Biomass Gasification Research Articles

Progress in Torrefaction Pretreatment for Biomass Gasification

Torrefaction is an effective method to improve the quality of biomass feedstocks for a subsequent thermal conversion process. Torrefaction has been widely developed for biomass upgrading in terms of increasing...

Adaptive plc intelligent control based on the integrated system of smart grid thermal energy conversion

During the construction of smart grids, due to technological limitations, traditional sequential control systems have been unable to meet the needs of grid operation, exposing problems such as single control methods and functions, low operational efficiency, inability to independently complete complex tasks, and poor anti-interference ability, which in turn affect the power supply quality and operational stability of the grid, and fail to truly achieve the reliability, safety, and reliability of smart grids Economic and efficient goals. For this purpose, the author describes an adaptive intelligent control method for an integrated biomass energy heat conversion system consisting of more than one suction biomass gasifier, biomass gas burner, and steam boiler. The system uses PLC as a tool and takes the boiler outlet steam pressure as the control parameter. Based on the changes in the boiler outlet steam pressure, it automatically adjusts the feed and gas production of the gasifier, and subsequently adjusts the air supply of the burner. Ultimately, it achieves the goal of automatically adjusting the boiler heating volume with changes in steam pressure. The integrated heating and adaptive intelligent control system based on biomass gasification has been reliably verified in industrial applications.

Cost-Effective Monitoring of the Fuel Air Equivalence-Ratio with a Lambda Sensor and a Microcontroller in a Downdraft Biomass Gasifier

Cost-Effective Monitoring of the Fuel Air Equivalence-Ratio with a Lambda Sensor and a Microcontroller in a Downdraft Biomass Gasifier

Hybridized power-hydrogen generation using various configurations of Brayton-organic flash Rankine cycles fed by a sustainable fuel: Exergy and exergoeconomic analyses with ANN prediction

This paper investigates different configurations of organic Rankine flash cycles combined with a Brayton cycle by performing thermodynamic, exergy, and exergoeconomic analyses. The thermal energy of the cycle is produced through burning gaseous methane generated via gasification of biomass. A systematic analysis of these configurations is conducted to enhance the exergy efficiency of the cycles. Additionally, the reutilization of the thermal energy that would otherwise be wasted in the Brayton cycle contributes to a notable enhancement in the overall thermal efficiency of the combined cycle. A range of working fluids, namely m-Xylene, o-Xylene, p-Xylene, toluene, and ethylbenzene are analyzed for the organic Rankine cycle. Predictions using an artificial neural network (radial base function) are also carried out. The results indicate that the p-Xylene increases exergy efficiency more than other working fluids. Further, the improved organic Rankine cycle mitigates exergy destruction by 10 %. Although applying double flash evaporators improves the exergy efficiency by 3 %, it increases the unit cost of power generated by more than 10 %. The application of a data-driven model to predict various configurations of combined organic Rankin cycle with a Brayton cycle fed by biomass has rarely been investigated.

Prefeasibility analysis of biomass gasification and electrolysis for hydrogen production

Hydrogen is a key energy vector to accomplishing energy transition and decarbonization goals proposed in the transport and industrial sectors worldwide. In recent years, research has focused on analyzing, designing, and optimizing hydrogen production, searching to improve economic prefeasibility with minimal emissions of polluting gases. Therefore, the techno-economic analysis of hydrogen production by electrolytic and gasification processes becomes relevant since these processes could compete commercially with industrial technologies such as SMR - Steam methane reforming. This work aims to analyze hydrogen production in stand-alone processes and energy-driven biorefineries. The gasification and electrolysis technologies were evaluated experimentally, and the yields obtained were input data for scaling up the processes through simulation tools. Biomass gasification is more cost-effective than electrolytic schemes since the hydrogen production costs were 4.57 USD/kg and 8.30 USD/kg at an annual production rate of 491.6 tons and 38.96 tons, respectively. Instead, the electrolysis process feasibility is strongly influenced by the recycled water rate and the electricity cost. A sensitivity analysis was performed to evaluate the temperature, pressure, and current density variability on the hydrogen production rate. The increase in pressure and current density induces parasitic currents while the temperature increases hydrogen production. Although higher hydrogen production rates from gasification, the syngas composition decreases the possibility of being implemented in applications where purity is critical.

