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Journal of Power and Energy Engineering 2022年第7期10卷 56-69页

作者： Emmanuel Okon Osung Sunday Boladale Alabi Department of Chemical and Petroleum Engineering University of Uyo Uyo Akwa Ibom State Nigeria

Techno-economic potentials of thermal and catalytic pyrolysis plants for the conversion of waste plastics to liquid fuels have been widely studied, but it is not obvious which of the two plants is more profitable, as the existing studies used different assumptions and cost bases in their analyses, thereby making it difficult to compare the economic potentials of the two plants. In this study, industrial-scale thermal and catalytic waste plastics pyrolysis plants were designed and economically analyzed using ASPEN PLUS. Amorphous silica-alumina was considered the optimum catalyst, with 3:1 feed to catalyst ratio. Based on 20,000 tons/year of feed and 20% interest rate, the catalytic plant, having a net present value (NPV) of � million, was found to be economically less attractive than the thermal plant, having the NPV of �.4 million. On the contrary, sensitivity analyses of the two plants at a feed rate of 50,000 tons/year gave rise to a slightly higher NPV for the catalytic plant (� million) than the thermal plant having NPV of � million, thereby making the former more economically attractive for processing large amounts of waste plastics into liquid fuels. Consequently, as the catalytic plant showed a better scale economy and would produce higher quality liquid fuels than the thermal plant, it is recommended for commercialization in Nigeria.

关键词： Waste Plastics Heterogeneous liquid fuels Thermal Pyrolysis Catalytic Pyrolysis

Dealuminated ZSM-5 Zeolite Catalyst for Ethylene Oligomerization to liquid fuels

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Journal of Natural Gas Chemistry 2002年第1期11卷 79-86页

作者： NorAishahSaidinaAmin DidiDwiAnggoro FacultyofChemicalandNaturalResourcesEgineering UniverstitTeknologiMalaysis81310SkudaiJohorMalaysia DepartmentofChemicalEngineering UniversityofDiponegoroSemarang50232Indonesia

Ethylene oligomerization using ZSM-5 zeolite was investigated to study the role of Bronsted acid sites in the formation of higher hydrocarbons. The oligomerization of olefins, dependent on the acidity of ZSM-5 zeolite, is an important step in the conversion of natural gas to liquid fuels. The framework Si/Al ratio reflects the number of potential acid sites and the acid strength of the ZSM-5 catalyst. ZSM-5 with the mole ratio SiO2/Al2O3 equal to 30 was dealuminated for different periods of time according to the acidic ion-exchange method to produce ZSM-5 with various Si/Al ratios. The FT-IR analysis revealed that the integrated framework aluminum band, non-framework aluminum band, and silanol groups areas of the ZSM-5 zeolites decreased after being dealuminated. The performance of the dealuminated zeolite was tested for ethylene oligomerization. The results demonstrated that the dealumination of ZSM-5 led to higher ethylene conversion, but the gasoline selectivity was reduced compared to the performance of a ZSM-5 zeolite. The characterization results revealed the amount of aluminum in the zeolitic framework, the crystallinity of the ZSM-5 zeolite, and the Si/Al ratio affected the formation of Bronsted acid sites. The number of the Bronsted acid sites on the catalyst active sites is important in the olefin conversion to liquid hydrocarbons.

关键词： ethylene liquid fuels oligomerization dealumination ZSM-5

Review of the direct thermochemical conversion of lignocellulosic biomass for liquid fuels

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Frontiers of Agricultural Science and Engineering 2015年第1期2卷 13-27页

作者： Jianchun JIANG Junming XU Zhanqian SONG Institute of Chemical Industry of Forestry Products CAF Key Laboratory of Biomass Energy and Material National Engineering Laboratory for Biomass Chemical Utilization Key Laboratory of Forest Chemical Engineering SFA

Increased demand for liquid transportation fuels, environmental concerns and depletion of petroleum resources requires the development of efficient conversion technologies for production of second-generation biofuels from non-food resources. Thermochemical approaches hold great potential for conversion of lignocellulosic biomass into liquid fuels. Direct thermochemical processes convert biomass into liquid fuels in one step using heat and catalysts and have many advantages over indirect and biological processes, such as greater feedstock flexibility, integrated conversion of whole biomass, and lower operation costs. Several direct thermochemical processes are employed in the production of liquid biofuels depending on the nature of the feedstock properties: such as fast pyrolysis/liquefaction of lignocellulosic biomass for bio-oil, including upgrading methods, such as catalytic cracking and hydrogenation. Owing to the substantial amount of liquid fuels consumed by vehicular transport, converting biomass into drop-in liquid fuels may reduce the dependence of the fuel market on petroleumbased fuel products. In this review, we also summarize recent progress in technologies for large-scale equipment for direct thermochemical conversion. We focus on the technical aspects critical to commercialization of the technologies for production of liquid fuels from biomass,including feedstock type, cracking catalysts, catalytic cracking mechanisms, catalytic reactors, and biofuel properties. We also discuss future prospects for direct thermochemical conversion in biorefineries for the production of high grade biofuels.

