| 1. |
- Aziz, M., et al.
(författare)
-
Production of hydrogen from algae : Integrated gasification and chemical looping
- 2017
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Ingår i: Proceedings of the 9th International Conference on Applied Energy. - : Elsevier. ; , s. 210-215
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Konferensbidrag (refereegranskat)abstract
- Due to their high potential and beneficial characteristics, algae is considered as very promising energy source in future. In this study, an integrated conversion system of algae to hydrogen is proposed with the objective of high total energy conversion efficiency. The proposed system mainly covers algal drying, gasification, and chemical looping. To facilitate optimum heat circulation throughout the proposed system, enhanced process integration is adopted. It combines exergy recovery and process integration technologies in order to achieve a wasted energy, hence the total energy efficiency can be improved significantly. In the proposed system, to convert algae to hydrogen, steam gasification and syngas chemical looping are integrated as the main conversion. Iron oxide is employed as the oxygen carrier, and is circulated among the reactors in the chemical looping module. Process modeling and calculation is performed using ASPEN Plus, and the total energy efficiency, including hydrogen production and power generation, is evaluated. Several operating parameters including target moisture content in drying, steam-to-biomass ratio in gasification, and chemical looping pressure, are observed. From the results, it is shown that the proposed system is potential to convert algae to hydrogen with high total energy efficiency, which is higher than 70%. Both target moisture content and steam-to-biomass ratio influence strongly the total energy efficiency. On the other hand, chemical looping pressure show insignificant effect to total energy efficiency.
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| 2. |
- Bolívar Caballero, José Juan, et al.
(författare)
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Advanced application of a geometry-enhanced 3D-printed catalytic reformer for syngas production
- 2023
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 287
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Tidskriftsartikel (refereegranskat)abstract
- Catalyst research on reforming processes for syngas production has mainly focused on the active metals and support materials, while the effect of the catalyst's geometry on the reforming reactions has been poorly studied. The application of 3D-printed materials with enhanced geometries has recently started to be studied in heterogeneous catalysis and is of interest to be implemented for reforming biomass and plastic waste to produce H2-rich syngas. In this study, a geometry-enhanced 3D-printed Ni/Al2O3/FeCrAl-based monolithic catalyst with a periodic open cellular structure (POCS) was designed and fabricated. The catalyst was used for batch steam reforming biomass pyrolysis volatiles for syngas production at different parameters (temperature and steam-to-carbon ratio). The results showed complete reforming of pyrolysis volatiles in all experimental cases, a high H2 yield of ≈ 7.6 wt% of biomass was obtained at the optimized steam-to-carbon ratio of 8 and a reforming temperature of 800 °C, which is a higher yield compared to other batch reforming tests reported in the literature. Moreover, CFD simulation results in COMSOL Multiphysics demonstrated that the POCS configuration improves the reforming of pyrolysis volatiles for tar/bio-oil reforming and H2 production thanks to enhanced mass and heat transfer properties compared to the regular monolithic single-channel configuration.
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| 3. |
- Bolívar Caballero, José Juan, et al.
(författare)
-
Reforming processes for syngas production : A mini-review on the current status, challenges, and prospects for biomass conversion to fuels
- 2022
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Ingår i: Applications in Energy and Combustion Science. - : Elsevier BV. - 2666-352X. ; 10, s. 100064-
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Tidskriftsartikel (refereegranskat)abstract
- Dedicated bioenergy combined with carbon capture and storage are important elements for the mitigation scenarios to limit the global temperature rise within 1.5 °C. Thus, the productions of carbon-negative fuels and chemicals from biomass is a key for accelerating global decarbonisation. The conversion of biomass into syngas has a crucial role in the biomass-based decarbonisation routes. Syngas is an intermediate product for a variety of chemical syntheses to produce hydrogen, methanol, dimethyl ether, jet fuels, alkenes, etc. The use of biomass-derived syngas has also been seen as promising for the productions of carbon-negative metal products. This paper reviews several possible technologies for the production of syngas from biomass, especially related to the technological options and challenges of reforming processes. The scope of the review includes partial oxidation (POX), autothermal reforming (ATR), catalytic partial oxidation (CPO), catalytic steam reforming (CSR) and membrane reforming (MR). Special attention is given to the progress of CSR for biomass-derived vapours as it has gained significant interest in recent years. Heat demand and efficiency together with properties of the reformer catalyst were reviewed more deeply, in order to understand and propose solutions to the problems that arise by the reforming of biomass-derived vapours and that need to be addressed in order to implement the technology on a big scale.
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| 4. |
- Budiman, B. A., et al.
(författare)
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Experimental verification of interfacial strength effect on the mechanical properties of carbon fiber-epoxy composite
- 2017
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Ingår i: International Journal on Advanced Science, Engineering and Information Technology. - : Insight Society. - 2088-5334 .- 2460-6952. ; 7:6, s. 2226-2231
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Tidskriftsartikel (refereegranskat)abstract
- The effects of carbon fiber-epoxy interfacial strength on the mechanical properties of the corresponding fiber-matrix composites are experimentally demonstrated in this work. Two composites containing different carbon fibers were tested: as-received fibers and fibers soaked in acetone to remove adhesive on their surfaces. The fiber surfaces were first characterized by scanning electron microscopy and time-of-flight secondary-ion mass spectrometry to verify removal of the adhesive. Further, single-fiber fragmentation tests were conducted to evaluate the fiber strength and the interfacial strength. The mechanical properties of the composites were evaluated via tensile testing under longitudinal and transverse loadings. The results show that interfacial strength does not decrease the mechanical properties of the composites under longitudinal loading. In contrast, under transverse loading, the interfacial strength significantly decreases the mechanical properties, specifically the ultimate tensile strength and toughness of the composites.
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| 5. |
- Gomez-Rueda, Yamid, et al.
(författare)
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Seashell waste-derived materials for secondary catalytic tar reduction in municipal solid waste gasification
- 2020
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 143
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Tidskriftsartikel (refereegranskat)abstract
- Catalytic tar removal from producer gas is critical for the economic feasibility of Municipal Solid Waste (MSW) gasification in the waste-to-energy(WtE) approach. Nickeland noble-metal catalysts have the highest tar cracking activities, but they increase costs, use scarce materials, and generate dangerous byproducts. To overcome these drawbacks, naturally occurring materials should be used for tar cracking. In this paper, two nanomaterials, synthesized from oyster and mussel waste shells respectively, are used to clean syngas from MSW in a secondary tar cracking unit. We observed that they reform class 1 tar (heavy tars that condense at high temperatures at very low concentrations) into class 3 tar (light hydrocarbons that are not important in condensation) and benzene. Although both catalysts' composition and textural properties were identical, crystallite size and especially specific surface area variation was enough to generate a change in product selectivity. A larger crystallite size and SSA shows a soot yield reduction of 95% with respect to the non-catalytic case, simultaneously increasing the H-2/CO at 1000 degrees C.
