Gasification Performance Research Articles

Study on improving the performance of blended Semi-coke coal water slurry based on multi-peak gradation technology

ABSTRACT Semi-coke is a problematic material to burn, and how to use it is a typical problem enterprises face. This paper proposes a method to improve the performance of blended Semi-coke coal water slurry based on multi-peak distribution technology. By blending Semi-coke, the coal water slurry concentration can be increased by a maximum of 3.83%. In addition, the blending of Semi-coke reduced the flow property index (n) of coal water slurry from 0.66 to 0.51, the yield stress from 29.25 Pa to 12.45 Pa, and enhanced the pseudoplasticity of coal water slurry. Meanwhile, this paper establishes the relationship between the bimodal parameters and coal water slurry concentration and finds that the peak 2 positions, peak 2 height, peak 2 areas, and peak spacing negatively correlate with the slurry formation concentration. Finally, this paper found that the doping of Semi-coke can improve the gasification performance of coal water slurry. The ignition temperature was reduced from 884.9°C to 854.3°C and the burnout temperature from 1067.4°C to 1026.6°C after Semi-coke blending.

Investigation on Syngas production from forest Biomass (Sapele, Sypo and Ayous) wood in the downdraft gasifier using Aspen plus and IC engine integration

This study aims to evaluate the potential for syngas production from three types of equatorial forestry biomass Sapele, Sipo, and Ayous using a downdraft gasifier. The main objective is to assess the energy potential of the produced syngas when used in an internal combustion engine with a 30% efficiency, coupled with a DC generator operating at 93% efficiency. The research focuses on determining the composition and energy output of syngas from these biomass types, as well as exploring the integration of downdraft gasification with internal combustion engines for localized energy production, particularly in decentralized power systems and microgrids. The research involved modeling and simulating the gasification process using Aspen Plus software. Proximate and ultimate analyses of the biomass samples were used to simulate gasification in a downdraft gasifier. The gasifier's performance was assessed through syngas composition analysis, focusing on energy output and overall system efficiency. The integration of downdraft gasification with an internal combustion engine was simulated to determine its feasibility in decentralized power systems and microgrids. The study revealed that all three biomass types produced syngas with high concentrations of carbon monoxide (CO) and hydrogen (H2), which are critical for energy generation. The lower heating value (LHV) of the syngas remained consistent among the samples, with Sapele at 13.51 MJ/Nm³, Sipo at 13.63 MJ/Nm³, and Ayous at 13.54 MJ/Nm³. Ayous achieved the highest gasification efficiency at 79.36%, followed by Sipo at 78.89% and Sapele at 76.05%. The simulation performed in Aspen Plus showed that Ayous produced the highest electric power output at 53.55 kW, followed by Sapele at 51.86 kW and Sipo at 49.18 kW. The results highlight the potential of equatorial forestry biomass, particularly Ayous, as a renewable energy source. All three biomass types can generate syngas of comparable quality in terms of energy content, with Ayous showing the highest efficiency. This research emphasizes the feasibility of using equatorial biomass for syngas production and its integration into internal combustion engines, supporting decentralized energy generation and reducing reliance on fossil fuels.

Fuzzy Neural Network Applications in Biomass Gasification and Pyrolysis for Biofuel Production: A Review

The increasing demand for sustainable energy has spurred interest in biofuels as a renewable alternative to fossil fuels. Biomass gasification and pyrolysis are two prominent thermochemical conversion processes for biofuel production. While these processes are effective, they are often influenced by complex, nonlinear, and uncertain factors, making optimization and prediction challenging. This study highlights the application of fuzzy neural networks (FNNs)—a hybrid approach that integrates the strengths of fuzzy logic and neural networks—as a novel tool to address these challenges. Unlike traditional optimization methods, FNNs offer enhanced adaptability and accuracy in modeling nonlinear systems, making them uniquely suited for biomass conversion processes. This review not only highlights the ability of FNNs to optimize and predict the performance of gasification and pyrolysis processes but also identifies their role in advancing decision-making frameworks. Key challenges, benefits, and future research opportunities are also explored, showcasing the transformative potential of FNNs in biofuel production.

