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Review of post-combustion carbon dioxide capture technologies using activated carbon

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Journal of Environmental Sciences 2019年第9期31卷 46-63页

作者： Alivia Mukherjee Jude A.Okolie Amira Abdelrasoul Catherine Niu ajay k.dalai Department of Chemical and Biological Engineering University of Saskatchewan Saskatoon 57 Campus Drive

Carbon dioxide(CO2) is the largest anthropogenic greenhouse gas(GHG) on the planet contributing to the global warming. Currently, there are three capture technologies of trapping CO2 from the flue gas and they are pre-combustion, post-combustion and oxy-fuel combustion. Among these, the post-combustion is widely popular as it can be retrofitted for a short to medium term without encountering any significant technology risks or changes.Activated carbon is widely used as a universal separation medium with series of advantages compared to the first generation capture processes based on amine-based scrubbing which are inherently energy intensive. The goal of this review is to elucidate the three CO2 capture technologies with a focus on the use of activated carbon(AC) as an adsorbent for post-combustion anthropogenic CO2 flue gas capture prior to emission to atmosphere. Furthermore, this coherent review summarizes the recent ongoing research on the preparation of activated carbon from various sources to provide a profound understanding on the current progress to highlight the challenges of the CO2 mitigation efforts along with the mathematical modeling of CO2 capture. AC is widely seen as a universal adsorbent due to its unique properties such as high surface area and porous texture. Other applications of AC in the removal of contaminants from flue gas, heavy metal and organic compounds, as a catalyst and catalyst support and in the electronics and electroplating industry are also discussed in this study.

关键词： Post-combustion Greenhouse gas Carbon dioxide capture Activated carbon Adsorption

Comparative evaluation for catalytic gasification of petroleum coke and asphaltene in subcritical and supercritical water

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Journal of Energy Chemistry 2019年第4期28卷 107-118页

作者： Rachita Rana Sonil Nanda Aimee Maclennan Yongfeng Hu Janusz A.kozinski ajay k.dalai Department of Chemical and Biological Engineering University of Saskatchewan Department of Chemical and Biochemical Engineering University of Western Ontario Soft X-Ray Micro-Characterization Beamline Canadian Light Source Inc. New Model in Technology & Engineering

Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnated activated carbon(Ni/AC)was synthesized as a catalyst for enhancing syngas yields at optimal gasification conditions(650°C,15 wt%and 60 min).Structural chemistry of precursors and chars developed at different gasification temperatures was studied using physicochemical and synchrotronbased approaches such as carbon–hydrogen–nitrogen–sulfur(CHNS)analysis,thermogravimetric and differential thermogravimetric analysis(TGA/DTA),scanning electron microscopy(SEM),Fourier-Transform Infrared spectroscopy(FTIR),Raman spectroscopy,X-ray diffraction(XRD)and X-ray absorption spectroscopy(XAS).Asphaltene testified to be a better precursor for catalytic hydrothermal gasification leading to 11.97 mmol/g of total gas yield compared to petroleum coke(8.04 mmol/g).In particular,supercritical water gasification using 5 wt%Ni/AC at 650°C with 15 wt%feed concentration for 60 min resulted in 4.17 and 2.98 mmol/g of H_2from asphaltene and petroleum coke,respectively.Under the same conditions,the respective CH_4yields from catalytic gasification of asphaltene and petroleum coke were 2.54and 1.07 mmol/g.Nonetheless,asphaltene also seemed to an attractive feedstock for the production of highly aromatic chars through hydrothermal gasification.

