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Asuquo, A. J., Zhang, X., Lin, L. & Li, J. (2024). Green heterogeneous catalysts derived from fermented kola nut pod husk for sustainable biodiesel production. International Journal of Green Energy
Open this publication in new window or tab >>Green heterogeneous catalysts derived from fermented kola nut pod husk for sustainable biodiesel production
2024 (English)In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083Article in journal (Refereed) Epub ahead of print
Abstract [en]

The use of green heterogeneous catalysts that are obtained from waste agricultural biomass can make the production of biodiesel more economical. In this research, three solid base heterogeneous catalysts (Catalyst A, B, and C) were synthesized from kola nut pod husks, and the synergistic effects of the elemental composition on catalytic activities for biodiesel production were studied. The results revealed a high surface area of Catalysts A, B, and C at 419.90 m2/g, 430.54 m2/g, and 432.57 m2/g, respectively. Their corresponding pore diameters are 3.53 nm, 3.48 nm, and 3.32 nm, showing that the catalysts are mesoporous in nature. The X-ray Fluorescence (XRF) results revealed the presence of a variety of alkaline earth metals and their corresponding metal oxides in substantial amounts. Catalyst A was produced with the highest concentration of calcium at 40.84 wt.% and calcium oxide at 68.02 mole%. The substantial concentration of other elements, such as potassium, magnesium, and aluminum, and their corresponding metal oxides are the proof of high catalytic activity of the produced green catalysts. The high CaO contents of all three produced catalysts and their high surface areas indicate their strong potential for good catalytic activities applied to the synthesis of biodiesel.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2024
Keywords
Biodiesel production, green catalyst, synthesis, characterization, sustainability
National Category
Chemical Process Engineering Bioenergy
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-126199 (URN)10.1080/15435075.2023.2297781 (DOI)001136780400001 ()2-s2.0-85181471360 (Scopus ID)
Available from: 2024-01-04 Created: 2024-01-04 Last updated: 2024-01-19
Ahmad, W., Lin, L. & Strand, M. (2024). Investigation of different configurations of alumina packed bed reactor for coke free conversion of benzene. Chemical engineering research & design, 201, 433-445
Open this publication in new window or tab >>Investigation of different configurations of alumina packed bed reactor for coke free conversion of benzene
2024 (English)In: Chemical engineering research & design, ISSN 0263-8762, E-ISSN 1744-3563, Vol. 201, p. 433-445Article in journal (Refereed) Published
Abstract [en]

Conversion of producer gas tar without coke generation is a great challenge. This study investigates conversion of tar model benzene using different configurations of highly non-porous ɣ-Al2O3 packed bed reactor at 1000–1100 0C. The configurations comprised of different positions (relative to top (P1), center (P2) and bottom (P3) of reactor furnace), heights (5, 13 and 25 cm) and particles sizes (0.5, 3 and 5 mm) of alumina packed bed. Steam and CO2 were used as reforming media for tested benzene concentrations (0.4–1.8 vol%). The results showed benzene conversions of 48–91% with negligible steady thin coke generation using a packed bed (height: 25 cm, particles size: 3 mm) at P1. Whereas, relative high benzene conversions of 63–93 and 68–95% at P2 and P3 respectively with unsteady thick coke generation at benzene concentrations greater than 0.4 vol% increased differential upstream pressures (DUPs) of beds. Similar unsteady coke generation at benzene concentrations greater than 0.8 vol% and temperature of 1100 0C was observed with packed beds of heights of 5 and 13 cm, and particles size of 0.5 mm at P1. Generation of unsteady coke with condensed structure as evidenced by its characterization was attributable to increased benzene polymerization and reduced bed surface gasification reactions due to improperly installed packed bed. Developed kinetic model predicted well the generated coke. As conclusion, properly installed alumina packed bed pertaining to tar concentration and other experimental conditions may inhibit coke generation during tar conversion.