Design and operation of a demonstration plant for fluidized bed low-temperature gasification of alternative fuels applied to cement production

A fluidized bed low-temperature gasification technology for solid waste treatment is proposed, which provides an effective solution for energy saving and carbon reduction in the cement industry. A demonstration plant was designed and constructed, which is a fluidized bed low-temperature gasifier coupled to the calciner, capable of treating more than 4,000 kg/h of solid waste. The project involved detailed equipment configuration to ensure stable operation. Commissioning tests for rice husk and textile waste gasification assessed system reliability and gasification performance, with a thermal substitution rate (TSR) of 53.10 % for the calciner. At the same time, targeting a clinker production capacity of 2500 t/d, the gasification plant could achieve an annual net profit of at least 753,100 USD. The fluidized bed low-temperature gasification technology not only has a good economic and environmental value for the use of alternative fuels in the cement production process, but also is important for the design and operation of industrial-scale gasifiers and for numerical modeling.

Thermal coupling study during the co-processing of coal and biomass in the lab-scale adiabatic reactor

A lab-scale adiabatic reactor has been self-made to characterize the coupled properties of heat and reactions during the co-thermal-processing of coal and biomass with steam or steam/O2 gasification agents. Results showed that the synergistic effects caused by heat transfer between corncob and coal at different mixing ratios were heavily determined by coal rank and gasification agent. During steam co-processing, the heat transfer from corncob char to adjacent bituminous coal char promoted the water-gas reaction on coal char and contributed to synergistic effects; the heat transfer from anthracite char to adjacent corncob char reduced the kinetic rate of the water-gas reaction on coal char and contributed to inhibitory effects, and the inhibitory effect caused by heat transfer was greater than the promotion effects of biomass mass transfer. The introduction of O2 diminished the impact of inter-particle heat transfer and altered the intensity of synergy, decreasing the values of synergy factor of bituminous coal/corncob blends by 17% and increasing the value of synergy factor of anthracite/corncob blends by 142.5%. This study provides sufficient support for the process conditions selection for the production of syngas with specific H2/CO molar ratios and the desired level of gasification performance.

Comparative downdraft gasification performance using falcata wood pellets and chips

Abstract Tropical off-grid regions are rich in biomass resources like Falcata, a fast-growing tree species. This study examines the optimal form of Falcata wood, comparing pellets (FWP) and chips (FWC) for community-based gasification systems using a downdraft gasifier. Key methods included feedstock uniformity assessment, syngas composition analysis, and efficiency calculations. Results showed FWP provided better uniformity and consistent feeding, while FWC may need further processing for improved efficiency. FWC had a higher heating value (17.92 MJ/kg) and volatile matter (84.29%) than FWP, which had more fixed carbon (18.20%) but also higher ash content (1.98%). FWP produced syngas with higher CO and H2 concentrations, leading to better overall syngas quality, while FWC yielded more non-combustible CO2. Energy Conversion Efficiency (ECE) and Gas Efficiency (GE) indicated that FWP is four times more effective and twice as efficient for gasification compared to FWC. The study concludes that both forms can produce high-quality syngas, but further research is needed to assess the economic viability and optimize gasification parameters for improved efficiency.

Chemical looping gasification of vinegar residue with enhanced LD slag composite Ca-Fe oxygen carrier for syngas production

Biomass chemical looping gasification (BCLG) is an emerging technology that enables waste co-processing into clean energy. A laboratory-scale vertical fixed-bed reactor was used to conduct CLG experiments with vinegar residue (VR) as a biomass fuel, and the effect of enhanced LD slag composite Ca-Fe material as an oxygen carrier (OC) on the production of syngas from BCLG was investigated. This study analyzed the influence of LD slag proportion, kinds of OC, and operational conditions (temperature, oxygen carrier/biomass (OC/B) ratio, and steam/biomass (S/B) ratio) on gasification performance. Results indicate that the syngas yield under the gasification operating conditions at about 850 °C, OC/B = 1, and S/B = 2.5 obtained 1.36 Nm3/kg, the CCE and CGE achieved about 80.82 % and 98.16 %, respectively, and the H2/CO molar ratio was as high as 2.57. The OCs multi-redox cycle test revealed that after undergoing 10 redox cycles under the conditions mentioned above, the gas yield, CCE, and CGE were reduced to varying extents, but still maintained impressive reactivity. The mechanism analysis showed that the performance degradation of the LD slag composite Ca-Fe OC during the multi-cycle process was related to its agglomeration due to thermal stress and steam. This study provides a new perspective on the synthesis of low-cost OCs and the co-utilization of solid wastes.