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| 6. |
- Gomez-Rueda, Yamid, et al.
(författare)
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Thermal tar cracking enhanced by cold plasma - A study of naphthalene as tar surrogate
- 2020
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Ingår i: Energy Conversion and Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0196-8904 .- 1879-2227. ; 208
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Tidskriftsartikel (refereegranskat)abstract
- Gasification has been proposed as a good solution for recovering energy from waste and biomass in the form of syngas. However, the presence of tar limits syngas applications. Tar model molecules have been removed by cold plasmas up to 400 degrees C, but to avoid syngas cooling tar removal above 600 degrees C is required. To investigate tar removal by cold plasma at higher temperatures, two sets of experiments were done, one to identify tar composition from MSW gasification, and a second one to crack in a nanosecond-pulsed corona plasma at high temperatures the most refractory tar compound found, naphthalene. In this paper, we report the first results of cold plasma for tar cracking at temperatures up to 1100 degrees C, revealing that this tandem can remove naphthalene completely at 800 degrees C, compared to the 1000 degrees C needed in case of thermal cracking alone. The synergy between plasma and thermal cracking is driven by higher energy densities when temperatures increase. However, this synergy stops when thermal cracking reactions predominate.
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| 7. |
- Jagodzińska, Katarzyna, 1990-, et al.
(författare)
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Pyrolysis of excavated waste from landfill mining: Characterisation of the process products
- 2021
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Ingår i: Journal of Cleaner Production. - The Netherlands : Elsevier BV. - 0959-6526 .- 1879-1786. ; 279
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Tidskriftsartikel (refereegranskat)abstract
- The current transition to a circular economy model laid the foundations for the development of the Enhanced Landfill Mining concept. Hitherto, a few studies have been performed on the thermochemical valorisation of excavated waste, of which a majority concern incineration or gasification. Nonetheless, no previous studies on excavated waste pyrolysis, including the characterisation of the process products, have been identified. Ergo, this study aims at filling this knowledge gap. The pyrolysis of refuse-derived fuel formed from excavated waste was performed in a lab-scale reactor in the temperature range of 400–700 °C. The non-condensable products (non-condensables) were analysed using Micro GC, whereas the condensable products (condensables) were characterised using GC/MS. Additionally, the distribution of C, H, N, S, O, and Cl among the process products was analysed. The high content of C2–C3 hydrocarbons was detected in non-condensables, whereas the abundance of polycyclic aromatic hydrocarbons (PAHs) was detected among condensable products. However, due to feedstock complex thermal decomposition pattern, no overall tendency, covering the process product properties in relation to the process temperature, can be determined. These fluctuations of composition, therefore, have to be taken into account in the planning of the future utilisation of the excavated waste pyrolysis products. Moreover, two possible risks, connected with the further process products utilisation, were identified – namely, chlorine forming primarily organic compounds and sulphur forming mostly gaseous compounds (H2S).
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| 8. |
- Jin, Yanghao, et al.
(författare)
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A novel three-stage ex-situ catalytic pyrolysis process for improved bio-oil yield and quality from lignocellulosic biomass
- 2024
-
Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 295
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Tidskriftsartikel (refereegranskat)abstract
- This study aims to improve the quality and yield of bio-oil produced from ex-situ catalytic pyrolysis of lignocellulosic biomass (sawdust) using a combination of stage catalysts with Al-MCM-41, HZSM-5, and ZrO2. The research employed various methods, including thermogravimetric analysis (TGA), differential scanning calorimetry, bench-scale experiments, and process simulations to analyze the kinetics, thermodynamics, products, and energy flows of the catalytic upgrading process. The introduction of ZrO2 enhances the yield of monoaromatic hydrocarbons (MAHs) in heavy organics. Compared with the dual-catalyst case, the MAHs yield escalates by approximately 344% at a catalyst ratio of 1:3:0.25. Additionally, GC-MS data indicate that the incorporation of ZrO2 promotes the deoxygenation reaction of the guaiacol compound and the oligomerization reactions of PAHs. The integration of ZrO2 as the third catalyst enhances the yield of heavy organics significantly, achieving 16.85% at a catalyst ratio of 1:3:1, which increases by nearly 35.6% compared to the dual-catalyst case. Also, the addition of ZrO2 as the third catalyst enhanced the energy distribution in heavy organics. These findings suggest that the combination of these catalysts improves the fuel properties and yields of the bio-oil.
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| 9. |
- Nurdiawati, A., et al.
(författare)
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Dual-stage chemical looping of microalgae for methanol production with negative-carbon emission
- 2019
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Ingår i: Innovative Solutions for Energy Transitions. - : Elsevier. ; , s. 842-847
-
Konferensbidrag (refereegranskat)abstract
- As the world is transitioning towards a low-carbon economy, it is becoming important to develop ways to reduce carbon dioxide (CO2) emissions. Chemical looping, a low carbon technology for the industry, is considered as a potential breakthrough technology and a viable option for efficient fuel conversion and carbon capture and storage, with the successful completion of pilot plant trials in the USA. The conversion of captured CO2 to methanol can be considered a promising method for significantly reducing CO2 emissions, while the produced methanol can be used as a convenient energy carrier for hydrogen storage. This study focuses on a process of converting microalgae, a potential fuel feedstock, into methanol by utilizing CO2 generated within the process. The specific focus lies on the conversion of the microalgae into methanol through dual-stage chemical looping and efficient process integration with maximum energy recovery. Aspen Plus® was used to simulate the facility producing 42 mt (metric tons) methanol/h using 60.1 mt/h CO2 and 8.2 mt/h H2. The process was divided into four-module operations: drying, chemical looping gasification, syngas chemical looping, and methanol synthesis. The energy efficiency of this process is around 45-51% which is comparative with the concentrated CO2-based methanol and typical biomass-based syngas to methanol processes. Because the separated CO2 obtained via chemical looping is utilized for methanol synthesis, the carbon-negative value is attained.
