Browsing by Author "Idem, Raphael"

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Open Access
A commercial pathway for evaluating the performance of a novel amine solvent blend in a mini-pilot plant for carbon capture
(Faculty of Graduate Studies and Research, University of Regina, 2024-08) Bekoe, Patience Tiorkor; Idem, Raphael; Supap, Teeradet; Tontiwachwuthikul, Paitoon (P.T.)
This study investigates the performance of a novel solvent bi-blend, 4M (2:2) AMP:1-(2HE) PRLD, for CO2 capture through absorption and desorption, providing a potential alternative to the conventional 5M Monoethanolamine (MEA). The pathway utilized to assess the performance of the amine bi-blend for commercial application involved conducting carbon capture experiments in a laboratory bench-scale mini-pilot plant. This approach aimed to validate the solvent's performance under conditions that mimic a full-scale commercial industrial CO2 capture plant. The research also addresses the urgent need for more efficient and cost-effective carbon capture solutions to combat increasing greenhouse gas emissions and global warming. Experiments were conducted with varying feed gas compositions, with CO2 concentrations ranging from 4.5% to 30%, to simulate different industrial emission scenarios. Key performance metrics, including CO2 absorption efficiency, cyclic capacity, mass transfer rates, and energy consumption for solvent regeneration, were meticulously evaluated. For a CO2 partial pressure of 4.5%, the novel solvent blend demonstrated significant performance enhancements compared to 5M MEA. Specifically, the 4M (2:2) AMP:1-(2HE) PRLD blend exhibited an enhancement in absorption efficiency by up to 25% at a reboiler temperature of 110 °C, 41% at 100 °C, and over 700% at 90 °C. Additionally, there was a reduction in regeneration energy requirements by approximately 30% at 110 °C, 43% at 100 °C, and 84% at 90 °C. The novel blend showed robust performance across a wide range of these parameters, indicating its versatility and suitability for diverse industrial applications. The study also revealed an average increase of 150% in the overall gas phase volumetric mass transfer coefficient (KGav) and 110% for the overall liquid-phase volumetric mass transfer coefficient (KLav). These significant improvements emphasize the novel blend's superior mass transfer performance, which is crucial for maximizing CO2 capture efficiency and column design. Parametric studies were conducted to understand the influence of various operational parameters on mass transfer performance. It was observed that the absorption efficiency and mass transfer rates were significantly influenced by CO2 loading, gas flow rate, desorption temperature and pressure. Results from this exercise showed that there is a strong positive correlation between the reboiler temperature and the efficiency as well as the overall mass transfer coefficient. It was also noted that the mass transfer was mainly controlled by the liquid phase while increasing the desorber pressure had an inverse effect on the lean amine loading which was attributed to the higher gas solubility at the higher pressure. The effect of CO2 partial pressure was also studied and a negative correlation was observed between CO2 partial pressure and the absorber efficiency, overall gas phase mass transfer coefficient. Heat duty analysis revealed that the novel solvent blend required less energy for regeneration, thus offering a more energy-efficient solution. The specific energy consumption for the AMP-PRLD blend was found to be significantly lower than that for 5M MEA, highlighting its potential to reduce operational costs and environmental impacts. The study concludes that the novel solvent blend not only provides a more efficient CO2 capture solution but also aligns with the goals of reducing greenhouse gas emissions and achieving net-zero emissions from the indirect co-combustion of natural gas and biomass for energy generation even at relatively lower desorption temperature (100-110 °C) thus significantly contributing to energy savings.
Open Access
Achieving net-zero CO2 emissions from indirect co-combustion of biomass and natural gas with carbon capture using a novel amine blend
(Faculty of Graduate Studies and Research, University of Regina, 2022-09) Avor, Esther Praise; Idem, Raphael; Jia, Na; Supap, Teeradet; Narku-Tetteh, Jessica; Torabi, Farshid
Due to the aggravating effect of climate change as a result of unprecedented levels of greenhouse gases, particularly CO2, in the atmosphere, the need to minimize CO2 emissions into the atmosphere has become very crucial. The energy sector remains the largest source of CO2 emissions, therefore, a technology which allows for achieving netzero CO2 emissions in this sector is imperative. This research work evaluated the possibility of achieving net-zero emissions (on the minimum) through the application of co-combustion of natural gas and biomass for electricity generation. Based on the study, it is was identified that indirect co-combustion of natural gas with biomass (in the form of producer gas) with carbon capture technology is the way to go towards achieving net-zero CO2 emissions. To effectively describe the process as being a net-zero CO2 emissions approach, Life Cycle Assessment data was applied to the various processes involved in the indirect co-combustion of biomass and natural gas coupled with carbon capture technology. In the first phase of this work, 5M MEA, which is the benchmark solvent for CO2 capture was used as the worst-case scenario to determine the ratio of producer gas-to natural gas (on energy basis) sufficient for achieving net-zero CO2 emissions. Using the SaskPower forecasted electricity generation capacity for 2025/2026 as a case study and applying LCA data to 5M MEA as the solvent for CO2 capture, it was determined that on energy basis, 14.5% of producer gas (balance natural gas) is sufficient for achieving netzero CO2 emissions while satisfying the set electricity generation target. The next phase of the work was to develop an amine blend with an improved CO2 removal efficiency compared to the bench-scale 5M MEA. Four different blends were screened to assess their respective performance against 5M MEA. These included 2:2 AMP: 1-(2HE) PRLD, 2:2 AMP: DEA-1,2-PD, 3:1 1-(2HE) PRLD: AMP and 3:1 1-(2HE) PRLD: DEA-1,2-PD bi-blends. Among these solvents, 2:2 AMP: 1-(2HE) PRLD was the optimum solvent as it demonstrated a high CO2 absorption-desorption parameter compared to the other blends. The absorption parameter for 2:2 AMP:1-(2HE) PRLD was 4.5% higher than that for 5M MEA and the desorption parameter 1,667% higher than 5M MEA. In the last phase, the increased CO2 removal efficiency of the solvent was applied to LCA data to determine the ratio of electricity generation from natural gas and producer gas towards achieving net-zero CO2 emissions when the optimum solvent developed is used in place of 5M MEA. It was determined that at a desorption temperature of 110℃, nearly all the CO2 in the rich amine for the optimum was removed. The CO2 removal efficiency of this solvent is about 31% higher than that for 5M MEA, implying this solvent allows for the removal of higher amount of CO2 in the flue gas stream. From the life cycle massessment, using 2:2 AMP: 1-(2HE) PRLD as the absorbent for CO2 capture in place of 5M MEA, it was determined that the producer gas requirements on energy basis, for cocombusting indirectly with natural gas towards achieving net-zero CO2 emissions is just about 8%. The findings from this work demonstrates that co-combusting biomass with natural gas (which is a lesser emitter of CO2 compared to other fossil fuels) allows for satisfying the energy demands while achieving net-zero CO2 emissions when CO2 capture is applied. The major limitation that has faced the application of bioenergy with carbon capture technology has been concerns over its competition with farmlands for food production. The results obtained from this work has showed that lower amount of biomass would be needed for energy generation via co-combustion with natural gas towards achieve net-zero emissions when a solvent with an improved CO2 removal ability is used as the absorbent in the CO2 capture process.
