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Chemical looping reforming is a promising option for the conversion of gaseous fuels to high quality syngas suitable for gas-to-liquids (GtL) processes. This work evaluates the potential for syngas, heat, power, and steam generation for diluent production at steam assisted gravity drainage (SAGD) facilities using low cost ilmenite ore pressurized chemical looping reforming (PCLR). Preliminary fixed-bed reactor testing on a naturally occurring Canadian ilmenite ore was performed to determine the optimal operating regime for syngas generation. Based on SEM characterization, EDX elemental mapping, XRD, and Mossbauer spectroscopy measurements it was demonstrated that partial reduction to Fe2.5+ and Fe2+ containing species is required to avoid the production of CO2. Additionally, the reduction to Fe° containing species should be minimized to limit the formation of carbon and metal carbides. These results were used to generate material and energy balances via Aspen HYSYS V9 process simulation software of the entire PCLR process for SAGD applications using a Canada’s Oil Sands Innovation Alliance (COSIA) SAGD facility template. Thorough energy integration of the combined PCLR-SAGD process using Pinch Analysis suggests that steam and diluent requirements can be met, with excess power generation, at lower costs than more traditional syngas generation technologies, while meeting CO2 emissions targets and reducing boiler feed water (BFW) make-up. Having shown that process performance is attractive, a techno-economic assessment to establish the most economical design for the PCLR-SAGD process is now required.

This work introduces a novel approach to reduce the energy demand as well as capital and operating costs in a widely used gas purification process by optimal integration of ejector technology. Three scenarios for ejector integration have been identified into a dual-stage Selexol™ process configuration for H2S and CO2 removal from syngas. The clean syngas met the requirement to be used in an integrated gasification combined cycle. The intention was to unload or eliminate compressors used in the conventional design, and to reduce the capital and operating costs. Aspen HYSYS® is used to develop a detailed simulation model of the Selexol™ process and to assess the impacts of the proposed design configurations from an energy and economic perspective. A predictive design model is also used to evaluate the operating conditions of the proposed ejectors. Among the scenarios investigated, it is found that ejector integration is attractive only if one or some compressors can be eliminated. This work shows that an optimally integrated ejector in the CO2 recovery and compression section of the Selexol™ process can reduce the capital costs by up to 28%, while reducing the operating costs by up to 6%.

Chemical looping combustion is a promising option for the conversion of fossil fuels with inherent separation of CO2 and efficient use of energy. Nevertheless, key process challenges such as oxygen carrier reaction rates, costs, and environmental concerns still exist. We expected that these challenges would be overcome by operating chemical looping combustors at elevated pressures with ilmenite ore as the oxygen carrier. This work describes a design study that was performed to examine the potential for replacement of once-through steam generators (OTSGs) at steam assisted gravity drainage (SAGD) facilities for bitumen production with near zero CO2 emission pressurized chemical looping combustors. In order to minimize capital costs for the systems, design was constrained to ensure that all major components could be shop built. Heat and material balances for many different process configurations were generated using Aspen HYSYS process simulation software allowing for a range of options to be evaluated. We determined that operating pressures should be restricted to between 4 and 7 bar(g) to achieve very high steam generation efficiencies, while avoiding high power demand. Energy integration of pressurized chemical looping combustion with a Canada’s Oil Sands Innovation Alliance (COSIA) typical SAGD plant using Pinch analysis was performed resulting in a significant decrease in natural gas and boiler feed water (BFW) make-up requirements, while at the same time reducing CO2 emissions by over 95% down to 2.85 kg CO2/bbl bitumen. Having established that process performance is attractive, an economic study to establish the most economical design for pressurized chemical looping combustion for steam generation is now required.