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| 10. |
- Nurdiawati, A., et al.
(författare)
-
Efficient hydrogen production from algae and its conversion to methylcyclohexane
- 2018
-
Ingår i: Chemical Engineering Transactions. - : AIDIC - associazione italiana di ingegneria chimica. - 1974-9791 .- 2283-9216. ; 70, s. 1507-1512
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Tidskriftsartikel (refereegranskat)abstract
- Herein, the supercritical water gasification (SCWG) of microalgae combined with syngas chemical looping (SCL) for H2 production and storage employing liquid organic H2 carrier (LOHC) system have been proposed and analysed in terms of energy efficiency. Microalgae are converted to syngas in the SCWG module and then introduced into the SCL module to produce high-purity of H2 and a separated CO2 stream. H2 storage is achieved via the hydrogenation reaction using toluene to produce methylcyclohexane (MCH). The heat released from the exothermic hydrogenation reaction is exploited to generate steam for sustaining the SCWG reaction. Simulations were performed using Aspen Plus™ considering the feed concentration and SCWG temperature as the system variables. The simulation results show that the SCWG reaction can be energetically self-sustained using the proposed configuration. Based on the process modelling and calculations, the proposed integrated system exhibited of approximately 13.3 %, 42.5 %, and 55.8 % for power generation, H2 production, and total energy efficiency.
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| 11. |
- Nurdiawati, Anissa, et al.
(författare)
-
Microalgae-based coproduction of ammonia and power employing chemical looping process
- 2019
-
Ingår i: Chemical engineering research & design. - : Elsevier. - 0263-8762 .- 1744-3563. ; 146, s. 311-323
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen (H-2) production and storage technologies are the main challenges in the realization of H-2 utilization in which the goal is to achieve high conversion efficiencies and a high storage density. In this study, microalgae gasification and ammonia (NH3) production are proposed to efficiently convert microalgae to NH3 for efficient H-2 storage. The integrated system comprises drying, gasification, syngas chemical looping (SCL), NH3 synthesis, and power generation. Microalgae are converted to syngas in the gasification module and then introduced into the SCL module to produce high-purity H-2 and a separated carbon dioxide (CO2) stream. SCL is also employed to produce a nitrogen (N-2)-rich stream, which can replace a conventional air separation unit (ASU) system. The three operating parameters that are evaluated in this study include the steam to biomass (S/B) ratio during gasification, reducer operating temperature during chemical looping, and recycle to feed streams ratio. An increase in the S/B ratio has a negative effect on the total energy efficiency because the efficiency decreases owing to the reduced production of H-2 in the oxidizer. To maximize the efficiency of NH3 production, a higher recycle ratio is favorable. The proposed integrated system can obtain high total energy efficiency of up to 64.3%, comprising 63.8% NH3 production efficiency and 0.05% power generation efficiency.
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| 12. |
- Nurdiawati, Anissa, et al.
(författare)
-
Novel configuration of supercritical water gasification and chemical looping for highly-efficient hydrogen production from microalgae
- 2019
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 112, s. 369-381
-
Tidskriftsartikel (refereegranskat)abstract
- This study proposes a novel system to efficiently produce hydrogen from microalgae, based on supercritical water gasification and syngas chemical looping, and its conversion to methylcyclohexane. The process consists of a gasifier, a syngas chemical looping reactor, and a methylcyclohexane synthesis reactor as the main units. Microalgae are converted to syngas in the supercritical water gasification reactor. Thereafter, the produced syngas is introduced into the syngas chemical looping module to produce pure hydrogen and a separated carbon dioxide stream. The hydrogen is then reacted with toluene through the hydrogenation reaction to produce methylcyclohexane as a hydrogen carrier. The heat released from the methylcyclohexane synthesis module and chemical looping combustor is utilized to sustain the thermal balance of the supercritical water gasification unit. The system performance is observed under different feed moisture contents, operating temperatures in the supercritical water gasification unit, and operating pressures in the syngas chemical looping unit. A steady-state process simulation of Aspen Plus software is used for this purpose. The proposed integrated system exhibits of approximately 13.7%, 45.3%, and 59.1% for power generation efficiency, hydrogen production efficiency, and total energy efficiency, which demonstrates an efficient process of hydrogen production. The preliminary economic assessment shows that more than half of the operating cost accounts for microalgae production. This indicates the microalgae feedstock is one of the critical cost drivers in the microalgae-to-hydrogen production system.
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| 13. |
- Nurdiawati, Anissa, et al.
(författare)
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Towards fossil-free steel : Life cycle assessment of biosyngas-based direct reduced iron (DRI) production process
- 2023
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 393
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Tidskriftsartikel (refereegranskat)abstract
- Given the urgent need for transitions towards global net zero emissions, decarbonisation of the iron and steel industry is critical. Deep decarbonising this sector requires a breakaway from current blast furnace-basic oxygen furnace (BF-BOF) technologies that largely depend on fossil resources. Biosyngas is considered to be a promising alternative to fossil energy and reductants used in existing ironmaking due to its renewability, technological maturity and compatibility for use in existing furnaces. The present work assesses the environmental impacts of biosyngas-based direct reduced iron production followed by electric arc furnace (DRI-EAF) routes for crude steel production. Further, the proposed routes are compared with the other steelmaking routes, including BF-BOF, natural gas (NG)-based and hydrogen-based direct reduction routes by performing life cycle assessment (LCA). The results indicate that the global warming potential (GWP) value for the biosyngas-based DRI-EAF system is 75% lower than the existing NG-based DRI-EAF route and 85% lower than the BF-BOF route. Moreover, the proposed system possibly has lower GWP values than the renewable hydrogen-based DRI-EAF route. The pro-posed system has an estimated cradle-to-gate GWP of 251 kg CO2 eq./t crude steel, of which 80% is from up-stream emissions. Combined with CO2 storage, the GWP of the proposed system is a net negative, estimated at-845 kg CO2 eq./t crude steel for the selected system boundary. In addition to GWP, other non-climate impact indicators are also evaluated to identify potential burden shifting. The results highlight the emissions reduction potential of the novel biosyngas DRI production route. Large-scale deployment, however, requires sustainable forest management and adequate CCS infrastructure, along with a strong, long-term policy framework to incentivise the transitions.
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| 14. |
- Salem, A. M., et al.