Open Access
Adaptive Neuro-Fuzzy Inference Systems (ANFIS) - Based Model Predictive Control (MPC) for Carbon Dioxide Reforming of Methane (CDRM) in a Plug Flow Tubular Reactor for Hydrogen Production
(Faculty of Graduate Studies and Research, University of Regina, 2013-01) Essien, Ememobong Ita; Ibrahim, Hussameldin; Mehrandezh, Mehran; Idem, Raphael; Shirif, Ezeddin; deMontigny, David; Azam, Shahid
The current sources of our energy supply are plagued with many problems, and the impact on the climate is of grave concern. To preserve and sustain our environment, a non-polluting and renewable energy source is required. Hydrogen (H2), when extracted from one of its many sources during carbon dioxide (CO2) capture, is considered a non-polluting, efficient and environmentally sustainable energy source. In this research work, the control of a pilot-scale reformer for the production of hydrogen was studied. Hydrogen was produced through the carbon dioxide reforming of methane (CDRM). This process was used to convert methane (CH4) and carbon dioxide into hydrogen. A high methane conversion was maintained by controlling the temperature in the reformer at the thermodynamically desired level. The control strategy applied to this process was the model predictive control (MPC) based on an adaptive neuro-fuzzy inference system (ANFIS) model. MPC has, among other advantages, the ability to predict the response of the system over a given prediction horizon. Experimental results showed that the ANFIS model was able to accurately replicate the response of the process to changes in temperature. Based on the ANFIS model, an MPC strategy was formulated for the process.
Open Access
Algal control and prevention technologies for Lake Diefenbaker irrigation canals
(Faculty of Graduate Studies and Research, University of Regina, 2023-03) Gebreselassie, Samuel Teclemariam; Young, Stephanie; Huang, Gordon; Sharma, Satish; Idem, Raphael
The Lake Diefenbaker irrigation project makes up an extensive 500 km of canals that officially began in July 2020. These canals contain pumps for increased and enhanced irrigation throughout southern and central Saskatchewan. However, the efficiency of the canals is hindered by the growth of filamentous algae. The filamentous algae are a nuisance and block pumps, making it difficult for water to be distributed to all the desired locations within the province. Currently, a synthetic chemical, Magnacide H, is utilized to control the growth of the algae at the cost of approximately $1 million per year, which is high cost. This study, as such, seeks to review, evaluate, compare, and develop algal prevention and control technologies as well as propose a suitable canal design option that would minimize algae growth. Five field trips to Lake Diefenbaker Irrigation Canals were conducted in June, July, August, September, and October to ascertain the factors contributing to the canal's algal blooms. Tests were also conducted to determine the canal's suitability for irrigation to check whether the key parameters were within the optimal range. According to the test results, all the parameters were within the recommended Saskatchewan irrigation guideline. This study considers three algal prevention and treatment options: 1) Non-toxic dyes and colorants, 2) microbubbles and nanobubbles, and 3) Ultrasound technology. The use of microbubbles and nanobubbles technology was selected as the most suitable option. Although highly efficient, the other options failed because of their high costs and low location suitability. Furthermore, the study recommends that the modified canal design be deeper, narrower, sloped, or trapezoidal. Such a design is recommended because it can limit the amount of sunlight entering the water. In addition, deepening the canal's edges with an inclination ratio of 2:1 can help control the growth of algae by minimizing the number of shallow areas that receive sunlight penetration. As research and testing for algal control and prevention methods are still relatively new, further research is required to understand the effectiveness of algal control and prevention technologies fully.
Open Access
Amine and Catalyst Stability Studies in the Catalyst-Aided CO2 Capture Process
(Faculty of Graduate Studies and Research, University of Regina, 2021-08) Amoako, Benjamin; Idem, Raphael; Supap, Teeradet; Narku-Tetteh, Jessica; Tontiwachwuthikul, Paitoon; Torabi, Farshid
The application of sol id base and sol id acid catalysts to improve CO2 capture has been one of the most notable technological advancements in amine-based post -combust ion capture. Despite the inherent benefits of the catalysts, the amine solvent is st i l l prone to degradation, which is a major operational problem associated with the capture process. The nature of solvent degradation in catalyst -aided CO2 capture has not been reported before, and thus, the effect of catalyst on solvent or vice versa is unknown. This work evaluates the effect of catalyst on solvent degradation and vice versa using BEA-AMP bi -blend solvent and recent absorber and desorber catalysts , which have produced remarkable CO2 capture performance. The absorber and desorber catalysts are CNTs/K-MgO and Ce(SO4 )2 /ZrO2 , respectively. A preliminary stability study was conducted under typical absorption conditions in a semi -batch mode. The results revealed that CNTs/K-MgO increases solvent degradation. Degradation was direct ly proportional to temperature in the region of 313-333K. It was also found that the catalyst reduces the activat ion energy of degradation by 11%. In addition, NH3 emissions from the degradation cell s increased wi th temperature . However, emissions were lower with the addition of catalyst due to the presence of colloidal silica used in binding the catalyst . The absorber catalyst was further investigated using normal conditions of the absorber during capture . The results showed 41 and 30% increments in degradation rates of BEA and AMP, respectively, with the catalyst . The effect of Ce(SO4 )2 /ZrO2 on the solvent was investigated in a bench-scale CO2 capture plant . The catalyst increased degradation by 23% for BEA and 20% for AMP. The effect of catalytic degradation on performance was evaluated by comparing the CO2 cyclic capacities of the catalytic and non-catalytic runs on the f irst and last days of the experiment . The results showed that the cyclic capacity of the catalytic run was 25% higher than the non-catalytic run on the last day, which is 18% lower than that obtained on the first day. Again, the decline in cyclic capacity of the catalytic system was faster by 10% due to the additional effect of catalyst on speeding amine degradation. The Ce(SO4 )2 /ZrO2 -aided degraded solvent was further tested with CNTs/K-MgO in the semi -batch mode. Further degradation was observed, showing that the combined ef fect of both catalysts would be higher in a typical capture plant . The fresh and spent catalysts from the test runs were characterized and compared to assess the stability of the catalysts. From the results, there were changes to the physical and chemical properties of the catalysts, which are known to be essential for CO2 capture. Increased degradation translates to a higher solvent replacement cost . Therefore, the findings of this work would represent the first step in developing better catalysts that would have a significantly reduced effect on the stability of the solvent to lower the cost of capture.