Preparation of pitch semi-coke water slurry and its properties of slurryability and gasification

ABSTRACT A new strategy for the preparation of pitch semi-coke water slurry (p-SCWS) with pitch as raw material and semi-coke powder was proposed. The slurryability and gasification performance of p-SCWS were evaluated by apparent viscosity, stability, FTIR, XRD, and TG/DTG characterization methods. Compared with SCWS, the hydrophilic functional groups of SCWS prepared by coal pitch (CP), modified pitch (MP), and petroleum pitch (PP) increased significantly. p-SCWS and SCWS have similar pseudoplastic rheological properties-shear thinning. p-SCWS exhibits better stability than SCWS, with the lowest WSR at 0% and the highest at 8.49%. The addition of pitch lowered the initial (Ts) and final reaction temperatures (Te) of gasification, increased the activation energy and pre-exponential factor, and enhanced the gasification activity. The Ts and Te of CP-SCWS showed the most significant decrease, reaching 869.95°C and 1010.96°C, respectively, compared to 902.39°C and 1075.60°C for SCWS. The activation energy and pre-exponential factor were highest for PP-SCWS.

Investigations on performance and combustion of gasifier engine integration using three different biomasses as feedstocks

The integration of a downdraft gasifier with modified internal combustion engines presents a feasible solution for heat and power production, such as off-grid areas. This study conducted an experimental analysis to evaluate combustion in a modified engine. The morphological characteristics of the agricultural residue used in the gasifier were analyzed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM), along with an examination of the slagging inorganic constituents. The engine used in the experiments was a modified single-cylinder design paired with a downdraft gasifier. Three types of biomass feedstocks—eucalyptus, corncob, and pearl millet in pellet form —were tested. The performance of the downdraft gasifier was stabilized, and the engine was run independently on each type of producer gas at a constant speed under different loads to determine the optimum load. Cylinder pressure measurements were taken to estimate the heat release rate.The study found that power generation was lower than typical woody biomasses due to the lower calorific value of the producer gas from the tested feedstocks. Additionally, lower cylinder pressures and heat release rates were recorded, along with longer combustion durations. The varying proportions of producer gas affected combustion stability. Among the studied ashes, pearl millet corncob (PMC) exhibited the highest slagging tendency, followed by corncob (CC). Morphological analysis indicated that the eucalyptus residue's increased porosity was caused by the volatiles changing, forming pores and tube-like structures. An aliphatic C–H peak (3000–2500 cm⁻1) is absent from the residue, indicating that the aliphatic structure was disturbed during thermochemical conversion. During the gasification process, the residue's crystallinity reduced as it split down.

Evaluating the role of feedstock composition and component interactions on biomass gasification

Biomass gasification offers a solution to waste concerns while generating clean energy. This study examines the gasification of pine sawdust (PS), used ground coffee (UGC), and wheat straw (WS) under identical conditions. The compositions of the biomass samples are determined, and the gasification of individual components (hemicellulose, cellulose, and lignin) are conducted to understand the process’ dependency on the biomass characteristics. The results suggest cellulose and cellulose-rich biomass (PS) produces more tar and less hydrogen than lignin and lignin-rich biomass (UGC and WS). High lignin and hemicellulose content leave more char. Gasification of PS, UGC, and WS yields 12.7, 15.7, and 17.2 vol% hydrogen, respectively. Additionally, cellulose, hemicellulose, and lignin gasification yield 10.5, 22.1, and 30.4 vol% hydrogen, respectively. Comparing experimental and theoretical values for the three biomass samples reveals significant differences due to component interactions. Thermogravimetry analysis (TGA) indicates significant degradation interactions between hemicellulose-lignin, cellulose-hemicellulose, and cellulose-lignin. It is concluded that high cellulose content biomass shows more predictable results, while high lignin and hemicellulose biomass increases secondary reactions or interactions, exacerbating predictability. These findings assist in estimating gasification performance for better biomass selection.