关键词： Asphaltene Petroleum coke Subcritical water Supercritical water Gasification Char

无铬Co-Cu/SBA-15催化剂催化生物质衍生α-,β-不饱和醛加氢制醇（英文）

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催化学报 2015年第7期36卷 933-942页

作者： Sanjay Srivastava Pravakar Mohanty Jigisha k.Parikh ajay k.dalai S.S.Amritphale Anup k.khare DepartmentofChemicalEngineering S.V.NationalInstituteofTechnologylchchhanathSURAT-395007GujaratIndia DepartmentofChemicalEngineering IndianInstituteofTechnologyNewDelhi-l10016India SardarPatelRenewableEnergyResearchInstitute(SPRERI) VVNagarGujarat388120India CatalysisandChemicalReactionEngineeringLaboratories DepartmentofChemicalandBiologicalEngineeringUniversityofSaskatchewanSaskatoonSaskatchewanS7N5/t9Canada AdvancedMaterialandProcessesResearchInstitute(AMPRI CouncilofScientific&IndustrialResearch(CSIR)Bhopa1462054India

Cr-free bi-metallic SBA-15-supported Co–Cu catalysts were examined in the conversion of biomass-derived α-, β-unsaturated aldehyde(furfural) to value-added chemical furfuryl alcohol(FOL).Co–Cu/SBA-15 catalysts with a fixed Cu loading of 10 wt% and varying Co loadings(2.5, 5, and 10 wt%) were prepared by the impregnation method. The catalysts were characterized by X-ray diffraction, N2 sorption, H2 temperature-programmed reduction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, CO chemisorption, and inductively coupled plasma mass spectrometry. The influence of different reaction parameters such as temperature, pressure, catalyst dosage, and furfural concentration on the catalyst performance was evaluated. Relative to catalysts supported on amorphous silica, the current SBA-15-supported Co–Cu catalysts displayed higher performance, attaining a furfural conversion of 99% and furfuryl alcohol selectivity of 80%. The catalytic reactions were conducted in a 100-mL autoclave at 170 °C and 2 MPa H2 pressure for 4 h.

关键词： SBA-15 催化剂用量不饱和醛 Cu 电感耦合等离子体质谱法 Cr 糠醇高分辨透射电子显微镜

Photocatalysis of Naphthenic Acids in Water

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Journal of Water Resource and Protection 2010年第7期2卷 644-650页

作者： Sabyasachi Mishra Venkatesh Meda ajay k. dalai Dena W. McMartin John V. Headley kerry M. Peru 不详

Naphthenic acids (NAs) are soluble in water and are concentrated in oil sand process water (OSPW) as a result of caustic oil sands extraction processes. Significant environmental and regulatory attention has been focused on the naphthenic acids. A laboratory scale photocatalysis system was developed using UV254 florescent lamps. Experiments were conducted to determine the NA degradation efficiency of this system in presence of TiO2 catalyst. Degradation kinetics for total NAs as well as individual z-families was calculated. The developed treatment system was able to degrade OSPW NAs with half life values ranging between 1.55 and 4.80 h. This system also completely reduced the acute toxicity associated with NAs (up to 5 min. IC50 v/v > 90%) based on Microtox assays.

关键词： Photocatalysis Naphthenic Acids Treatment kinetics Toxicity

Mixing and segregation of binary mixtures of biomass and silica sand in a fluidized bed

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Particuology 2021年第5期19卷 58-73页

作者： Tolu Emiola-Sadiq Jiachen Wang Lifeng Zhang ajay dalai Department of Chemical and Biological Engineering University of Saskatchewan.SaskatoonSK S7N 5A9Canada

In this work,mixing and segregation of binary mixtures involving biomass materials in a fluidized bed was experimentally investigated.A frozen bed method was employed to investigate both axial and radial distribution of biomass particles in silica sand.Three different biomass materials were studied:willow sawdust,pelletized soy and oat hull materials.Biomass loading investigated ranged from 5% to 30% by weight.The extent of mixing for each of the biomass composition was investigated using Lacey’s mixing index which is based on the standard deviations of the sample at different axial positions in the bed.The radial composition was also investigated by means of digital imaging analysis using a high-resolution digital camera.The experiments revealed the differences in the extent of particle distribution for pelletized biomass materials vs non-densified materials as a result of differences in particle size,density and importantly,the particle shape of the materials utilized.The results showed an increase in the extent of mixing as the fluidizing velocity increased for both pellet materials while the mixing index for sawdust decreased beyond a loading of 20%.With an increase in biomass loading,an increase in mixing index was found for the two pellet materials.A similar trend was observed for sawdust at the lower loading level.However,the mixing index started to decrease at higher loading level beyond 20%.The results greatly contributed to the understanding of the hydrodynamics of binary and multicomponent mixtures involving biomass materials,especially pelletized materials in fluidized beds.