Place, publisher, year, edition, pages
Elsevier, 2024
National Category
Energy Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-126019 (URN)10.1016/j.cherd.2023.11.063 (DOI)001139578000001 ()2-s2.0-85180412311 (Scopus ID)
Available from: 2023-12-18 Created: 2023-12-18 Last updated: 2024-02-01Bibliographically approved
Ahmad, W., Lin, L. & Strand, M. (2023). Coke-free conversion of benzene at high temperatures. Journal of the Energy Institute, 109, Article ID 101307.
Open this publication in new window or tab >>Coke-free conversion of benzene at high temperatures
2023 (English)In: Journal of the Energy Institute, ISSN 1743-9671, E-ISSN 1746-0220, Vol. 109, article id 101307Article in journal (Refereed) Published
Abstract [en]

This study investigates the conversion of benzene in a novel highly non-porous ɣ-Al2O3 packed bed reactor at 1000–1100 °C. The influences of packed bed presence, reforming medium (steam and CO2), gas flow rate and benzene concentration on steady state benzene conversion are examined. In presence of packed bed, benzene conversions of 52, 75, and 84% were achieved with combined steam and CO2 reforming at 1000, 1050, and 1100 °C, respectively. Whereas, benzene conversion of 65% without the packed bed at 1000 °C experienced a continuous increase in differential upstream pressure (DUP) of high temperature (HT) filter at reactor downstream due to deposition of in situ generated coke. High concentrations of generated CO and H2 of 2.3 and 6 vol% with packed bed than 1.4 and 4.7 vol% without the packed respectively, were achieved. CO2 reforming achieved high benzene conversions of 68–98% than 42–80% achieved with stream reforming at packed bed reactor temperatures of 1000–1100 °C. The results indicated that presence of ɣ-Al2O3 packed bed with possible surface reactions directed the conversion of benzene to combustible gases instead of coke. Hence, ɣ-Al2O3 packed bed reactor could be a suitable choice for coke-free conversion of tar of gasifier producer gas.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Steam reforming, CO reforming, Benzene conversion, Coke deposits, Combustible gases
National Category
Energy Engineering Bioenergy Chemical Process Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-122025 (URN)10.1016/j.joei.2023.101307 (DOI)001025198800001 ()2-s2.0-85161330969 (Scopus ID)
Available from: 2023-06-16 Created: 2023-06-16 Last updated: 2023-11-14Bibliographically approved
Johansson, W., Li, J. & Lin, L. (2023). Module-based simulation model for prediction of convective and condensational heat recovery in a centrifugal wet scrubber. Applied Thermal Engineering, 219, Article ID 119454.
Open this publication in new window or tab >>Module-based simulation model for prediction of convective and condensational heat recovery in a centrifugal wet scrubber
2023 (English)In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 219, article id 119454Article in journal (Refereed) Published
Abstract [en]

Biomass combustion is a carbon–neutral method to generate heat and power and is integral to combating climate change. The wet scrubber is a promising device for recovering heat and reducing particle emissions from flue gas, under the driving force of new European Union legislation. Here, the heat recovery of a wet scrubber was investigated using process data and computer simulations. The process data showed that the scrubber could continuously recover heat corresponding to 10–20% of the energy input. The simulation model consists of two interlinked modules: Module 1 simulates droplet movement in the scrubber, while Module 2 uses the output of Module 1 to predict the heat recovery. The model was validated against process data, showing a mean error of 5.6%. Further optimization was based on the validated model by varying different process parameters, including nozzle position and moisture addition to the flue gas. Moisture addition was shown to be a feasible strategy for potentially increasing heat recovery by up to 3.3%. These results indicate that heat recovery in wet scrubbers is a feasible way to make particle removal cost effective in medium-scale combustion facilities, and that the developed simulation model can play an important role in optimizing these processes.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Simulation model, Heat recovery, Centrifugal wet scrubber, Condensation, Biomass, Combustion
National Category
Energy Engineering Chemical Process Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-117167 (URN)10.1016/j.applthermaleng.2022.119454 (DOI)000882026900003 ()2-s2.0-85140738410 (Scopus ID)
Funder
Knowledge Foundation, 20190090
Available from: 2022-10-28 Created: 2022-10-28 Last updated: 2023-06-21Bibliographically approved
Ahmad, W., Lin, L. & Strand, M. (2022). Benzene conversion using a partial combustion approach in a packed bed reactor. Energy, 239(Part C), Article ID 122251.
Open this publication in new window or tab >>Benzene conversion using a partial combustion approach in a packed bed reactor
2022 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 239, no Part C, article id 122251Article in journal (Refereed) Published
Abstract [en]