Evaluation of the chemical looping gasification characteristics of kitchen waste using CuFe2O4 and NiFe2O4 as oxygen carriers

Chemical looping gasification (CLG) technology is promising for renewable energy, efficiently transforming biomass into high-quality syngas with minimal tar and pollutants. In this study, we examined the CLG characteristics of soy protein (SP), a model compound present in kitchen waste (KW), using two different oxygen carriers (OCs): Cu-Fe and Ni-Fe. The study revealed that enhancing the carbon conversion ratio (ηc) could be effectively achieved by increasing the oxygen equivalent coefficient (α) and the steam content. Consequently, the optimal gasification performance was attained when the Cu-Fe and Ni-Fe OCs were operated at the α values of 0.3 and 0.4, and steam contents of 30 % and 40 %, respectively. After ten cycles of chemical looping, both OCs retained their robust oxidation activity, ensuring that the ηc remained consistent throughout the ten cycles. Under optimized experimental conditions, the CLG characteristics of KW were successfully determined. Notably, the ηc of KW was substantially enhanced, doubling in comparison to previous levels. The Cu-Fe OC emerged as a more suitable candidate for the CLG of KW due to its lower cost and non-toxic nature. This study provides important theoretical support and practical insights for the harmless treatment and resource utilization of KW.

Comprehensive experimental assessment of biomass steam gasification with different types: correlation and multiple linear regression analysis with feedstock characteristics

In order to reveal the correlation between gasification behavior and products with feedstock characteristics, the steam gasification of 13 biomasses was investigated using a thermogravimetric analyzer and a fixed-bed reactor. Meanwhile, a multiple linear regression was used to construct correlation models. The results showed that cellulose content and crystallinity had the greatest influence on pyrolysis reactivity, which was reflected that the cellulose content was strongly positively correlated with the pyrolysis reactivity (Pmax = 0.77), while the lignin content and cellulose crystallinity were opposite. H/C, O/C ratios and SiO2 content had the greatest influence on gasification stage. O/C were strongly negatively correlated with gasification reactivity (Pmax = −0.81). But correlations of K and Ca contents were much less than that of Si. Husk has the best gasification performance than straw and woody with highest H2 and total gas yield of 28.26 and 68.93 mmol·g−1. H2 concentration and yield were significantly affected by the cellulose crystallinity and the fixed carbon content with positively correlation (P = 0.69–0.85). CH4 and CnHm were also influenced by them, but the trend was opposite to that of H2. Cellulose content, followed by SiO2 content mainly affected CO and CO2 and negatively correlated with CO while positively with CO2.

Waste-to-Energy technologies for municipal solid waste management: Bibliometric review, life cycle assessment, and energy potential case study

Inadequate municipal solid waste (MSW) management threatens public health and the environment. The waste-to-energy (WtE) route allows the production of electricity, heat, and other valuable chemical products. WtE consists of incineration, gasification, pyrolysis, and some emerging technologies. This study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct a bibliometric analysis of WtE technologies for MSW management research. Scopus-indexed articles were examined between 1971 and 2023. Four periods were defined and analyzed in terms of their most significant results. In addition, the most pertinent journals (Waste Management, Chemosphere, and Waste Management & Research) ranked first, second, and third, respectively. Moreover, the top contributor countries include one in America (the United States), three in Asia (China, Japan, and India), and five in Europe (Spain, Italy, Germany, Sweden, and the United Kingdom). Throughout a Life Cycle Assessment (LCA) case study, the environmental performance of gasification and incineration were compared as relevant technologies for treating MSW were contrasted. Gasification excelled in seven environmental parameters, suggesting that developing strategies for MSW gasification on a commercial scale should prioritize this aspect. Finally, the energy potential was assessed, which provided valuable information on the societal benefits of WtE technologies in various sectors, such as education, health, and electromobility. Under their respective contexts, stakeholders should enhance MSW sorting policies, pretreatment methods, and emerging valorization options. The growing global interest in WtE requires a social, environmental, and economic evaluation before implementation.

CO2 Conversion by Oxygen-Enriched Gasification of Wood Chips

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.

