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In this study, reactive molecular dynamics simulations were employed to investigate cellulose gasification using different gasifying agents (i.e., O 2 , steam, and CO 2). The simulation results were analyzed by various indicators, including product distribution, generation pathways of gaseous products, evolutions of bonds and pyran rings, carbon conversion efficiency, and kinetic parameters. Moreover, the differences among three gasifying agents were highlighted. Results show that O 2 gasification yields a higher CO yield while inhibiting H 2 production. The introduction of gasifying agents promotes cleavage of C–C bonds while facilitating the formation of C–O and H–O bonds, compared to cellulose pyrolysis. The addition of O 2 exhibits the most pronounced enhancement in carbon conversion efficiency, followed by H 2 O and CO 2. Additionally, the activation energies of gasification processes are lower than that of cellulose pyrolysis, and a general decreasing trend in activation energy is observed with increasing the amount of gasifying agent. All these observations, particularly regarding the effects of gasifying agents on cellulose gasification products and the formation pathways of major product species, provide valuable insights for predicting and optimizing the cellulose gasification process. • Cellulose gasification was studied by reactive molecular dynamics simulations. • Effects of three different gasifying agents (O 2 , steam, and CO 2) were explored. • Product distribution and generation pathways of gaseous products were presented. • Temporal evolutions of bonds and pyran rings were analyzed. • Carbon conversion efficiency and kinetic parameters were also discussed. [ABSTRACT FROM AUTHOR]

Air gasification of biomass (sawdust) has been studied using an ASPEN plus model capable of predicting the producer gas composition and gasifier performance at different conditions. The methodology is based on an equilibrium-kinetic concept, which uses an equilibrium approach for combustion of tar and volatiles and a kinetic approach for char gasification. Gasification profiles identified by model showed that higher temperatures and equivalence ratios (ERs) are favorable for tar reduction and char conversion. With the increase of temperature, H2 and CO contents increase while CO2 content decreases. The lower heating value (LHV) of producer gas increased as the temperature increased owing to both an increase of energetic components and an increase of char conversion. Model-predicted gas compositions were consistent with the experimental results. This shows that the developed model is accurate and it can play an important role in the simulation of air gasification of biomass and a wide variety of solid fuels such as municipal solid wastes and low-grade biomasses. [ABSTRACT FROM AUTHOR]

Producing hydrogen (H2) from biomass gasification offers exceptional benefits regarding renewable energy sources, zero‐carbon emission, cost‐effective processes, and high efficiency. The addition of catalysts to biomass gasification could accelerate the process and minimize the formation of coke. However, the catalyst deactivation caused by carbon deposition, poisoning, and sintering is still a significant problem in the gasification process. Therefore, achieving sustainable exploitation of the renewable natural resource of biomass requires substantial development and optimization of the present gasification process. The efficiency of gasification might decrease because of such a process. In this study, CeO2(111) is chosen to investigate the analysis of adsorption molecules during catalytic gasification using the density functional theory method. Three catalyst models, CeO2(111), Zr‐CeO2(111), and Ni‐CeO2(111), have been studied in this work in terms of structural, electronic, and adsorption molecule properties. The structural and electronic properties of the modified catalyst model show the ligand and strain effect on the alloy, with the addition of Zr and Ni as second metals promoting the adsorption capability. Searching for active sites is also carried out by adsorption of selected atoms and molecules and used as a preliminary study to find possible active sites for gasification reactions. The Zr‐CeO2(111) and Ni‐CeO2 catalysts exhibit better adsorption ability on atomics and molecules. The Zr and Ni metals are suitable second metal candidates for the catalyst to proceed with the gasification reaction and simultaneously reduce carbon deposition, poisoning, and sintering problems. [ABSTRACT FROM AUTHOR]

As a new type of energy that can meet the requirements of carbon neutrality, biomass has received wide attention in recent years, and its rational and efficient thermal utilization can help reduce greenhouse gas emissions and establish an energy-saving, low-carbon energy system to promote sustainable development. In this paper, the current utilization and research status of plant-based biomass waste is comprehensively summarized from four aspects, namely component properties, industrial thermal utilization means, experiments and theoretical calculations. In addition, this paper summarizes the research progress in several aspects, such as microscopic experimental studies, macroscopic pyrolysis characterization, and multiscale theoretical model construction of biomass waste. However, due to the diversity and heterogeneity of biomass, there are still some challenges to extending the laboratory research results to large-scale industrial production, for which we also provide an outlook on future technological innovations and development directions in this research area. [ABSTRACT FROM AUTHOR]

This article presents a device for the storage and gasification of cryogenic working fluid, which is named a cryogenic fuelling tank. A cryogenic fuel tank can serve both as a fuel vessel and a pressure accumulator due to the regasification process that takes place inside. Application of this tank is slowed by the lack of theoretical and experimental research on its working process. This article deals with an investigation of the working process of the energy plant based on a cryogenic fuel tank coupled with a rotor-vane expander. Developed mathematical models include evaporation and condensation processes within the tank, heat exchange between gas chambers and between the tank and environment, and changes in energy due to incoming and leaving mass. Mechanical work used to determine the efficiency of a power plant is generated by a steam expander. Research shows that it is possible to achieve specific work outputs up to 110–160 kJ/kg with relative deviation of power and specific work determination equal to 1.4% and 1.9% correspondingly. [ABSTRACT FROM AUTHOR]

An integrated thermochemical-biochemical Biomass-to-Liquid (BtL) pathway for the production of aviation and maritime liquid fuels from biogenic residues is introduced. The presence of a semi-commercially proven technology like Dual Fluidized Bed Gasification (DFBG) ensures extended fuel flexibility, syngas of high quality, complete fuel conversion, and optimal heat integration while avoiding CAPEX (Capital Expenditure) intensive equipment like air separation unit. Then, a two-stage biochemical route is proposed: initially syngas fermentation (anaerobic) into acetate and subsequently acetate fermentation (aerobic) into targeted triglycerides (TAGs) that will be finally purified and hydrotreated to form the desired drop-in biofuels. The tolerance of the bacteria to syngas contaminants minimizes the gas cleaning requirements. Moreover, the low-pressure requirements (1–10 bar) along with the mild operating temperatures (30–60 °C) reduce drastically the capital and operational cost of the process. The biological process of syngas fermentation inherently has limited side products, a fact that reduces the risk of deactivation of hydrotreatment catalysts. Heat and mass balances are calculated for the proposed concept via full-scale process simulations in Aspen Plus™ assuming a thermal input of 200 MWth with crushed bark as feedstock. Three different operational scenarios are examined mainly through overall performance indicators such as carbon utilization (CU) and energetic fuel efficiency (EFE). Competitive performance compared to technologies that exploit similar feedstock (i.e., biogenic residues) was noticed, since values in the range of 22–27% and 31–37% were obtained for the CU and EFE, respectively. The aim of this study is to determine the appropriate key process specifications and assess the potential of the proposed concept compared to other competitive technologies. [ABSTRACT FROM AUTHOR]