Open Access
Analytical and Semi-Analytical Models for Composite Reservoirs with Complex Well Completions
(Faculty of Graduate Studies and Research, University of Regina, 2016-04) Idorenyin, Etim Hope; Shirif, Ezeddin; Torabi, Farshid; Zeng, Fanhua; Idem, Raphael; Henni, Amr; Volodin, Andrei; Mouhoub, Malek; Azaiez, Jalel
With the current increasing productivity and the proliferation of shale and tight sand resource plays in Canada, and North America in general, the need to understand and characterize these resource plays, for the purpose of recovery optimization, has taken center stage in reservoir management. It is, however, important to note that these hydrocarbon environments are fundamentally different from conventional reservoirs for which there is an abundance of high-yield technical know-how. In a technical sense, these plays are not reservoirs but source rocks; their permeabilities are in the micro- to nano-darcy range. Hence, they cannot sustain economic hydrocarbon production unless they are engineered using unconventional stimulation methods like multi-stage hydraulic fracturing, for instance. As a result, traditional reservoir modeling methods fail, or give misleading results at best, when used to study these hydrocarbon plays. The objective of this research work is to develop rigorous (and yet) practical analytical and semi-analytical models for multi-well performance in petroleum reservoirs, with a view to simulating and forecasting production from unconventional resources. The models will address flow in different reservoir systems (homogeneous reservoirs and composite reservoirs) produced by various well completion types, including vertical, horizontal, fractured vertical and multiply fractured horizontal wells. It is also worth mentioning that most reservoir studies ultimately dwell on numerical simulation because of the flexibility and ease with which geological features can be incorporated in numerical simulation models. However, field-wide simulation studies are resource intensive and time consuming. In addition, the results obtained are heavily dependent on the quantity and quality of data available. It is therefore advisable and much more affordable to carry out simulations of this magnitude only when an initial performance study has been conducted and initial estimates of reservoir parameters have been obtained from the more tractable analytical and semi-analytical models. The models presented in this research work are practicable for reliable investigation of flow behavior in both conventional and unconventional reservoirs, and also provide results that can be used to seed the more involving numerical simulation.
Open Access
Assessing the Performance of Aspen Plus and Promax for the Simulation of CO2 Capture Plants
(Faculty of Graduate Studies and Research, University of Regina, 2012-05) Ahmadi, Fakhteh; deMontigny, David; Henni, Amr; Idem, Raphael; Shirif, Ezeddin
Carbon dioxide is a prominent greenhouse gas whose emissions have significantly increased due to human activities. Fossil fuel-fired power plants are the largest source of CO2 emissions, which results in a need for CO2 capture at these power plants. Prior to building a large scale CO2 capture plant, a pilot or demonstration plant is set up to confirm the feasibility of the plant. Simulation techniques are needed before actually constructing the plant, in order to improve the reliability and to increase productivity. A number of simulation software tools have been developed and are widely used to complete the simulation of a power plant integrated with a CO2 capture plant. Therefore, the capability of the software to model and simulate the plant correctly, and to generate accurate and reliable results, is of particular importance. In this work, the performance of two of the most commonly used process simulators for CO2 capture, namely ASPEN Plus and PROMAX, was evaluated and compared. In order to achieve this goal, eight data series from two CO2 capture pilot plants were selected and simulated with the above-mentioned simulators. The pilot plant data came from the International Test Centre for CO2 Capture (ITC) and the Esbjerg CO2 from Capture to Storage (CASTOR) project. Simulations were compared to experimental results using several parameters, including CO2 recovery, lean and rich loadings, steam and heat duties, CO2 percentage in the product stream, and the temperature and concentration profiles in the columns. Results showed that both software packages could predict the behavior of the system accurately and generate reliable results. The obtained results showed that in most cases, particularly in predicting the absorber and stripper profile along the column, PROMAX generated results that were closer to the actual experimental data, when compared to ASPEN.
Open Access
Beyond Net-Zero Carbon Emissions in Industrial Process through Catalyst-Aided Amine Solvents for the Indirect Co-Combustion of Natural Gas and Biomass
(2024-11-06) Nii-Adjei Adjetey, Samuel; Appiah, Foster; Natewong, Paweesuda; Narku-Tetteh, Jessica; Supap, Teeradet; Idem, Raphael
This poster demonstrate research efforts undertaken to explore innovative approaches to achieving net-zero carbon emissions in industrial processes by integrating catalyst-enhanced amine solvents for the indirect co-combustion of natural gas and biomass. The research focuses on the development and optimization of heterogeneous solid-base catalysts to enhance CO₂ absorption rates, improve solvent loading, and increase overall process efficiency. Various catalysts, including PEI-modified catalysts, K/MgO, K/MgO-CaO, and activated carbon blends, were synthesized and evaluated. Results indicated significant improvements in CO₂ capture rates, with the K/MgO-CaO catalyst demonstrating notable chemical, thermal, and mechanical stability. Furthermore, a life cycle assessment (LCA) based on the ReCiPe methodology highlighted the environmental benefits of this novel catalyst-solvent system compared to conventional MEA-based carbon capture and the novel solvent AMP:PRLD. This work presents a promising pathway for power and energy sectors to enhance sustainability, reduce emissions, and move beyond net-zero targets.
Open Access
Carbon Dioxide Absorption into Aqueous Ammonia in a Hollow Fiber Membrane Contactor
(Faculty of Graduate Studies and Research, University of Regina, 2016-07) Cui, Zheng; deMontigny, David; Idem, Raphael; Henni, Amr; Wee, Andrew; Liang, Zhiwu
Chemical absorption has been considered as a promising technology for carbon dioxide (CO2) capture from different industrial waste gases. However, this technology has not been widely commercialized due to its high capital and operational costs, especially the cost for solvent regeneration. Studies have been focused on developing more efficient gas/liquid contactors or superior solvents that require less energy for regeneration. Aqueous ammonia (NH3) has been recently studied as a CO2 absorption solvent in many traditional gas/liquid contactors due to its lower cost and low energy requirement for solvent regeneration compared to traditional amine solutions. Since membrane contactors offer more advantages than traditional gas/liquid contactors, it could be more efficient and economic to capture CO2 using aqueous ammonia as a solvent in a membrane contactor. However, little research has been reported in this field. The main objective of this research is to investigate the CO2 absorption performance of aqueous ammonia in a hollow fiber membrane contactor. In order to achieve this research goal, a number of lab-scale CO2 absorption experiments were conducted using aqueous ammonia and monoethanolamine (MEA) as absorption solvents in a membrane contactor fitted with polytetrafluoroethylene (PTFE) hollow fiber membranes at ambient temperatures. The CO2 absorption performance was evaluated in terms of the volumetric overall mass transfer coefficient (KGav) under different operating parameters. The absorption performance of aqueous ammonia was compared to that of MEA solvent under the same experimental conditions. The longterm membrane stability was evaluated by continuously running the CO2 absorption experiments using aqueous ammonia as a solvent for up to ten hours.