(författare)
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The evolution and formation of tar species in a downdraft gasifier : Numerical modelling and experimental validation
- 2019
-
Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 130
-
Tidskriftsartikel (refereegranskat)abstract
- Gasification is one of the most important methods for converting biomass to syngas currently used in energy production. However, tar content in syngas limits its direct use and thus requires additional removal techniques. The modelling of tar formation, conversion and destruction along a gasifier could give a wider understanding of the process and subsequently help in tar elimination and reduction. However, tar complexity, which contains hundreds of species, makes the modelling process hard and computationally intensive, because the chemistry of the formation and the combustion of many species have not yet been fully studied. In this work, a detailed kinetic model for the evolution and formation of tar from downdraft gasifiers, for the first-time, was built. The model incorporates four main tar species (benzene, naphthalene, toluene, and phenol) with a total of eighteen different kinetic reactions implemented in the code for every zone. Experimental work was carried out to initially validate the results of the kinetic code and found a good agreement. Further experiments were conducted at three different equivalence ratios (ERs) and at three different temperatures (800, 900, and 1100 °C). Sensitivity analysis was then carried out by the kinetic code to optimise the working parameters of a downdraft gasifier that led to a higher calorific value of syngas. The results reveal that a tar evolution model is more accurate for wood biomass materials and that using ER around 0.3, and moisture content levels lower than 10% lead to the production of higher value syngas with lower tar amounts.
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| 15. |
- Sophonrat, Nanta, et al.
(författare)
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Stepwise pyrolysis of mixed plastics and paper for separation of oxygenated and hydrocarbon condensates
- 2018
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 229, s. 314-325
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Tidskriftsartikel (refereegranskat)abstract
- Mixed plastics and papers are two of the main fractions in municipal solid waste which is a critical environmental issue today. Recovering energy and chemicals from this waste stream by pyrolysis is one of the favorable options to achieve a circular economy. While pyrolysis products from plastics are mainly hydrocarbons, pyrolysis products from paper/biomass are highly oxygenated. The different nature of the two pyrolysis products results in different treatments and applications as well as economic values. Therefore, separation of these two products by multi-step pyrolysis based on their different decomposition temperatures could be beneficial for downstream processes to recover materials, chemicals and/or energy. In this work, stepwise pyrolysis of mixed plastics and paper waste was performed in a batch type fixed bed reactor using two different pyrolysis temperatures. Neat plastic materials (polystyrene, polyethylene) and cellulose mixtures were used as starting materials. Then, the same conditions were applied to a mixed plastics and paper residue stream derived from paper recycling process. The condensable products were analyzed by GC/MS. It was found that pyrolysis temperatures during the first and second step of 350 and 500 °C resulted in a better separation of the oxygenated and hydrocarbon condensates than when a lower pyrolysis temperature (300 °C) was used in the first step. The products from the first step were derived from cellulose with some heavy fraction of styrene oligomers, while the products from the second step were mainly hydrocarbons derived from polystyrene and polyethylene. This thus shows that stepwise pyrolysis can separate the products from these materials, although with some degree of overlapping products. Indications of interaction between PS and cellulose during stepwise pyrolysis were observed including an increase in char yield, a decrease in liquid yield from the first temperature step and changes in liquid composition, compared to stepwise pyrolysis of the two materials separately. A longer vapor residence time in the second step was found to help reducing the amount of wax derived from polyethylene. Results from stepwise pyrolysis of a real waste showed that oxygenated and acidic products were concentrated in the liquid from the first step, while the product from the second step contained a high portion of hydrocarbons and had a low acid number.
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| 16. |
- Wang, Shule, 1994-, et al.
(författare)
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A machine learning model to predict the pyrolytic kinetics of different types of feedstocks
- 2022
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 260, s. 115613-
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Tidskriftsartikel (refereegranskat)abstract
- An in-depth knowledge of pyrolytic kinetics is vital for understanding the thermal decomposition process. Numerous experimental studies have investigated the kinetic performance of the pyrolysis of different raw materials. An accurate prediction of pyrolysis kinetics could substantially reduce the efforts of researchers and decrease the cost of experiments. In this work, a model to predict the mean values of model-free activation energies of pyrolysis for five types of feedstocks was successfully constructed using the random forest machine learning method. The coefficient of determination of the fitting result reached a value as high as 0.9964, which indicates significant potential for making a quick initial pyrolytic kinetic estimation using machine learning methods. Specifically, from the results of a partial dependence analysis of the lignocellulose-type feedstock, the atomic ratios of H/C and O/C were found to have negative correlations with the pyrolytic activation energies. However, the effect of the ash content on the activation energy strongly depended on the organic component species present in the lignocellulose feedstocks. This work confirms the possibility of predicting model-free pyrolytic activation energies by utilizing machine learning methods, which can improve the efficiency and understanding of the kinetic analysis of pyrolysis for biomass and fossil investigations.
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| 17. |
- Wang, Shule, 1994-, et al.
(författare)
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Novel carbon-negative methane production via integrating anaerobic digestion and pyrolysis of organic fraction of municipal solid waste
- 2021
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The use of bioenergy with carbon capture and storage (BECCS) is vital to reaching the desired climate goals. This study proposed a novel process combining anaerobic digestion, pyrolysis, catalytic reforming and methanation (APRM) to produce biomethane and to capture carbon emission from the organic fraction of municipal solid waste (OFMSW). The evaluation of the process was conducted by using modelling software and techno-economic analysis. The process modelling and evaluation result showed that 151.4 kg CH4 and 355.64 kg stored carbon emission can be produced from 1 ton dry matter of OFMSW with an energy efficiency of 0.40. 6.74 MJ electricity was required to capture 1 kg of CO2 via the proposed process. The energy balance of the pyrolysis reaction was investigated. The sensitivities of the pyrolysis temperatures, dewatering technologies and conversion of catalytic reforming on the process performance were analyzed. The result also indicated a positive net profit when using the APRM process to treat the OFMSW based on the calculation of operating expenses and revenue, when the CO2 negativity can be sold as commodity.
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| 18. |
- Wang, Shule, 1994-, et al.