Self-activation is an endothermic process in the form of physical/thermal activation that utilizes the gases produced during the high temperature pyrolysis of a carbonaceous material. This serves as the activation agent resulting in the conversion of the material into activated carbon. Because the pyrolysis happens in a sealed high temperature environment, it is currently difficult to monitor and understand the interactions between the gasses present and the state of the carbons present. The objective of this study was to develop a real-time gas monitoring system to monitor gas changes during the self-activation process in the pyrolysis of biomass. Southern yellow pine was subjected to self-activation where an external gas sensor array was used to observe the real-time changes in the CO2 and H2; the gas concentrations were measured at intervals throughout the dwelling time from the sealed environment to observe the changes that occurred. Gas chromatography and surface area characterization were performed in order to compare what happened within the furnace to the resulting products of the self-activation and the gas concentration readings. The effectiveness of the gas sensor array was corroborated by showing that the peak CO2 around sample run 6 coincided with peak CO2 reading in the gas chromatography which declined as processing continued. Peak X-ray diffraction (XRD) value and a sharp peak in the Fourier-transform infrared spectroscopy (FTIR) due to degradation of cellulose and hemicellulose were contributed to the carbonization of the southern yellow pine. These findings can be correlated to the changes in gasses throughout pyrolysis processing showing the effectiveness of the gas sensor array used to monitor the process. [ABSTRACT FROM AUTHOR]

The end-of-life tyres (ELTs) are currently critical environmental and societal problems due to their large quantity and chemical structure. The thermochemical process has been acknowledged as a viable option for extracting material and energy from ELTs. This review outlines the cutting-edge thermochemical techniques for recycling tyres, encompassing gasification, pyrolysis, and incineration. Additionally, it delves into the primary by-products, including oil, gas, and char. The advantages and disadvantages of each process are discussed in terms of energy efficiency, product yield, and environmental impact. The optimal reaction conditions for each product yield and quality are identified and described. The correlation between process parameters and product composition, yield and quality is clarified. Products after further processing are illustrated with specific examples. Future research directions such as upgrade of char product using low-temperature partial-oxidation process are given. This review is novel in its comprehensive synthesis of the latest advancements in thermochemical techniques for recycling ELTs, highlighting recent innovations in gasification, pyrolysis, and incineration methods. It is also a timely review due to the urgent need for sustainable waste management solutions amidst growing environmental concerns and stringent regulations on tyre disposal. Highlights: • Thermochemical innovation — exploring cutting-edge gasification, pyrolysis, and incineration for recycling end-of-life tyres. • Product analysis — examining oil, gas, and char, evaluating their efficiency and environmental impact. • Optimal conditions — identifying the key factors that influence optimal yield and quality in tyre recycling processes. [ABSTRACT FROM AUTHOR]

The effect of potassium impregnation at different concentrations during gasification, under nitrogen/water steam atmosphere, of char produced via pyrolysis of olive mill residues blended or not with pine sawdust was investigated. Three concentrations (0.1 M, 0.5 M, and 1.5 M) of potassium carbonate solution (K2CO3) were selected to impregnate samples. First, four types of pellets were prepared; one using exhausted olive mill solid waste (G) noted (100G) and three using G blended with pine sawdust (S) in different percentages (50%S–50%G (50S50G); 60%S–40%G (60S40G); 80%S–20%G (80S20G)). Investigations showed that when isothermal temperature increases during the gasification conducted with two water steam percentages of 10% and 30%, the reactivity increases with potassium concentration up to 0.5 M, especially for 100G. Still, higher catalyst concentration (1.5 M) showed adverse effects attributable to silicon release and char pore fouling. Moreover, the effect of the steam concentration on the gasification reactivity was significant with the non-impregnated sample 100G. Finally, a kinetic study was carried out to determine the different kinetic parameters corresponding to the Arrhenius law. [ABSTRACT FROM AUTHOR]

The burgeoning environmental crisis and the urgent need for sustainable energy solutions underscore the importance of innovative waste-to-energy conversion technologies. This study aims to an efficient utilize of face mask waste for a novel energy system to address waste management and energy production simultaneously by introducing an integrated system comprising a gasifier reactor, steam methane reformer, and water-gas shift reactor, designed to convert face mask waste into a hydrogen-rich syngas. The gasifier reactor initiates the process with a hydrogen flow rate of 2.352 mol/h, which is subsequently enriched to 5.405 mol/h in the steam methane reformer and further to 6.132 mol/h in the water-gas shift reactor, marking a cumulative increase of 160%. Methane content, initially at 2.017 mol/h, is reduced by 38.4% post-reforming and remains stable through the water-gas shift reaction. Carbon monoxide sees a significant reduction from 0.8558 mol/h to 0.1817 mol/h, a decrease of 78.8%. The findings of this study have profound implications for the energy sector, demonstrating the potential of the integrated system to not only mitigate waste but also to produce clean energy efficiently. The substantial increase in hydrogen content across the reactors highlights the system's capability to support the burgeoning hydrogen economy, while the management of carbon oxides aligns with environmental sustainability goals. The value of this study lies in its contribution to the advancement of waste-to-energy technologies and its role in shaping future energy policies and practices. • An innovative waste-to-energy conversion technology is developed. • Face mask waste gasification is integrated with SMR and WGSR. • Hydrogen flow rate in the gasifier is 2.352 mol/h. • Hydrogen flow rate is increased to 5.405 mol/h in SMR and 6.132 mol/h in WGSR. • This integration improves the hydrogen flow rate by 160%. [ABSTRACT FROM AUTHOR]

The safe disposal of large irradiated cation exchange resin waste in nuclear power plant has drawn worldwide attention. The kinetic characteristics and product characteristics of the simulated spent cation exchange resin in the pyrolysis and gasification were evaluated based on thermogravimetric analysis as well as TG-FTIR and TG-GC/MS. The temperature ranges at different decomposition stages of the resins were determined. In nitrogen atmosphere, the metal nuclides would hinder the reaction of waste resin in the first stage and promote the reaction in the second stage. The second-order reaction model was the best one to describe the kinetic mechanism in the first and second stages of the spent resins in different atmospheres, while Mample Power model (n = 1) and two-dimensional shrinking cylinder model were for the third gasification stage of the waste resins in 10 % oxygen atmosphere and 10 % steam atmosphere, respectively. The average mass loss ratio of the waste resin in 10 % oxygen atmosphere almost reached to 90 % that was higher than in 10 % steam atmosphere (80 %) and much higher than in nitrogen atmosphere (55 %). The initial reaction temperature in the third stage in 10 % oxygen was about 100 °C earlier than that in 10 % steam atmosphere, indicating that the sulfur bond would easily break due to the strong oxidization action of the oxygen. In the nitrogen atmosphere, the sulfur bond broke at 700 °C, which would lead to low mass loss ratio of the waste resin since the copolymer matrix is difficult to decompose. This work could supply basic data for the pyrolysis and gasification treatment of irradiated spent cation exchange resin in nuclear power plant. [ABSTRACT FROM AUTHOR]

With increasing efforts to lower CO2 emissions globally, the demand for carbon-based resources in industries remains on a high level, leading to new technologies being able to provide those essential carbon sources. To the best of our knowledge, we were able to show for the first time the adaption of a readily available gasifier for the gasification of wood chips using only O2 (18.4–23.1 Vol.-%) and CO2 as gasification agents, creating a nitrogen-free product gas. It was found that the setup used was able to convert up to 27.2% of the CO2 from the gasification agent to CO, creating a promising route for the production of renewable carbon sources for future carbon-based applications. Furthermore, no decrease in gasification performance was observed as the cold gas efficiency was at 83.5–95.5% with only minor formation of tar. [ABSTRACT FROM AUTHOR]

