Fouling and Mechanism

Fouling is the deposition of material on the heat transfer surface which reduces the film heat transfer coefficient. The impact of fouling on the heat exchanger is manifested as the reduction of thermal and hydraulic performance, in which the latter has a minor effect. This factor needs to be considered when calculating the effectiveness of the heat exchanger. During the design of heat exchangers, the fouling factor increases the required heat transfer area, which adds extra manufacturing costs. With less efficient heat exchangers, the economic cost of fouling is related to excess fuel consumption, loss of production, and maintenance or cleaning. The extra fuel consumption also damages the environment by increasing greenhouse gas production. Although much of the research work has been done on modeling and predicting fouling, it is still a poorly understood phenomenon representing the complexity of its mechanism. The common fouling mitigation action after the onset of fouling is to optimize the operating condition, e.g., increase the bulk flow velocity or decrease surface temperature. However, many quantitative and semi-empirical models have been developed to predict the fouling rate for preventive actions and optimizing cleaning schedules

A process integration approach for design of hybrid power systems with energy storage

Selection of energy storage technology in hybrid power systems (HPS) is vital due to the unique advantages and capabilities offered by different storage technologies. For an optimal operation, the efficient and economical storage system for an HPS should be selected. This work introduces a new systematic generic framework to determine the most cost-effective storage technology for an HPS. A Power Pinch Analysis tool called the AC/DC modified storage cascade table has been developed to optimise the HPS by considering various storage technologies. The economics of the various types of storage modes was analysed, taking into account the associated energy losses, among others. The method was applied to two case studies with different power trends to evaluate the effect of storage efficiencies and storage form on the performance of HPS. A superconducting magnetic storage system of 26.12 kWh capacity, that gives an investment payback period of 3.6 years, is the most cost-effective storage technology for the small-scale household system in Case Study 1. For the large-scale industrial application presented in Case Study 2, the Lead-Acid battery with a capacity of 15.38 MWh gives the lowest payback period (1.43 years)

Energy–Water–Carbon Nexus Study for the Optimal Design of Integrated Energy–Water Systems Considering Process Losses

Integrated energy–water systems have been explored using different process integration techniques considering the energy–water–carbon nexus to minimize the carbon footprint, e.g., pinch analysis techniques (power cascade table, water cascade table, and energy planning pinch diagram). However, the power and water losses while considering the energy–water–carbon nexus have not been explored in detail in the previous works. This work focuses on the modifications of the existing pinch analysis methods for energy–water–carbon nexus study while considering power and water losses, for an optimized energy–water system. Power and water losses should not be neglected in the analysis as they have a significant impact on the carbon emissions and overall capacities of energy and water. The effect of losses on energy storage capacity, outsourced electricity, water supply volume and water storage capacity were evaluated on an industrial case study. Results from the case study demonstrate that, while considering power losses during power allocation can lower storage capacity, it tends to raise the needed outsourced electricity supply. As water supply volume tends to increase, the water storage capacity tends to decline when losses are considered. The results were compared to the data without losses, and it was observed that the storage capacity of energy decreases by 4% while outsourced energy increases by 6%. Water supply volume increases by 20% but water storage capacity decreases by 13.7%. The emissions from energy system remains same while from the water system the emissions rise significantly by 20%. It is expected that consumers that takes power and water losses into account will produce more realistic and reliable energy, water, and carbon reduction targets and prevent under-sizing issues in designing integrated energy–water systems

Advancing low-carbon emissions in Asia: mitigation of greenhouse gases and enhancing economic feasibility for major sectors

Asia is the factory of the world for many manufacturing activities, for which promoting sustainable growth while maintaining a low-carbon or CO2 emission profile is crucial. Decoupling emission of high greenhouse gases without compromising the economic growth is a great challenge. Advancement in clean technology and environmental policies, targeting the key emitter of GHG emissions, is crucial to drive the low CO2 emissions development. Implementation of these measures would require continuous consensus building and the concerted efforts, involving multiple stakeholders at local and international levels, to reduce the carbon footprints

Energy–Water–Carbon Nexus Study for the Optimal Design of Integrated Energy–Water Systems Considering Process Losses