(författare)
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Novel carbon-negative methane production via integrating anaerobic digestion and pyrolysis of organic fraction of municipal solid waste
- 2022
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 252, s. 115042-
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Tidskriftsartikel (refereegranskat)abstract
- The use of bioenergy with carbon capture and storage (BECCS) is vital to reaching the desired climate goals. This study proposed a novel process combining anaerobic digestion, pyrolysis, catalytic reforming and methanation (APRM) to produce biomethane and to capture carbon emission from the organic fraction of municipal solid waste (OFMSW). The evaluation of the process was conducted by using modelling software and techno-economic analysis. The process modelling and evaluation result showed that 151.4 kg CH4 and 355.64 kg stored carbon emission can be produced from 1 ton dry matter of OFMSW with an energy efficiency of 0.40. 6.74 MJ electricity was required to capture 1 kg of CO2 via the proposed process. The energy balance of the pyrolysis reaction was investigated. The sensitivities of the pyrolysis temperatures, dewatering technologies and conversion of catalytic reforming on the process performance were analyzed. The result also indicated a positive net profit when using the APRM process to treat the OFMSW based on the calculation of operating expenses and revenue, when the CO2 negativity can be sold as commodity.
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| 19. |
- Wang, Shule, 1994-, et al.
(författare)
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Renewable hydrogen production from the organic fraction of municipal solid waste through a novel carbon-negative process concept
- 2022
-
Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 252
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Tidskriftsartikel (refereegranskat)abstract
- Bioenergy with carbon capture and storage (BECCS) is one of the prevailing negative carbon emission technologies. Ensuring a hydrogen economy is essential to achieving the carbon-neutral goal. In this regard, the present study contributed by proposing a carbon negative process for producing high purity hydrogen from the organic fraction of municipal solid waste (OFMSW). This integrated process comprises anaerobic digestion, pyrolysis, catalytic reforming, water-gas shift, and pressure swing adsorption technologies. By focusing on Sweden, the proposed process was developed and evaluated through sensitivity analysis, mass and energy balance calculations, techno-economic assessment, and practical feasibility analysis. By employing the optimum operating conditions from the sensitivity analysis, 72.2 kg H2 and 701.47 kg negative CO2 equivalent emissions were obtained by treating 1 ton of dry OFMSW. To achieve these results, 6621.4 MJ electricity and 325 kg of steam were utilized during this process. Based on this techno-economic assessment of implementing the proposed process in Stockholm, when the negative CO2 equivalent emissions are recognized as income, the internal rate of return and the discounted payback period can be obtained as 26% and 4.3 years, respectively. Otherwise, these values will be 13% and 7.2 years.
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| 20. |
- Wang, Shule, et al.
(författare)
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Van Krevelen diagrams based on machine learning visualize feedstock-product relationships in thermal conversion processes
- 2023
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Ingår i: Communications Chemistry. - : Springer Nature. - 2399-3669. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Feedstock properties play a crucial role in thermal conversion processes, where understanding the influence of these properties on treatment performance is essential for optimizing both feedstock selection and the overall process. In this study, a series of van Krevelen diagrams were generated to illustrate the impact of H/C and O/C ratios of feedstock on the products obtained from six commonly used thermal conversion techniques: torrefaction, hydrothermal carbonization, hydrothermal liquefaction, hydrothermal gasification, pyrolysis, and gasification. Machine learning methods were employed, utilizing data, methods, and results from corresponding studies in this field. Furthermore, the reliability of the constructed van Krevelen diagrams was analyzed to assess their dependability. The van Krevelen diagrams developed in this work systematically provide visual representations of the relationships between feedstock and products in thermal conversion processes, thereby aiding in optimizing the selection of feedstock and the choice of thermal conversion technique.
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| 21. |
- Wen, Yuming, et al.
(författare)
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H2-rich syngas production from pyrolysis of agricultural waste digestate coupled with the hydrothermal carbonization process
- 2022
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 269, s. 116101-116101
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Tidskriftsartikel (refereegranskat)abstract
- A novel process to produce a H2-rich syngas from a high moisture-containing agricultural waste digestate is proposed. This process combines the use of hydrothermal carbonization (HTC), dewatering, pyrolysis, and catalytic reforming. Due to the feature of the high moisture content in the digestate, the effect of the HTC and dewatering on the process performance is of interest, and four scenarios were considered. Furthermore, three pyrolytic temperatures were chosen to understand the effect of pyrolysis conditions on the produced H2-rich syngas. A life cycle assessment was conducted to investigate the environmental impact of the proposed process. Results show that the application of HTC technology, increases the process efficiency, produces less syngas from one ton of digestate, lowers the cumulative energy demand and the negative carbon emissions. When the dewatering technology is used, the syngas yield is promoted but the H2 concentration in the syngas is reduced. The H2 to CO molar ratio reaches the maximum value of 9.2 when using a 450 ˚C pyrolysis temperature, by only using HTC. When the combining process of HTC and dewatering is used, it results in the highest process efficiency, but the smallest relative negative CO2 equivalent emissions by treating one ton of dry digestate.
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| 22. |
- Wen, Yuming, et al.
(författare)
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Synergistic effect of the co-pyrolysis of cardboard and polyethylene : A kinetic and thermodynamic study
- 2021
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 229
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis of municipal solid waste (MSW) represents one of the most promising solutions to recycle materials and recover energy. Two of the main components of MSW are waste cardboard and plastic. In this study, the pyrolysis of cardboard and polyethylene (PE) and the co-pyrolysis of their mixtures were conducted to investigate the synergistic effect by using thermogravimetric analysis. The whole reaction process was divided into four pseudoreactions, namely, hemicellulose, lignin, cellulose, and PE, by using the Frazer-Suzuki deconvolution method. It was found that the co-pyrolysis of cardboard and PE could promote the decomposition degrees of cardboard from 70.28% to 75.31%, when the PE fraction increased from 0 to 75%. However, the presence of cardboard can hinder the heat adsorption of PE, which shifts the peak of the PE reaction to a higher temperature. This results in higher E-a and Delta H double dagger values for PE pyrolysis with an increasing fraction of cardboard. On the other hand, the E-a and Delta H double dagger values of cellulose pyrolysis have their lowest values when the mixing rate is around 50%. This research deepens the understanding of the synergistic effect of co-pyrolysis of cardboard and PE, which supports the potential application of pyrolysis of MSW.
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| 23. |
- Yang, Hanmin, 1992-, et al.
