Dia Milani - Academia.edu (original) (raw)

Papers by Dia Milani

Evaluating Feed-in Tariff tool to revive Australian Solar PV market

A review of potential routes to zero and negative emission technologies via the integration of renewable energies with CO2 capture processes

International Journal of Greenhouse Gas Control, Mar 1, 2023

Modelling framework of solar assisted dehumidification system to generate freshwater from "Thin air

Journal of Environmental Chemical Engineering, 2018

Carbon capture and storage (CCS) community has been struggling over the past few decades to demon... more Carbon capture and storage (CCS) community has been struggling over the past few decades to demonstrate the economic feasibility of CO2 sequestration. Nevertheless, in practice, it has only proven feasible under conditions with a market for the recovered CO2, such as in the beverage industry or enhanced oil/gas recovery. The research community and industry are progressively converging to a conclusion that CO2 sequestration has severe limitations for the value proposition. Alternatively, creating diverse demand markets and revenue streams for the recovered almost-pure CO2 may prevail over CO2 sequestration option and improve the economic feasibility of this climate change mitigation approach. As such, research in the carbon capture and management field is seen to be shifting towards CO2 utilization, directly and indirectly, in energy and chemical industries. In this paper, we critically reviewed the literature on carbon capture, conversion, and utilization routes and assessed the progress in the research and developments in this direction. We discussed both physical and chemical CO2 utilization pathways and probed the literature in addressing the process integration scenarios and the performance assessment benchmarks. The literature was critically reviewed, and principles of key CO2 utilization routes were identified.

Modeling and Simulation Environments for Sustainable Low-Carbon Energy Production – A Review

Energy and Buildings, Oct 1, 2017

The concept of integrating latent heat with domestic solar water heater (DSWH) has been around fo... more The concept of integrating latent heat with domestic solar water heater (DSWH) has been around for few decades but commercial application has not been recognized yet. This might be due to the lack of feasibility studies for latent heat technology particularly for long-term operation. In this paper, we developed a process flowsheet to integrate a latent heat 'battery' (LHB) into a domestic solar water heater (LHB-DSWH) and eliminate the traditional water tank. In this novel tankless LHB-DSWH, the hot water does not need to be continuously maintained at healthregulation-constraint temperature (viz. 60 o C to prevent the breeding of Legionella bacteria) as in the case of conventional DSWH or other literature LHB-DSWH processes. A dynamic model of the proposed LHB-DSWH process was developed and validated against experimental data. The 2 dynamic characteristics for the proposed system were examined and discussed. An annual simulation for a case-study (Townsville, QLD Australia) showed that the proposed LHB process consumes 86.6 % less fossil-fuel compared to a conventional system and increases the fossil fuel savings of DSWH from 81.7% up to 97.4%. Process operability was also considered in process development.

A novel design protocol for solar-powered carbon capture

Thermal science and engineering progress, Dec 1, 2021

Process control strategies for solar-powered carbon capture under transient solar conditions

Energy, 2022

Computers & Chemical Engineering, Nov 1, 2018

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Research Highlights  Modeling of a new adsorption chiller under transient condition was conducted  Performance analysis of the composite adsorption materials were evaluated  The thermodynamic framework and the mathematical model were analyzed  A massive Coefficient of performance improvement of 95.7% was reported

Journal of Cleaner Production, 2016

This paper investigates a methanol (MeOH) synthesis route based on CO 2 utilization integrated wi... more This paper investigates a methanol (MeOH) synthesis route based on CO 2 utilization integrated with enhanced gas recovery (EGR) and geo-sequestration (e.g. depleted gas wells near EGR unit). A key driver behind this work is the need to understand the proposed MeOH synthesis route in relation to the dynamics of the CO 2 breakthrough phenomenon associated with EGR. The performance of the proposed MeOH synthesis is evaluated via model analysis of various process flowsheet configurations and reported in terms of CH 4 intensity, CO 2 intensity, thermal energy intensity, methanol productivity and CO 2 uptake flexibility. It is found that the proposed MeOH scheme can effectively consume natural gas (NG) with relatively high CO 2 content (up to 23.2% mole). Simulation results show that the proposed MeOH synthesis process configuration, utilizing EGR and using CO 2 geo-sequestration and utilization components, results in the highest CO 2 abatement intensity (45.5%) among other comparable scenarios investigated here.