Grid aided combined heat and power generation system for rural village in north China plain using improved PSO algorithm

The rural areas of North China Plain, an important grain producer in China, are endowed with abundant new energy resources such as biomass, solar, and wind energy. The revitalization of the rural villages is confronted with the shortage of clean and low carbon energy supply. This work proposes a multi-energy complementary distributed energy system (DES) tailored for daily energy consumption in a typical scattered village on the basis of the field survey results. The geothermal heat pump, photovoltaic system (PV), biomass gasification equipment, and other energy conversion devices are integrated in the DES model. The state grid is used as a fundamental ensuring resource to improve the robustness of the system. The improved particle swarm optimization (PSO) algorithm is employed to determine the optimal unit capacity configuration by examining investment cost, payback period, system self-sufficiency, accommodation rate, and annual CO2 emissions. The main available renewable energy resources are biomass and solar energy with the annual amount of 1608.9 tons and 1679 kW h/m2. The heat, gas, and electricity load account for 76.84%, 3.14%, and 20.02%, respectively. Based on the daily peak-to-valley price differentials in Beijing of over $0.15/kWh, DES optimization was carried out with PSO module in MATLAB software. The cost of the energy supply with DES, Scenario 3, was compared with that of the mere grid and renewable systems, Scenario 1 and Scenario 2. The direct DES cost is $0.52 million with the internal rate of return of 8.46%, resulting in a payback period of 6.15 years. The overall system self-sufficiency index except for grid achieved a value of 0.42. The application of the DES lead to energy costs of residents and annual carbon emission reduction by 32.5% and more than 3800 tons, respectively, compared to grid-only energy consumption, showcasing the feasibility of grid-aided combined heat and electricity production in rural areas.

Energy, exergy and thermo-economics analyses of hybrid solar, steam turbine and biomass gasification system for hydrogen production by polymer membrane electrolyzer

This study presents an evaluation of the energy exergy and thermo-economics of a hybrid power generation system that simultaneously produces power, heat, and hydrogen using solar and biomass energy. The system employs a polymer membrane electrolyzer for hydrogen production, with heat exchangers utilized to attain the desired water temperature instead of conventional heaters. The steam turbine section is heated using exhaust gas from the combustion chamber and heated water from the condenser. Simulation of the system's thermodynamic, exergy, and exergy-economic analyses was conducted using the ESS tool. Analytical assessments were performed based on the provided data. The system achieves a power output of 25 MW, marking the highest level for solar-based systems. The results showed that the cost of the solar section, which constitutes around 68 % of the overall cost, rises with the number of mirrors. The exergy destruction rate of the entire system decreases from 25.71 MW to 24.95 MW. The total cost of operating the system increases by 175.5 dollars per hour at the highest temperature and decreases by 173 dollars per hour at the lowest temperature. The power consumption of electrolyzers directly affects the overall cost of the system, with a range of 0.05 to 0.07 MW resulting in total cost changes of 1.52 USD per hour. The transition to the work requiring the most energy by the electrolyzer causes a loss of 0.27 MW of exergy.

Parametric evaluation of clean syngas production from pine forest residue by chemical looping gasification at the 20 kWth scale

In the framework of the EU H2020 CLARA project, jet biofuel production via Fischer-Tropsch synthesis is intended from syngas generated by Biomass Chemical Looping Gasification (BCLG). BCLG is based on the lattice oxygen transference between a solid oxygen carrier and the biofuel to energetically support the biomass gasification. This process produces low tar and nitrogen-free syngas under autothermal conditions, and at the same time includes an intrinsic separation of carbon compounds from nitrogen in air, avoiding future carbon capture costs. This work evaluates the syngas production from pine forest residue (PFR) through the BCLG process with ilmenite as the oxygen carrier. The effects of several key operating variables, including temperature, oxygen-to-biomass ratio and mean residence time of solids, on the performance of the BCLG process were analyzed at 20 kWth scale. The syngas yield depended on the oxygen-to-biomass ratio and improved with the char conversion in the fuel reactor. Temperature and mean residence time of solids in the fuel reactor were identified as the primary factors affecting char conversion. A dedicated study was performed to assess the impact of the biomass size on char conversion, as well as the relevance of a carbon stripper unit on the improvement on char gasification due to its role either as a secondary gasifier or as a char-oxygen carrier separator. Higher char conversion values were achieved with the lowest biomass particle size (1–2 mm vs. pellets 6 mm Ø) due to lower restrictions to gas diffusion inside the particles. The carbon stripper may act as a secondary gasifier, thus improving the char conversion, but it was not able to take away the unconverted char particles from ilmenite in any case due to it was designed for powdered fuels. Besides, the generation of light hydrocarbons was hardly affected by any operating variables. The tar content remained below 4.5 g/kg dry biomass. The ilmenite showed a good performance during the continuous operation without signs of defluidization.