Open Access
Catalyst-aided CO2 capture from exhaust gases of industrial point sources for utilization in cement-based industry
(Faculty of Graduate Studies and Research, University of Regina, 2024-01) Brakwah, Emma Kwarteng; Idem, Raphael; Supap, Teeradet; Ibrahim, Hussameldlin; Tontiwachwuthikul, Paitoon(P.T)
The utilization of solid-base catalysts to improve CO2 capture in amine-based postcombustion processes represents a significant technological advance. However, addressing both cost and catalytic efficiency remains crucial. Given the inherently expensive nature of amine-based post-combustion, there is an urgent need to explore innovative strategies to alleviate financial burdens. Research has shown that costs can be reduced by eliminating the desorption tower and utilizing enriched solvent directly from the absorber column. Accelerating the capture process via catalyst introduction reduces column height and further cuts costs. The primary focus of our study was to develop an alkaline catalyst to enhance CO2 loading in Potassium Glycinate salt solution. Our ultimate goal was to apply this enriched solution in the cement-based industry for producing concrete, mortar, and grout. In the course of this research, a total of twelve super basic catalysts were synthesized and rigorously assessed using a semi-batch apparatus. Their initial absorption rates were meticulously scrutinized and juxtaposed against the baseline scenario devoid of any catalyst. Notably, the introduction of most catalysts yielded a marked acceleration in CO2 absorption, resulting in remarkably increased absorption rates. These initial absorption rates were observed to follow a discernible ascending order Ce/CaO < K/MgO < Blank < AGO* < K/MgO + AGO < K/MgO + GO < Ce/MgO < AC (H) < AC (H) + MgO < GO < AGO + AC (H) < K-MgO/AC (C) < AGO. Outstandingly, AGO exhibited the highest initial absorption rate at 5.12×10-2 (mol CO2/l.min), closely traced by KMgO/ AC (C) at 4.77×10-2 (mol CO2/l.min), while Ce/CaO and K/MgO displayed relatively lower performance at 3.56×10-2 and 3.63×10-2, respectively. Intriguingly, it was noted that Ce/CaO and K/MgO, rather than facilitating CO2 absorption by the Potassium Glycinate salt solution, reverted to their starting materials, Ca(OH)2 and Mg(OH)2 respectively, in the presence of water which formed carbonates with the CO2, diminishing the readily available CO2 for the Potassium Glycinate salt solution to capture. Considering the intricate and potentially hazardous nature of the AGO preparation process, along with environmental and safety concerns related to the chemicals used, KMgO/ AC (C) was selected as the preferred catalyst for this study. It exhibited a 25.2% enhancement in the absorption process, in contrast to the 34.4% improvement achieved by AGO. K-MgO/AC (C) underwent comprehensive characterization to determine both its chemical and physical properties, and the findings are meticulously documented in this study. Moreover, the results derived from the characterization of K-MgO/AC (C) were juxtaposed with existing data on AC (H) and K/MgO from literature, providing insights into and comparisons of the performance of these three catalysts based on their respective characteristics. In an effort to assess the stability of the K-MgO/AC (C) catalyst, two distinct approaches were employed. In the first approach, the same catalyst was utilized for three consecutive runs, with fresh solvent introduced between each run. In the second approach, the catalyst underwent washing, drying, and high-temperature calcination to eliminate any residual deposits before being reused. The stability analysis outcomes corroborated the robust stability of the K-MgO/AC (C) catalyst for up to three successive cycles of usage, a conclusion reinforced by the results obtained from thermal gravimetric analysis (TGA). Worth noting is the fact that all experiments conducted during the course of this study remained well within the acceptable margin of error, not exceeding 8%.
Open Access
Catalystic Pyrolysis for the Production of Stable Phenol Rich Bio-Oil from Wood Biomass
(Faculty of Graduate Studies and Research, University of Regina, 2016-09) Kaushik, Priyanka; Ibrahim, Hussameldin; Idem, Raphael; Henni, Amr
Biomass studies over the last two decades shows its use as an alternate source for the production of chemicals and fuels. This can help in reducing our load on the conventional hydrocarbon use and be shared with renewable sources such as forest and agricultural wastes. In Saskatchewan, there is abundant availability of wood waste from the timber industry; hence wood can be used as biomass raw material for the production of bio-chemicals. Pyrolysis is the most promising technology for the conversion of biomass into liquids. In this research, wood pellets obtained from a lumber company were used as the feed for pyrolysis to produce a phenol-rich stable bio-oil. Usually, after the bio-oil production, catalytic cracking is done to produce valuable products. In this research, the aim was to produce phenol-rich bio-oil in single step. The experiments were carried out in three phases; Phase I: Parametric study, Phase II: optimized conditions and best-suited catalyst for stable phenol rich bio-oil and Phase III: kinetic study of the process. Experiments were performed in a packed bed reactor under varying temperatures (400,500, 6000C), acidic catalysts (H-ZSM-5, γ-alumina and silica alumina), feed size (0.71, 0.85, 1, 1.18 and 1.44mm) and catalyst weights (1g and 2g). For the kinetic study, experiments were carried out at varying residence times (0, 30, 60 and 90 minutes). Products were collected and analyzed in three phases: bio-oil, gas and char. Gas Chromatography - Mass Spectroscopy (GC-MS) and online GC equipment was used to analyze bio-oil and gases respectively. Significant in phenol derivatives is observed with the use of acid catalyst along with the reduction of oxygenates or sugars. The reduction in sugar content shows the stabilization of bio-oil as the amount of free radicals is reduced hence polymerization of undesired products can be avoided thus increasing the bio-oil shelf life. Catalyst acidity, strength and number of acid sites showed a significant effect on yield of phenol derivatives in bio-oil. Kinetic study of wood catalytic pyrolysis was performed in a batch reactor; component content data was obtained at increasing time intervals and temperatures. The gases were analyzed with the help of GC and carbon content in char was analyzed by sending samples to the Saskatchewan Research Centre (SRC) in Saskatoon. Using the ultimate analysis of wood and carbon in char, carbon conversion was calculated. The rate of reaction can be expressed by a 2 order kinetic model with an activation energy of 17104.04 J/mol and a preexponential factor of 0.000567/s. Statistical analysis was also carried out using the physical and chemical properties of the catalysts. Using MINITAB, a statistical model for the yield of phenol derivatives was determined for 1g and 2g acidic catalysts. The analysis for second resolution interaction model shows the main effect of pore volume, surface area and number of acid site on phenol derivatives yield. Also, interactions of these factors help to understand the effect on phenol yield. The predicted yield from these models and experimental yield gave overall AAD of 7% that shows a good agreement with the model.