This study investigates the partial combustion technique for tar conversion using a modified experimental set up comprising a packed bed reactor with bed-inside probe for air supply. Simulated producer gas (SPG) and benzene were selected as a real producer gas alternative and model tar component respectively. The benzene conversion was investigated under different experimental conditions such as reactor temperature (650–900 °C), packed bed height (0–12 cm), residence time (1.2–1.9 s), air fuel ratio (0.2 and 0.3) and SPG composition. The results showed insignificant effect of temperature over benzene conversion while air fuel ratio of 0.3 caused high benzene conversion than at 0.2. Absence of packed bed lead high benzene conversion of 90% to polyaromatic hydrocarbons (PAHs) compared to similar low PAHs free benzene conversion of 32% achieved at both packed heights. In SPG composition effect, H2 and CH4 had a substantial inverse effect on benzene conversion. An increase in H2 concentration from 12 to 24 vol% increased the benzene conversion from 26 to 45% while an increase in CH4 concentration from 7 to 14 vol% reduced the benzene conversion from 28 to 4%. However, other SPG components had insignificant impacts on benzene conversion.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Partial combustion, Gasification, Tar, Simulated producer gas
National Category
Chemical Process Engineering
Research subject
Technology (byts ev till Engineering), Sustainable Built Environment
Identifiers
urn:nbn:se:lnu:diva-107478 (URN)10.1016/j.energy.2021.122251 (DOI)000711155600008 ()2-s2.0-85116867387 (Scopus ID)2021 (Local ID)2021 (Archive number)2021 (OAI)
Projects
Char and tar conversion in an internally heated packed bed
Available from: 2021-10-14 Created: 2021-10-14 Last updated: 2023-06-21Bibliographically approved
Johansson, W. & Lin, L. (2022). Full year assessment of small-scale biomass-fueled district heating system with waste heat recovery. In: Chevet P.-F., Scarlat N., Grassi A. (Ed.), European Biomass Conference and Exhibition Proceedings: . Paper presented at 30th European Biomass Conference and Exhibition, EUBCE 2022, Virtual Online, 9-12 May 2022 (pp. 696-698). ETA-Florence Renewable Energies
Open this publication in new window or tab >>Full year assessment of small-scale biomass-fueled district heating system with waste heat recovery
2022 (English)In: European Biomass Conference and Exhibition Proceedings / [ed] Chevet P.-F., Scarlat N., Grassi A., ETA-Florence Renewable Energies , 2022, p. 696-698Conference paper, Published paper (Refereed)
Abstract [en]

The use of biomass for district heating is a carbon neutral and efficient way to heat buildings. To ensure a sustainable use of the biomass, it is important to ensure a high thermal efficiency not only in combustion facilities of all sizes. In this paper, the thermal efficiency of a 3 MW combustion unit with recovery of waste flue gas energy has been evaluated, using process data from a full year. A decreased efficiency is observed at boiler loads below 1 MW, while the efficiency is more stable at higher load. The furnace and boiler efficiency are stable over different moisture contents of the fuel, while the efficiency including heat recovery is greatly enhanced at high moisture content. High return water temperature was linked to a decreased efficiency of the whole system due to decreased efficiency of the heat recovery unit.

Place, publisher, year, edition, pages
ETA-Florence Renewable Energies, 2022
Series
European biomass conference and exhibition proceedings, E-ISSN 2282-5819
Keywords
Biomass, Boilers, Moisture, Moisture determination, Waste heat, Waste heat utilization, Waste incineration, A-carbon, Carbon neutrals, District heating system, Heat building, High thermal, Small scale, Sustainable use, Thermal Performance, Thermal-efficiency, Waste-heat recovery, District heating
National Category
Bioenergy
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-122824 (URN)2-s2.0-85142542487 (Scopus ID)
Conference
30th European Biomass Conference and Exhibition, EUBCE 2022, Virtual Online, 9-12 May 2022
Available from: 2023-06-28 Created: 2023-06-28 Last updated: 2023-08-17Bibliographically approved
Fu, D., Truong, N. L., Lai, Y., Lin, L., Dong, Z. & Lyu, M. (2022). Improved pinch-based method to calculate the capital cost target of heat exchanger network via evolving the spaghetti structure towards low-cost matching. Journal of Cleaner Production, 343, Article ID 131022.
Open this publication in new window or tab >>Improved pinch-based method to calculate the capital cost target of heat exchanger network via evolving the spaghetti structure towards low-cost matching
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2022 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 343, article id 131022Article in journal (Refereed) Published
Abstract [en]