A novel strategy for efficient utilization of carbon residue from biomass gasification loaded NiCo2O4 to construct composite catalysts for activation of peroxymonosulfate to effectively remove antibiotics

Carbon residue (CR) derived from biomass gasification is a type of solid waste discharged from the biomass gasifier. CR is a carbon-rich material with a large specific surface area. Herein, NiCo2O4 nanoparticles were generated in situ on CR via a facile solvothermal method and the NiCo2O4-CR (NCCR) composite catalysts were prepared via solvothermal synthesis followed calcination method. The catalytic activity of NCCR was investigated by activating peroxymonosulfate (PMS) for the ciprofloxacin (CIP) degradation. The NCCR/PMS system exhibited the degradation efficiency, TOC removal efficiency, and removal reaction rate constant (k) of 93.86 %, 44.09 %, and 0.049 min−1 for CIP in 60 min, respectively, which were 1.17, 1.21 and 1.20 times of those in the NiCo2O4/PMS system, suggesting that CR had a positive impact on the improvement of the catalytic properties of NiCo2O4. Significantly, NCCR showed remarkable performance in terms of pH adaptation range, resistance to environmental disturbances, reusability, and other contamination applications. SO4•–, O2•– and 1O2，as the dominant reactive oxygen species, disrupt the molecular structure of CIP. PMS activation with NCCR mainly form free radicals and non-free radicals catalyzed by the redox couples of Co (III)/Co (II) and Ni (III)/Ni (II). Specially, Co (IV) = O also form and participate in the CIP degradation via a non-free radical pathway. Three possible degradation pathways of CIP were suggested by the degradation intermediates. The CIP degradation in the NCCR/PMS system was a process of reducing toxicity, protecting water ecosystem. The study provides a method to improve the catalytic properties of transition metal for activating PMS to purify antibiotic contamination wastewater, and opens a novel insight to deal with the solid waste from biomass gasification.

Multi-energy pricing strategy for port integrated energy systems based on contract mechanism

This article studies a pricing scheme to increase the profit of ports and gas utility company (GUC), and improve social welfare. Firstly, a system model of the port integrated energy system (PIES) is established and the government green subsidy on biomass gas is considered. Secondly, a multi-stage game is formulated to characterize the interaction between the port, GUC and the government. Besides, the contract mechanism is used to improve the operation performance of the energy supply chain. Then, the equilibrium solutions of the game are obtained by the backward induction. Finally, the theoretical analysis and simulation show that the proposed pricing strategy can improve the profit of GUC, ports and government, and the proposed revenue sharing contract mechanism can coordinate the energy supply chain.

Improvement of biohydrogen production from biomass using supercritical water gasification and CaO adsorption

Producing biohydrogen is a promising alternative to fossil fuels, sourced from renewable energy like wind, solar, and biomass, known for its eco-friendliness and minimal greenhouse gas emissions. This study focuses on the process design and simulation of producing biohydrogen from biomass (bagasse) gasification. New integration of the water gas shift reactor and CaO adsorption process is connected to biomass gasification with the steam/supercritical water agents for improving the hydrogen production process. Simulations show that steam gasification integrated with CaO adsorption (SG-CaO) is optimized at specific conditions, resulting in high-purity hydrogen at 99.95 %. Similarly, the supercritical water gasification integrated with CaO adsorption (SCWG-CaO) requires specific conditions, achieving exceptionally pure hydrogen at 99.99 %. In terms of energy analysis, SCWG-CaO outperforms SG-CaO, with higher hydrogen yield (14.16 % vs. 14.12 %) and greater energy efficiency (42.32 % vs. 40.26 %). It shows that the SCWG-CaO is a suitable and efficient approach for biohydrogen production, considering factors such as hydrogen purity, yield, and energy efficiency.