关键词： lignocellulosic biomass thermochemical liquid fuels upgrading biofuels

Dealuminated ZSM-5 Zeolite Catalyst for Ethylene Oligomerization to liquid fuels

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Journal of Energy Chemistry 2002年第Z1期 79-86页

作者： Nor Aishah Saidina Amin,Didi Dwi Anggoro1. Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia2. Department of Chemical Engineering, University of Diponegoro, Semarang 50232, Indonesia[Manusc

关键词： ethylene liquid fuels oligomerization dealumination ZSM-5

Development of high intensity low emission combustor for achieving flameless combustion ofliquid fuels

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Propulsion and Power Research 2013年第2期2卷 139-147页

作者： V.Mahendra Reddy Sudarshan Kumarn deparment of aerospace engineering indian nstitute of technologybombaypowai mumbai-400076india

This paper presents the experimental and numerical results for a two stagecombustor capable of achieving flameless combustion with liquid fuels for different thermalheat inputs of 20,30,40 and 60 kW and heat release density of 5-15 MW/m^(3).Combustioncharacteristics and pollutant emissions are studied for three different fuels,kerosene,diesel *** influence of droplet diameter on pollutant emissions at all conditions is *** fuel and oxidizer are supplied at ambient *** concept of high swirl flows hasbeen adopted to achieve high intemal recirculation rates,residence time and increased dilutionof the fresh reactants in the primary combustion zone,resulting in flameless combustion *** is injected through four tangential injection ports located near the bottom of the combustorand liquid fuel is injected through a centrally mounted pressure swirl *** of the flow features shows that decrease in the exit port diameter of the primarychamber increases the recirculation rate of combustion products and helps in achieving theflameless combustion *** on preliminary computational studies,a 30 mm primarychamber exit pont diameter is chosen for experimental *** experimentalinvestigations show that flameless combustion mode was achieved with evenly distributedcombustion reaction zone and unifom temperature distribution in the *** emissions of CO, NO_(x),C_(x)H_(y) are measured and compared for all operating conditions ofdifferent fuels and different thermal inputs. The acoustic emission levels are reduced by6-8 dB as combustion mode shifts from conventional mode to flameless combustion mode.

关键词： Swirl flow combustion Flameless combustion Internal recirculation liquid fuels Spray combustion Low emissions

Characteristics of penetration and distribution of a liquid jet in a divergent cavity-based combustor

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Chinese Journal of Aeronautics 2023年第12期36卷 139-150页

作者： Yaozhi ZHOU Zun CAI Qinglian LI Chenyang LI Mingbo SUN Shaotian GONG Hypersonic Technology Laboratory National University of Defense TechnologyChangsha 410073China Beijing Institute of Tracking and Telecommunication Technology Beijing 100094China

The atomization process of a liquid jet in a divergent cavity-based combustor was investigated experimentally using high-speed photography and schlieren techniques under a Mach number 2.0 supersonic ***-liquid flow field was studied at different divergent angles and injection *** is found that complex wave structures exist in the divergent cavity-based *** spray field can be divided into three distinct zones:surface wave-dominated breakup zone,rapid atomization zone and cavity mixing zone.A dimensionless spray factor is defined to describe the concentration of spray inside the cavity *** a result,it is revealed that for the large divergent angle cavity,the injection scheme near the upstream inlet has a higher penetration depth but a lower spray distribution,where the injection scheme near the cavity has a more spray *** the small divergent angle cavity,the injection scheme near the upstream inlet also has a higher penetration depth and the injection scheme near the start point of the divergent section has a more sufficient spray *** small divergent angle cavity-based combustor with the upstream wall transverse injection is an optimized injection scheme to improve both penetration and spray distribution inside the ***,a penetration depth formula is proposed to explain the spray and distribution behaviors in the divergent cavity-based combustor.

关键词： Atomization liquid fuels Spray nozzles Supersonic flow Two-phase flow

Review of atomization mechanism and spray characteristics of a liquid jet in supersonic crossflow

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Chinese Journal of Aeronautics 2023年第8期36卷 1-23页

作者： Yaozhi ZHOU Zun CAI Qinglian LI Chenyang LI Mingbo SUN Peibo LI Hongbo WANG College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Beijing Institute of Tracking and Telecommunication Technology Beijing 100094China