Energy Conversion and Management, Sep 1, 2017

Current worldwide infrastructure of electrical power generation would mostly continue to rely on ... more Current worldwide infrastructure of electrical power generation would mostly continue to rely on fossilfuel but require a modest transition for the ultimate goal of decarbonizing power generation industry. By relying on those already established and carefully managed centrepiece power plants (PPs), we aim at filling the deficits of the current electrical networks with smaller, cleaner, and also more efficient PPs. In this context, we present a unique model for a small-scale decentralized solar-assisted supercritical CO 2 closed Brayton cycle (sCO 2-CBC). Our model is based on the optimized values of three key performance indicators (KPIs); thermal efficiency, concentrated solar power (CSP) compatibility, and water demand for cooling. For a case-study of 10 MW e CSP-assisted sCO 2-CBC power plant, our dynamic model shows a 52.7% thermal efficiency and 25.9% solar penetration and up to 80% of water saving in heatrejection units. These KPIs show significant promise of the solar-assisted supercritical CO 2 power cycle for an imperative transformation in the power industry towards future sustainable electricity generation.

Journal of Supercritical Fluids, Feb 1, 2017

Electrical power generation by closed loop Brayton cycle using supercritical CO 2 (sCO 2) as a wo... more Electrical power generation by closed loop Brayton cycle using supercritical CO 2 (sCO 2) as a working fluid has gained significant interest in recent years. Integrating sCO 2 cycle with renewable energy technology (i.e. solar heliostat field) at high temperature ranges has shown promising results. This study highlights the thermodynamic benefits of recompression sCO 2 Brayton cycle and presents a modelling and control strategy to optimize operating conditions for a constant power output utilising solar-and fossil-based heat sources. This optimization maximizes solar field contribution and minimizes the role of auxiliary fossil-fuelled backup (AFB) heating system. The performances of two common solar heat input (direct and indirect) configurations are compared. It is found that for a specific day, an indirect cycle consumes 19.5% less fossil fuel compared to an equivalent direct cycle. This is mainly attributed to the usage of thermal energy storage (TES) in the indirect cycle. However, the high capital cost of TES and operability/controllability issues may decrease the merits of the indirect cycle. Although the reliance on fossil fuel contribution in direct cycle is higher by a magnitude of 4.2% or less, this may be economically admissible compared to the substantial reduction in capital cost as in the case of indirect cycle.

Applied Energy, Aug 1, 2017

h i g h l i g h t s Investigated the operation of sCO 2 Brayton cycle in transient conditions. St... more h i g h l i g h t s Investigated the operation of sCO 2 Brayton cycle in transient conditions. Start-up to full-load scheme for a solar-assisted recompression cycle is developed. The scheme consists of four consecutive phases with distinct control events. Flexible heat sources (fossil fuel, solar energy) can be used during the start-up. Initial cooler bypassing is a vital event for sustaining supercritical condition.

Energy, Apr 1, 2017

In this paper, we perform a comprehensive parametric study for supercritical CO 2 (sCO 2) Brayton... more In this paper, we perform a comprehensive parametric study for supercritical CO 2 (sCO 2) Brayton cycle integration with a concentrated solar thermal (CST) plant. The main focus is to develop operational strategies for the cycle to adapt to fluctuations in solar energy availability. Several cycle layouts are analysed and a 'combined' cycle comprising recompression, reheat and intercool is found to be the most efficient cycle. Two key cycle parameters (sCO 2 circulation rate and splitting fraction) are sensitized while net shaft power (NSP) output is controlled at 11.5 MW. By manipulating these two parameters, the cycle can adapt to heat input variations without affecting NSP output. This finding leads to two operational modes: flexible temperature mode (FTM) and constant temperature mode (CTM). A solar-assisted case study is used to test the proposed strategies, and an auxiliary fossil-fuelled backup (AFB) unit is utilised when solar energy is insufficient. In general, the proposed solar-assisted cycles (CTM and FTM) were able to achieve the highest fossil fuel savings of 28.9% and 31.2%, respectively compared to a conventional cycle without solar. It is found that both FTM and CTM can deal with fluctuations in solar thermal energy supply. However, FTM is more effective in tolerating drops in solar energy supply and considerably outperforms CTM in lowering contributions from AFB unit. Thus, even at the most efficient conditions, CTM still underperformed FTM by 4.5% in term of fossil fuel saving.

International Journal of Hydrogen Energy, Sep 1, 2020

The role of hydrogen as a mean of future sustainable energy carrier is recognized. Renewable inte... more The role of hydrogen as a mean of future sustainable energy carrier is recognized. Renewable integration routes in hydrogen production technologies are categorized. The key drivers for commercialscale hydrogen production in Australia are identified. Fossil fuel cracking coupled with CCS is the most viable hydrogen production route. Electrolysis coupled with renewable is costly and would require more R&D to contest.

