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Waste electrical and electronic equipment (WEEE) has become a critical environmental problem. Catalytic pyrolysis is an ideal technique to treat and convert the plastic fraction of WEEE into chemicals and fuels. Unfortunately, research using real WEEE remains relatively limited. Furthermore, the complexity of WEEE complicates the analysis of its pyrolytic kinetics. This study applied the Fraser-Suzuki mathematical deconvolution method to obtain the pseudo reactions of the thermal degradation of two types of WEEE, using four different catalysts (Al2O3, HBeta, HZSM-5, and TiO2) or without a catalyst. The main contributor(s) to each pseudo reaction were identified by comparing them with the pyrolysis results of the pure plastics in WEEE. The nth order model was then applied to estimate the kinetic parameters of the obtained pseudo reactions. In the low-grade electronics pyrolysis, the pseudo-1 reaction using TiO2 as a catalyst achieved the lowest activation energy of 92.10 kJ/mol, while the pseudo-2 reaction using HZSM-5 resulted in the lowest activation energy of 101.35 kJ/mol among the four catalytic cases. For medium-grade electronics, pseudo-3 and pseudo-4 were the main reactions for thermal degradation, with HZSM-5 and TiO2 yielding the lowest pyrolytic activation energies of 75.24 and 226.39 kJ/mol, respectively. This effort will play a crucial role in comprehending the pyrolysis kinetic mechanism of WEEE and propelling this technology toward a brighter future., QC 20240815

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., QC 20240524

The blooming of beach-cast seaweed has caused environmental degradation in some coastal regions. Therefore, a proper treating and utilizing method of beach-cast seaweed is demanded. This study investigated the potential of producing power or biofuel from pyrolysis of beach-cast seaweed and the effect of the ash-washing process. First, the raw and washed beach-cast seaweeds (RS and WS) were prepared. Thereafter, thermogravimetric analysis (TG), bench-scale pyrolysis experiment, process simulation, and life cycle assessment (LCA) were conducted. The TG results showed that the activation energies of thermal decomposition of the main organic contents of RS and WS were 44.23 and 58.45 kJ/mol, respectively. Three peak temperatures of 400, 500, and 600 degrees C were used in the bench-scale pyrolysis experiments of WS. The 600 degrees C case yielded the most desirable gas and liquid products. The bench-scale pyrolysis experiment of RS was conducted at 600 degrees C as well. Also, an LCA was conducted based on the simulation result of 600 degrees C pyrolysis of WS. The further process simulation and LCA results show that compare to producing liquid biofuel and syngas, a process designed for electricity production is most favored. It was estimated that treating 1 ton of dry WS can result in a negative cumulative energy demand of -2.98 GJ and carbon emissions of -790.89 kg CO2 equivalence., QC 20240613

