a sustainable environment. Interestingly, oxy-fuel combustion in fluidized bed for carbon capture and minimized NOx emissions is strongly sustainable compare to the other approaches. It was assessed that NOx formation and fuel-N conversion have significant limitation under oxy-fluidized bed compared to air mode and the mechanism of NOx formation is still deficient and requires further development. In addition, this review paper discussed the potential of primary measure as low emission process with others supplementary techniques for feasible NOx reduction. The influences of combustion mode, operating parameters, and reduction techniques such as flue gas recirculation, oxygen staging, biomass co-firing, catalyst, influence of fluidized bed design and structure, decoupling combustion and their merges are respectively evaluated. Findings show that significant minimization of NOx emission can be achieved through combination of primary and secondary reduction techniques.  相似文献   
6.
石墨烯能够在一定的程度上对藜麦的根系形态及生物量产生巨大的影响。主要研究石墨烯对藜麦幼苗的根系形态、生物量的影响。  相似文献   
7.
A series of ZnxNiyCrOm±δ catalysts were synthesized via a typical co-precipitation method, in which Zn-Cr layered double hydroxides (LDHs) were found and Ni-Zn intermetallic compound (IMC) was formed after reduction in hydrogen. During auto-thermal reforming (ATR) of acetic acid (HAc), the Ni-Zn IMC was transformed into Ni/(amorphous-ZnO)-ZnCr2O4 species with uniformed distribution and appropriate interaction within these Ni-Zn-Cr-O species; besides, the adsorbed oxygen promoted the activation and transfer of oxygen species; therefore, deactivation by oxidation, sintering and coking was inhibited. And the optimized Zn2.37Ni0.63CrO4.5±δ catalyst presented high activity and stability in a 45-h ATR test with HAc conversion near 100% and hydrogen yield at 2.7 mol-H2/mol-HAc, showing potential for hydrogen production via ATR of HAc.  相似文献   
8.
With the seasonal availability and low energy density of biomass and the high environmental impact of coal, the co-gasification of biomass and coal is an alternative approach facilitating a trade-off between renewable and non-renewable resources. The aim of this study was to investigate hydrogen production from the co-gasification of biomass and coal integrated by means of the sorption-enhanced water gas shift reactor (G-SEWGS) for a high temperature proton exchange membrane fuel cell (HT-PEMFC). The effects of the gasifier temperature, the steam to fuel ratio (S/F ratio), and the equivalence ratio (ER) on the hydrogen production performance and environmental impact of the G-SEWGS were theoretically analysed and compared with the conventional gasifier integrated with the water gas shift reactor (G-WGS) and the sorption-enhanced gasifier integrated with the water gas shift reactor (SEG-WGS). As compared to the conventional water gas shift reactor, the addition of a CaO sorbent in the modified water gas shift reactor not only reduces the amount of the CO2 emission but also leads to an increase in the hydrogen concentration and hydrogen content. The G-SEWGS provides better performance in terms of its fuel processor efficiency and CO2 emission than the G-WGS and the SEG-WGS. Also, the problem of sulphur compound in the hydrogen-rich gas can be reduced by using of the sorption-enhanced water gas shift reactor (SEWGS). The best system exergy efficiency, which was around 22% for the power generation, was determined from the HT-PEMFC integrated with the G-SEWGS. The main exergy destruction of around 70% of the total loss was caused by hydrogen production processes.  相似文献   
9.
In this work, we study the gasification of pellets produced, after densification, by blending olive mill solid wastes, impregnated or not by olive mill waste water, and pine sawdust under different steam/nitrogen atmospheres. The charcoals necessary for the gasification tests were prepared by pyrolysis using a fixed bed reactor. The gasification technique using steam was chosen in order to produce a hydrogen-enriched syngas. Gasification tests were performed using macro-thermogravimetric equipment. Tests were carried out at different temperatures (750 °C, 800 °C, 820 °C, 850 °C and 900 °C), and at different atmospheres composed by nitrogen and steam at different percentages (10%, 20% and 30%). Results show that the mass variation profiles is similar to the usual lingo-cellulosic gasification process. Moreover, the increase of temperatures or water steam partial pressures affects positively the rate of conversion and the char reactivity by accelerating the gasification process. The increase of the gasification yields demonstrates the promise of using olive mill by-products as alternative biofuels (H2 enriched syngas).  相似文献   
10.
Aspen Plus has become one of the most common process simulation tools for both academia and industrial applications. In the last decade, the number of the papers on Aspen Plus modeling of biomass gasification has significantly increased. This review focuses on recent developments and studies on modeling biomass gasification in Aspen Plus including key aspects such as tar formation and model validation. Accordingly, challenges in modeling due to specific assumptions and limitations will be highlighted to provide a useful basis for researchers and end-users for further process modeling of biomass gasification in Aspen Plus.  相似文献   
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