Records with Keyword: Syngas
Showing records 1 to 25 of 76. [First] Page: 1 2 3 4 Last
The design and operational space of syngas production via integrated direct air capture with gaseous CO2 electrolysis
Hussain M. Almajed, Omar J. Guerra, Ana Somoza-Tornos, Wilson A. Smith, Bri-Mathias Hodge
April 4, 2024 (v1)
Keywords: Carbon Dioxide Capture, CO2 electrolysis, Direct air capture, Modelling, Syngas, Technoeconomic Analysis
The overarching goal of limiting the increase in global temperature to ≤ 2.0˚ C likely requires both decarbonization and defossilization efforts. Direct air capture (DAC) and CO2 electrolysis stand out as promising technologies for capturing and utilizing atmospheric CO2. In this effort, we explore the details of designing and operating an integrated DAC-electrolysis process by examining some key parameters for economic feasibility. We evaluate the gross profit and net income to find the most appropriate capacity factor, average electricity price, syngas sale price, and CO2 taxes. Additionally, we study an optimistic scenario of CO2 electrolysis and perform a sensitivity analysis of the CO2 capture price to elucidate the impact of design decisions on the economic feasibility. Our findings underscore the necessity of design improvements of the CO2 electrolysis and DAC processes to achieve reasonable capacity factor and average electricity price limits. Notably, CO2 taxes and tax credits... [more]
A New Approach to the Preparation of Stable Oxide-Composite Cobalt−Samarium Catalysts for the Production of Hydrogen by Dry Reforming of Methane
A. G. Dedov, A. S. Loktev, V. A. Arkhipova, M. A. Bykov, A. A. Sadovnikov, K. A. Cherednichenko, G. A. Shandryuk
September 20, 2023 (v1)
Keywords: cobalt–samarium oxide catalysts, dry reforming of methane, heterogeneous catalysis, Hydrogen, Syngas
A new approach to preparing a series of Co/Sm2O3 catalysts for hydrogen production by the dry reforming of methane has been developed. The catalyst precursors were synthesized with a simple method, including the evaporation of aqueous solutions of cobalt and samarium nitrates, followed by a short-term calcination of the resulting material. The as-prepared and spent catalysts were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, temperature-programmed reduction, and thermogravimetric analysis. The content of cobalt in the synthesized materials affects their phase composition and carbonization resistance in the dry reforming of the methane reaction. It has been shown that preheating in N2 atmosphere produces catalysts that provide a stable yield of hydrogen and CO of 94−98% for at least 50 h at 900 °C. These yields are among the highest currently available for the dry reforming of methane catalysts made from Co-Sm complex oxides. It h... [more]
High-Quality Syngas Production by Chemical Looping Gasification of Bituminite Based on NiFe2O4 Oxygen Carrier
Ming Yang, Da Song, Yang Li, Jinzeng Cao, Guoqiang Wei, Fang He
April 28, 2023 (v1)
Keywords: alkali metal, bituminite, chemical looping gasification (CLG), NiFe2O4, oxygen carrier, Syngas
Chemical looping gasification (CLG) is an effective coal utilization technology. In this work, the CLG of bituminite was investigated through fixed-bed batch experiments using NiFe2O4 oxygen carrier (OC) to achieve high-quality syngas. The changes in the phase of the oxygen carrier during the chemical looping reaction and the reaction mechanism were explored. The results show that elevated temperature and adding a fraction of steam facilitate the gasification reaction. Adding an appropriate amount of ZrO2 into the NiFe2O4 and modification with alkali metal can enhance the performance of the oxygen carrier. A carbon conversion of 95% and a syngas (CO and H2) selectivity of 86% were obtained under the optimized reaction conditions of 950 °C, an oxygen-carrier-to-bituminite (O/B) ratio of 7:3, a NiFe2O4/ZrO2 ratio of 7:3, and a steam rate of 0.08 mL/min. Modification of the NiFe2O4 by doping alkali metal can significantly facilitate the CLG process. Alkali lignin ash has a more pronounced... [more]