Some of the naturally accumulated biomass and the massive production of waste by human activities have caused serious environmental problems. The degradation of biomass and waste is one of the main greenhouse gasses (GHG) emission sources. Pyrolysis is a technique that can convert the organic feedstock into char, bio-oil, and gas at 350 - 800 °C and in the absence of oxygen. The diversity of the pyro-products makes pyrolysis one of the most promising techniques for biomass and waste refineries. One of the main challenges of the technique is that the unfavorable physical and/or chemical properties of the feedstock would increase the energy and cost required for the whole refinery process. Combining feedstock pretreatment with a pyro-refinery has the potential to make the entire process more efficient from a cost, energy, and climate perspective. In this thesis, the performance of the peat moss pyrolysis is firstly investigated. It was found that it has a potential to convert peat moss into fuels through pyrolysis. Thereafter, beach-cast seaweed is further considered as a feedstock for the process, which is a high-ash content biomass. Three refinery processes were designed and simulated based on the pyrolysis results. Results showed that it was necessary to have a washing pretreatment for the beach-cast seaweed pyro-refinery. The implementation of washing pretreatment could decrease the direct energy for the whole process from 1485.8 to 1121.0 MJ for treating one ton of dry beach-cast seaweed. The further life cycle assessment (LCA) analysis showed that using the pyro-refinery process with washing pretreatment to treat one ton of dry beach-cast seaweed for the electricity production had the lowest cumulated energy demand (CED). Specifically, it has a value of -3.0 GJ and the lowest global warming potential within a 100-year time frame (GWP100) with a value of -790.9 kg CO2eq compared to the other scenarios of producing liquid biofuel and syngas. Digestate from ana, En del av den naturligt ackumulerade biomassan samt den stora avfallsproduktionen som orsakats av mänskliga aktiviteter har orsakat allvarliga miljöproblem. Nedbrytningen av biomassa och avfall utgör några av de största källorna till utsläpp av växthusgaser. Pyrolys är en teknik som kan omvandla organiska råmaterial till biokol, bioolja och gas vid 350 till 800 °C i en syrefri atmosfär. Mångfalden av produkter från pyrolys gör att tekniken är en av de mest lovande för raffinering av biomassa och avfall. En av de största utmaningarna med tekniken är att ofördelaktiga fysikaliska och kemiska egenskaper hos råmaterial kan leda till ökad kostnad och energiåtgång för hela raffineringsprocessen. Det finns dock en potential att göra hela processen mer hållbar genom att kombinera förbehandling av råvaran med ett pyrolysbaserat raffinaderi. I avhandlingen så behandlas inledningsvis pyrolys av torv. Resultaten visar att det finns en potential att kunna omvandla torv till bränslen genom att använda pyrolysprocessen. Därefter behandlar avhandlingen tång, vilken är en biomassa med ett högt askinnehåll. Tre raffineringsprocesser designades och simulerades baserat på pyrolysprocessen. Resultaten visar att det är nödvändigt att använda tvättning av tången som en förbehandling innan pyrolyssteget. Införandet av denna förbehandling kan minska den direkta energiförbrukningen för hela processen från 1485.8 till 1121.0 MJ vid behandling av ett ton torr tång från stränder. Dessutom visar resultaten från en efterföljande livscykelanalys (LCA) att denna kombination av en tvättning som förbehandling följt av pyrolys av ett ton torr tång från stränder med en efterföljande elproduktion leder till den minsta ackumulerade energiåtgången (CED) med ett värde av -2.98 GJ. Dessutom så är värdet på den globala uppvärmningspotentialen inom en hundraårsperiod (GWP100) -790.89 kg CO2eq, vilket är lägre i jämförelse med de andra scenarierna fokuserade på en produktion av flytande biobränslen och synteti

Anaerobic digestion is an efficient way of using a wet fraction of municipal solid waste (MSW) for energy purposes as it can produce biogas. The moisture content of the digestate after application of mechanical dewatering is still high, and the amount of heat needed for drying is significant. Hydrothermal carbonization (HTC) is a process that can potentially offer great benefits by improved mechanical dewatering and valorization of the digestate into a better quality solid fuel. This study focuses on the determination of the optimum HTC process conditions to recover water from the MSW digestate. Different process conditions as temperature (180, 200, and 230 °C) and residence time (30, 60, and 120 min) were tested. Furthermore, a mass and energy balance was carried out and a process model in Aspen Plus was built. Results showed that HTC treatment increased the water recovery (40–48%) during the dewatering process compared with the original feedstock (18%). The process model showed a positive energy balance of 110 kWh per ton of MSW digestate treated with an electrical efficiency of 23.9%., QC 20220421

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., Not duplicate with Diva 1612933, QC 20220517