Experimental study on hydrogen production from heavy tar in biomass gasification furnace catalyzed by carbon-based catalysts

High boiling point heavy tar compounds such as pyrene and naphthalene are key factors causing corrosion and blockage in the pipelines of biomass thermal utilization equipment, and catalytic reforming represents an effective means to address heavy tar issues. Biomass carbon, characterized by its cost-effectiveness, high efficiency, and environmental friendliness, is envisioned as a catalyst carrier with extensive application prospects. In this study, the tar produced by a biomass fixed-bed gasifier was investigated, with an initial analysis of the pyrolysis process and definition of its different stages conducted. It was discovered that the condensation and secondary cracking stages are the predominant phases for the formation of heavy tars, including polycyclic aromatic hydrocarbons (PAHs). Carbon-based carriers were prepared using apricot shell as the raw material, and biomass carbon-based catalysts were synthesized via impregnation methods. The heavy tar extracted from the original tar through distillation was utilized in the hydrogen production tests of steam catalytic reforming with biomass carbon-based catalysts. The investigation into the impact of temperature, steam-to-tar mass ratio (S/T), and tar-to-catalyst mass ratio (T/C) on the catalytic reforming of tar has been conducted. In considering a variety of parameters, including hydrogen production rate, tar conversion rate, and the volume of hydrogen generated, it was found that under the conditions of 800 °C, S/T = 3, and T/C = 2, the Ni/C catalyst yielded the highest amount of hydrogen (91.52 g H2/kg tar) with a tar conversion rate of 93.30 %. The Ni-Co/C composite catalyst exhibited stronger catalytic activity and superior deactivation resistance compared to the monometallic catalysts. For the latter, steam regeneration methods effectively restored the catalytic activity of the carbon-based catalysts, enhancing the hydrogen yield rates of Ni/C and Co/C catalysts by 2.74 and 1.55 times respectively.

Hydrogen production via gasification of corn stover: modeling and simulation using Aspen Plus®

The gasification of biomass is one of the most promising technologies for the sustainable production of hydrogen. Although several studies have been conducted on biomass gasification, a detailed numerical investigation of factors affecting hydrogen production and optimization of experimental variables are required. In addition, a comprehensive kinetic model that accounts for specific reactions encountered during biomass gasification is needed to simulate the effect of experimental conditions on hydrogen production. Therefore, in this study, a kinetic model for gasification of corn stover is developed and simulated in Aspen Plus®. Furthermore, the effect of key variables, i.e. gasification temperature, selection of proper gasifying agent, hydrogen production efficiency (HPE), higher heating value (HHV), and lower heating value (LHV), of the produced hydrogen have been investigated in order to select the optimal process conditions. Results indicate that a maximum HPE of 59% is obtained for steam gasification, whereas air gasification yielded an HPE of 26%, implying that steam as a gasifying agent demonstrated increased hydrogen production. Further, the optimized gasifying agent flow rate in both cases is observed to be 1200 kg/h (steam or air) at 900 °C. The energy and economic analysis of this study indicates the viability of the presented approach.

Synergizing Aspen plus and life cycle assessment of nascent photocatalytic dry methane reforming over thermocatalytic and biomass gasification toward syngas generation

Synergizing Aspen plus and life cycle assessment of nascent photocatalytic dry methane reforming over thermocatalytic and biomass gasification toward syngas generation

Modulation of Rh species in Rh/Al2O3/FeCrAl-foam structured catalysts for steam reforming of toluene