A conceptual design of coffee stem biomass gasification was developed using the Aspen Plus process simulator, which was analyzed based on energy criteria such as the lower heating value of the produced synthesis gas and cold gas efficiency. The results yielded a lower heating value of 5.07 kJ/MJ, with a cold gas efficiency of 77.45% and a yield of 2.75 kg gas/kg biomass, all operating under optimal conditions with studied parameters including an air-to-biomass ratio between 1.8 and 2.5, gasifying agent temperature of 260 °C, and biomass moisture content below 10%. A sensitivity analysis was conducted on the formation of the most important compounds for synthesis gas quality (H2, CO, CO2, H2O, CH4). This involved understanding the reactions occurring throughout the gasification reactor and evaluating process parameters such as feed moisture content, gasification section temperature, and the ratio between feed and gasifying agent flows to optimize the process with the aim of improving product quality and reducing residue formation. The simulation scheme was validated against experimental data, yielding results consistent with reality. This contributed valuable information towards process optimization for projects targeting the Colombian coffee sector, paving the way for future gasifier designs tailored to the quantity of raw material to be processed. [ABSTRACT FROM AUTHOR]

The gasification removal behaviour of phosphorus from high‐phosphorus iron ore is theoretically and experimentally studied in the temperature range of 400–900 °C under H2 reducing and N2 atmospheres. In the first step, thermodynamic analysis is conducted to reveal the gasification and reaction behaviours of common phosphorus compounds, namely P4O10, FePO4, AlPO4, Ca2P2O7, and Ca3(PO4)2. The results indicate that P4O10, FePO4, and AlPO4 under H2 reducing atmosphere and P4O10 under a N2 atmosphere can be removed by gasification, and the influence of the interaction between the vaporized gases and iron ore should be investigated. Therefore, dephosphorization experiments are performed on simulated iron ores containing P4O10, FePO4, or AlPO4. For the sample containing P4O10, ferric phosphates and iron phosphides are formed under the N2 and H2 reducing atmospheres, respectively, and their formation rates decreases with decreasing temperature, becoming almost stagnant at 400 °C. Moreover, it is confirmed that FePO4 and AlPO4 cannot be removed even when pure H2 is introduced. [ABSTRACT FROM AUTHOR]

The use of fossil fuels has been essential to the development of society, but has also contributed partly to global warming. For example, carbon dioxide emissions from fossil fuels and industries have increased by 60% since 1990, calling for the recycling of modern biomass in the context of a carbon neutral economy. Here we review the hydrothermal conversion of biomass into biofuels, chemicals and biomaterials with emphasis on subcritical water properties, hydrolysis of biomass, steam explosion, fractionation, carbonization, liquefaction, gasification, and fractionation of bio-oil. We observe that hydrothermal conversion of biomass in the presence of water at subcritical conditions produces value-added compounds with high process efficiency. Subcritical water allows rapid reaction rates, low mass transfer resistance, and gas-like diffusivity. [ABSTRACT FROM AUTHOR]

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Spent coffee grounds (SCGs), a waste product of the coffee industry, present a significant untapped resource for fuel production. This study aims to optimize the gasification of SCG using various metal catalysts (NiO, MnO2, Al2O3, and Fe2O3) to maximize syngas yield. SCG samples were gasified at different temperatures (800 °C, 900 °C, 1000 °C) and analyzed using Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TG-DTA), and Fourier Transform Infrared (FTIR) spectroscopy to evaluate catalyst performance and reaction mechanisms. The findings indicated that utilizing mixing techniques for physical contact to introduce catalysts led to a uniform distribution of catalyst particles throughout the sample. The decomposition rate of the gasification experiment after adding the catalyst was 24% faster than that of the pure SCGs. In the gasification experiment, the MnO2 catalyst showed the highest CO production, which was 71% higher than that of NiO under the same conditions. At this temperature, MnO2 generated around 171% more CO than at 800 °C, surpassing the yields observed with other catalysts. The study concludes that Mn emerged as the most promising catalyst, significantly improving both CO and CH4 yields. Selecting the appropriate metal catalyst and optimizing operational temperatures are crucial for enhancing the efficiency of SCG gasification. [ABSTRACT FROM AUTHOR]

The increasing waste generation trends resulted in growing attention to the technologies that aim to reduce or prevent landfilling. The pyrolysis and gasification of refuse-derived fuel (RDF) allow waste to be turned into new raw materials, like pyrolysis gas and syngas. However, the wet gas cleaning processes result in the production of highly contaminated liquid waste. Phenolic compounds are common constituents of this wastewater and often appear in the wastewater of other industries as well. In this research, the laboratory-scale steam gasification of an RDF char was performed to produce syngas and adsorbent simultaneously. The RDF was previously pyrolyzed at 700 °C maximum temperature in a Hungarian pyrolysis pilot plant with approximately 120 kg h−1 capacity. In this thermal waste processing plant, the pyrolysis gas is already utilised by burning, but currently, the char ends up in landfills. The gasification of char samples was examined with different steam-to-carbon ratios (0.56, 0.84, and 1.12) and duration (30, 60, and 120 min) at 900 °C. Following gasification, the phenol removal capability of the solid by-products was investigated. The results show that its composition and energetic properties make the produced syngas more suitable to use as a raw material in the chemical industry rather than a fuel. At lower concentrations, the effectiveness of the solid by-product for phenol removal was comparable to commercial activated carbon. These are promising results about producing activated carbon from waste without any chemical treatment. [ABSTRACT FROM AUTHOR]

The catalytic activity of Ni/dolomite during biomass (wood chips) gasification was examined in a fluidized bed reactor. Ni-dolomite with Ni contents of 0% (dolomite), 10%, 20% and 25% (25%Ni/dolomite) was prepared by precipitating method. Effect of equivalence ratio, ER (0.078–0.128), temperature (700–850 °C) and Ni content on syngas composition, gas yield (GY), tar content in the product gas (TC), char conversion efficiency (CCE) and cold gas efficiency (CGE) was studied. An increase in ER led to an increase in GY and CCE, while TC gradually decreased. Increasing temperature contributed to more char conversion, gas production and tar elimination. The results also showed that Ni/dolomite had a high catalytic activity in terms of tar cracking/reforming, upgrading the produced syngas quality, as well as enhancing char conversion. Higher Ni content (0–20%) was more favorable for gas production, char conversion and tar reduction. However, a further increase in Ni content led to a slight increase in the gas quality and yield due to coke formation and subsequently a reduction in the availability of CaO and MgO active sites. Comparing with dolomite, the use of Ni/dolomite improved the gas quality and the gasifier performance, the optimal value of Ni content was found to be 20% at 850 °C and ER of 0.128. [ABSTRACT FROM AUTHOR]

A detailed process model is proposed to simulate the air-gasification of biomass (wood chips) in a bubbling fluidized bed gasification system at different temperatures (650–800 °C) and equivalence ratios, ERs (0.08–16), using ASPEN Plus simulator. The process was assumed fully steady-state, and gasification section was modeled by implementing FORTRAN user-subroutines for reaction kinetics and hydrodynamic parameters. Experimental results from air-gasification of wood chips in a bubbling fluidized bed gasifier were used to validate the model. The model predictions were in good agreement with experimental results. The validation results also showed that ASPEN Plus can describe the gasification process in fluidized bed gasifiers well. Specifically, ER initially decreased the carbon conversion efficiency (CCE), with a minimum followed by an increase. An optimal ER was crucial for minimizing tar yield (TY). Higher temperatures yielded higher H2 contents and lower tar yields. Smaller particles decreased TY and increased gas lower heating value (LHV). Under optimal conditions (ER = 0.13, T = 750 °C, and D = 0.2 mm), the product gas generated during air-gasification of wood chips achieved a low tar yield of 4.61 g/Nm3. These results confirmed the significant potential of biomass gasification in high-quality syngas production with low tar content. This article also provides valuable information for selecting operation conditions to achieve high-quality syngas for engineering applications and lays a foundation for the design of industrial-scale fluidized bed gasifiers in the future. [ABSTRACT FROM AUTHOR]