Combustion Characteristics of Coal-Water Slurry Droplets in High-Temperature Air with the Addition of Syngas
Maxim Belonogov, Vadim Dorokhov, Dmitrii Glushkov, Daria Kuznechenkova, Daniil Romanov
April 28, 2023 (v1)
Subject: Other
Keywords: coal-water slurry, combustion, droplet, high-temperature air, Syngas, waste
An experimental study of the ignition and combustion processes of coal-water slurry (CWS) droplets based on coal enrichment waste in a high-temperature oxidizer at 650−850 °C with a syngas addition was carried out. The fuel slurry was a mixture of finely dispersed solid combustible particles (coal sludge, 10−100 µm in size) and water. The syngas was a product of biomass pyrolysis and two waste-derived fuels in a laboratory gasifier. Composition of the syngas was controlled by a precision analytical gas analyzer. The feasibility of co-firing CWS with syngas was experimentally established. Under such conditions, the CWS droplets ignition process was intensified by 15−40%, compared to fuel combustion without the addition of syngas to the combustion chamber. The greatest positive effect was achieved by adding the gas obtained during the biomass pyrolysis. The ignition delay times of CWS droplets are 5.2−12.5 s versus 6.1−20.4 s (lower by 15−39%) when ignited in a high-temperature medium wi... [more]
Model-Free Control of UCG Based on Continual Optimization of Operating Variables: An Experimental Study
Ján Kačur, Marek Laciak, Milan Durdán, Patrik Flegner
April 24, 2023 (v1)
Keywords: calorific value, control algorithm, operating variables, optimal control, Optimization, Syngas, underground coal gasification (UCG)
The underground coal gasification (UCG) represents an effective coal mining technology, where coal is transformed into syngas underground. Extracted syngas is cleaned and processed for energy production. Various gasification agents can be injected into an underground georeactor, e.g., air, technical oxygen, or water steam, to ensure necessary temperature and produce syngas with the highest possible calorific value. This paper presents an experimental study where dynamic optimization of operating variables maximizes syngas calorific value during gasification. Several experiments performed on an ex situ reactor show that the optimization algorithm increased syngas calorific value. Three operation variables, i.e., airflow, oxygen flow, and syngas exhaust, were continually optimized by an algorithm of gradient method. By optimizing the manipulation variables, the calorific value of the syngas was increased by 5 MJ/m3, both in gasification with air and additional oxygen. Furthermore, a high... [more]
A Phenomenological Model of a Downdraft Biomass Gasifier Flexible to the Feedstock Composition and the Reactor Design
Michela Costa, Maurizio La Villetta, Daniele Piazzullo, Domenico Cirillo
April 21, 2023 (v1)
Keywords: biomass gasification, downdraft, hydro-char, phenomenological model, Syngas
The development of a one-dimensional (1D) phenomenological model for biomass gasification in downdraft reactors is presented in this study; the model was developed with the aim of highlighting the main advantages and limits related to feedstocks that are different from woodchip, such as hydro-char derived from the hydrothermal carbonization of green waste, or a mix of olive pomace and sawdust. An experimental validation of the model is performed. The numerically evaluated temperature evolution along the reactor gasifier is found to be in agreement with locally measured values for all the considered biomasses. The model captures the pressure drop along the reactor axis, despite an underestimation with respect to the performed measurements. The producer gas composition resulting from the numerical model at the exit section is in quite good agreement with gas-chromatograph analyses (12% maximum error for CO and CO2 species), although the model predicts lower methane and hydrogen content i... [more]
Computational Analysis of Premixed Syngas/Air Combustion in Micro-channels: Impacts of Flow Rate and Fuel Composition
Sunita Pokharel, Mohsen Ayoobi, V’yacheslav Akkerman
April 21, 2023 (v1)