Steam reforming of tar is an appealing way for tar elimination during biomass gasification. In this work, structured Rh/Al2O3 supported on FeCrAl-foam catalysts with different Rh species contents (Rh0, RhiOx and Rh(AlO2)y) were modulated through calcination and/or reduction at different temperatures for toluene steam reforming. Among all the structured catalysts and conventional supported catalysts, the structured Rh/Al2O3/FeCrAl-foam catalyst, calcined in air at 300 °C followed by reduction with hydrogen at 600 °C, showed superior activity as well as excellent resistance to sintering and coke deposition. Such high performance can be attributed to the suitable Rh0/RhiOx ratio as well as the enhanced mass transfer capability. The integrated studies of controlled catalytic tests, catalyst characterizations, TPSR, H2O-TPD and in-situ DRIFTS revealed that metallic Rh0 site was responsible for the cleavage of the C-C/C-H bonds in toluene. The activate ability of H2O was governed by the Rh0/RhiOx ratio, while the RhiOx specie played a significant role, which further promotes the reaction activity and eliminate coke deposition. Furthermore, the RhiOx specie enable the catalyst with high sintering resistance, due to the strong affinity to the Al2O3 surface. However, the Rh(AlO2)y specie was inactive. The catalytic performance was controlled by balancing the toluene activation and H2O dissociation. Consequently, rational tuning of these species is crucial for obtaining high-performance Rh/Al2O3 catalysts for steam reforming of toluene.

Enhancement of reaction rate prediction of biomass: A focus on experimental and numerical simulation approaches

While the biomass gasification and cofiring technology is promising for future energy, including green technologies, such as carbon capture and storage and bioresource feedstock, negative carbon emissions are simultaneously possible using these technologies. However, despite these functions, our previous study established that for simulating a biomass reactor, a new model needed to be designed that could improve the accuracy of both real and lab-scale simulations for carbonaceous fuels, such as coal-based applications. Hence, in this study, a biomass experiment utilizing a thermogravimetric analyzer was conducted to obtain varying reaction rate data over carbon conversion, which may then be used to simulate the biomass conversion model and 3D simulation was also conducted for a 500 MWe coal-biomass cofiring boiler. Gasification was obtained at 1000 °C and 1200 °C using CO2 at constant temperature for different biomasses. Compared to the peak exhibited by the random pore model, biomass gasification reaction rates shifted into the later stage of the reaction, thereby yielding irregular reaction rate developments and poor prediction accuracies. With flexibility-enhanced random pore model(FERPM), we observed that correlation factors increased from the previously reported value of 0.7–0.95. In the coal-biomass cofiring boiler, the difference between the Kinetics/Diffusion-limited model and FERPM in biomass combustion aspect was examined, and it was ultimately determined that characteristics of particle reactions through FERPM are valid in 3D analysis. Therefore, this paper proposed a flexibility-enhanced random pore model proven to enhance the prediction accuracy of a simulation.

Ca2Fe2O5-Based WGS Catalysts to Enhance the H2 Yield of Producer Gases

Ca2Fe2O5-based catalysts were synthesized from siderite and calcite precursors, which were processed in the form of pelletized samples and tested as water gas shift catalysts. Catalytic tests were performed in a tubular reactor, at temperatures in the range 400–500 °C and with different H2O:CO ratios, diluted with N2; this demonstrates the positive impact of Ca2Fe2O5 on conversion of CO and H2 yield, relative to corresponding tests without catalyst. The catalytic performance was also remarkably boosted in a microwave-heated reactor, relative to conventional electric heating. Post-mortem analysis of spent catalysts showed significant XRD reflections of spinel phases (Fe3O4 and CaFe2O4), and SiO2 from the siderite precursor. Traces of calcium carbonate were also identified, and FTIR analysis revealed relevant bands ascribed to calcium carbonate and adsorbed CO2. Thermodynamic modelling was performed to assess the redox tolerance of Ca2Fe2O5-based catalysts in conditions expected for gasification of biomass and thermochemical conditions at somewhat lower temperatures (≤500 °C), as a guideline for suitable conditions for water gas shift. This modelling, combined with the results of catalytic tests and post-mortem analysis of spent catalysts, indicated that the O2 and CO2 storage ability of Ca2Fe2O5 contributes to its catalytic activity, suggesting prospects to enhance the H2 content of producer gases by water gas shift.