Open Access
Catalysts for Hydrogen Production by the Auto-Thermal Reforming of Glycerol
(Faculty of Graduate Studies and Research, University of Regina, 2013-01) Sabri, Faezeh; Ibrahim, Hussameldin; Idem, Raphael; deMontigny, David; Shirif, Ezeddin; Henni, Amr
Due to a number of major environmental issues, essentially greenhouse gas emissions and fossil fuel reliance, the implications of hydrogen as a promising clean energy carrier have significantly increased. In this respect, the use of bio-renewable feedstock such as glycerol for hydrogen production is becoming important. The majority of natural glycerol is produced as a by-product of the bio-diesel industry. Presently, almost all crude glycerol is refined before its ultimate end use. It is the ultimate goal of the present study to develop an effective catalytic auto-thermal reforming process to convert glycerol into top value bio-based products. Glycerol can be converted to hydrogen-rich streams by steam reforming (SR), partial oxidation (POX), gasification, auto-thermal reforming (ATR), supercritical water reforming (SCWR) or aqueous-phase reforming (APR). Most of the studies have focused on SR processes for producing hydrogen over various costly noble metal-based catalysts. A portfolio of nickel-based catalysts with nominal composition 5% Ni/Ce0.5Zr0.33M0.16O2- [where M is the promoter element(s) selected from Mg, Ca, Y, La, or Gd] was prepared and examined for their catalyst activity for glycerol auto-thermal reforming. The catalysts’ activity was evaluated using a plug flow reactor at atmospheric pressure and in the temperature range of 450°C to 700°C, steam-to-glycerol ratio of 6, 9, and 12, and oxygen-to-glycerol ratio of 0.2, 0.5, and 0.8 at atmospheric pressure in a packed bed tubular reactor (PBTR). The preliminary screening studies were carried out for a time-on-stream (TOS) of 6 hours with sampling intervals of 1 hour. The physicochemical and textural characteristics of the catalysts were investigated by means of a variety of characterization techniques such as temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), nitrogen (N2) physisorption, hydrogen (H2) chemisorption, UV-Vis diffuse, thermogravimetry analysis (TGA), and X-ray diffraction (XRD). The gaseous products were analyzed by online gas chromatography equipped with a thermal conductivity detector (GC/TCD). The structural, textural, and physicochemical characteristics of the catalysts have been investigated with the help of different bulk and surface characterization techniques. Different ratios of steam/glycerol and oxygen /glycerol were employed to optimize the conditions to achieve the highest conversion as well as H2 selectivity. Based on the above analyses, glycerol conversion and H2 selectivity were calculated. Among all the catalyst formulations screened in the current study, the catalyst formulations prepared with Ca, Y, Mg, La, and Gd exhibit stable and steady activity even at 500°C. The catalyst formulation with Gd as a promoter element performed the best at all the investigated temperatures. Hence, it is a potential candidate for future commercialization and plausible membrane reactor applications. The thermal and catalytic effects on catalytic auto-thermal reforming were identified by performing a number of non-catalytic reaction runs and then comparing the results with the corresponding catalytic reactions.
Open Access
Catalytic Hydrothermal Liquefaction of Camelina Sativa Residues for the Production of Biogasoline Range Liquid Biofuel
(Faculty of Graduate Studies and Research, University of Regina, 2018-01) Akande, Abayomi; Ibrahim, Hussameldin; Idem, Raphael; Salad Hersi, Osman; Henni, Amr; deMontigny, David; Shirif, Ezeddin; Saberian, Mohammad
Camelina Sativa residue was used as a feedstock to investigate the production of biogasoline from the biomass material by catalyst-assisted hydrothermal liquefaction process. In the new process development, a non-catalytic experimental performance evaluation was conducted as a baseline process to compare and evaluate catalytic performance. Four commercially available catalysts otherwise called precursors were initially tested to set the stage for the performance evaluation of the in-house developed catalysts. The commercial catalysts used were HZSM-5, SiO2-Al2O3, SBA-15 and γ-Al2O3. The performance activities of the commercial catalysts show no sign of improved biomass conversion compared to non-catalytic process, which has a maximum biomass conversion of 72 wt. %. However, of all commercial catalysts used, γ-Al2O3 under subcritical water condition produced the best biogasoline yield performance of 15 wt. %, an improvement over the non-catalytic process which produced 12 wt. % under same condition. The marginal increase was even further improved when 5% cobalt was impregnated on the γ-Al2O3 to form a new bifunctional catalyst, 5Co/γ-Al2O3. In this case, the biogasoline yield increased from 15 wt. % to 23 wt. %. When molecular hydrogen was introduced into the process at pressure 5 MPa hydrogen pressure and 14 MPa process autogenic pressure, 5Co/γ-Al2O3 produced even an improved performance, with biogasoline yield was increase to 28 wt. %. Furthermore, different bifunctional and dual support catalysts were developed with two commercial catalysts as precursors. This development produced new hybrid and synergy catalysts. These catalysts were tested for performance evaluation and the best performing catalyst was 5Co/γ-Al2O3/HZSM-5. The new catalyst under the same experimental conditions gave the best performance, and the biomass conversion increased to 79 wt. %, an improvement over 70-72 wt. % obtained from most catalyst-assisted and non-catalytic cases. Also, the biogasoline yield was 43%, which was the highest obtained in all cases. Addition of nickel as promoter did not add values to the process as the biogasoline yield declined. The best process parameters optimization show that biomass size of 1.0 mm, catalyst metal loading 5%, catalyst weight/biomass weight ratio of 0.2, hydrogen pressure 2 MPa, and retention time 30 minutes are optimum for the best performance. The intrinsic kinetic analysis of this process shows there are two different temperature regimes with different kinetic parameters; this effect was attributed to different factors, one was the ionic product of water that varies exponentially with temperature and second was the heating rate of 5oC/min that was used as a fixed parameter. The low and high temperatures regimes have order of reaction 2 and 1 respectively. The activation energies were 16,420 and 12,627 J/mol respectively and the collision factors were also 0.7603 and 0.1715 s-1 respectively. An overall kinetic parameter shows that the slower high temperature reaction was the rate controlling with collision factor of 0.1970 s-1, activation energy 12,783 J/mol and reaction order 1.0. The parity chart for the experimental and model predicted rate using the overall model gave an average deviation of 6.64%. Two other regression models were developed to estimate the performance of the best selected catalyst for solid biomass conversion and biogasoline range liquid production. The models are given in equation 7.1 and 7.2 respectively. The parity chart developed using results from these models showed an average deviation of 0.99% and 6.53% between the experimental and model derived values. The statistical analysis provided showed relationships between various parameters which could optimize the process. The conclusion of this section would be based on future economic analysis.