Keywords: flame instabilities, micro-combustion, numerical simulations, repetitive extinction and ignition (FREI), Syngas
Due to increasing demand for clean and green energy, a need exists for fuels with low emissions, such as synthetic gas (syngas), which exhibits excellent combustion properties and has demonstrated promise in low-emission energy production, especially at microscales. However, due to complicated flame properties in microscale systems, it is of utmost importance to describe syngas combustion and comprehend its properties with respect to its boundary and inlet conditions, and its geometric characteristics. The present work studied premixed syngas combustion in a two-dimensional channel, with a length of 20 mm and a half-width of 1 mm, using computational approaches. Specifically, a fixed temperature gradient was imposed at the upper wall, from 300 K at the inlet to 1500 K at the outlet, to preheat the mixture, accounting for the conjugate heat transfer through the walls. The detailed chemistry of the ignition process was imitated using the San Diego mechanism involving 46 species and 235 r... [more]
Complementing Syngas with Natural Gas in Spark Ignition Engines for Power Production: Effects on Emissions and Combustion
Carlo Caligiuri, Urban Žvar Baškovič, Massimiliano Renzi, Tine Seljak, Samuel Rodman Oprešnik, Marco Baratieri, Tomaž Katrašnik
April 20, 2023 (v1)
Keywords: combustion, Natural Gas, renewable fuels, spark ignition engines, Syngas
Power generation units based on the bio-syngas system face two main challenges due to (i) the possible temporary shortage of primary sources and (ii) the engine power derating associated with the use of low-energy density fuels in combustion engines. In both cases, an external input fuel is provided. Hence, complementing syngas with traditional fuels, like natural gas, becomes a necessity. In this work, an experimental methodology is proposed, aiming at the quantification of the impact of the use of both natural gas and syngas in spark ignition (SI) engines on performance and emissions. The main research questions focus on investigating brake thermal efficiency (BTE), power derating, and pollutant emission (NOx, CO, THC, CO2) formation, offering quantitative findings that present the basis for engine optimization procedures. Experimental measurements were performed on a Toyota 4Y-E engine (a 4-cylinders, 4-stroke spark ignition engine) at partial load (10 kW) under different syngas ene... [more]
Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production
Arslan Mazhar, Asif Hussain Khoja, Abul Kalam Azad, Faisal Mushtaq, Salman Raza Naqvi, Sehar Shakir, Muhammad Hassan, Rabia Liaquat, Mustafa Anwar
April 20, 2023 (v1)
Keywords: dry reforming of methane, hydrothermal process, MgAl2O4, Syngas, TiO2
Co/TiO2−MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2−MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2−MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2−MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2−MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieve... [more]
Ag Nanowires/C as a Selective and Efficient Catalyst for CO2 Electroreduction
Li Zeng, Jun Shi, Hanxin Chen, Chong Lin
April 20, 2023 (v1)
Subject: Materials
Keywords: Ag nanowires, carbon support, CO2 reduction, electrocatalysis, Syngas
The development of a selective and efficient catalyst for CO2 electroreduction is a great challenge in CO2 storage and conversion research. Silver metal is an attractive alternative due to its enhanced catalytic performance of CO2 electroreduction to CO. Here, we prepared Ag nanowires anchored on carbon support as an excellent electrocatalyst with remarkably high selectivity for the CO2 reduction to CO. The CO Faradic efficiency was approximately 100%. The enhanced catalytic performances may be ascribed to dense active sites exposed on the Ag nanowires’ high specific surface area, by the uniform dispersion of Ag nanowires on the carbon support. Our research demonstrates that Ag nanowires supported on carbon have potential as promising catalysts in CO2 electroreduction.