A comparative study of CO2 utilization in methanol synthesis with various syngas production technologies

Journal of CO2 utilization, Dec 1, 2015

This paper explores a possible ‘methanol economy’ transition strategy—a novel carbon capture and ... more This paper explores a possible ‘methanol economy’ transition strategy—a novel carbon capture and utilization (CCU) configuration for methanol (MeOH) production (CCU–MeOH). In this CCU–MeOH, the captured CO2 is co-fed with natural gas (NG) to produce syngas suitable for MeOH synthesis. The main objective of this work is to compare two aspects, namely CO2 emission intensity and the extent of methane reliance, of six CCU–MeOH scenarios derived from four reforming methodologies (steam methane reforming (SMR), dry methane reforming (DMR), bireforming and trireforming). Among the studied CCU–MeOH scenarios, Scenario 2 (DMR with H2 addition) significantly outperformed the other scenarios by 12.7% and 22% on average in terms of CO2 emission intensity and methane reliance, respectively. The outperformance of Scenario 2 in CO2 emission intensity is found to originate from a 22% reduction in CH4 consumption on average compared to the other scenarios. In intermediate term, Scenario 2 may provide an attractive option for transitioning into ‘methanol economy’ of the future.

Renewable Energy, Apr 1, 2017

The energy for the solvent regeneration of post-combustion carbon capture (PCC) process is typica... more The energy for the solvent regeneration of post-combustion carbon capture (PCC) process is typically provided by steam bleeding from the power plant (PP) steam cycle. The energy penalty for steam bleeding results in serious reduction in the PP capacity estimated to be in the range of 10-40%. Power plant repowering or hybridization using solar-assisted PCC (SPCC) is a promising approach to satisfy carbon capture targets as well as PP load, concurrently. The drawback of this methodology is that notable amounts of solar energy are wasted during heat transfer from solar radiation to rich solvent. This paper presents a novel approach by eliminating the costly desorber system and using solar collector pipe (i.e. parabolic trough pipe) to directly heat the rich solvent and disassociate the bonds of CO 2solvent. This novel technology lowers the process capital expenditure, and also reduces the solvent regeneration energy bringing it close to its theoretical values. The elimination of the complex desorber column also increases the flexibility of the PP operation in response for market dynamics. A case-study for Sydney-Australia shows that in comparison with SPCC methodology, this state-of-the-art approach could notably improve the economics of the process and reduce the size of solar collector field (SCF).

Computer-aided design for high efficiency latent heat storage – a case study of a novel domestic solar hot water process

Computer-aided chemical engineering, 2017

Abstract Latent heat storage (LHS) with high energy storage density and near isotherm operation h... more Abstract Latent heat storage (LHS) with high energy storage density and near isotherm operation has emerged as an attractive sustainable alternative to the conventional sensible heat storage. In this paper, a novel domestic solar-assisted hot water (DSHW) process coupled to a LHS module is presented and assessed. Process simulation and sensitivity analyses are carried-out using an in-house 2-D dynamic model of the proposed DSHW. A simulation for a full year shows that with an appropriately customized design, the proposed process consumes about 86% less fossil-fuel compared to a conventional system, demonstrating the superiority of LHS over sensible heat storage in this DSHW application. The examination of the controllability of the system is warranted in order to mitigate the overheating phenomenon. The optimization of the LHS medium properties should be explored to further enhance the efficiency of the process. The current design approach can be implemented for various LHS applications ranging from simple DSHW to the large concentrated solar thermal industrial applications.

Applied Thermal Engineering, May 1, 2020

Solar collector field is sized for direct heat utilization in the SPCC solvent regeneration. • Un... more Solar collector field is sized for direct heat utilization in the SPCC solvent regeneration. • Underground solvent storage is proposed to ensure solvent availability in winter times. • A clear trade-off between the solar multiple and solvent storage capacity is found. • The massive solvent storage capacity and solvent demand are the major cost contributors. • The levelized cost of desorption is more reasonable in locations near the Equator.

Renewable Energy, Feb 1, 2016

Using evacuated tube collectors (ETCs) in solar water heaters (SWHs) may endure deficiencies (i.e... more Using evacuated tube collectors (ETCs) in solar water heaters (SWHs) may endure deficiencies (i.e. in winter season) in collecting the necessary thermal energy for water heating. This is because of the cylindrical shape of evacuated tubes which makes the upper circumference of the cylinder is directly exposed to sunrays, while the lower circumference usually misses the beam and also most of the diffuse irradiance. In this paper, the role of using a diffuse flat reflector (DFR) at the back of ETC array to improve heat capture rate is examined. A comprehensive model to estimate the annual energy savings and small-scale technology certificates (STCs) is developed. This model is applied on four major Australian cities representing four Australian solar zones. The tilt and azimuth angles for these four zones are optimized. This optimal setting along with DFR presence could improve the STC entitlements by 14.6% for zone 1; 20.2% for zone 2; 25.9% for zone 3; and 27.9% for zone 4, respectively. This specific-tailored model may increase the annual energy saving up to 95.8% for zone 1; 91.3% for zone 2; 81% for zone 3; and 74% for zone 4 correspondingly.