This study aims to provide a comprehensive comparison of different configurations of amine-based Post-combustion carbon capture (PCC) using Mono-Ethanol Amine and activated Methyl Di-Ethanol Amine (MEA and a-MDEA) solvents. A base case simulation model of a process with MEA is developed and validated at two capture rates, of 20 and 2000 tonnes per day, with the data reported in a study prepared by Nexant. The model was then used for a 1900 tonnes-per-day capture facility, and several combinations of substantial process modifications, including absorber intercooling (AIC), lean vapor recompression (LVR), and parallel exchanger arrangement (PEA) are investigated. Various scenarios for the two amine-based solvents are simulated in Aspen HYSYS®, and the results are compared with a base case conventional process for the same solvent. Results from the studied scenarios showed that a-MDEA with AIC-LVR modifications is a more attractive option due to an 8% reduction in stripper reboiler energy and its associated steam costs. The analysis of the studied cases showed that the effect of solvent on energy saving is more important than that of process modification, with the combined effect of both modification and solvent bringing higher benefits. It is also concluded that a complex process such as PCC with AIC-LVR-PEA modifications has the highest energy savings although it is less cost-effective. While OPEX (Operating Expenditure) values (mainly associated with utility steam and cooling water consumption) are still considerable, we ended up with CAPEX-intensive (Capital Expenditure) capture plants. For typical PCC equipped with combined AIC and LVR modifications (total capital investments of $136 million and $147 million were estimated for MEA and a-MDEA, respectively, translating to capture costs of US$58.80 and US$53.80 per tonne of CO2 captured. Potential savings of approximately 4–15% (for MEA) and 3–12% (for a-MDEA) were calculated depending on the scenario of combined process modifications among a shortlist of attractive options. These energy reductions portray promising reductions in the energy consumption imposed by an amine absorption-based PCC technology.

The process design and life cycle assessment (LCA) of various methanol production processes, including the conventional natural gas reforming process and alternative CO2 utilization-based pathways, are performed in this work. Three main technologies are considered for the CO2 conversion to methanol: direct CO2 hydrogenation, dry reforming and tri-reforming of methane. For each pathway, a process simulation that includes the CO2 capture from typical flue gas of a cement kiln, the methanol synthesis and purification steps, is performed using the Aspen engineering suite. In addition, for each process, several heat integration measures are considered to maximize thermal efficiency. According to the simulation results, the thermal efficiency of the direct CO2 hydrogenation process (47.8 % LHV) is higher than the dry reforming (40.6 % LHV) while it is lower than the conventional (68.4 % LHV) and tri-reforming (57.9 % LHV) processes. The LCA results showed that the direct CO2 hydrogenation pathway is an environmentally friendly option, only when the electricity GHG intensity is lower than 0.17 kg CO2 equivalent per kWh of electricity. As a result, in the context of Canada, the CO2 hydrogenation options can be recommended only for the provinces where low-carbon electricity is available, such as Quebec, British Columbia, Manitoba and Ontario.

This paper introduces a new stepwise approach for the optimal retrofit of heat exchanger networks. At each iteration, the proposed method involves superstructures which embed retrofit alternatives as well as numerical optimization to minimize the project’s total annualized cost. In order to reduce calculation times, new algorithms are proposed to thin out superstructures. These are based on thermodynamic criteria, namely on the concept of heat path, and on new graph theoretical results. To carry out the numerical optimization tasks, novel mixed integer nonlinear models are developed. These models support any combination of constant, polynomial and (continuous) piecewise linear enthalpy functions of temperature. Numerical examples are presented for the retrofit of the preheat train of an atmospheric crude unit and for the retrofit of a fluid catalytic cracking plant. The new method is shown to reduce calculation times and total annualized costs reported in the literature.

The Canadian in-situ bitumen extraction is one of the most energy-intensive processes and a large GHG producer. In an increasingly carbon-constrained environment, industry and technology developers aim towards decarbonization of their operations by considering several design strategies. Post-combustion carbon capture (PCC) and heat integration are available solutions that can significantly reduce GHG emissions produced by in-situ extraction plants such as steam-assisted gravity drainage (SAGD) facilities. An important challenge that currently limits the use of carbon capture in SAGD facilities, apart from the capital cost, is the large quantity of energy needed and the associated GHG emissions. In this work, the energy performance of two typical SAGD configurations was optimized with and without PCC technologies. Aspen HYSYS® was used to model each configuration for a standard capacity and CanmetENERGY’s INTEGRATION software was used to optimize heat recovery. First, it was shown that SAGD facilities’ energy consumption and GHG emissions could be reduced by up to 8% through optimized heat recovery leading to a significant increase in the boiler feedwater and combustion air temperatures. Then, two PCC technologies were integrated into the SAGD configurations. Several energy integration strategies were considered to provide part of the regeneration energy required in the PCC units by using the excess heat in the SAGD and PCC plants. The analysis revealed that, depending on the SAGD process configuration, the PCC technology considered and the level of heat integration within the SAGD plant, 13–47% of the regeneration energy could be provided by heat recovery. Additionally, the techno-economic analysis results showed a capture cost of US$34.6–55.3/t-CO2 for different studied scenarios.