(författare)
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Carbon-negative valorization of biomass waste into affordable green hydrogen and battery anodes
- 2023
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The global Sustainable Development Goals highlight the necessity for affordable and clean energy, designated as SDG7. A sustainable and feasible biorefinery concept is proposed for the carbon-negative utilization of biomass waste for affordable H2 and battery anode material production. Specifically, an innovative tandem biocarbon + NiAlO + biocarbon catalyst strategy is constructed to realize a complete reforming of biomass pyro-vapors into H2+CO (as a mixture). The solid residues from pyrolysis are upgraded into high-quality hard carbon (HCs), demonstrating potential as sodium ion battery (SIBs) anodes. The product, HC-1600-6h, exhibited great electrochemical performance when employed as (SIBs) anodes (full cell: 263 Wh/kg with ICE of 89%). Ultimately, a comprehensive process is designed, simulated, and evaluated. The process yields 75 kg H2, 169 kg HCs, and 891 kg captured CO2 per ton of biomass achieving approx. 100% carbon and hydrogen utilization efficiencies. A life cycle assessment estimates a biomass valorization process with negative-emissions (−0.81 kg CO2/kg-biomass, reliant on Sweden wind electricity). A techno-economic assessment forecasts a notably profitable process capable of co-producing affordable H2 and hard carbon battery anodes. The payback period of the process is projected to fall within two years, assuming reference prices of 13.7 €/kg for HCs and 5 €/kg for H2. The process contributes to a novel business paradigm for sustainable and commercially viable biorefinery process, achieving carbon-negative valorization of biomass waste into affordable energy and materials.
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| 24. |
- Yang, Hanmin, 1992-, et al.
(författare)
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Distributed electrified heating for efficient hydrogen production
- 2024
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Ingår i: Nature Communications. - : Nature Research. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- This study introduces a distributed electrified heating approach that is able to innovate chemical engineering involving endothermic reactions. It enables rapid and uniform heating of gaseous reactants, facilitating efficient conversion and high product selectivity at specific equilibrium. Demonstrated in catalyst-free CH4 pyrolysis, this approach achieves stable production of H2 (530 g h−1 L reactor−1) and carbon nanotube/fibers through 100% conversion of high-throughput CH4 at 1150 °C, surpassing the results obtained from many complex metal catalysts and high-temperature technologies. Additionally, in catalytic CH4 dry reforming, the distributed electrified heating using metallic monolith with unmodified Ni/MgO catalyst washcoat showcased excellent CH4 and CO2 conversion rates, and syngas production capacity. This innovative heating approach eliminates the need for elongated reactor tubes and external furnaces, promising an energy-concentrated and ultra-compact reactor design significantly smaller than traditional industrial systems, marking a significant advance towards more sustainable and efficient chemical engineering society.
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| 25. |
- Yang, Hanmin, 1992-, et al.
(författare)
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Distributed electrified heating for efficient hydrogen production
- 2024
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Ingår i: Nature Communications. - : Nature Research. - 2041-1723. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- This study introduces a distributed electrified heating approach that is able to innovate chemical engineering involving endothermic reactions. It enables rapid and uniform heating of gaseous reactants, facilitating efficient conversion and high product selectivity at specific equilibrium. Demonstrated in catalyst-free CH4 pyrolysis, this approach achieves stable production of H2 (530 g h−1 L reactor−1) and carbon nanotube/fibers through 100% conversion of high-throughput CH4 at 1150 °C, surpassing the results obtained from many complex metal catalysts and high-temperature technologies. Additionally, in catalytic CH4 dry reforming, the distributed electrified heating using metallic monolith with unmodified Ni/MgO catalyst washcoat showcased excellent CH4 and CO2 conversion rates, and syngas production capacity. This innovative heating approach eliminates the need for elongated reactor tubes and external furnaces, promising an energy-concentrated and ultra-compact reactor design significantly smaller than traditional industrial systems, marking a significant advance towards more sustainable and efficient chemical engineering society.
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| 26. |
- Zaini, Ilman Nuran, et al.
(författare)
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A pilot-scale test of plasma torch application for decarbonising the steel reheating furnaces
- 2023
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Ingår i: THERMAL SCIENCE AND ENGINEERING PROGRESS. - : Elsevier BV. - 2451-9049. ; 40
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Tidskriftsartikel (refereegranskat)abstract
- The decarbonisation of the Swedish iron and steel industry is crucial in achieving Sweden's target to achieve zero net emissions of greenhouse gases (GHG) by 2045. Direct electrification of industrial furnaces could be an important milestone in decarbonising the iron and steel plants. In this study, pilot-scale trials were performed to investigate the possibility of plasma torch application for steel reheating furnaces. A 250 kW DC plasma torch was used to heat the furnace from room to the operating temperature of 1200 degrees C. Different plasma carrier gases were then used to study their impact on the plasma torch efficiency, furnace temperature profile, NOX emission, and steel oxidation. The results show that the furnace could be heated at a relatively uniform temperature and reasonable time. The combination of air and LPG in the plasma generator provides the most uniform temperature distribution and highest plasma torch efficiency, but it generates the highest NOX emission. N2 as plasma gas resulted in notably poorer temperature distribution and lower plasma torch efficiency; however, it can suppress the oxide formations. Meanwhile, CO2 as plasma gas could be a promising option among the studied gas mixtures as it can provide a good heating performance with a low NOX formation. In summary, the current study has proved that it is practical and functionally possible to heat steel using plasma technology.
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| 27. |
- Zaini, Ilman Nuran, et al.
(författare)
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Characterization of pyrolysis products of high-ash excavated-waste and its char gasification reactivity and kinetics under a steam atmosphere
- 2019
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Ingår i: Waste Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0956-053X .- 1879-2456. ; 97, s. 149-163
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Tidskriftsartikel (refereegranskat)abstract
- The focus of this study is the pyrolysis and gasification of Refuse Derived Fuel (RDF) and fine fractions recovered from the excavation of landfill waste, with an emphasize on the characterization of the reactivity and kinetics of the char-steam gasification. The results from the pyrolysis tests demonstrated that CO and CO2 are the main produced gases during the pyrolysis of the finer fraction of landfill waste. This might be caused by the accumulation of degraded organic materials. The oil products from the pyrolysis of landfill waste were dominated by the derivative products of plastics such as styrene, toluene, and ethylbenzene. The chars obtained from the pyrolysis process were gasified under steam and steam/air atmospheres at temperatures between 800 and 900 degrees C by using thermogravimetry. The results from the gasification tests demonstrated that the char reactivity was mainly affected by the amount ratio between catalytic elements (K, Ca, Na, Mg, and Fe) over the inhibitor elements (Si, Al, and Cl), as well as the ash amount in the char. The results showed that char from the fine fraction of landfill waste has a higher reactivity than the RDF fraction, due to the high content of catalytic metal elements. These results suggest the use of a smaller sieve opening size for landfill waste separation processes may produce waste fuels with a high reactivity during gasification. Further, based on the thermogravimetric data, the kinetic parameters of landfill waste char gasification were calculated to have activation energies ranging from 54 to 128 kJ/mol. Author(s). Published by Elsevier Ltd.