Open Access
Catalytic Production of Furfural by the Subcritical Hydrothermal Gasification of Flax Straw
(Faculty of Graduate Studies and Research, University of Regina, 2013-12) Jaafari, Laila Ibrahim; Idem, Raphael; deMontigny, David; Ibrahim, Hussamedin; Aroonwilas, Adisorn; Shirif, Ezeddin
Developing new sources of energy that can mitigate greenhouse gas (GHG) emissions has generated a strong research interest in the past two decades. Renewable sources of energy have become strong candidates for replacing the conventional resources in order to ameliorate the high level of pollution caused by the use of conventional fossil fuels. Biomass is a type of renewable resource that is considered to be carbon neutral when used in producing fuels and chemicals. Flax straw is an example of biomass that accumulates in Canada in high amounts. It is difficult to dispose of because it does not decompose easily as a result of its tough fibrous nature. However, it can be used through a hydrothermal gasification process to produce gaseous fuels as well as some important liquid products. Hydrothermal gasification process was used in this research because it can deal with wet biomass without the necessity of the drying step. Furfural is an important chemical that has many industrial applications, and as such, was considered to be the major desired product through the hydrothermal gasification of flax straw using a solid acid catalyst. This study focused on the catalytic subcritical hydrothermal gasification of flax straw. The study was performed using a 600 mL autoclave batch reactor using flax straw with a fixed weight (10 g) in all the experimental runs. Three types of solid acid catalysts were explored in this study: γ–alumina, H-ZSM-5, and silica-alumina. Experimental parameters such as temperature (200-325 oC), pressure (0-60 bar), residence time (0-120 min) and weight of solid acid catalysts (0.5-1.5 g) were varied in order to obtain the optimum conditions and to select the best catalyst for producing furfural. The yields of both gas and phenol were also monitored in the study. The yield of gas was quantified using an online gas chromatograph (GC). The gas products included hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2) and trace amounts of methane (CH4) and ethane (C2H6). The yields of furfural and phenol were measured by gas chromatograph/mass spectrometer (GC/MS). The results showed that the production of furfural was affected by all the experimental parameters (temperature, pressure, residence time and weight of the solid acid catalysts). The highest yield of furfural was obtained using γ-alumina with 0.1 g as the optimum weight of catalyst per g of flax straw. The ranking of the three catalysts based on furfural production was: γ–alumina > HZSM- 5 > silica-alumina. This had a direct correlation with the ratio of Lewis to Brϕnsted acid sites which decreased similar to the ranking of the performance of the catalysts. A kinetic study of the catalytic subcritical hydrothermal gasification of flax straw using 1 g of γ–alumina was also performed. Kinetic data were obtained using 10 g of flax straw, autogenous pressure, temperatures in the range of 225-325 oC, and residence time in the range of 0-120 min. The data were analysed using an empirical power law rate model. The carbon conversion was calculated using the ultimate analysis, which gave the highest conversion of 66% at 325 °C compared to the conversion of 40% obtained for a previous non-catalytic study. The final kinetic model was: -rA = 􀯗􀯑􀮺 􀯗􀯧 = 7.038 * 10-2 e -9463.5/R*T (1 – XA)2. The activation energy achieved in this study was lower than the activation energy of 27,969.6 J/mol obtained by the non-catalytic study thus showing the importance of the catalyst in lowering the energy barrier. The predicted rates from the model showed good agreement with the experimental rates with an average absolute deviation of 8.6%.
Open Access
CO2 emissions reduction through catalytic production & use of fuels derived from biomass
(Faculty of Graduate Studies and Research, University of Regina, 2023-03) Anokye-Poku, Terza; Idem, Raphael; Ibrahim, Hussameldin; Supap, Teeradet; Jia, Na
This study focused on the preparation of environmentally friendly heterogenous catalyst from biomass specifically waste egg shells, cow bones and fish scales for use in the production of biodiesel from waste cooking oil (WCO) which is also a biomass-based waste feedstock collected from households that will be an alternative fuel source and contribute to reducing CO2 emissions into the environment as well as the cost of biodiesel production To begin, the biodiesel feedstock properties needed to be checked for its suitability in making fuel because the feedstock properties were going to impart the properties of biodiesel. The first property of the oil checked was the fatty acid composition. The need for a further purification step apart from filtration was confirmed and other properties of the feedstock such as viscosity, density, acid value and water content of the WCO were also checked. Based on these, the WCO fell in the range within which it could be used in making biodiesel, there was no need for further physical purification steps because the properties of both the crude and purified WCO were very close. In addition, the properties showed that a catalyst basic in nature was suitable for the transesterification process. The next phase involved carrying out reactions with the conventional basic catalyst (KOH) to serve as a baseline for the work to which heterogenous catalytic reactions would be compared. The heterogenous catalysts were then synthesized from waste egg shells (ES), cow bones (CB) and fish scales (FS) separately before bi-blend (CBES, FSCB, FSES) and tri-blend mixtures (M3) of these components were made in a ratio of 1:1 and 1:1:1 respectively and characterized. The focus of the catalyst was on the performance of M3 and how CB, FS and ES contributed to that as well as its performance in comparison to biii blend mixtures that have been the kind of blends prepared in literature for biodiesel catalysts. All seven heterogenous catalysts were utilized in transesterification reaction of the WCO at the same process conditions to evaluate their performance with respect to biodiesel yield. The biodiesel yield of these catalysts followed a trend of decreasing order as follows: M3 > FSES > CBES > ES > FSCB > FS >CB mainly due to the basicity resulting from the type of active components present in these catalysts. Regression analysis was performed to further validate which characteristics affected the performance and it was confirmed that the most important characteristic of the catalysts in this work was basicity. Furthermore, since M3 was the focus and the best performing catalyst amongst the heterogenous catalysts as well, it was compared to the yield of the homogenous reactions that was used as the baseline and a difference of averagely 27% was observed. M3 was then used in reactions to study the effect of the process variables on the biodiesel yield and the optimum conditions were found to be a temperature of 60°C, 6 hours of reaction time, stirring speed of 600 rpm, ethanol-to-oil molar ratio of 15:1 and catalyst concentration of 2wt% of the oil.