This work introduces design improvements for an integrated biomass-derived syngas purification process based on a holistic integration approach. Optimal heat recovery measures and ejector integration are used as key components of the proposed designs in order to valorize untapped waste heat and reduce energy inefficiencies within this process. The steam saving in the solvent regeneration column of the acid gas removal unit that uses MDEA solvent is considered as a key performance indicator to assess the proposed designs since it represents the major part of the whole gas purification process’s operating costs. We used Aspen HYSYS® to assess technical feasibility and economic viability of the proposed designs. We found that combining optimal heat recovery and ejector integration led to the overall process seeing substantial utility savings. More precisely, we showed that this approach can reduce steam and cooling water consumption by up to 23 % and 16 %, respectively.

Pinch Analysis was used to improve the energy performance of a typical steam-assisted gravity drainage (SAGD) process. The objective of this work was to reduce the amount of natural gas used for steam generation in the plant and the associated greenhouse gas emissions. The INTEGRATION software was used to analyze how heat is being used in the existing design and identify inefficient heat exchanges causing excessive use of energy. Several modifications to improve the base case heat exchanger network (HEN) were identified. The proposed retrofit projects reduced the process heating demands by improving the existing heat recovery system and by recovering waste heat and decreased natural gas consumption in the steam production unit by approximately 40 MW, representing approximately 8% of total consumption. As a result, the amount of glycol used to transfer energy across the facility was also reduced, as well as the electricity consumption related to glycol pumping. It was shown that the proposed heat recovery projects reduced natural gas costs by C$3.8 million/y and greenhouse gas emissions by 61,700 t/y of CO 2 .

Pinch analysis was employed to recover and reuse a part of the waste energy during the production and cleaning periods of a slaughterhouse in Canada. The INTEGRATION software was used to find possible options for HR (heat recovery). Several HR opportunities were identified in various systems of the slaughterhouse including boilers, hot water production, singeing, refrigeration, and barn air heating. A recommendation was also made to store more energy in the form of hot water. Opportunities for using heat pumps for additional HR were also investigated. The proposed projects can significantly reduce natural gas consumption in the steam and hot water boilers as well as in the air heating systems. It is shown that the proposed projects can reduce natural gas use by approximately half a million dollars per year.

Pulp-and-paper mills produce various types of contaminants and a significant amount of wastewater depending on the type of processes used in the plant. Since the generated wastewaters can be potentially polluting and very dangerous, they should be treated in wastewater treatment plants before being released to the environment. This paper reviews different wastewater treatment processes used in the pulp-and-paper industry and compares them with respect to their contaminant removal efficiencies and the extent of greenhouse gas (GHG) emission. It also evaluates the impact of operating parameters on the performance of different treatment processes. Two mathematical models were used to estimate GHG emission in common biological treatment processes used in the pulp-and-paper industry. Nutrient removal processes and sludge treatment are discussed and their associated GHG emissions are calculated. Although both aerobic and anaerobic biological processes are appropriate for wastewater treatment, their combination known as hybrid processes showed a better contaminant removal capacity at higher efficiencies under optimized operating conditions with reduced GHG emission and energy costs.

Greenhouse gas (GHG) emission and energy consumption in wastewater treatment plants (WWTPs) of the pulp and paper industry were modeled and estimated. Aerobic, anaerobic, and hybrid biological processes were used for the removal of contaminants. In addition to the removal of carbonaceous compounds, anaerobic digestion of the produced sludge and the removal of excess nitrogen in the effluent of treatment plants by nitrification/denitrification processes were incorporated in the model. Carbon dioxide, methane, and nitrous oxide were the major GHGs generated during the biological treatment, combustion, energy generation, and transportation. The generated biogas from the anaerobic processes was assumed to be recovered and used as a source of energy for the treatment plant, in an effort to reduce GHG emissions while decreasing the total energy needs of the WWTP. The established kinetic relationships of wastewater treatment processes along with mass and energy balances were employed for the simulation of different treatment systems and estimation of GHG emissions. Various sources of GHG emission were divided into on-site and off-site sources to simplify the modeling and simulation procedure. The overall GHG generation in the presence of biogas recovery was equal to 1.576, 3.026, and 3.271 kg CO2-equivalent/kg BOD by the three examined systems. The energy produced by the recovery and combustion of biogas could exceed the energy demands of all different treatment plants examined in this study and reduce off-site GHG emission. The generation of GHGs from aerobic and hybrid processes increased by 27% and 33.2%, respectively, when N2O emission from nitrogen removal processes was taken into consideration.