Maximizing Energy Recovery from Beauty Leaf Tree (Calophyllum inophyllum L.) Oil Seed Press Cake via Pyrolysis
Nanjappa Ashwath, Hyungseok Nam, Sergio Capareda
April 19, 2023 (v1)
Keywords: batch pyrolysis, Beauty Leaf Tree (BLT), bio-liquor, bio-oil, biochar, Calophyllum inophyllum, oil seed press cake, Optimization, response surface methodology (RSM), Syngas
This study optimizes pyrolysis conditions that will maximize energy recovery from the Beauty Leaf Tree (BLT; Calophyllum inophyllum L.) oil seed press cake. Response surface methodology (RSM) was used to determine the behavior of pyrolysis coproducts (solid, liquid and gas) at various temperatures and residence times. One significant discovery was that 61.7% of the energy (of the whole BLT oil seed) was still retained in the BLT oil seed cake after oil extraction. Controlled pyrolysis produced various proportions of biochar, bio-oil and syngas coproducts. Predictive models were developed to estimate both the mass and energy yields of the coproducts. In all experimental runs, the biochar component had the highest mass yield and energy content. Biochar mass yields were high at the lowest operating temperature used, but the energy yields based on a high heating value (HHV) of products were optimal at higher operating temperatures. From the RSM models, energy from the biochar is optimized... [more]
The Underground Coal Gasification Process in Laboratory Conditions: An Experimental Study
Marek Laciak, Milan Durdán, Ján Kačur, Patrik Flegner
April 17, 2023 (v1)
Subject: Materials
Keywords: efficiency, ex-situ reactor, experiment, material balance, Syngas, underground coal gasification
The underground coal gasification (UCG) process represents a modern and effective coal mining technology that enables coal energy extraction through thermic decomposition. The coal is transformed into syngas by oxidizers (e.g., air, technical oxygen, or water steam) and is injected into a georeactor. The produced syngas is exhausted on the surface, where it is transformed into the desired form of energy. This paper presents an experimental study of two experiments performed in ex-situ reactors. The paper describes the equipment for the UCG process, the physical models of the coal seam, and the analysis of coal. The obtained results from the experiments are presented as the behavior of the temperatures in the coal during the experiment, the syngas composition, and its calorific value. The material balance and effective gasification time of the UCG process were also identified for the individual experiments. The aim was to evaluate the impact of the coal seam model on the gasification pr... [more]
CFD Simulations of Allothermal Steam Gasification Process for Hydrogen Production
Tomasz Janoszek, Wojciech Masny
April 14, 2023 (v1)
Keywords: CFD method, coal gasification, Energy, numerical modeling, Syngas
The article presents an experimental laboratory setup used for the empirical determination of the gasification of coal samples in the form of solid rock, cut out in the form of a cylinder. An experimental laboratory set enabled a series of experiments carried out at 700 °C with steam as the gasification agent. The samples were prepared from the coal seam, the use of which can be planned in future underground and ground gasification experiments. The result of the conducted coal gasification process, using steam as the gasification agent, was the syngas, including hydrogen (H2) with a concentration between 46% and 58%, carbon dioxide (CO2) with a concentration between 13% and 17%, carbon monoxide (CO) with a concentration between 7% and 11.5%, and methane(CH4) with a concentration between 9.6% and 20.1%.The results from the ex-situ experiments were compared with the results of numerical simulations using computational fluid dynamics (CFD) methods. A three-dimensional numerical model for... [more]
Solar Thermochemical Green Fuels Production: A Review of Biomass Pyro-Gasification, Solar Reactor Concepts and Modelling Methods
Stéphane Abanades, Sylvain Rodat, Houssame Boujjat
April 14, 2023 (v1)
Keywords: Biomass, solar pyrolysis–gasification, solar reactor, spouted bed, Syngas, Synthetic Fuels, waste conversion
This paper addresses the solar thermochemical conversion of biomass or waste feedstocks based on pyro-gasification for the clean production of high-value and energy-intensive fuels. The utilization of solar energy for supplying the required process heat is attractive to lower the dependence of gasification processes on conventional energy resources and to reduce emissions of CO2 and other pollutants for the production of high-value chemical synthetic fuels (syngas). Using concentrated solar energy to drive the endothermal reactions further allows producing more syngas with a higher gas quality, since it has not been contaminated by combustion products, while saving biomass resources. The solar-driven process is thus a sustainable and promising alternative route, enabling syngas yield enhancement and CO2 mitigation, thereby potentially outperforming the performance of conventional processes for syngas production. This review presents relevant research studies in the field and provides t... [more]