The sustainable utilization of biomass, particularly troublesome waste biomass, has become one of the pathways to meet the urgent demand for providing energy safety and environmental protection. The variety of biomass hinders the design of energy devices and systems, which must be highly efficient and reliable. Along with the technological developments in this field, broad works have been carried out on the mathematical modeling of the processes to support design and optimization for decreasing the environmental impact of energy systems. This paper aims to provide an extensive review of the various approaches proposed in the field of the mathematical modeling of the thermochemical conversion of biomass. The general focus is on pyrolysis and gasification, which are considered among the most beneficial methods for waste biomass utilization. The thermal and flow issues accompanying fuel conversion, with the basic governing equations and closing relationships, are presented with regard to the micro- (single particle) and macro-scale (multi-particle) problems, including different approaches (Eulerian, Lagrangian, and mixed). The data-driven techniques utilizing artificial neural networks and machine learning, gaining increasing interest as complementary to the traditional models, are also presented. The impact of the complexity of the physicochemical processes and the upscaling problem on the variations in the modeling approaches are discussed. The advantages and limitations of the proposed models are indicated. Potential options for further development in this area are outlined. The study shows that efforts towards obtaining reliable predictions of process characteristics while preserving reasonable computational efficiency result in a variety of modeling methods. These contribute to advancing environmentally conscious energy solutions in line with the global sustainability goals. [ABSTRACT FROM AUTHOR]

Fossil fuels are deemed to diminish because of their limited availability, no renewability, and emissions of greenhouse gases and other poisonous materials to the atmosphere and the ecosystem. Renewable energy based on sustainable biomass has occupied an increasing share of the energy system over the past decade. Among several massively cultivated crops worldwide, corn, sugarcane bagasse, and soybean straws are some of the leading agricultural by-products that can generate substantial energy (e.g., biofuels, hydrogen) as vital sustainable energy to substitute non-renewable fossil fuels. This paper aims to review recent progress in renewable energy generation from biomass based on thermochemical techniques-i.e., gasification, pyrolysis, and liquefaction-detailed technical features and their application for extraction energy from biomass. The quality, composition, and productivity of renewable energy extracted from biomass based on existing thermochemical techniques are compared, and their technical dependencies upon the thermochemical processes are discussed. Furthermore, analysis of technical deficiencies of existing methods, and exploration of innovative emerging technologies for high-efficiency and high-quality renewable energy generation from biomass straws. In general, biomass gasification stands out as the most efficient technique for hydrogen production (HP) from biomass due to mature technology, high hydrogen yield, and potential for integration with other presented techniques. [Display omitted] • A detailed review of HP from biomass using thermochemical techniques. • Discussion about gasification, pyrolysis, and liquefication working principles. • Comparison between all types of presented thermal techniques. • Advantages and disadvantages of gasification, pyrolysis, and liquefication. • Overall performance of all thermal techniques presented in this review. [ABSTRACT FROM AUTHOR]

This review examines the potential of municipal solid waste (MSW) as a renewable energy source, focusing on recent advances in thermochemical conversion technologies and their environmental impacts. The exponential growth of urban populations has led to a surge in MSW, necessitating sustainable waste management solutions. Traditional disposal methods, such as landfilling and incineration, have significant environmental drawbacks. However, advancements in waste-to-energy (WtE) technologies, including incineration, pyrolysis, and gasification, offer promising alternatives for energy recovery and resource utilization. This review explores the composition of MSW, its classification as a renewable resource, and the thermochemical conversion technologies that transform waste into energy. The environmental impacts of these technologies, particularly emissions and air quality concerns, are critically analyzed. The review highlights the evolving regulatory landscape and the implementation of advanced emission reduction systems. The findings underscore the importance of integrating innovative waste management strategies to promote a circular economy and achieve sustainable development goals. [ABSTRACT FROM AUTHOR]

The gasification of sewage sludge (SS) and digestate was investigated in a pilot-scale fluidized bed gasifier with an output of 100 kWt. The treatment of these by-products is an ongoing challenge for sustainable development. SS and digestate are most commonly used as fertilizers. However, regulations restrict their use, mainly because of the content of heavy metals, pathogens and bacteria. Gasification of these by-products instead of application to agricultural land seems to be more efficient, as the syngas can subsequently be used for combined heat and power (CHP) generation. A series of measurements were carried out to get a better understanding of the gasification process of these fuels and to study the effects of gasifying agent on the syngas composition, particulate matter (PM) and tar. The produced syngas and tar were analyzed using a gas chromatograph with mass spectrometry (GC–MS). The results showed that no ash slagging was observed and therefore it is feasible to operate digestate and SS gasification at 750°C. The lower heating value (LHV) of the syngas from digestate and SS with air as the gasifying agent is comparable, 4.06 MJ·Nm−3 for digestate and 4.11 MJ·Nm−3 for SS. The addition of steam had a positive effect on the amount of tar and the tar dew point, which was below 150°C. Tar reduction in digestate was 5037.3 mg·Nm−3 to 3566.3 mg·Nm−3 and in SS 7447.7 mg·Nm−3 to 3390.3 mg·Nm−3. Furthermore, the concentrations of the individual tar compounds were determined and subsequently divided into tar classes. [ABSTRACT FROM AUTHOR]

With the increasingly serious problems of energy shortage and environmental degradation, countries around the world are actively developing safe, environmentally friendly, and renewable energy. Biomass energy has become an ideal substitute for fossil fuels due to its abundant reserves, good renewable performance, and zero carbon emissions. This paper discusses the importance and potential of biomass energy as a renewable energy source for China's energy development, mainly including the three biomass conversion methods of physics, chemistry, and biology, seven utilization technologies, such as direct combustion, gasification, and pyrolysis, and five application approaches, such as biomass power generation, biomass gas fuel, biomass liquid fuel, and bio-based materials. This review systematically analyzes the challenges faced by China's development of biomass energy and discusses the future development direction of biomass. The utilization of biomass resources should take a comprehensive and high-value path. China is actively looking for new energy utilization paths, and biomass energy has become a key measure to cope with carbon emission reduction, climate change, and ecological environment protection. [ABSTRACT FROM AUTHOR]

The increasing amount of sewage sludge produced demands new methods of its management to minimize socioeconomic and environmental problems related to its current treatment. An effective solution may be the thermochemical conversion of sewage sludge through gasification. First, the most known sewage sludge gasification processes are presented along with the challenges that they face. Then the detailed characteristics of sewage sludge are discussed from the point of view of its use in the gasification process, as well as research on the kinetics of gasification of sewage sludge char using various models. As scientific reports on sewage sludge gasification focus on the influence of process parameters on gas yield and composition (especially H2 and tar content), the main part of the work is devoted to the discussion on the influence of temperature, type, and amount of the gasifying agent and the presence of a catalyst on these parameters. Moreover, the co-gasification of sewage sludge as well as advanced gasification methods, i.e., supercritical water gasification and plasma gasification, are analyzed. Finally, the possibilities of utilization of sewage sludge gasification process by-products were discussed and the impact of the process on the environment was assessed. The review concludes with indications of directions for further research. [ABSTRACT FROM AUTHOR]