关键词： Mixing Segregation Biomass Binary Fluidization Pellets

Effect of fuel additives on agricultural straw pellet quality

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International Journal of Agricultural and Biological Engineering 2014年第2期7卷 92-100页

作者： Shahram Emami Lope G.Tabil Phani Adapa Elizabeth George Ashwini Tilay ajay dalai Mark Drisdelle Lily ketabi Department of Plant Science University of Saskatchewan51 Campus DriveSaskatoonSKS7N 5A8Canada Department of Chemical and Biological Engineering University of Saskatchewan57 Campus DriveSaskatoonSK S7N 5A9Canada Global Institute for Water Security University of Saskatchewan11 Innovation BoulevardSaskatoonSK S7N 3H5Canada Evergreen Biofuels Inc. 129 Como GardensHudsonQC J0P 1H0Canada

An investigation was conducted to determine the effect of addition of different levels of Ak2,a fuel additive that reduces ash fusion for agricultural biomass,on the physico-chemical properties of biomass pellets.Three different biomass straws,barley,oat,and wheat were ground at two hammer mill screen sizes of 0.8 mm and 1.6 mm.Each ground biomass sample was mixed with three levels of Ak2,0.05%,0.10%,and 0.15%by mass and also a blank(no Ak2)was set aside for comparison.Pellets were made using single-pelleting unit at a pre-set load of 4400 N corresponding to a pressure of 138.9 MPa.Physical quality of pellets were determined by measuring pellet density,relaxed density,durability,and the specific energy required to make a pellet.Pellets having higher durability values(74%-88%)were obtained from ground straw at hammer screen size of 0.8 mm and Ak2 level of 0.15%compared to other treatments.Carbon,hydrogen,nitrogen,and sulfur content of blank pellets and those with 0.15%Ak2 at hammer screen size of 0.8 mm were determined.Pellets made with 0.15%Ak2 at hammer screen size of 0.8 mm,manufactured by pilot-scale pellet mill,were gasified and the tar content was determined.The tar content of pellets with 0.15%Ak2 was significantly lower than blank pellets.

关键词： biomass biofuels slag foul pelleting fuel additive

Parametric Sensitivity Studies in a Commercial FCC Unit

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Advances in Chemical Engineering and Science 2012年第1期2卷 136-149页

作者： Prabha k Dasila Indranil Choudhury Deoki Saraf Sawaran Chopra ajay dalai 不详

A steady state model was developed for simulating the performance of an industrial fluid catalytic cracking (FCC) unit which was subsequently used in parametric sensitivity studies. The simulator includes kinetic models for the riser reactor and the regeneration systems. Mass and energy balances were performed for each of these sections and simulation results were compared with the plant data available in the literature. Model predictions were found to be in close agreement with the reported data. Finally this validated model was used for studying the effects of independent variables such as feed preheat temperature (Tfeed) and feed flow rate (Ffeed) on the unit performance at either fixed regenerated catalyst temp/regenerator temp (Trgn) or constant reactor outlet temperature (ROT). The catalyst circulation rate (CCR) was automatically adjusted to keep the ROT constant with varying the independent variables feed preheat temperature while the air rate adjusted for keeping the regenerator temperature constant which consequences the dependency of both dependent and independent variables on the unit performance. The air flow rate to the regenerator was also an independent variable during the parametric sensitivity analysis and its effect on FCC performance was investigated at constant Tfeed, Ffeed and CCR. Combining all the sensitivity analysis, it has been found to increase gas oil conversion and product yields by 5 to 6 percent with decrease of say, 10 k, in the feed preheat temperature (Tfeed) and corresponding increase in air rate (Fair) and catalyst circulation rate (Frgc) at constant reactor outlet temperature (ROT) and regenerated catalyst temperature (Trgc).

关键词： Fluid Catalytic Cracking Parametric Sensitivity Analysis kinetic Modeling of FCC Riser/Reactor Regenerator Modeling