Size-Segregated Particulate Matter from Gasification of Bulgarian Agro-Forest Biomass Residue
Ricardo Ferreira, Tsvetelina Petrova, Ana F. Ferreira, Mário Costa, Iliyana Inaydenova, Stela Atanasova-Vladimirova, Bogdan Ranguelov
April 13, 2023 (v1)
Keywords: gasification, particulate matter, rapeseed, softwood, sunflower husk, Syngas
The main purpose of the present work was to evaluate the efficiency of the gasification process of three different types of agro-forest biomass residue (rapeseed, softwood, and sunflower husks) along with the characterization of size-segregated particulates’ emissions. The experiments were carried out in a drop tube furnace (DTF), using two different gasifying agents (O2/N2 and O2/N2/CO2) at atmospheric pressure and a constant temperature of 1000 °C. In focus was the effect of biomass and the gasifying agent on syngas composition (CO, H2, CH4, and CO2), cold gas and carbon conversion efficiency, and on the emissions of by-products, such as particulate matter (PM), known for having negative environmental and health impacts. The collected particulates were characterized by SEM/EDS and XPS analysis. The results reveal that: (i) the introduction of CO2 increased the production of CO and CH4 and syngas’ lower heating value (LHV), thus leading to higher cold gas and carbon conversion efficie... [more]
Solar-hybrid Thermochemical Gasification of Wood Particles and Solid Recovered Fuel in a Continuously-Fed Prototype Reactor
Houssame Boujjat, Sylvain Rodat, Stéphane Abanades
April 3, 2023 (v1)
Keywords: beechwood, Biomass, hybridization, solar gasification, solid recovered fuels, Syngas, waste conversion
Solar thermochemical gasification is a promising solution for the clean production of low-emission synthetic fuels. It offers the possibility to upgrade various biomasses and waste feedstocks and further provides an efficient way to sustainably store solar energy into high-value and energy-intensive chemical fuels. In this work, a novel continuously-fed solar steam gasifier was studied using beechwood and solid recovered fuels (SRF) particles. Solar-only and hybrid solar/autothermal gasification experiments were performed at high temperatures to assess the performance of the reactor and its flexibility in converting various types of feedstocks. The hybrid operation was considered to increase the solar reactor temperature when the solar power input is not sufficient thanks to partial feedstock oxy-combustion. The hybrid solar process is thus a sustainable alternative option outperforming the conventional gasification processes for syngas production. Wood and waste particles solar conver... [more]
Gasification of Cup Plant (Silphium perfoliatum L.) Biomass−Energy Recovery and Environmental Impacts
Adam Koniuszy, Małgorzata Hawrot-Paw, Cezary Podsiadło, Paweł Sędłak, Ewa Możdżer
April 3, 2023 (v1)
Subject: Environment
Keywords: biochar, bioenergy, cup plant, ecotoxicity, gasification of biomass, Syngas, tar
Biomass from cup plant (Silphium perfoliatum L.) is considered a renewable energy source that can be converted into alternative fuel. Calorific syngas, a promising type of advanced fuel, can be produced through thermochemical biomass gasification. In this study, the suitability of cup plant biomass for gasification was assessed, including the process energy balance and environmental impacts of waste from syngas purification. Silphium perfoliatum L. was cultivated as a gasification feedstock in different conditions (irrigation, fertilization). The experiments were performed in a membrane gasifier. All obtained energy parameters were compared to the biomass yield per hectare. The toxic effects of liquid waste were assessed using tests analyzing germination/seed root elongation of Sinapsis alba. Leachates collected from condensation tanks of a gas generator were introduced to soil at the following doses: 100, 1000 and 10,000 mg kg−1 DM of soil. The usefulness of Silphium perfoliatum L. fo... [more]
Comparison between Hydrogen and Syngas Fuels in an Integrated Micro Gas Turbine/Solar Field with Storage
Maria Cristina Cameretti, Alessandro Cappiello, Roberta De Robbio, Raffaele Tuccillo
April 3, 2023 (v1)
Keywords: agricultural product, cogeneration, exergetic analysis, Hydrogen, micro gas turbine, Syngas