Ahead of heat exchanger network (HEN) design, setting an optimal pinch temperature difference for pinch analysis depends vitally on the capital cost target. Conventional methods based on the spaghetti (SPA) structure ignoring matching optimization might result in calculated cost targets of large deviations. This work evolved the SPA structure via four stages by shifting energy towards low-cost matching. The fourth structure evolved from the SPA structure (ESPA-IV structure) with the lowest-cost matching after loops elimination forms the base to establish the ESPA method. It is validated by numerical experiment and applied to a case reported in literature, meanwhile comparisons are always made to the SPA method. The numerical experiment proves that the ESPA method can obtain capital cost targets with higher accuracy than the SPA method. The target deviations (often within ±5%) given by the ESPA method are much lower than those (well above 10%) derived by the SPA method. In the case study, the given HEN is further optimized as hinted by ESPA method results. Of two target methods, the cost target indicated by ESPA method is closer to the optimum capital cost newly derived after optimization. The high accuracy of the ESPA method is further verified.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Heat exchanger network, Capital cost target, Low-cost matching, Spaghetti structure, Pinch analysis, Temperature difference
National Category
Energy Engineering Chemical Process Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-110642 (URN)10.1016/j.jclepro.2022.131022 (DOI)000807372500001 ()2-s2.0-85125226463 (Scopus ID)2022 (Local ID)2022 (Archive number)2022 (OAI)
Available from: 2022-02-28 Created: 2022-02-28 Last updated: 2023-06-22Bibliographically approved
Zhang, X., Zhang, F., Song, Z., Lin, L., Zhao, X., Sun, J., . . . Wang, W. (2022). Review of chemical looping process for carbonaceous feedstock Conversion: Rational design of oxygen carriers. Fuel, 325, Article ID 124964.
Open this publication in new window or tab >>Review of chemical looping process for carbonaceous feedstock Conversion: Rational design of oxygen carriers
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2022 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 325, article id 124964Article, review/survey (Refereed) Published
Abstract [en]

The chemical looping partial oxidation (CLPO) process as a technology of chemical looping process (CLP) is recognized as a potential strategy for the efficient and clean conversion of fuels into syngas/H2. Herein, in view of the importance of low-cost high-performance metal oxides as oxygen carriers (OCs) for this conversion, we systematically review the classification and CLPO applications of such OCs and discuss the improvement of OC reactivity and stability via the creation of metal–metal or metal–support synergism, the generation of oxygen vacancies, and the enhancement of deactivation resistance. Further, we present the results of theoretical and experimental characterizations probing ion diffusion and surface reactions to provide insights into the related reaction mechanisms and touch on the challenges and opportunities of developing metal oxides with excellent reactivity and long-term cycling stability in CLP. Thus, this review facilitates the design and performance regulation of OCs for future energy conversion systems.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Chemical looping partial oxidation process, Metal oxides, Performance regulation strategies, Mechanisms Decipherment
National Category
Energy Engineering Energy Systems Chemical Engineering Renewable Bioenergy Research
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-114828 (URN)10.1016/j.fuel.2022.124964 (DOI)000824770700001 ()2-s2.0-85132904972 (Scopus ID)
Available from: 2022-06-25 Created: 2022-06-25 Last updated: 2023-06-22Bibliographically approved
Cao, W., Li, J., Lin, L. & Zhang, X. (2021). Release of potassium in association with structural evolution during biomass combustion. Fuel, 287, 1-9, Article ID 119524.
Open this publication in new window or tab >>Release of potassium in association with structural evolution during biomass combustion
2021 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 287, p. 1-9, article id 119524Article in journal (Refereed) Published
Abstract [en]