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., QC 20221003

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., QC 20220613

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., QC 20220617

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., QC 20211215

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., QC 20210720

Organic-rich pulp and paper mill sludge (PPMS) has the potential to become a renewable carbon source for producing alternatives to fossil-based product. In this work, PPMS treated by hydrothermal carbonization (HTC) was investigated based on its pyrolysis properties. The pyrolytic mechanism, kinetics data and product of the sample were studied using TG as well as pyrolysis tests in Py-GC/MS and a bench-scale reactor at 450, 550, and 650 degrees C. The results show that the thermal decomposition of feedstock is a two-stage reaction. The mean activation energy of the pyrolysis of HTC treated PPMS was estimated as 233.08 kl/mol, which is higher than that of the pyrolysis of paper sludge reported before. The changes in enthalpies, entropies and Gibbs free energies from the reactants to the activated complex were estimated. The concentration of monocyclic aromatic hydrocarbons in the derived organic liquid fraction shows a positive correlation with the pyrolysis temperature. At 550 degrees C, the organic liquid fraction reached its highest yield at 13.7% with an oxygen level of 10.7 wt% and a higher heating value of 35.9 MJ/ kg. The pyrolytic chars show that a molar ratio of O:C is less than 0.2, which shows potential for use as a carbon sink., QC 20210825

A series of magnetic bio-activated carbon (MBAC) has been produced from lignin and ferrous salts following to the process including impregnation, carbonization, and steam activation. The influence of the impregnation methods and the steam flow rate on the quality and the maximum phosphorus adsorption capacity of the produced MBACs has been investigated. The phosphorus adsorption performance in real domestic wastewater of the MBAC with the highest maximum phosphorus adsorption capacity has been investigated. The results show that all of the produced MBACs have a relatively rich porous structure, and all surface iron species exist as magnetite (Fe3O4). Compared with the MBACs that are produced via the dry impregnation method using a lower steam flow rate, the MBACs that are produced via the wet impregnation method using a higher steam flow rate are believed to have a higher iron content and better iron species dispersion. The highest maximum phosphorus adsorption capacity of all the produced MBACs is estimated to be as high as 69.80 mg-P/g according to the best-fitting Langmuir model. The MBAC that shows the highest maximum phosphorus adsorption capacity could also remove 84.65% and 96.97% of the total phosphorus from the filtered raw domestic wastewater (FRDW) and treated domestic wastewater (TDW), respectively, which indicates a good potential for using MBACs for domestic wastewater treatment., QC 20210420

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., QC 20230920

Peat moss in drained peatlands has become a non-negligible source of greenhouse gases (GHG) emission. Pyrolysis is a potential technique to convert carbon-emitting peat moss to carbon-storage materials. This work investigates the behavior of peat moss pyrolysis by a combined in-situ thermal analysis and bench-scale pyrolysis experiment methodology. The simultaneous thermal analyzer, which provides the simultaneous TG/DTA analysis, was employed to reveal the thermal decomposition behavior of peat moss. The samples were heated up to 900 degrees C with different heating rates of 10, 15, and 20 degrees C/min. Thereafter, pyrolysis experiments with peak temperatures of 450, 500, 550 and 600 degrees C were performed in a bench-scale pyrolyzer. It was found that there are four main stages and two micro stages of mass loss during peat moss pyrolysis from room temperature to 900 degrees C. Also, kinetic parameters were calculated based on the results of TG and DTG by the Kissinger-Akahira-Sunose (KAS) method and the Coats-Redfern (CR) method. In the bench-scale pyrolysis experiments, four phases, i.e., char, tar, aqueous phase, and gas, were obtained and characterized. The carbon distribution and the GHG emission from peat moss pyrolysis were determined., QC 20200715