To increase the carbon conversion of char in gasification, this paper aimed to reveal the gasification behaviours of char residues. Char residues with different ash contents in this work were prepared from Shenmu char and Tejing char. Those char residues were gasified by different CO2 gas mixtures at different temperatures. The gasification process of char residue was different from the end stage of the gasification process of the corresponding raw char: the gasification rate of the char residue increased at first and then decreased, whereas the gasification rate of the corresponding raw char kept decreasing during the end stage of gasification. The highest gasification rate was achieved at a lower conversion in the gasification of char residue than in the gasification of the corresponding raw char. Catalytic minerals, high temperature, and high CO2 partial pressure benefited the gasification of gasified char residues. The char residues that contained more catalytic minerals were more reactive in gasification and were less sensitive to changes in temperature and CO2 partial pressure. The Modified Random Pore Model (MRPM) and Random Pore Model (RPM) were used to predict the gasification kinetics of the chars, and the MRPM describes the gasification processes of gasified char residues well. [ABSTRACT FROM AUTHOR]

Biochar, a solid material derived from a thermochemical process, has received significant attention due to its usefulness in various sectors. Previous studies have been conducted to improve the properties and quality of this material by altering the thermochemical processes, treating the feedstock, hybridizing the feedstock, and so forth, but little has been done on the effect of varying the reactor's configuration. This research aims to study the effect of varying the stainless‐steel‐based combustion compartment volume of a biomass‐fueled top‐lit updraft gasifier on the groundnut shell biochar. The biochar yields for reactors ranged from 34.9% to 51.2%. The sample produced in the smallest combustion compartment volume showed the highest carbon content, according to energy dispersive X‐ray spectroscopy (EDX) analysis. Potassium, another major element, decreased as the combustion compartment was reduced. Scanning electron microscopy (SEM) analysis revealed that the biochar samples produced had an irregular shape and rough surfaces, and reducing the combustion compartment volume resulted in larger particles on the surface. Fourier transform infrared (FTIR) spectroscopy analysis showed similarities and differences in peaks observed for all the samples. The biochar samples produced can find applications in wastewater treatment, energy conversion and storage, and soil amendment, and the findings contribute to the design and optimization of biomass‐based gasifiers. [ABSTRACT FROM AUTHOR]

In the process of poplar fermentation for ethanol, different methods are adopted to achieve efficient treatment and resource utilization of fermentation residues, which meets the current demand for green energy and carbon neutrality. Therefore, this work aims to establish an evaluation method on energy consumption, pollutant emissions, and cost expenditures in the production process for biofuels from poplar wood and residue. The process was simulated with commercial software (Aspen Plus for chemical production simulation and cost estimation and eBalance for LCA). Results showed that compared to FCE, it made a higher conversion efficiency of CFG because of the biojet fuel and gasoline from the gasification and conversion of residual lignin. And the flash evaporator, hydrolysis reactor, and fermentation reactor were components with the highest exergy loss. The economic cost of CFG was 9.63% less than that of FCE, and cellulase enzymes and poplar wood in variable costs were main factors in the total cost. Comparing environmental impacts from four perspectives, it was found that the total comprehensive impact of FCE was higher than that of CFG under each weight. The degree of influence of the first level indicator layer was energy consumption, environmental impact, and economic cost in descending order. [ABSTRACT FROM AUTHOR]

Energy sources all around the world are degrading at a rapid pace. The exponential rise in population, along with urbanization, requires exploration and advancement in diverse fuel resources. Municipal solid waste (MSW) disposal requires urgent intervention in terms of its utilization and conversion into useful energy forms than being dumped into landfills. Though efforts are being made for its combustion in furnaces, the plastic contents in RDF often pose environmental concerns when used for combustion. The gasification process has been explored for the effective processing of different forms of waste in the present study. The composition of MSW varies widely with demography, weather, and habitats. In the present study, MSW of Surat metropolitan city of India is processed post collection, through sorting, segregation, and compaction, and transformed to fuel, which is termed as refuse-derived fuel (RDF). A chemical representation of the RDF is used to perform gasification studies with the help of two thermodynamic equilibrium models. Parametric analysis of the gasification models is performed to analyze the effect of equivalence ratio and gasification reaction temperatures on the product gas composition for the prepared composition of RDF. Results reveal that the combined equilibrium model is more accurate in predicting product gas composition compared to the Homogeneous model. It is observed that the variation of the equivalence ratio has a more significant influence on the product gas composition than the variation in the gasification temperature. The study concludes that RDF from MSW may be efficiently transformed into useful gaseous fuel through gasification resulting in product gas with a calorific value of approximately 25 MJ per kg of RDF gasified. [ABSTRACT FROM AUTHOR]

Last few decades observed decrease in the quality of the extracted crude oil. Moreover, heavy crudes are cumbersome to refine with conventional processes due to the production of high sulfur residues and low light distillates. Their combustion also generates significant pollutants including particulates, sulfur and nitrous oxides. Gasification is a potential pathway for the declining quality of the crude oil and avoiding environmentally harmful residuals. Here, the technical viability of gasifying different crude oil was investigated with numerical and equilibrium analysis, and the output performance was compared to the gasification of baseline coal. The equilibrium model is based on elemental mass and energy conservations. The assessment of the influence of different parameters such as equivalence ratio, crude oil type and operating temperature on the efficiency of the gasification process was conducted. Results reveal a high gasification efficiency ~ 77% which surpasses the coal efficiency (~ 73%). Furthermore, similar sensitivity trend was observed for both fuels with varying moderator and oxidizer conditions. Devolatilization kinetics of crude oil was determined to run high-fidelity gasification. The third order Coats-Redfern provided the best fit method with dual kinetics for the activation energies and frequency factors of 463.648 kJ/mole and 1.455E+56 s−1, 276.408 kJ/mole and 3.325E+20 s−1 and 96.281 kJ/mole and 5.186E+03 s−1 for the light-, semi- and heavy crudes, respectively. Furthermore, gasification economics assessment of crude oils was conducted given their technical viability and environmental advantages. Using the current crude oil price of about $80/barrel ($0.588/kg) and considering the local sensible energy price in UAE (i.e., 38 fils/kWh) (~ $0.10354/kWh), the process shows potential economic viability between 1150 °C and 1300 °C. [ABSTRACT FROM AUTHOR]

The production of heterogeneous solid waste, such as municipal solid waste (MSW), construction and demolition waste (CDW), and industrial solid waste (ISW), has increased dramatically in recent decades, and its management is one of today's biggest concerns. Using waste as a resource to produce value-added materials such as char is one of the most promising strategies for successful and sustainable waste management. Virtually any type of waste, through various thermochemical technologies, including torrefaction, pyrolysis, hydrothermal carbonization, and gasification, can produce char with potential material and energy applications. Pyrolysis is the most widespread technology, and there are more studies on producing and applying waste-derived char using this technology. The properties of waste-derived char seem to be influenced by the conversion technology and conditions, as well as by the composition of the source waste. A literature search indicated that the properties of waste-derived char are highly variable with the composition of the raw material, with carbon content in the range 8–77%, a higher heating value of 2.5–28.4 MJ/kg and a specific surface area of 0.7–12 m2/g. Depending on the properties of char derived from waste, there are greater or minor difficulties in applying it, with ash content, heavy metals, and polycyclic aromatic hydrocarbon (PAH) concentrations being some of its limiting properties. Therefore, this review attempts to compile relevant knowledge on the production of waste-derived char, focusing on heterogeneous solid waste, applied technologies, and practical application routes in the real world to create a supply chain, marketing, and use of waste-derived char. Some challenges and prospects for waste-derived char are also highlighted in this study. [ABSTRACT FROM AUTHOR]