Open Access
Comparative Assessment, Parametric Sensitivity, Economics, and Modeling of Novel 1,5-diamino-2-methylpentane Based Amine Solvent Blend for CO2 Capture From Large Industrial Sources
(Faculty of Graduate Studies and Research, University of Regina, 2018-11) Nwaoha, Chikezie Ndubuisi; Tontiwachwuthikul, Paitoon; Idem, Raphael; Ibrahim, Hussameldin; Torabi, Farshid; Raina-Fulton, Renata; Mahinpey, Nader
This research investigates the development of novel 1,5-diamino-2-methylpentane (DA2MP) based amine solvent blend for CO2 capture from large industrial sources. The lab-scale absorber and desorber pilot plant (2 inch by 42 inch each) were used to investigate the comparative CO2 capture analysis of the novel 2 kmol/m3 AMP-(1 to 3) kmol/m3 DA2MP blend to 5 kmol/m3 MEA and 2 kmol/m3 AMP-1 kmol/m3 PZ blend for the power plants (8 vol.% CO2 and 15.1 vol.% CO2), and lime kiln (30 vol.% CO2) industries. For the water-gas shift process plant (50 vol.% CO2) the CO2 capture performance of novel 3 kmol/m3 MDEA-(0.5 to 1.5) kmol/m3 DA2MP blend was compared to the benchmark 3 kmol/m3 MDEA-0.5 kmol/m3 PZ. The main key performance indicators (KPIs) are mass transfer coefficients, regeneration energy, CO2 absorption efficiency, CO2 absorption rate, and viscosity and density of the CO2 loaded amine solutions. A nonlinear correlation was developed and compared to the artificial neural network (ANN) for accurate prediction of viscosity and density of AMP-DA2MP and MDEA-DA2MP blends. The effect of the carbon tax, CO2 sales price and a newly developed carbon tax model/correlation on the CO2 capture cost was studied. Results from the KPIs revealed that the 2 kmol/m3 AMP-1.5 kmol/m3 DA2MP is the optimal amine concentration and has superior CO2 capture performance compared to MEA and AMP-PZ blend while 3 kmol/m3 MDEA-1 kmol/m3 DA2MP was optimal and performed better than the MDEA-PZ blend. Parametric sensitivity analysis of 2 kmol/m3 AMP-1.5 kmol/m3 DA2MP showed that the amine flow rate and concentration, and reboiler temperature of integral in optimizing the performance and reducing carbon capture cost. The developed nonlinear correlation accurately predicted the density and viscosity of the amine blends (R2 up to 0.9309), however, the ANN model has a superior predictive accuracy (R2 up to 0.9999). The effect of the CO2 sales price was observed to reduce the CO2 capture cost iii compared to the carbon tax. Also, the proposed carbon tax model reduced the CO2 capture cost compared to the carbon tax from the government. Overall, the novel AMP-DA2MP and MDEA-DA2MP blends are capable of costeffective and energy efficient CO2 capture.
Open Access
Comparative Evaluation of the Performance of Synthetic Polymer and Biopolymer as a Means of Enhanced Oil Recovery Method
(Faculty of Graduate Studies and Research, University of Regina, 2017-10) Du, Ye; Torabi, Farshid; Gu, Peter; Jia, Na; Idem, Raphael
After regular primary and secondary recovery treatments with ideal oil production no longer occur, enhanced oil recovery methods are introduced to produce the “leftover” oil in reservoir formations. Among the enhanced oil recovery (EOR) methods, polymer flooding is regarded as the most common and widely used treatment globally. By adding water-soluble high molecular weight polymers into water, viscous fluids This work aims to analyze the performance of two types of polymers as a means of EOR by comparing their rheological properties and laboratory 1D sandpack flooding studies. It compares the performance of these polymers against the performance of waterflooding as a secondary recovery method. The synthetic polymer partially hydrolyzed polyacrylamide (HPAM) Flopaam 3630S and biopolymer diutan gum are selected for this study, where higher recovery factors are observed than waterflooding. For rheological studies of both polymers, a cone/plate viscometer was introduced to investigate the apparent viscosity of polymer solutions over varying influential factors at various shear rates. The findings show that the biopolymer solution demonstrated a much larger viscosity loss compared to the HPAM polymer solution over the shear rate at the same concentration. Polymer concentration and temperature both presented a positive impact on viscosity loss, as the higher their values, the more the viscosity decreased. A larger viscosity deduction was observed when the ions concentration increased before the limitation of 1.0 wt%, whereas the divalent cation (Ca2+) presented a greater degree of effect than the monovalent one (Na+). Nine sets of 1D sandpack flooding experiments were carried out for polymer flooding with different saturated oils ranging from 500 mPa.s to 2,000 mPa.s, various concentrations of HPAM solutions (1,000~4,000 ppm), and a 2,000 ppm biopolymer solution with various injected pore volumes (0.2 ~ 0.5 PV). All tests were conducted with 1.0 wt% NaCl brine at room temperature (22◦C) at a flow rate of 1 cc/min. The ultimate oil recovery factor and water cut variation were recorded with respect to the injected fluid volumes. Overall, biopolymer presented a better performance compared to HPAM in most aspects. The ultimate oil recovery of biopolymer was 20% more than that of HPAM, and biopolymer also significantly altered the mobility ratio and improved the water cut. Polymer concentration and the injected polymer volume indicated a positive effect on oil production with the increase of their values. However, they did not ensure a significant improvement in production during polymer floods. A comparison between the results of varied oil samples suggested less impact on the performance of polymer flooding, although more viscous oil generated less production.
Open Access
A Comparison Study of Carbon Dioxide Absorption Performance in MEA and Blended Amine Solvents for Post-combustion Process: Experiment, Modeling and Simulation
(Faculty of Graduate Studies and Research, University of Regina, 2020-04) Li, Tianci; Tontiwachwuthikul, Paitoon; Idem, Raphael; Supap, Teeradet; Na, Jia
In recent years, industrialization causes excess carbon dioxide emissions. Carbon dioxide (CO2) is one of the main greenhouse gases due to human activities. However, high costs remain the main challenge to control the carbon dioxide from industry. Due to this issue, the carbon capture technique is developing slowly in most developing countries. This work is going to compare and explore a more effective blended amine solvent comparing with current common single amine solvents for the CO2 chemical absorption process for improving absorption performance and reducing the investment and operating costs. In this research, the CO2 absorption performance of aqueous MDEA/PZ blends and aqueous MEA/MDEA/PZ blends were comprehensively investigated experimentally and compared with the benchmark aqueous solution 5M MEA in terms of CO2 absorption rate, CO2 absorption efficiency, mass transfer efficiency and CO2 equilibrium solubility using a bench-scale packed column and a CO2 solubility apparatus. The simulation results have been validated with the experimental date from this research work other published experimental data. Different scenarios were assessed to evaluate the absorption performance using experiment method and simulation method. The overall mass transfer coefficient of the aqueous solvents and the CO2 absorption rate under ambient pressure is ranked as 2M MDEA+3M PZ>1M MEA+2M MDEA+2M PZ > 3M MDEA+2M PZ > 5M MEA. The measurements of the CO2 solubility experiments were performed over the CO2 partial pressure range of 8-51 kPa at 40oC. A new set of experimental data for the CO2 solubility in an aqueous solution of 1M MEA+2M MDEA+2M PZ blended solvent and aqueous MDEA/PZ blends were investigated and compared with the prediction results from the Artificial Neural Network model and the simulation results using MATLAB and ProMax, respectively. The prediction results from ANN model confirmed that the CO2 equilibrium solubility of 2M MDEA+3M PZ was higher than other blend amine solvents and the conventional amine (5M MEA). Also, the comparison results indicate that the neural network modeling provides more accurate prediction results of CO2 solubility test than the simulation results when compared with new experimental results in this research.