Peat moss, also called sphagnum, has become a big problem in many countries such as China and Sweden due to its high green-house gas emission from chemical and biological degradation. In this work, the performance of peat moss pyrolysis has been studied, to investigate the potential of application of peat moss pyrolysis on fuel and chemical production. Thermalgravimetric analysis (TGA), differential thermal analysis (DTA), and pyrolysis experiments in a bench-scale reactor have been conducted. Kinetic parameters were calculated based on the results of TG and DTG by Kissinger-Akahira-Sunose (KAS) method and Coats-Redfern method. 450, 500, 550, 600 °C were chosen as the pyrolytic peak temperatures and four phases of products (char, aqueous phase, tar, and gas) were collected. It was found that the peat moss pyrolysis from room temperature to 900 °C could be classified as a six stages reaction. Stage 1 to stage 5 were estimated to be the results of the removal or decomposition of moisture content, hemicellulose, cellulose, lignin, and CaCO3, respectively. The results of activation energies calculated by Coats-Redfern method revealed that, when the heating rate different from 10, 15, and 20 °C/min: stage 3 had the activation energy of 276389, 262587, and 239049 J/mol; stage 4 had the activation energy of 252851, 248918, and 307427 J/mol; stage 5 had the activation energy of 1108268, 814402, and 857437 J/mol, respectively. When the peak pyrolytic temperature raised from 450 to 600 °C: the production of char would decrease; the 500 °C one had the highest production of tar; the aqueous phase produced had the highest TAN value at 500 °C., Torvmossa, även kallad sphagnum, har blivit ett stort problem i många länder som Kina och Sverige på grund av dess stora utsläpp av växthusgaser från kemisk och biologisk nedbrytning. I detta arbete har torvmossans egenskaper vid pyrolys studerats för att undersöka dess potential att användas inom bränsle- och kemisk produktion.Termogravimetrisk analys (TGA), differentiell termisk analys (DTG) och pyrolysförsök i en bench-scale reaktor har genomförts. Kinetiska parametrar beräknades baserat på resultaten av TGA och DTG med Kissinger-Akahira-Sunose (KAS) metoden och Coats-Redfern metoden. 450, 500, 550, 600 °C valdes som temperaturer vid pyrolys och fyra olika produkter (kol, vattenfas, tjära och gas) uppsamlades. Det visade sig att torvmosspyrolysen från rumstemperatur till 900 °C kunde klassificeras som en reaktion på sex steg. Steg 1 till steg 5 uppskattades vara resultaten av avlägsnande eller sönderdelning av fuktinnehåll, hemicellulosa, cellulosa, lignin respektive CaCO3. Resultaten av aktiveringsenergier beräknade med CoatsRedfern-metoden och visade att: när uppvärmningshastigheten skiljer sig från 10, 15 och 20 °C/min; steg 3 hade aktiveringsenergin 276389, 262587 och 239049 J/mol; steg 4 hade aktiveringsenergin 252851, 248918 och 307427 J/mol; steg 5 hade aktiveringsenergin 1108268, 814402 respektive 857437 J/mol. När den högsta pyrolytiska temperaturen höjdes från 450 till 600 °C: minskade produktionen av kol; 500 °C hade den högsta produktionen av tjära; den producerade vattenfasen hade det högsta TAN-värdet vid 500 °C.

Spatial diffusion is a stochastic spatio-temporal process. Spatial diffusion phenomena occur because of the existence of a concentration gradient of information or material flow. At a regional level, most human-induced land-use and land-cover change, including urban land-cover change, can be considered as a spatial diffusion process. In this research, a spatial diffusion (SDIF) model has been developed to simulate urban land cover change at a regional level. This research aims to establish a theoretical framework for spatial diffusion modeling and build a spatial diffusion modeling system for simulation of urban land-cover change. The Chicago metropolitan region was selected as the study area. The land-cover data derived from Landsat images of 1972, 1985 and 1997 were used as seed data sets for the SDIF model to simulate and predict urban land-cover change. US Census information, biophysical and socioeconomic factors were incorporated into the SDIF model. Spatial restrictions such as protected areas were used to restrain future urban development. Data sensitivity analysis indicates that the SDIF model output is sensitive to census data. Based on the population, household and employment projections for 2020, SDIF simulation of urban land cover through the year of 2020 has been achieved. The SDIF model evaluation indicates that the overall modeling simulation accuracies for the years of 1985, 1997 and 2002 are 65.4%, 66.8%, and 72.2% respectively. The SDIF model performs well in comparison with the Dynamic Landscape Simulation (DLS) models for the simulation of landscape change for the same study area.