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| 28. |
- Zaini, Ilman Nuran, et al.
(författare)
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Creating Values from Biomass Pyrolysis in Sweden : Co-Production of H-2, Biocarbon and Bio-Oil
- 2021
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen and biocarbon are important materials for the future fossil-free metallurgical industries in Sweden; thus, it is interesting to investigate the process that can simultaneously produce both. Process simulations of biomass pyrolysis coupled with steam reforming and water-gas-shift to produce H-2, biocarbon, and bio-oil are investigated in this work. The process simulation is performed based on a biomass pyrolysis plant currently operating in Sweden. Two co-production schemes are proposed: (1) production of biocarbon and H-2, and (2) production of biocarbon, H-2, and bio-oil. Sensitivity analysis is also performed to investigate the performance of the production schemes under different operating parameters. The results indicated that there are no notable differences in terms of the thermal efficiency for both cases. Varying the bio-oil condenser temperature only slightly changes the system's thermal efficiency by less than 2%. On the other hand, an increase in biomass moisture content from 7 to 14 wt.% can decrease the system's efficiency from 79.0% to 72.6%. Operating expenses are evaluated to elucidate the economics of 3 different cases: (1) no bio-oil production, (2) bio-oil production with the condenser at 50 degrees C, and (3) bio-oil production with the condenser at 130 degrees C. Based on operation expenses (OPEX) and revenue alone, it is found that producing more bio-oil helps improving the economics of the process. However, capital costs and the cost for post-processing of bio-oil should also be considered in the future. The estimated minimum selling price for biocarbon based on OPEX alone is approx. 10 SEK, which is within the range of the current commercial price of charcoal and coke.
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| 29. |
- Zaini, Ilman Nuran, et al.
(författare)
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Decarbonising the iron and steel industries: Production of carbon-negative direct reduced iron by using biosyngas
- 2023
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 281
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Tidskriftsartikel (refereegranskat)abstract
- Bioenergy with carbon capture and storage (CCS) in iron and steel production offers significant potential for CO2 emission reduction and may even result in carbon-negative steel. With a strong ambition to reach net-zero emissions, some countries, such as Sweden, have recently proposed measures to incentivise bioenergy with CCS (BECCS), which opens a window of opportunities to enable the production of carbon-negative steel. One of the main potential applications of this route is to decarbonise the iron reduction processes that account for 85 % of the total CO2 emission in the iron and steel plants. In this study, gasification is proposed to convert biomass into biosyngas to reduce iron ore directly. Different cases of integrating the biomass gasifier, Direct Reduced Iron (DRI) shaft furnace, and CCS are evaluated through process simulation work. Based on the result of the work, the proposed biosyngas DRI route has comparable energy demand compared to other DRI routes, such as the well-established coal gasification and natural gas DRI route. The proposed process can also capture 0.65–1.13 t of CO2 per t DRI depending on the integration scenarios, which indicates a promising route to achieving carbon-negative steel production.
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| 30. |
- Zaini, Ilman Nuran, 1990-
(författare)
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Enhancing the circular economy: Resource recovery through thermochemical conversion processes of landfill waste and biomass
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Currently, the global economy looses a considerable amount of potential secondary raw materials from the disposed waste streams. Furthermore, the existing landfill sites that often do not have proper environmental protection technologies pose a long-lasting risk for the environment, which urge immediate actions for landfill remediations. At the same time, the energy recovery from waste through conventional incinerators has been criticized for its CO2 emissions. Alternatively, pyrolysis and gasification offer the potential to recover secondary resources from waste and biomass streams, which can increase the circularity of the material resources and limit the CO2 emissions.This thesis aims to realize feasible thermochemical processes to enhance the material resources' circularity by treating landfill waste and biomass. Correspondingly, fundamental studies involving experimental works and process developments through lab-scale experiments and process simulations are carried out. The thesis is written based on the results from five different studies that cover the investigation regarding the effect of waste/biomass fuel properties on the performance of the pyrolysis and gasification processes, as well as the process development and improvement of thermochemical conversion processes of waste and biomass.The first study investigates the primary fragmentation behaviour of waste fuel pellets during the pyrolysis stage of thermochemical conversion processes. This study shows that the fragmentation degree of waste pellets correlates well with their volatile matter contents. Meanwhile, there is no clear relation between the fragmentation degree and the pellets’ mechanical strength. Generally, due to the high volatile matter content from plastic, fuel pellets from waste tend to fragment into a high number of smaller particles than typical biomass or coal pellets during thermochemical processes. Hence, for some processes, improving the thermal stability of waste pellets is more relevant than improving their mechanical strength. Subsequently, the second study examines the reactivity and kinetics behaviour of waste-derived char during gasification. In general, it is found that the char reactivity is a function of the ash amount and the ratio of inorganic catalytic elements (K, Ca, Na, Mg, and Fe) to the inhibitor elements (Si, Al, and Cl). More importantly, the char gasification test results demonstrated the significance of the waste sorting processes' operating conditions on the thermal behaviour of the waste fuel, especially during the gasification process.Meanwhile, the third study investigates the syngas and tar formations resulting from different interactions between plastic and paper fractions of solid waste. The results show that the interaction between plastic and paper significantly depends on the hydrocarbon chain structures of the plastic polymer. Specifically, the interactions of aliphatic-structured plastic polymers (represented by PE) and paper cause synergistic effects that reduce the tar and increase the syngas yields. Meanwhile, the synergistic effects tend to be less evident in the case of co-gasification between paper and an aromatic hydrocarbon polymer, represented by PS. Based on the results of the previous studies, a co-gasification process of waste with biomass or biochar is proposed in the fourth study. It is found that adding biochar during the gasification of waste could significantly increase the syngas and H2 production to become higher than that of when adding biomass. Synergistic effects are observed in the form of an extensive syngas yield increment and a tar yield reduction, due to the tar reforming reactions over biochar particles. In general, both biochar and biomass additions result in a higher energy yield ratio, suggesting that it could improve the efficiency of the waste gasification.Finally, the fifth study focuses on process simulations and operational cost assessments of co-production of H2, biochar, and bio-oil from biomass. The process simulation study is carried out to evaluate different scenarios for producing biochar, bio-oil, and H2 based on a biomass pyrolysis process coupled with a steam reforming and a WGS process. Based on the calculations of the total operating cost and the potential revenue, it is found that the production of bio-oil is more economically beneficial than the production of H2. The estimated minimum selling price for biochar and bio-oil based on the operating cost alone is within the price ranges of related commodities in Sweden (i.e., charcoal, coal, coke and oil crude). Nevertheless, capital and operating costs for post-processing of bio-oil should also be considered in the future to obtain a more complete economic judgement.