Open Access
A Comprehensive Evaluation of Off-Gas Emissions From A Catalyst-Aided, Amine-Based, Post Combustion Capture of CO2 From Industrial Exhaust Gas Streams
(Faculty of Graduate Studies and Research, University of Regina, 2021-12) Sai-Obodai, Lois Sandra Naa Oboshie; Idem, Raphael; Ibrahim, Hussameldin; Supap, Teeeradet; Young, Stephanie
The major focus of all CO2 capture technologies is to reduce emission of CO2 which is undoubtedly one of the major greenhouse gases blamed for global warming. It is imperative to ensure that while we aim to capture CO2 to achieve the production of clean energy, other contaminants are not released into our environment, so as not to defeat the main purpose of ensuring the safety of the environment. In the amine-based, catalyst-aided post combustion capture of CO2 technology, amine degradation occurs, and the degradation products are present in both the liquid and gas phases. It is important to know the composition and quantities of these degradation products to optimize the capturing process and ascertain that the capture process will not have a negative impact on the environment. For the amine solvent selection process two single amines: hexamethylenediamine (HMDA), and 2-amino-2-methyl-1-propanol (AMP), two polyethyleneimine (PEI) blends: HMDA/PEI and AMP/PEI and two 2-amino-2-methyl-1-propanol (AMP) blends: DMAE/AMP and BEA/AMP which served as the benchmark amine blend for this study were screened. After screening and comparing these amines based on their absorption and desorption properties, DMAE/AMP involving a tertiary amine and a sterically hindered amine with a total concentration of 4M was selected as the optimal amine solvent for the CO2 capture process in this study. The next phase of the work was to synthesise, characterise and screen two solid basic absorber catalysts; Activated Carbon Spheres (ACS) and a proprietary absorber catalyst (APC) and one solid acid desorber catalyst, a proprietary desorber catalyst (DPC). The screening results for the absorber catalysts showed that the equilibrium loading, and initial absorption rate were enhanced by 5.6% and 33.3 % respectively for ACS and by 3.9% and 29.4% respectively for APC. For the desorber catalyst, DPC, the lean loading was enhanced by 16%, the initial rate of desorption by 25.6% and the heat duty by 20.3%. The last phase of the work was to apply the selected amine solvent, DMAE-AMP, and a catalyst in a pilot plant set-up in two separate runs which lasted for a total of 15 days (360 hours) each. The desorber catalyst was used due to its high yield and direct involvement in helping to reduce the heat duty required for the regeneration process as observed during the screening tests. For each run, the off gas from the absorber column was trapped and analysed using the relevant EPA methods to access the volatile species qualitatively and quantitatively. The data obtained confirmed the presence of ammonia and four different aldehydes namely formaldehyde, acetaldehyde, acrolein and butyraldehyde in all samples taken. Traces of propionaldehyde and crotonaldehyde were observed in some samples of both runs with traces of valeraldehyde observed in some samples of only the run with the desorber catalyst. Ammonia had the highest rate of emission of 0.43ppmV/h and this was recorded in the blank run. The emissions of all observed compounds were higher in the blank run than the run with desorber catalyst under the same conditions. Finally, the emissions of both runs were found to be within the stipulated occupational limits set by the relevant regulatory board, confirming the overall environmental safety of the emissions of the capture process using DMAE/AMP, with and without the selected catalyst.
Open Access
Comprehensive Evaluation of the Physical and Chemical Properties of 1-dimethylamino-2-propanol for Post Combustion CO2 Capture
(Faculty of Graduate Studies and Research, University of Regina, 2018-05) Liu, Helei; Idem, Raphael; Tontiwachwuthikul, Paitoon; Supap, Terradet; Liang, Zhiwu; Torabi, Farshid; Mobed, Nader; Ricardez-Sandoval, Luis A.
Recently the worsening global warming issue caused by emissions and accumulation of greenhouse gases in the atmosphere has become a subject of public concern. Carbon dioxide (CO2) is widely considered as the predominant contributor of greenhouse gases. The absorption of CO2 into aqueous amine solution is regarded to be one of the most promising technologies for CO2 capture due to its maturity, cost effectiveness, and capacity to handle large amounts of exhaust streams. Recently, a new tertiary amine, 1- dimethylamino-2-propanol (1DMA2P), has drawn significant attention for its good performance in capturing CO2. The objectives of the overall work are to study the physical properties and chemical properties of the potential solvent (1DMA2P) for use in the field of CO2 capture. In order to achieve this goal, the study of the physical and chemical properties of 1DMA2P was presented in terms of density, viscosity, specific heat capacity, the physical solubility, diffusivity, CO2 equilibrium solubility, ions speciation plots and reaction kinetics. The densities, viscosities, and specific heat capacity of pure 1DMA2P, unloaded 1DMA2P solution and loaded 1DMA2P solution were measured over different 1DMA2P concentration and temperature ranges. In order to correlate the obtained results, some empirical models were employed to represent the experimental physical properties of 1DMA2P. In addition, ANNs models (BPNN and RBFNN model) were developed and used to correlate the physical properties of 1DMA2P. Henry’s law constants of N2O in pure 1DMA2P as well as in 1DMA2P solutions were measured over temperature and concentration ranges. The N2O diffusivity in aqueous 1DMA2P solution was measured over concentration and temperature ranges of 1.0-3.0mol/L and 298K-333K. The present ii models and the newly developed model were used to represent those results. In order to better correlate the experimental results of N2O diffusivity and understand the process of diffusivity, a new model mechanism was developed in the present work. The equilibrium CO2 solubility in 1DMA2P solution were measured at the different conditions of concentration, temperature range, and CO2 partial pressure. All experimental values of CO2 solubility were represented by applying correlation models for K2, for the present models (Kent-Eisenberg model, Austgen model, and Li-Sheng model). A new K2 correlation model has been developed to predict CO2 solubility. In addition, the CO2 absorption heat in 1DMA2P solution was estimated by using Gibbs-Helmholtz equation. Ions (1DMA2P, 1DMA2PH+, HCO3 -, CO3 2-) speciation plots for the 1DMA2P-H2O-CO2 system were developed based on the 13C NMR technique. A new method for selecting the protonation calibration curve was also developed by considering the charge balance in the 1DMA2PH2O- CO2 system in order to give better accuracy. A comprehensive reaction kinetics model for CO2 absorption in 1DMA2P solution was developed. The reaction constant (k1DMA2P) of CO2 with 1DMA2P solution was extracted from the model. Based on the CO2 capture performance of 1DMA2P in CO2 absorption parameters, the 1DMA2P could be considered as one of the alternative solvents as DEAB and, AMP for mixing with the solvents with higher reaction rate and higher absorption heat (i.e. MEA and PZ). On the basis of the absorption parameters provided in this work, both the conventional amines and this alternative amine were analyzed for the purpose of providing the guidelines or information on how to effectively screen solvents. Key words: 1DMA2P, physical properties, Henry’s law constants, diffusivity, CO2 equilibrium solubility, ions speciation plots, comprehensive kinetics model.