The average annual global production of waste textiles exceeds 92 million tons, with the majority landfilled and incinerated, resulting in energy waste and environmental pollution. In this study, a thermal conversion process for waste textiles by gasification coupling with catalytic reforming under a steam atmosphere was proposed. The gasification performance of the waste textiles jumped with the introduction of steam and catalyst compared to pyrolysis at 800 °C. The syngas yield increased from 20.86 to 80.97 mmol/g and the hydrogen concentration increased from 17.79 to 50.91 vol.%, which was an increase of 288.12% and 186.18%, respectively. The excellent gasification performance mainly came from two sources: steam promotion for volatiles production and Fe-N-BC promotion for steam reforming of volatiles by Fe2O3, Fe3O4, Fe-Nx, etc. This study has achieved the efficient production of hydrogen-rich syngas from waste textiles, providing a new idea and theoretical basis for the effective removal and utilization of waste textiles. [ABSTRACT FROM AUTHOR]

Purpose. To justify and develop a model that describes the effect of magnetic treatment of blast reagents and carbon-containing products on the gasification process for predicting the intensification of gas formation. Methodology. The study involves theoretical modeling based on experimental data to investigate the influence of magnetic fields on the underground coal gasification process and co-gasification of coal and carbon-containing products. The Arrhenius equation was used to estimate the rate constants of gasification reactions in the temperature range of 800–1,000 °C. The effect of the magnetic field was incorporated by adjusting the activation energy (Ea). The results of analytical and experimental studies were processed using methods of computer and mathematical modeling. Findings. The results show that the application of magnetic fields significantly intensifies the gasification process of carbon containing products. Increasing the reactivity of the blast reagents, particularly water and oxygen, leads to a higher overall yield of combustible gases. The use of magnetic fields in the gasification process substantially increases the reaction rate (k) due to the reduction in activation energy (Ea), improving the overall efficiency of gasification. Originality. For the first time, an analytical model has been developed to describe the effect of magnetic treatment of blast reagents and carbon-containing products on the gasification process in the temperature range of 800–1,000 °C. The obtained reaction rates follow an exponential trend. The established and correlation-validated pattern shows the relationship between changes in the approximation coefficient (F) and the change in the carbon fraction (C, %) during the magnetic treatment of blast components within the specified temperature range. Practical value. The results of this study can be applied to enhance the efficiency of industrial gasification processes, particularly underground coal gasification and co-gasification of coal and carbon-containing productss. [ABSTRACT FROM AUTHOR]

Since 1950, only 9% of all plastic produced has undergone recycling, and a mere 10% of that has been recycled multiple times. Most discarded plastic (around 73%) ends up in landfills or is improperly managed, resulting in widespread littering. The main reason for low recycling rates is the lack of recycling technology for multi‐polymer and multi‐layer materials and unsortable mixed plastic waste. This plastic waste is one of the most accumulating types, including for example single‐use food packaging with an average lifetime of less than 6 months. These multi‐layer films, consisting of various polymer types, are not feasible for traditional mechanical recycling, which requires well‐sorted, clean, and homogeneous materials. Several methods for plastic recycling have been proposed to address this issue and tackle the overwhelming influx of plastic waste, among which steam gasification stands out as one of the most promising approaches for recycling mixed, contaminated, and unsortable plastics. This method utilizes high temperatures (≥800°C) to atomize the plastics, resulting in a gas mixture of H2, CO, and CO2 and small hydrocarbons. The resulting gas can be reformed through hydrocarbon syntheses, for example, via methanol to propylene and ethylene, and successive into new mono‐ and polymers of equal quality to fossil‐based plastics. Moreover, since the high temperatures atomize any organic structure, biomass can be used as a substitute for an extension of the carbon feed, ultimately reducing reliance on fossil feedstock. With these advantages, steam gasification can significantly increase recycling rates and contribute to a bio‐integrated circular carbon economy. [ABSTRACT FROM AUTHOR]

Energy is a crucial factor for urban development. Cities have a crucial role in climate change, as they use 2/3 of the world's energy, producing 70% of greenhouse gas (GHG) emissions. In order to reduce the large ecological footprint of the utilization of conversional energy sources (coal, gas, and oil) and enhance a nation's energy independence (security), it is crucial to find alternative fuels. Biomass residues are characterized as a sustainable and carbon-neutral energy source. Hence, this review describes a critical assessment of not only the quality characteristics of several waste and biomass residues for bioenergy production and biofuels but also the value-added products that could be produced from wastes to enhance industry (e.g., pharmaceutical, cosmetics, packaging industry, etc.). Furthermore, the challenges and potential solutions of waste utilization for bioenergy production and the transformation of value-added products for urban sustainability are also explored. Despite the high-quality characteristics and the availability of these wastes, several critical factors should be taken into account. Biomass residues could contribute to sustainable development goals (SDG), such as sustainable cities and communities, clean energy, responsible consumption and production, the economic growth of a country, and, as a result, urban development. [ABSTRACT FROM AUTHOR]

Indonesia is a country that has abundant natural resources such as palm oil, coal and so on. These two types of coal mining and palm oil plantation sectors have provided many benefits for community welfare. The aims of research is to utilize palm oil industry waste in the form of empty fruit bunch (EFB) and fine coal waste (FCW) into synthetic gas (syngas) through a catalytic gasification process which is then used as a source of energy and/or synthesis chemicals. Gasification temperatures are 450 oC, 550 oC and 650 oC. Gasification time 20, 30 and 40 minutes. The ratio between pillared bentonite catalyst and EFB is 0.125 and 0.25. The resulting syngas is analyzed for the content of H2, CO, CH4 and CO gases. At gasification temperatures of 650 oC, the H2/CO gas ratio is 2.27. The comparison value between combustible gas (H2, CO and CH4) and non-combustible gas (CO2), namely the CG/NCG ratio shows the quality of a syngas. The higher the CG/NCG value, the better syngas is as a gas fuel because it has a higher heating value. The CG/NCG value at a temperature 650 oC it is 21.41. With an increase in temperature from 450 oC to 650 oC the increase in CG/NCG value is 51%. Thus, increasing the temperature from 450 oC to 650 oC, there is an increase in HHV of 86.21%. This result is economically beneficial because the increase in calorific value will increase the benefits of syngas. The higher the HHV value, the better the syngas is used as gas fuel. The HHV value at a temperature of 650 oC is 13.91 MJ/Nm3. Thus, by increasing the gasification temperature from 450 oC to 650 oC, there is also an increase in LHV of 85.71%, meaning it has increased quite significantly. When compared with the use of 0.125% catalyst, the increase in catalyst concentration of 0.25% is smaller than 91.90%. From the experimental results it can be concluded that increasing temperature will improve the quality of syngas.