Sustainable Energy Production From Biomass: A Case Study On Tasmanian Blue Gum Eucalyptus Gasification

The global transition to renewable energy sources is a crucial response to the urgent need to reduce global warming and its negative environment consequences. One feasible approach within this paradigm is to generate steam from syngas produced by biomass gasification. Background: Gasification is a thermochemical process that transforms organic materials into combustible gas mixtures, provides a sustainable and renewable way to generate energy, chemicals and fuels. This technology helps to minimize greenhouse gas emissions and reliance on fossil fuels. Materials and methods: In this experiment, Tasmanian blue gum eucalyptus sawdust is used to generate pellets which will subsequently be processed into syngas using downdraft gasifier. The experiment investigates the effect of increasing air velocities specifically 10, 15, 20 and 25 M/sec as a gasifying agent to the gasification process. Results: The air velocity is measured at 10, 15, 20 and 25 m/s resulting in the time taken of 2280, 1860, 1560 and 1380 with efficiency increases of 41.11, 47.73, 49.62 and 54.67, respectively. This implies that optimizing air velocity is crucial for improving the overall performance of biomass gasification. The proximate and ultimate results of pellet are some better compared to the raw eucalyptus by researcher Filomena Pinto [16]. The efficiency is slightly high compared with the researcher R. Ravi Kumar [25]. The generated syngas may eventually replace the fossil fuel LPG for domestic purposes. Conclusion: The time taken for the gasification decreases with the increase of air velocity up to 25m/s. As the result the efficiency increases.

Configuration optimization of a biomass chemical looping gasification (CLG) system combined with CO2 absorption

Biomass chemical looping gasification (CLG) combined with CO2 absorption in a dual circulating fluidized bed (DCFB) has emerged as an advanced technology for clean and efficient biomass utilization, yet the reactor design for achieving higher gasification performance and the in-depth understanding of physical-thermal-chemical characteristics is still lacking. This study presents an optimized design aimed at enhancing hydrogen production and carbon reduction in the biomass CLG process with a DCFB reactor by employing the multiphase particle-in-cell (MP-PIC) method integrated with thermochemical sub-models. The proposed reactor is comprehensively compared with the original reactor from the experimental setup in terms of particle mixing, heat transfer, and gasification behaviors. The results indicate that compared to the original setups, the proposed CLG system demonstrates: (i) an improved gas-solid mixing, as evidenced by the particle mixing index rising from 0.23 to 0.34; (ii) an enhanced particle heat transfer coefficient, which boosts heat and mass transfer process; (iii) a 10.11 % increase in H2 concentration alongside a 23.71 % decrease in CO2 concentration; (iv) a particle distribution characterized by higher concentration at the bottom and lower concentration at the top, along with intensified particle back-mixing. The pressure drop inside the combustor is higher than that in the gasifier. A smaller absorbent mean particle diameter and lower-positioned biomass feeding port contribute to the improvement of the CLG performance.

Performance analysis of a pilot gasification system of biomass with stepwise intake of air-steam considering waste heat utilization

Although the fixed-bed gasifier is widely used because of their simple structure, easy operation, and strong adaptability to biomass type, its economy is weakened by their low bioenergy conversion ability and heat utilization efficiency. Therefore, a novel biomass gasifier with stepwise intake of air–steam is proposed, which also innovatively integrates the concept of multi-stage utilization of waste heat generated during the gasification process into its design. And a pilot system comprising the novel biomass gasifier with a biomass consumption of 30 kg/h has been built. A series of continuous air-steam gasification experiments on pine wood particles shown that, the high-temperature steam in the reduction zone enhanced the ring opening of aromatic hydrocarbons, decarboxylation, dehydroxylation, and the conversion of long-chain to short-chain hydrocarbons, thus increasing the yield of small-molecule gases. The steam reforming reaction played an active role in increasing the hydrogen content, the gasification gas's production and low calorific value. And the relationship among the reaction rates on the surface of char should be VC + H2O＞VC+2H2O＞VC + CO2＞VC+2H2. The minimum input temperature of steam was 350 °C, otherwise more char would be consumed in the oxidation zone to provide heat. The proposed steam-air gasification system achieved optimal performance with an air-to-steam mass ratio (A/S) of approximately 8, a steam temperature of 400 °C, and an air-to-biomass mass ratio (A/B) of 1.2. The average gas production could reach 2.67 m3/kg, with the average low calorific value of 5.1 MJ/m3. The average hydrogen content could reach 20 %, with the average H2/CO ratio of 2. The average effective gasification efficiency could reach 69.72 %. Compared with air gasification, the proposed air-steam gasification was equivalent to the use of 1 kWh of electricity to produce 2.4 kWh of electricity. Combining market research, the price of steam produced by the proposed system was approximately 70 CNY/t less than when using natural gas. This study aims to provide a technical reference for improving the performance of biomass gasification in practical applications.