The injection and atomization process of a liquid fuel jet is critical for an ignition start of a scramjet ***-mounted crossflow injection strategy is widely used in scramjet combustors,avoiding high total pressure loss and allowing the liquid fuel to rapidly undergo atomization,mixing,and *** this review,research progress on a liquid jet in supersonic crossflow was evaluated from aspects of atomization mechanism and spray *** a liquid jet is injected into a supersonic crossflow,primary and secondary breakups occur *** surface instability of liquid can significantly affect the breakup *** review discusses the current understanding of the breakup process and spray characteristics of a liquid jet in supersonic crossflow including the mechanism of atomization and the characteristics of distribution and *** development of windward Rayleigh-Taylor(R-T)unstable waves is the main factor in column *** development of Kelvin-Helmholtz(K-H)unstable waves along the circumferential direction of the jet or droplets is the main factor of surface and droplet *** liquid-gas momentum ratio is the most important factor affecting the penetration *** span width of the liquid jet is affected by the windward *** and coalescence lead to a transformation of the size distribution of droplets from S-or C-shaped to I-shaped,and the velocity distribution of the droplets on the central symmetry plane has a mirrored *** droplet distribution on the spanwise cross-section retains a structure similar to an“Ω”*** last,some promising recommendations have been proposed,namely a theoretical predictive model which can describe the breakup mechanism of a liquid jet,the distribution characteristics and droplets size distribution of a liquid jet under a cavity combustion chamber,especially for enthalpy flows with complex wave structures.

关键词： Atomization liquid fuels Spraynozzles Supersonicflow Two phase flow

Nanosized cobalt-based catalyst prepared by supercritical phase condition for Fischer-Tropsch synthesis

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Journal of Natural Gas Chemistry 2009年第3期18卷 325-330页

作者： Jingmiao Li Jingchang Zhang Runduo Zhang Weiliang Cao Institute of Modern Catalysis Beijing University of Chemical Technology State Key Laboratory of Chemical Resource Engineering Beijing 100029 China

A series of nanosized Co/Zn/Mn/K composite catalysts for Fischer-Tropsch synthesis （FTS） were prepared by supercritical fluid drying （SCFD） method and common drying （CD） method. The nanosized cobalt-based catalysts were characterized by XRD, TEM and BET techniques. Their catalytic performances were tested in a slurry-bed reactor under FTS reaction conditions. The drying and crystallization were carried out simultaneously during SCFD, therefore, the catalysts prepared by SCFD method have ideal structure and show the FTS performance superior to the others prepared by CD method. The FTS activity and selectivity were improved via adding Zn, Mn and K promoters, and less CH4 and CO2 as well as higher yield of C5＋ products were achieved. The optimal performance of a 92% CO conversion and a 65% C5＋ product yield was obtained over a catalyst with the component of Co/Zn/Mn/K = 100/50/10/7. Furthermore, the catalytic performance was studied under the conditions of liquid-phase and supercritical phase slurry-bed, and C5＋ product yield were 57.4% and 65.4%, respectively. In summary, better catalytic performance was obtained using the nanosized catalyst prepared by SCFD method under supercritical reaction conditions, resulting in higher conversion of CO, less CO2 byproduct, and higher yield of C5＋ products.

关键词： nanosized catalyst supercritical combined technique Fischer-Tropsch synthesis supercritical phase liquid fuels

Effect of operating conditions and potassium content on Fischer-Tropsch liquid products produced by potassium-promoted iron catalysts

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Journal of Natural Gas Chemistry 2008年第2期17卷 175-178页

作者： Francisco E.M.Farias Fernando G.Sales Fabiano A.N.Fernandes Universidade Federal do Ceará Departamento de Engenharia QuímicaCampus do PiciBloco 70960455-760 Fortaleza-CEBrazil

The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures （25 to 30 arm） favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure （20 arm） using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.

关键词： Fischer-Tropsch synthesis liquid fuels iron-based catalyst potassium

Waste plastics-to-fuel using fly ash catalyst

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Waste Disposal and Sustainable Energy 2021年第1期3卷 13-30页

作者： Bijoy Kumar Mondal Falguni Guha MdNurul Abser Department of Chemistry Jahangirnagar UniversitySavarDhakaBangladesh Department of Biochemistry and Microbiology North South UniversityDhakaBangladesh

Suitable disposal pathways of waste plastics and coal fly ash have yet not been established which is a matter of great envi-ronmental *** low-density polyethylene(LDPE)and high-density polyethylene(HDPE)were degraded using a semi-batch reactor along with acid or alkali modified fly ash *** high yield of liquid fuel product(about 87.24 wt%)was achieved for low-density polyethylene at a polymer and catalyst ratio of 25 w/*** 96%conversion was found with very few amount of gaseous *** of the waste plastics were degraded at 400-450℃.The liquid products were analyzed using Fourier-transform infrared spectroscopy(FTIR),nuclear magnetic resonance(^(1)H,^(13)C,and DEPT-135 NMR),and gas chromatography-mass spectrometry(GC-MS).Fly ash is an efficient catalyst to degrade waste plastic into light weight liquid(gasoline and kerosene)*** NMR results accompanied by GC-MS data ensure that obtained fuels contain both aliphatic(saturated and unsaturated)and aromatic *** plastic-to-fuel technology should be commercialized owing to be profitable and eco-friendly.

关键词： Solid waste Catalytic pyrolysis liquid fuels