Greenhouse gas (GHG) emission and energy consumption were estimated in wastewater treatment plants using an elaborate mathematical model that included coagulation/flocculation, anaerobic digester, nitrification/denitrification, and biogas recovery. The examined treatment systems used aerobic, anaerobic, and hybrid biological processes. The impact of pertinent operating parameters including reactor temperature, solid retention time (SRT), primary clarifier underflow rate, and biochemical oxygen demand concentration on GHG emission and energy consumption were investigated, leading to the identification of controlling operating parameters and adequate strategies to reduce GHG emission and energy consumption. The overall GHG emission was 3152, 6051, and 6541 kg CO2-equivalent/day, while the estimated energy consumption amounted to 4028, 2017, and 3084 MJ/day in the three examined systems, respectively. Parametric studies showed that the best strategy to reduce GHG emission and energy consumption would result from 12% increase in the bioreactor temperature in the aerobic system, 10% increase of the bioreactor temperature and five days increase of SRT in the anaerobic system, and 10% increase of temperature and five days reduction of SRT in the anaerobic bioreactor of the hybrid system. Additional reductions in the GHG emission and energy consumption would result from 50% increase of the primary clarifier underflow rate.

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid-anaerobic/aerobic-biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ± 30, ± 19, and ± 17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ± 6, ± 7, and ± 4 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.

A population balance model is developed to investigate the steady state particle size distribution developments in a gas-phase fluidized-bed ethylene polymerization reactor. The model considers the combined effects of particle growth and elutriation for size distributed prepolymer feed. In the proposed model, the bed is divided into several sections consisting of bubble and emulsion phases. The population balance differential equations derived for each section were simultaneously solved to determine the density function of the size distribution of the polymer particles in each section. The model is able to estimate the axial profile of particle size distribution along the reactor height. It was shown that the mean size of the particles is larger at the bottom of the bed and becomes smaller when moving toward top of the reactor. The size distribution of the polymer particles in the product becomes sharper and their mean size decreases by increasing the superficial gas velocity. Also, mean size of the particles in the product increases by increasing the temperature of the reactor.

A population balance model is developed to investigate the particle size distribution (PSD) developments in a gas-phase fluidized bed ethylene polymerization reactor. The model considers the combined effects of particle growth and elutriation for size-distributed prepolymer feed. In the proposed model, the bed is divided into several perfectly mixed serial sections. The population balance differential equations written for each section were simultaneously solved to determine the density function of the size distribution of the polymer particles in each section. The model is able to predict the profiles of the PSD along the reactor height. It was shown that the mean size of the particles is larger at the bottom of the bed and becomes smaller when moving toward the top of the reactor. The size distribution of the polymer particles in the product becomes sharper and their mean size decreases by increasing the superficial gas velocity. Also, the mean size of the particles in the product increases by increasing the temperature of the reactor.

Greenhouse gas (GHG) emission and energy consumption by on-site and off-site sources were estimated in two different wastewater treatment plants that used physical–chemical or biological processes for the removal of contaminants, and an anaerobic digester for sludge treatment. Physical–chemical treatment processes were used in the treatment plant of a locomotive repair factory that processed wastewater at 842 kg chemical oxygen demand per day. Approximately 80% of the total GHG emission was related to fossil fuel consumption for energy production. The emission of GHG was reduced by 14.5% with the recovery of biogas that was generated in the anaerobic digester and its further use as an energy source, replacing fossil fuels. The examined biological treatment system used three alternative process designs for the treatment of effluents from pulp and paper mills that processed wastewater at 2,000 kg biochemical oxygen demand per day. The three designs used aerobic, anaerobic, or hybrid aerobic/anaerobic biological processes for the removal of carbonaceous contaminants, and nitrification/denitrification processes for nitrogen removal. Without the recovery and use of biogas, the aerobic, anaerobic, and hybrid treatment systems generated 3,346, 6,554 and 7,056 kg CO2-equivalent/day, respectively, while the generated GHG was reduced to 3,152, 6,051, and 6,541 kg CO2-equivalent/day with biogas recovery. The recovery and use of biogas was shown to satisfy and exceed the energy needs of the three examined treatment plants. The reduction of operating temperature of the anaerobic digester and anaerobic reactor by 10°C reduced energy demands of the treatment plants by 35.1, 70.6 and 62.9% in the three examined treatment systems, respectively.

Mobile technology is increasingly drawing the attention of the healthcare sector. This paper analyses ways in which the implementation and use of new mobile technologies create new values and discusses how value development processes change as the mobile solution matures. Two issues are in focus: first, how the user involvement in developing mobile innovations changes as the new technology is established in the organisation; and second, how user involvement and the maturity of the mobile offering influence the co-creation of value between the technology supplier, the healthcare organisation and other actors.