The NO heterogeneous reduction mechanisms on both Ca-char and gasified Ca-char by b3lyp/6–311+g (d, p) group are systematically investigated to clarify the role of the catalyst. All the computed reaction paths can proceed smoothly after the first step occurs, and they are exothermic during the reaction process, which means this reaction is supported by thermodynamics and kinetics. The results indicated that Ca can promote NO heterogeneous reduction by increasing the adsorption energy and reducing the energy barrier of gas products (nitrous oxide N2O, nitrogen N2, CO and CO2) emission. Furthermore, the computed results also indicated that the model is a significant element affecting NO reduction. Compared with Ca-char model, gasified Ca-char model has higher potential energy surface and tends to remain O atoms. The computed reaction path on the surface of gasified Ca-char is a supplement to previous studies, which gives insight to the catalytic mechanisms of NO heterogeneous reduction in the presence of gasification. [ABSTRACT FROM AUTHOR]

The iron and steelmaking industries play a significant role in the manufacturing sector but result in significant greenhouse gas emissions. Biochar has recently gained attention as a potential substitute for coal in metallurgical processes due to its carbon capture potential. This review explores the potential of biochar as a sustainable substitute for coal in steelmaking industries. Notable research works have shown that substituting biochar in amounts ranging from as low as 5 % to as high as 50 % can be feasible and beneficial in processes such as coke making, iron sintering, blast furnaces, and electric furnaces. The information presented in this review can be applied to create sustainable and competitive alternatives to fossil fuels to help decarbonize metallurgical industries. [ABSTRACT FROM AUTHOR]

Optimal conditions for the gasification at the pilot scale of pine chips biomass feedstock with two different gasifying agents (air and an air/steam mixture) are determined. Ten experimental tests were performed at a fixed temperature, air stoichiometric ratio, and steam-to-biomass ratio. Results showed cold gas efficiencies circa 75 % (air) and 95 % (air/steam), yielding ∼3 Nm3 syngas /kg biomass , in both cases, and lower heating values of 7.6 and 8.5 MJ/Nm3, respectively. Hydrogen production and process performance were assessed and compared to those found in literature, showing a good performance considering biomass, ca. 35 g H2 /kg biomass. A techno-economic model fed with the experimental results obtained was validated. The model established that air gasification could be more profitable for energy than air/steam gasification, especially at higher scales. The internal return rate was less than 1.5 years; nevertheless, air/steam mixture as a gasifying agent more adequate for H 2 /biofuel production. • Experimental testing allowed to establish optimal conditions for biomass gasification. • Process performance was assessed based on cold gas efficiency (CGE) and lower heating value (LHV). • Syngas and hydrogen production was maximized compared to similar studies. • A techno-economic model was validated for gasification based on real operational outputs. [ABSTRACT FROM AUTHOR]

The energy sector, currently dominated by fossil fuels, significantly contributes to carbon emissions and climate impacts. This study addresses the urgent need for renewable energy resources and promotes the utilization of waste from Malaysia's palm oil industry. It proposes upgrading conventional palm oil mills to integrated mills to produce valuable biofuels such as methanol (MET) or dimethyl ether (DME). Using Aspen Plus V11 for simulation, mass and energy balances were provided for feasibility analysis, including techno-economic, exergy, and carbon analysis. The integrated process demonstrated 10 to 15% higher exergetic efficiency than conventional mills, enhancing the renewability index by 40% and reducing carbon emissions to 0.50 tonne CO2 per tonne of palm oil. The integrated mills, operating at 61–64% exergetic efficiency, achieve a 28% reduction in exergy destruction when palm wastes are recovered and transformed into biofuels. Despite an 87% increase in non-renewable exergy consumption due to additional operating requirements, the overall renewability index remains high (around 0.9), demonstrating the commercial viability and environmental benefits of this approach. Overall, this study lays the foundation for integrated palm oil mill operation by utilizing palm waste to achieve net zero waste emissions, which is a positive outlook. [ABSTRACT FROM AUTHOR]

The production of heterogeneous solid waste, such as municipal solid waste (MSW), construction and demolition waste (CDW), and industrial solid waste (ISW), has increased dramatically in recent decades, and its management is one of today’s biggest concerns. Using waste as a resource to produce value-added materials such as char is one of the most promising strategies for successful and sustainable waste management. Virtually any type of waste, through various thermochemical technologies, including torrefaction, pyrolysis, hydrothermal carbonization, and gasification, can produce char with potential material and energy applications. Pyrolysis is the most widespread technology, and there are more studies on producing and applying waste-derived char using this technology. The properties of waste-derived char seem to be influenced by the conversion technology and conditions, as well as by the composition of the source waste. A literature search indicated that the properties of waste-derived char are highly variable with the composition of the raw material, with carbon content in the range 8–77%, a higher heating value of 2.5–28.4 MJ/kg and a specific surface area of 0.7–12 m2/g. Depending on the properties of char derived from waste, there are greater or minor difficulties in applying it, with ash content, heavy metals, and polycyclic aromatic hydrocarbon (PAH) concentrations being some of its limiting properties. Therefore, this review attempts to compile relevant knowledge on the production of waste-derived char, focusing on heterogeneous solid waste, applied technologies, and practical application routes in the real world to create a supply chain, marketing, and use of waste-derived char. Some challenges and prospects for waste-derived char are also highlighted in this study.

Process design critically depends on the characterization of fuels and their kinetics under process conditions. This study steps beyond the fundamental methods of thermogravimetry to modulated (MTGA) and Hi-Res™ (high resolution) techniques to (1) add characterization detail and (2) increase the utility of thermal analysis data. Modulated TGA methods overlay sinusoidal functions on the heating rates to determine activation energy as a function of temperature with time. Under devolatilization conditions, Hi-Res™ TGA maintains a constant mass loss with time and temperature. These two methods, run independently or overlaid, offer additional analysis in which multiple samples at different heating rates are run to different final temperatures. Advanced methods allow researchers to use fewer samples by conducting fewer runs, targeting practical experimental designs, and quantifying errors easier. The parameters of the studies included here vary the heating rate at 10, 30, and 50 °C/min; vary gas-phase oxygen for pyrolysis or combustion conditions; and particle size ranges of 100–125 µm, 400–425 µm, and 600–630 µm. The two biomass fuels used in the studies are pinewood from Northern Sweden and wheat straw. The influence of torrefaction is also included at temperatures of 220, 250, and 280 °C. Apparent activation energy results align with the previous MTGA data in that combustion conditions yield higher values than pyrolysis conditions—200–250 kJ/mol and 175–225 kJ/mol for pine and wheat combustion, respectively, depending on pre-treatment. Results show the dependence of these parameters upon one another from a traditional thermal analysis approach, e.g., the Ozawa-Flynn-Wall method, as well as MTGA and Hi-Res™ thermogravimetric investigations to show future directions for thermal analysis techniques.

This proposed research investigates the sustainable and innovative use of biomass gasification for generating electricity. Biomass gasification is a versatile and eco-friendly technology that converts organic materials, such as agricultural residues, forestry waste, and even municipal solid waste, into a valuable source of clean energy. This research delves into the various aspects of this technology, including its processes, efficiency, environmental impact, and potential applications in power generation. Biomass gasification gas, often referred to as syngas, presents a promising avenue for addressing the rising energy demand while lowering greenhouse gas emissions and preventing climate change. This research seeks to offer a thorough insight into the principles and practices behind biomass gasification, highlighting its role in the transition towards a sustainable and renewable energy future. The research will investigate the technical and economic feasibility of utilizing biomass gasification gas for electricity generation, examining the benefits, challenges, and opportunities associated with this alternative energy source. By addressing critical issues such as feedstock availability, gasifier technology, gas cleaning processes, and power plant integration, this study seeks to offer valuable insights into the potential of biomass gasification gas as a clean and renewable energy solution.