Integrated energy–water systems have been explored using different process integration techniques considering the energy–water–carbon nexus to minimize the carbon footprint, e.g., pinch analysis techniques (power cascade table, water cascade table, and energy planning pinch diagram). However, the power and water losses while considering the energy–water–carbon nexus have not been explored in detail in the previous works. This work focuses on the modifications of the existing pinch analysis methods for energy–water–carbon nexus study while considering power and water losses, for an optimized energy–water system. Power and water losses should not be neglected in the analysis as they have a significant impact on the carbon emissions and overall capacities of energy and water. The effect of losses on energy storage capacity, outsourced electricity, water supply volume and water storage capacity were evaluated on an industrial case study. Results from the case study demonstrate that, while considering power losses during power allocation can lower storage capacity, it tends to raise the needed outsourced electricity supply. As water supply volume tends to increase, the water storage capacity tends to decline when losses are considered. The results were compared to the data without losses, and it was observed that the storage capacity of energy decreases by 4% while outsourced energy increases by 6%. Water supply volume increases by 20% but water storage capacity decreases by 13.7%. The emissions from energy system remains same while from the water system the emissions rise significantly by 20%. It is expected that consumers that takes power and water losses into account will produce more realistic and reliable energy, water, and carbon reduction targets and prevent under-sizing issues in designing integrated energy–water systems

Low-carbon emission development in Asia: energy sector, waste management and environmental management system

Mitigation of greenhouse gases (GHG) emissions is desirable without compromising the economic growth. This paper reviews the recent trends to mitigate GHG emissions in the key sectors of energy and solid waste. The energy sector is the key admitter for global GHG emissions, and a range of optimisation and modelling tool has been developed to minimise the GHG emissions and overall cost, especially for the implementation of renewable energies such as biofuel and biogas. A few carbon sequestration technologies such as the carbon capture and storage (CCS) and biochar application have been reviewed. The review included the challenges and knowledge gaps regarding the utilisation of CCS, such as the storage capacity, long-term policy framework, high costs and the potential risk. Although solid waste contributes about 40%) in the municipal solid waste for many developing countries in Asia, composting has been proposed as a viable treatment technology to convert waste-to-wealth. A range of waste management tools, including scenario analyses on different waste technologies, optimisation of waste collection routes, multi-criteria decision tools, is reviewed to support the decision-making for solid waste management. A range of environmental management system (EMS) has been adopted by organisations to improve product quality, reducing production cost and improves reputation of firms. An environmental policy such as tax exemption could be helpful to promote the adoption of EMS that could be costly. CO2 and material flow footprint tools, such as water–energy–materials nexus, are applicable at a city and regional level. The tools are used to mitigate GHG emissions by developing the mechanisms with shared markets of virtual resource flows (carbon, water, food, energy) between the trading partners regionally and internationally

A process integration targeting method for hybrid power systems

Pinch Analysis is a well-established methodology of Process Integration for designing optimal networks for recovery and conservation of resources such as heat, mass, water, carbon, gas, properties and solid materials for more than four decades. However its application to power systems analysis still needs development. This paper extends the Pinch Analysis concept used in Process Integration to determine the minimum electricity targets for systems comprising hybrid renewable energy sources. PoPA (Power Pinch Analysis) tools described in this paper include graphical techniques to determine the minimum target for outsourced electricity and the amount of excess electricity for storage during start up and normal operations. The PoPA tools can be used by energy managers, electrical and power engineers and decision makers involved in the design of hybrid power systems

Design of hybrid power systems with energy losses

The application of Process Integration using the Pinch Analysis technique has been recently extended to the design of hybrid power systems to determine the maximum power recovery and the battery storage capacity. The graphical and the numerical Power Pinch Analysis (PoPA) tools provide designers with visualisation tools that are systematic and simple to implement for the optimisation of power systems. However, the power losses incurred in the systems, have so far, not been considered in detail in the previous works. This paper extends the PoPA method by considering the power losses that occur during the power system's conversion, transfer and storage. The effects of the losses on the minimum outsourced electricity targets and the storage capacity are evaluated. The Storage Cascade Table (SCT) of PoPA has been further developed to include the effect of energy losses in the system's design. Application of the developed method on a case study yields the more realistic power targets for off-grid hybrid power systems

Utilization of Cold Energy from LNG Regasification Process: A Review of Current Trends

Liquified natural gas (LNG) is a clean primary energy source that is growing in popularity due to the distance between natural gas (NG)-producing countries and importing countries. The large amount of cold energy stored in LNG presents an opportunity for sustainable technologies to recover and utilize this energy. This can enhance the energy efficiency of LNG regasification terminals and the economic viability of the LNG supply chain. The energy stored in LNG in the form of low temperatures is referred to as cold energy. When LNG is regasified, or converted back into its gaseous form, this cold energy is released. This process involves heating the LNG, which causes it to vaporize and release its stored energy. The current state-of-the-art techniques for LNG cold energy utilization, including power generation, air separation, traditional desalination, and cryogenics carbon dioxide (CO2) capture are discussed in this review. While most of the current LNG cold energy utilization systems are presented, potential future applications are also discussed. The commercialization of sustainable technologies, such as improvement strategies for LNG cold energy utilization, is becoming increasingly important in the energy industry