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| 31. |
- Zaini, Ilman Nuran, et al.
(författare)
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Primary fragmentation behavior of refuse derived fuel pellets during rapid pyrolysis
- 2021
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Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 216
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Tidskriftsartikel (refereegranskat)abstract
- Primary fragmentation during rapid pyrolysis is considered to be the critical size reduction mechanism as it determines the particle size distribution and char conversion rates in the fixed bed gasifier. This study aims to investigate the primary fragmentation behavior of Refuse Derived Fuel (RDF) pellets during a rapid pyrolysis process. RDF pellets consisted of different blending ratios of cardboard and polyethylene (PE) were produced by a single-pellet densification process. Pyrolysis tests at temperature ranges of 500-700 degrees C were performed for each pellet type, and the number and particle size of the fragmented particles were analyzed. The results demonstrate that the different composition of RDF causes different particle binding mechanisms that behave differently during pyrolysis. Densification of cardboard particles can maintain the structure of the pellet char at higher temperatures compared to PE, due to the more stable lignin binding mechanism. A modified Fragmentation Ratio (FR) is introduced to quantify the degree of fragmentation. It is shown that a raise of the concentration of PE from 25 to 75 wt% increases the FR value by up to 4.2 times, whereas an increase in pyrolysis temperature from 500 to 700 degrees C only slightly changes the FR values. It can be concluded that the type of materials in the RDF pellet has a more dominating effect on the fragmentation compared to the pyrolysis temperature. Further, the volatile matter content of pellets shows a linear correlation with the FR value, whereas no clear relation is found in the case of the pellet's mechanical strength.
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| 32. |
- Zaini, Ilman Nuran, et al.
(författare)
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Production of H-2-rich syngas from excavated landfill waste through steam co-gasification with biochar
- 2020
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 207
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Tidskriftsartikel (refereegranskat)abstract
- Gasification of excavated landfill waste is one of the promising options to improve the added-value chain during remediation of problematic old landfill sites. Steam gasification is considered as a favorable route to convert landfill waste into H-2-rich syngas. Co-gasification of such a poor quality landfill waste with biochar or biomass would be beneficial to enhance the H-2 concentration in the syngas, as well as to improve the gasification performance. In this work, steam co-gasification of landfill waste with biochar or biomass was carried out in a lab-scale reactor. The effect of the fuel blending ratio was investigated by varying the auxiliary fuel content in the range of 15-35 wt%. Moreover, co-gasification tests were carried out at temperatures between 800 and 1000 degrees C. The results indicate that adding either biomass or biochar enhances the H-2 yield, where the latter accounts for the syngas with the highest H-2 concentration. At 800 degrees C, the addition of 35 wt% biochar can enhance the H-2 concentration from 38 to 54 vol%, and lowering the tar yield from 0.050 to 0.014 g/g-fuel-daf. No apparent synergetic effect was observed in the case of biomass co-gasification, which might cause by the high Si content of landfill waste. In contrast, the H-2 production increases non-linearly with the biochar share in the fuel, which indicates that a significant synergetic effect occurs during co-gasification due to the reforming of tar over biochar. Increasing the temperature of biochar co-gasification from 800 to 1000 degrees C elevates the H-2 concentration, but decreases the H-2/CO ratio and increases the tar yield. Furthermore, the addition of biochar also enhances the gasification efficiency, as indicated by increased values of the energy yield ratio.
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| 33. |
- Zaini, Ilman Nuran
(författare)
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Steam co-gasification of plastic and paper waste fractions: Synergistic effects on the tar and syngas formations
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The focus of this study is the investigation on the interaction between plastic and paper fractions of MSW during steam co-gasification. The steam co-gasification experiments were conducted by using PE-cardboard and PS-cardboard mixtures at gasification temperature between 800 – 1000 °C. The results from the experimental investigation shows that the interaction between PE and cardboard causes synergistic effects that lead to the reduction of tar and the increase of syngas yields. From the results of the tar analysis, it is shown that the aliphatic tar derived from the decomposition of PE undergoes cracking reaction to form lighter aromatic compounds due to the presence of cardboard volatiles. Meanwhile, there are not any clear synergistic effects found in the case of co-gasification between PS and cardboard, as their syngas and tar yields shift proportionally with the change of the fuel blending ratio. Furthermore, the result also suggest that the gasification temperature affects the degree of the synergistic effects, in which the highest degree of synergistic effects during co-gasification of PE and cardboard is found at 900 °C.
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| 34. |
- Zaini, Ilman Nuran, et al.
(författare)
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Steam gasification of solid recovered fuel char derived from landfill waste : A kinetic study
- 2017
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Ingår i: Proceedings of the 9th International Conference on Applied Energy. - : Elsevier. ; , s. 723-729
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Konferensbidrag (refereegranskat)abstract
- A kinetic study of steam gasification of char derived from solid recovered fuel (SRF) was performed. The char was prepared by using pyrolysis and using a nitrogen atmosphere at a temperature of 900°C for 1 h. Gasification in a steam atmosphere was conducted for the char product using isothermal thermogravimetry analysis (TGA). The gasification was carried out at three different temperatures: 800, 850, and 900°C for at least 1 h. The calculation of the kinetic parameters were done by considering the volumetric model, shrinking core model, and random pore model. The results show that the increase of the gasification temperature was linearly correlated to the rise of the reaction rate of the carbon conversion. Moreover, the activation energy of the char reaction is known to range between 58-83 kJ/mol. The kinetic parameters of char gasification were affected by their corresponding SRF component and the char particle size. Also, there were no significant different in the kinetic parameters calculated using the three different models as the difference between the results was less than 3.5 %.
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