In recent years, the use of alternative fuels in thermal engine power plants has gained more and more attention, becoming of paramount importance to overcome the use of fuels from fossil sources and to reduce polluting emissions. The present work deals with the analysis of the response to two different gas fuels—i.e., hydrogen and a syngas from agriculture product—of a 30 kW micro gas turbine integrated with a solar field. The solar field included a thermal storage system to partially cover loading requests during night hours, reducing fuel demand. Additionally, a Heat Recovery Unit was included in the plant considered and the whole plant was simulated by Thermoflex® code. Thermodynamics analysis was performed on hour-to-hour basis, for a given day as well as for 12 months; subsequently, an evaluation of cogeneration efficiency as well as energy saving was made. The results are compared against plant performance achieved with conventional natural gas fueling. After analyzing the perfor... [more]
Gasification of Spruce Wood Chips in a 1.5 MWth Fluidised Bed Reactor
Fabio Montagnaro, Lucio Zaccariello
March 28, 2023 (v1)
Keywords: Biomass, equivalence ratio, fluidised bed, gasification, Hydrogen, spruce wood chips, Syngas, tar
Production of syngas from the gasification of a biomass is attracting attention with an eye to the concepts of circularity, sustainability, and recent needs, triggered by socio-political events, to increase the level of self-sufficiency of energy sources for a given community. This manuscript reports on the gasification of spruce wood chips in a demonstration fluidised bed gasifier (1.5 MWth, height of 5.40 m, internal diameter of 1.2 m), with 0.2−0.4 mm olivine inventory (1000 kg). Gasification was carried out in air, at four different values of equivalence ratio (from 27% to 36%). The bed was fluidised at about 0.6 m/s, and the bed temperature resulted in the range of about 960−1030 °C as a function of the different tests. A mass flow rate of biomass in the range of about 360−480 kg/h (as a function of the different tests) was fed to the fluidised bed gasifier. Syngas lower heating value, specific mass and energetic yield, and chemical composition, were reported along with data on th... [more]
Oxygen-Blown Gasification of Pulp Mill Bark Residues for Synthetic Fuel Production
Fredrik Weiland, Sandra Lundström, Yngve Ögren
March 28, 2023 (v1)
Keywords: bark residues, gasification, online TDLAS process measurement, oxygen blown, pulp mill, Syngas
Synthetic fuel production via gasification of residual biomass streams from the pulp and paper industry can be an opportunity for the mills to enable improved resource utilization and at the same time reduce the production of excess heat. This paper summarizes initial oxygen-blown gasification experiments with two bark residues from a European pulp and paper mill, i.e., a softwood bark and a hardwood bark. The gasification process was characterized by measuring syngas yields and process efficiency to find optimum operating conditions. In addition, impurities in the syngas and ash behavior were characterized. Maximum yields of CO and H2 were obtained from softwood bark and amounted to approximately 29 and 15 mol/kg fuel, respectively. Optimum cold gas efficiency was achieved at an oxygen stoichiometric ratio of λ = 0.40 and was approximately 76% and 70% for softwood bark and hardwood bark, respectively. Increased λ had a reducing effect on pollutants in the syngas, e.g., higher hydrocar... [more]
Techno-Economic Assessment of Solar-Driven Steam Gasification of Biomass for Large-Scale Hydrogen Production
Houssame Boujjat, Sylvain Rodat, Stéphane Abanades
March 28, 2023 (v1)
Keywords: biomass/waste conversion, economics, hybridization, Hydrogen, solar gasification, Syngas
Solar biomass gasification is an attractive pathway to promote biomass valorization while chemically storing intermittent solar energy into solar fuels. The economic feasibility of a solar gasification process at a large scale for centralized H2 production was assessed, based on the discounted cash-flow rate of return method to calculate the minimum H2 production cost. H2 production costs from solar-only, hybrid and conventional autothermal biomass gasification were evaluated under various economic scenarios. Considering a biomass reference cost of 0.1 €/kg, and a land cost of 12.9 €/m2, H2 minimum price was estimated at 2.99 €/kgH2 and 2.48 €/kgH2 for the allothermal and hybrid processes, respectively, against 2.25 €/kgH2 in the conventional process. A sensitivity study showed that a 50% reduction in the heliostats and solar tower costs, combined with a lower land cost of below 0.5 €/m2, allowed reaching an area of competitiveness where the three processes meet. Furthermore, an increa... [more]
The “INNOVARE” Project: Innovative Plants for Distributed Poly-Generation by Residual Biomass