The fundamental significance of using cattle manure as a case study is the risk of continuing pollution, caused by its poor management in connection to the increasing demand for animal-derived food. Pyrolysis and gasification, effective solutions with real valorization potential, are the proposed techniques of converting this type of waste into valuable products. After a complete initial characterization, cattle manure is converted into hydrogen-rich syngas, using a modular hybrid fixed-bed reactor, at a generous thermal range, 700 °C to 875 °C, under different process agents, without the use of steam or the addition of catalysts. In comparison to gasification, the quantification of syngas demonstrates higher yields in pyrolysis processes, but with a lower energy potential. The content of the syngas in hydrogen, ⁓ 25 vol% and hydrocarbons, ⁓ 25 vol%, emphasized by an energetic value of ⁓ 17 MJ/m3, holistically places the gasification process in a slight advantage in relation to pyrolysis, exceeding the values presented by other studies on similar matrices and technical conditions. The forecast investigation of syngas composition through polynomial functions shows a significant drop in hydrogen and hydrocarbon concentrations after the 80-min sampling period. [Display omitted] • Pyrolysis and gasification are potential options for cattle manure management. • The experiments were developed into an updraft fixed bed modular hybrid reactor. • The process gas is critical in determining the composition development of syngas. • Temperature variation alone did not disclose distinct trends. • Superior performance in average H 2 production is ascribed to gasification with 21 vol% CO 2. [ABSTRACT FROM AUTHOR]

The gasification of olive cake is a promising method for converting this material into valuable energy. This work offers interesting results about the effect of equivalence ratio and temperature on the composition and quality of the produced gas obtained during olive cake gasification in a fluidized bed plant with air as a gasification agent. Additionally, the efficiency of the gasification process was evaluated. The results show that, for a specific temperature, an equivalence ratio of 0.3 showed a higher cold gas efficiency. For example, at 850 °C and an equivalence ratio of 0.1, the cold gas efficiency was 22.7%; however, at the same temperature but at an equivalence ratio of 0.3, the cold gas efficiency was increased to 61.2%. In addition, for a constant equivalence ratio, by increasing the operating temperature, there was no significant increase in the lower heating value of the exit gas, and the gas flow was practically constant with temperature, but it varied substantially with the equivalence ratio, reaching values in the range of 3.44–14.89 NL/min (825.6–3573.6 NL/kg feed). Finally, the production of CO, H2, and CH4 is estimated to be higher for tests conducted with an equivalence ratio of 0.3. [ABSTRACT FROM AUTHOR]

The utilization of coal for hydrogen generation presents a multifaceted approach employing processes like coal gasification, pyrolysis, or high-temperature steam reforming. These methodologies entail reacting coal with steam or oxygen under elevated temperatures, yielding a gas mixture comprising hydrogen, carbon monoxide, and various byproducts. This paper delves into the exploration of hydrogen generation from coal, highlighting techniques such as gasification, pyrolysis, and other emerging methods. Notably, hydrogen discoveries within coal basins have garnered significant attention due to their implications for energy production and environmental sustainability. Certain coal basins harbor deposits rich in hydrogen, surpassing conventional coal reserves in their hydrogen content. These hydrogen-rich coals, including select sub-bituminous and lignite varieties, offer promising avenues for hydrogen production and utilization. However, the utilization of coal for hydrogen generation is not without its challenges. Technical hurdles, such as process efficiency and environmental concerns, demand rigorous investigation and innovative solutions. This paper addresses the challenges faced in coal-based hydrogen generation while elucidating the potential future prospects. It explores avenues for enhancing process efficiency, mitigating environmental impacts, and integrating coal-based hydrogen generation into broader energy strategies. Moreover, it underscores the importance of interdisciplinary research and collaboration in unlocking the full potential of coal for sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

The global annual production of plastics and tires exceeds 6.5 billion tons, with only 10% being recycled, leading to significant environmental problems. Thermochemical gasification of these waste materials offers a potential avenue for producing renewable hydrogen while harnessing underutilized carbon-based waste streams. This review highlights the research on thermochemical conversion of plastics and tires, providing key inferences regarding yield optimization, technical hurdles, and techno-economic viability. It indicates that strategic catalyst design and optimized integrated system configurations can significantly improve the hydrogen yields from plastic and tire pyrolysis/gasification. The key results of this work are that catalyzed gasification reactions show the most potential for maximizing hydrogen yield from plastic and tire waste. The related studies demonstrated that catalysts like Ni, Fe and Ce-doped mixtures can significantly increase hydrogen yield from plastic waste pyrolysis and gasification by suppressing coke formation and promoting reforming/shift reactions. Optimization of temperature, steam ratio and residence time also improves yield. Feedstock synergies exhibiting multiple reaction pathways likewise maximize yield. Computational modeling plays a valuable role by providing mechanistic insights through equilibrium and kinetic simulations. Integrated gasification with carbon/methane reforming shows potential to improve efficiency and lower costs. Techno-economic analyses indicate plastic/tire gasification may achieve cost parity with steam methane reforming through optimized integrated designs incorporating heat recovery. Integrated processes combining multiple conversion steps could further boost efficiency but require additional modeling and testing. A deeper understanding of reaction mechanisms, achieved through advanced modeling approaches, coupled with comprehensive lifecycle analyses of integrated solutions, can pinpoint optimized processing conditions and system designs capable of matching or surpassing the economic and environmental performance of conventional fossil fuel-based hydrogen production. The recommendations provided aim to guide future research prioritization, facilitating the realization of the large-scale potential inherent in waste-derived renewable hydrogen pathways. [Display omitted] [ABSTRACT FROM AUTHOR]

South Africa is an energy-intensive developing country in Africa and ranked as the 1st and 14th emitter of greenhouse gas (GHG) in Africa and the world, respectively. The abundance and availability of coal in South Africa make it the mainstay primary source of energy contributing 56% of national total GHG emissions. This paper focused on the duo of energy generation and emission associated with coal processing and utilization in South Africa, and the urgent need to advance coal processing technologies marked by high carbon footprints in consonance with the sustainable development goals. Different gasification techniques and their performances have been compiled and discussed. The economic, environmental impact, energetic, and exergetic characteristics of existing hydrogen production technologies for renewable and non-renewable energy sources have been examined along with hydrogen production from plasma gasification of coal. Hydrogen production via coal or coal/biomass plasma gasification technology (nuclear-, wind-, PV solar-, and concentrated solar power-driven) in addition to carbon capture technology for transforming the captured CO 2 into value-added products appears to be the most viable option to considerably reduce emissions and meet the energy demand of South Africa. This proposed technology can be pivotal to achieving a low-carbon economy (medium-term) and transition to hydrogen economy (long-term) as championed by the global sustainable development agenda. Conclusively, hydrogen (stored in different forms e.g., liquid hydrogen, ammonia, and organic hydride) seems to find more applications (in the space industry, transport, energy storage, defense industry, etc.) than coal owing to its immediate use in distribution/demand centers and remote areas. • Coal is the primary energy source of South Africa and key driver of national CO 2 emissions. • Traditional coal gasification technologies are marked by high CO 2 emissions. • Coal plasma gasification technology is a viable option for low-carbon energy economy. • Hydrogen production via coal or coal/biomass plasma gasification technology leads to zero-carbon economy. • This immensely supports the drive towards attaining the sustainable development goals. [ABSTRACT FROM AUTHOR]