A novel supercritical carbon dioxide combined cycle fueled by biomass: Thermodynamic assessment

As a carbon-neutral type of renewable energy, biomass is beneficial for reducing carbon emissions in the electricity sector. A biomass gasification process integrated with a combined cycle is proposed here. Wood is chosen as the fuel and air as the gasifying agent. A supercritical carbon dioxide (SCO2) power cycle with recompression is selected for the recovery of waste heat from the combustion chamber. The net power output is considered to be 1 MW for the combined cycle in the investigation of component ratings and biomass feed rate. For a comprehensive thermodynamic analysis of this combined cycle, we examine three key parameters: gas turbine inlet temperature (1200–1400 K), topping cycle pressure ratio (5-10) and CO2 turbine inlet temperature (600–700 K). The maximum energy efficiency is achieved for the system at a specific pressure ratio and CO2 turbine inlet temperature. The energy efficiency rises with gas turbine inlet temperature, which reduces biomass consumption (at a fixed net power output). The CO2 emission rate to the environment is examined for various parameters; it is observed to decrease as biomass consumption decreases and to take on a value of 0.254 kg/s at an optimized state.

Effects of inherent AAEMs on catalytic gasification of biomass with large particle size under oxygen-steam atmosphere

Oxygen-steam gasification of biomass is a promising technology because of its ability to improve syngas quality and reduce energy consumption. In this study, a fixed-bed reactor is employed to assess the effects of inherent alkali and alkaline earth metals (AAEMs) on the catalytic gasification of candlenut wood with large particle size under the oxygen-steam atmosphere. Two grain directions, radial and axial, are considered for candlenut wood. Various characterization techniques, SEM, X-ray CT, BET, and FTIR, are employed to analyze biochar samples. GC-MS and GC are determined to tar and syngas respectively. The results show that char yield from biomass with axial grain is higher. Acid-washing removes alkali metals (K and Na) better from biomass with axial grain than radial grain, and vice versa for alkaline earth metals (Ca and Mg). In terms of the gasified chars derived from acid-washed biomass, AAEMs content gradually decreases along the end surface and radial direction, which could also be observed from the 3D reconstruction of X-ray CT images. In all samples, micropores (0–10 µm) dominate and are distributed along the grain direction. In general, pores of 20–30 µm and above 30 µm comprise a minor proportion. Inherent AAEMs facilitate an augmentation in char yield as well as BET and total pore volume of gasified char. AAEMs and grain direction have a slight effect on functional groups of gasified chars. Certain organic matter species and content in tar are remarkably affected by the grain direction, since the discrepancies of pore structure and specific surface area. Acid-washing pretreatment augments the content and organic species of M2-M4 compounds (containing 2–4 benzene rings) in the tar. K and Na significantly boost the char steam gasification, water-gas shift, and steam-tars reforming reactions. A decrement in concentrations of H2 (14.49% and 13.35%), CH4 (0.51% and 0.89%), and CO2 (2.32% and 1.37%) in syngas derived from acid-washed samples are acquired, respectively, compared to that of biomass samples with radial and axial grains. However, a reduction of 4.09% and 1.53% in syngas calorific value could be obtained. The CnHx volume fraction is significantly affected by grain direction and AAEMs, with axial grain yielding a higher volume fraction of C2H4 (49.07%), C2H2 (71.29%), and C3H8 (127.36%) from acid-washed sample than that of radial grain.

Energy, exergy and exergo-economic analysis of a novel SOFC based CHP system integrated with organic Rankine cycle and biomass co-gasification

This paper proposes a novel SOFC based cogeneration system, consisting of biomass co-gasification, SOFC power generation and ORC waste heat recovery, to achieve the efficient and clean utilization of poultry litter. Based on the conceptual design, the energy, exergy and exergo-economic analysis are conducted, including sensitivity analysis, uncertainty analysis and multi-objective optimization. Results show that when using straw as the co-gasification biomass with poultry litter, the highest energy utilization efficiency of 44.70 % is obtained with the electricity and heat production of 162.02 kW and 52.41 kW, respectively. The biomass gasifier and the SOFC stack have the highest exergy destruction, accounting for 24.43 % and 19.99 % of the total. Sensitivity analysis presents complex results concerning mass fraction of poultry litter, water content, equivalent air ratio and water-carbon ratio, etc. The optimal solution for the current optimization problem is obtained. When poultry litter mass fraction is fixed at 25 %, TSOFC = 852 °C and uf = 0.73, the exergy efficiency is obtained as 41.95 % and the overall exergy cost per unit is obtained as 42.35 $/GJ. This paper investigates a novel cogeneration system relying on the biomass co-gasification of poultry litter, providing a new solution for poultry litter treatment and sustainable development of agriculture, forestry and husbandry.