A mechanistic understanding of potassium release is essential to mitigate the potassium-induced ash problems during biomass combustion. This work studies the effects of operational condition on the potassium release and transition during the combustion of wheat straw, and elucidate the release potential of potassium associated with the structural change of biomass particles. The combustion tests were carried out in a laboratory-scale reactor, working in a wide range of temperatures and heating rates. It was found that the combustion of biomass sample at a temperature up to 1000 °C results in a release of over 60% of its initial potassium content. Raising the heating rate from 8 °C/min to 25 °C/min could lead to an additional release of up to 20% of the initial amount of potassium. A three-stage potassium release mechanism has been concluded from this work: the initial-step release stage (below 400 °C), the holding stage (400–700 °C) and the second-step release stage (above 700 °C). Comprehensive morphology analysis with elemental (i.e. K, S, O, Si) distribution was carried out; the results further confirmed that potassium is likely to exist inside the stem-like tunnel of biomass particles, mainly in forms of inorganic salts. During the heating-up process, the breakdown and collapse of biomass particle structure could expose the internally located potassium and thus accelerate the release of potassium and the transform of its existing forms. Lastly, a detailed temperature-dependent release mechanism of potassium was proposed, which could be used as the guidance to mitigate the release of detrimental potassium compounds by optimising the combustion process.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Biomass, Combustion, Potassium, Release mechanism
National Category
Energy Engineering Bioenergy Chemical Process Engineering Energy Systems
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-98946 (URN)10.1016/j.fuel.2020.119524 (DOI)000604276400001 ()2-s2.0-85096136211 (Scopus ID)
Note

Epub 2020

Available from: 2020-11-16 Created: 2020-11-16 Last updated: 2023-06-22Bibliographically approved
Wang, C., Wang, W., Lin, L., Zhang, F., Zhang, R., Sun, J., . . . Zhao, X. (2020). A stepwise microwave synergistic pyrolysis approach to produce sludge-based biochars: Feasibility study simulated by laboratory experiments. Fuel, 272, 1-10, Article ID 117628.
Open this publication in new window or tab >>A stepwise microwave synergistic pyrolysis approach to produce sludge-based biochars: Feasibility study simulated by laboratory experiments
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2020 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 272, p. 1-10, article id 117628Article in journal (Refereed) Published
Abstract [en]

A stepwise microwave synergistic pyrolysis (SMSP) approach is proposed as a new way to relieve disposal problems of the sewage sludge. Here the sludge is first pre-pyrolyzed by a conventional heating stage, and then rapidly pyrolyzed by a microwave-induced heating stage without any extra microwave absorbers or blending needed. Under simulated process pyrolysis conditions, the dried sludge, intermediate and final sludge-based biochar samples were prepared in the laboratory. Their chemical composition, microstructure and morphology, and leaching toxicity of heavy metals were carefully characterized and analyzed by various techniques such as proximate and ultimate analysis, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET), and scanning electron microscope equipped with energy-dispersive x-ray spectroscopy (SEM-EDX). Results showed that the pre-pyrolytic biochar can be rapidly heated up to 1100 °C within 5 min under microwave irradiation. The pre-pyrolytic stage increased the carbonization and ash enrichment degree of the sludge which itself acted as a good microwave absorber while achieving a quick temperature rise under microwave irradiation. The ash remaining ratio and the specific surface area of the biochar derived from the SMSP approach (labelled as SBC2) are increased by 6.46% and 16.17% respectively, compared with the conventional biochar sample (SBC1). And SBC2 still had diverse surface functional groups kept after SMSP. The residual ratios of Ni, Cu, Zn, Pb, Cr and Cd in SBC2 was more noticeable than in SBC1 but the leaching ratios quite the contrary. Vitrification is also well proved by the increment of quartz peak detected by XRD tests, and the formation of melted glassy spheres with elemental composition of Si, Ca, Al observed by SEM-EDX. It can favorably increase solidification level and decrease leaching toxicity of heavy metals in the SBC2. The feasibility of this proposed SMSP concept has been positively supported by our experimental results. The properties of the sludge-based biochar produced from the SMSP approach also show great potential to be utilized as precursors to produce various adsorbents.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Sewage sludge, Microwave, Pyrolysis, Biochar, Heavy metals immobilization
National Category
Chemical Process Engineering Energy Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-93237 (URN)10.1016/j.fuel.2020.117628 (DOI)000524118200004 ()2-s2.0-85082557768 (Scopus ID)
Available from: 2020-04-01 Created: 2020-04-01 Last updated: 2023-06-21Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-8964-116X

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