M. Costa, A. Buono, C. Caputo, A. Carotenuto, D. Cirillo, M. A. Costagliola, G. Di Blasio, M. La Villetta, A. Macaluso, G. Martoriello, N. Massarotti, A. Mauro, M. Migliaccio, V. Mulone, F. Murena, D. Piazzullo, M. V. Prati, V. Rocco, A. Stasi, L. Vanoli, A. Cinocca, D. Di Battista, A. De Vita
March 28, 2023 (v1)
Keywords: Biomass, combined heat and power generation (CHP), Syngas
The valorization of residual biomass plays today a decisive role in the concept of “circular economy”, according to which each waste material must be reused to its maximum extent. The collection and energy valorization at the local level of biomass from forest management practices and wildfire prevention cutting can be settled in protected areas to contribute to local decarbonization, by removing power generation from fossil fuels. Despite the evident advantages of bioenergy systems, several problems still hinder their diffusion, such as the need to assure their reliability by extending the operating range with materials of different origin. The Italian project “INNOVARE—Innovative plants for distributed poly-generation by residual biomass”, funded by the Italian Ministry of Economic Development (MISE), has the main scope of improving micro-cogeneration technologies fueled by biomass. A micro-combined heat and power (mCHP) unit was chosen as a case study to discuss pros and cons of bio... [more]
Experimental and Model Study on Raw Biomass Gasification Syngas Conditioning in a Molten NaOH-Na2CO3 Mixture
Xiaobo Wang, Anqi Liu, Zengli Zhao, Haibin Li
March 27, 2023 (v1)
Keywords: Biomass, conditioning, model, molten salts, Syngas
Raw syngas conditioning using molten salts was carried out in a fixed-bed reactor. The effects of the reaction conditions, including temperature, gas velocity, bubble diameter, molten salt static liquid heights, and inlet gas composition, on the composition of the syngas product and the properties of the spent molten salts were investigated. The molten salt absorbed CO2 in all of the experiments (at temperatures from 350 °C to 500 °C) and decreased its concentration down to 1%. The H2/CO increased from 0.94 to a maximum of 11.0, which may meet most of the synthetic process’ requirements. The temperature, gas velocity, and molten salt static liquid heights had significant effects on the H2 and CO concentrations in the gas product. Molten salt raw syngas conditioning can be a suitable follow-up procedure for gasification and pyrolysis.
Guest Partitioning and High CO2 Selectivity in Hydroquinone Clathrates Formed from Ternary (CO + CO2 + H2) Gas Mixtures
Sang Jun Yoon, Dongwon Lee, Ji-Ho Yoon, Jong-Won Lee
March 27, 2023 (v1)
Keywords: Carbon Dioxide, carbon monoxide, clathrate compounds, hydroquinone, Syngas
Clathrate formation and guest behaviors in hydroquinone (HQ) clathrates were investigated for the first time using ternary (CO + CO2 + H2) gas mixtures. Two gas compositions (low and high CO2 concentrations) were used to simulate synthesis gases generated from various sources. After reaction at 2.0, 4.0, and 6.0 MPa, the conversion yield of pure HQ to the clathrate form reached >90% if the CO2 partial pressure was 0.7 MPa or higher. In addition, CO2 was the most abundant occupant, whereas CO was only detectable at higher CO concentrations and experimental pressures. The separation efficiency values expressed as molar ratios of CO2 to CO in the solid clathrate form were found to be 12.7 and 23.9 MPa at 4.0 and 6.0 MPa, respectively. The experimental and the calculated results in this study provide information useful for the design of a clathrate-based separation process for synthesis gases from various sources (i.e., synthesis gases with various compositions).
Heterogeneous Catalysis in (Bio)Ethanol Conversion to Chemicals and Fuels: Thermodynamics, Catalysis, Reaction Paths, Mechanisms and Product Selectivities
Gabriella Garbarino, Giovanni Pampararo, Thanh Khoa Phung, Paola Riani, Guido Busca
March 27, 2023 (v1)
Subject: Materials
Keywords: acetaldehyde, acid catalysis, bioethanol conversion, cobalt catalysts, copper catalysts, Ethylene, nickel catalysts, Syngas
In gas/solid conditions, different chemicals, such as diethylether, ethylene, butadiene, higher hydrocarbons, acetaldehyde, acetone and hydrogen, can be produced from ethanol with heterogeneous catalytic processes. The focus of this paper is the interplay of different reaction paths, which depend on thermodynamic factors as well as on kinetic factors, thus mainly from catalyst functionalities and reaction temperatures. Strategies for selectivity improvements in heterogeneously catalyzed processes converting (bio)ethanol into renewable chemicals and biofuels are also considered.
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