Regulation mechanism of phenol on intermediates during supercritical water gasification of coal

Supercritical water (SCW) gasification technology can enable the efficient utilization of coal by converting it to hydrogen-rich gas. However, poly-cyclic aromatic hydrocarbons and heavy components, which are intermediates of supercritical water gasification, tend to generate char, hindering the complete gasification of coal. In this work, phenol is recycled to enhance the gasification process and reduce the formation of these intermediates during SCWG, and the regulation mechanism is investigated. The results demonstrate that both gas yield and gasification efficiency increase with the presence of phenol, reaching approximately 98.5% at 750 °C, concentration of 2%with the effect of phenol, which is 27% higher than that in the coal-water system. Organics removal rate reaches about 98% with the addition of phenol. Phenol can enhance the gasification performance by facilitating the conversion of heavy components to lightweight components. The transient reactivity of coal in the poly-condensation stage is increased by about 50 times with the presence of phenol. The regulation mechanism of phenol in the poly-condensation stage during coal gasification involves the decomposition of SCW forming hydroxyl radicals, which replaces the substituents on the benzene ring, facilitating the dissociation of benzene ring into small molecules that are prone to polymerize. The interacting force between phenol and multi-rings disrupts the conjugate structure, aiding in the decomposition of polycyclic organics into small molecules.

Rational design of enhanced oxygen deficiency-enriched NiFe2O4 embedded in silica matrix as oxygen carriers for high-quality syngas production via biomass chemical looping gasification (BCLG)

Biomass chemical looping gasification has attracted wide attention in syngas production. However, the major obstacle is deactivation of oxygen carriers (OCs) caused by sintering, leading to low gasification efficiency. Developing sintering-resistant oxygen carriers is crucial for enhancing the competitiveness of BCLG. This study proposes an effective strategy of embedding NiFe2O4 in silica matrix (NFSM) to fabricate highly dispersed OCs. The gasification performance and cycling stability of OCs for BCLG are systematically researched in a fixed-bed reactor. Based on the characterization analysis, NiFe2O4 is successfully incorporated into the silica matrix. The well-dispersed active components in OCs create more oxygen vacancies and metal adsorption sites, resulting in higher redox activity. Experimental results verify that the optimal parameters for achieving the highest syngas yield (1254 mL/g) and biomass gasification efficiency (68 %) are 0.6 OCs/B, a temperature of 850 °C, and a water injection rate of 0.3 mL/min. After 10 redox cycles, NFSM demonstrates superior redox activity and excellent cycle stability, maintaining its gasification performance and microstructural integrity throughout all chemical looping gasification processes. The silica matrix-supported NiFe2O4 can be a promising candidate for BCLG. This work provides a novel approach to develop and design future OCs of BCLG for alleviating sintering and deactivation phenomena.

Impact of geometric variables on the functionality of downdraft biomass gasifiers across diverse dimensions

This study offers an extensive examination of the fundamental design parameters that influence the performance of biomass downdraft gasifiers. The impact of design parameters such as reactor dimensions, throat diameter, length of converging and diverging section and ratio of maximum to minimum diameter (dmax/dmin) were analysed using FORTRAN code, which was initially developed for 4 kW Imbert gasifier. Simulation results highlight that the optimal range of hearth loads for gasifier operation is influenced by both the gasifier’s size and the particle size of the feedstock. Increasing gasifier size from 20 mm to 100 mm throat diameter, while maintaining the same superficial air velocity (SAV), escalates hearth load and superficial velocity due to heightened biomass consumption, leading to higher hearth temperature and improved gas calorific value. Similar trends are observed across varying SAV values (0.35 m/s to 1.8 m/s), suggesting a need for lower SAV values in larger gasifiers, possibly with larger particle sizes. Additionally, altering the length of the converging and diverging sections impacts gas quality, with deviations from recommended values affecting ignition and overall performance, while dmax/dmin variations show no significant impact.