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Cogeneration or combined heat and power (CHP) energy system could concurrently produce electrical and heat energies. Nonetheless, its integration in energy planning would need to consider interactions with other energy carriers, energy storages, and transmission networks. Previous works have used energy hub (EH) modelling to optimise the energy flow in a CHP energy system with predetermined energy components. In this paper, an Optimal Cogeneration Model (OCM) is proposed to consider the EH design which (1) enables the flexible selection between different energy transformation technologies, then (2) minimises the cost and environmental emission constraints concerning the technical characteristics and operating conditions of the selected EH components. Mixed-integer linear programming (MILP) has been used to model the optimisation problem in GAMS software. Based on the case study, an EH with CHP and energy storage system (ESS) has been developed with the minimised total annual cost (TAC) of 27.02 x 106 MYR/y for a pharmaceutical facility. The research output - the developed OCM serves as an integrated analysis tool for potential cogenerators to plan and determine the economic feasibility of CHP implementation. [ABSTRACT FROM AUTHOR]

Heat integration has played an important role in maximising heat recovery, improving energy efficiency and reducing environmental emissions of industrial processes. However, practical aspects of heat integration such as physical distances between pipelines and space constraints must be considered especially during retrofit of heat exchanger networks (HEN). During HEN retrofit, process streams are matched based on their thermodynamic profiles to achieve energy targets. The physical distances between process streams and the space available for heat integration are usually not considered during HEN retrofit even though these issues could offset the cost savings from heat recovery. Matching of process streams across long distances may impose extra piping and pumping costs in order to overcome pressure drop. Pumping cost is also affected by elevation apart from pipeline distance. This work proposes a new graphical tool for visualising the location of process streams as well as the available space within an existing process plant, based on a proposed graphical coordinate representation. With the aid of this graphical tool, process streams can be matched not only based on their thermodynamic profiles, but also by considering the nearest physical distance and elevation of process streams. Designers can also identify the physical locations of additional equipment such as heat exchangers and pumps using the coordinate representation based on a proposed set of heuristics for equipment placement. Pumping and piping costs are included in the capital-energy trade-off analysis. Results of the study show that the coordinate representation of the existing plant can help generate a more practical HEN retrofit design for actual implementation. [ABSTRACT FROM AUTHOR]

CO2 Capture, Utilisation and Storage (CCUS) has been gearing towards the technology viable for CO2 removal from the atmosphere. The successful implementation of an integrated CCUS system would open up the opportunity to develop high CO2 gas field as well ensures the sustainability of gas production while minimising the impact on the environment. A methodology of CO2 integration management by maximising the recovery of CO2 for future utilisation and minimising CO2 to be sent for sequestration through centralised CO2 headers or known as CO2 Total Site has been developed. It consists of one high-purity header that is attached to CO2 storage or reservoir and low-purity headers that accept CO2 sources at different purity to satisfy CO2 demands. The multiple headers with consideration of different purity range of headers and a different number of headers are studied in this work. The application of the CO2 Total Site-Problem Table Analysis (CTS-PTA) has potentially resulted in an optimal CO2 target with the reduction of carbon storage of 32% with a lower risk of CO2 leakage and low CO2 emission. [ABSTRACT FROM AUTHOR]

The minimum approach temperature (ΔTmin) has been used in the design of heat exchanger networks (HEN) and in energy targeting based on Pinch Analysis. It refers to the minimum allowable temperature difference between a heat source and a heat sink for designing an energy-efficient HEN. Smaller ΔTmin can improve process heat recovery but require large heat transfer area and may result in a higher capital cost. Capitalenergy trade-off is typically performed to determine the cost-optimum ΔTmin during HEN synthesis (HENs). Conventionally, an entire process is analysed to obtain the optimum value of ΔTmin. In this work, the capitalenergy trade-off is performed using the individual stream temperature versus enthalpy plot (STEP) to obtain an optimum ΔTmin for each identified STEP. First, simultaneous area and utility targeting of HEN is performed using the established STEP HEN targeting procedure. The capital-energy trade-off is then analysed separately for every identified STEP. The different values of ΔTmin obtained are then applied for the grassroots synthesis of HEN. Application of the proposed procedure on a literature case study shows that the total annualised cost is reduced by 7.03 % when the capital-energy trade-off is performed separately for every STEP as compared to trading-off ΔTmin for an entire process. [ABSTRACT FROM AUTHOR]

Medium and large scale industries typically consume large amounts of energy, and are under pressure to increase energy efficiency and reduce energy wastages. Conventional insight-based heat exchanger network (HEN) retrofit methods typically combine graphical visualisation and algebraic tools to manage different retrofit stages. These stages often involve repetitive calculations of approach temperature, enthalpy balance and heat transfer area to assess the HEN feasibility and cost-effectiveness. This paper extends the individual stream temperature versus enthalpy plot (STEP) methodology that was introduced for HEN synthesis, to HEN retrofit. The STEP retrofit method proposed in this work enables users to simultaneously diagnose and retrofit existing HEN by using only the STEP diagram that maintains the characteristics of individual process streams. Users can graphically perform individual stream mapping without having to calculate stream enthalpies or to check for minimum temperature approach ( Δ T m i n ) violation during retrofit. Application of the new STEP retrofit method on an industrial case study demonstrates its advantages in terms of user interactiveness, simplicity of use, flexibility to customise the methodology to achieve retrofit goals of plant owners, and the least amount of efforts needed to achieve comparable results as those of established retrofit methods. [ABSTRACT FROM AUTHOR]

The current drive towards sustainability are putting pressure on organizations worldwide to implement procedures to manage the elements of sustainability for an organisation that include emissions, effluent discharge, waste disposal and energy efficiency. Even though these green elements can be managed, monitored and analysed in an integrated manner using some common resources and information, they are typically handled piecemeal under different types of management standards; and quite often, as ad-hoc projects as opposed to programs. This paper reviews the current management systems that relate to sustainability, and proposes the development an integrated green management framework called the Sustainable Green Management System (SGMS). A systematic, integrated and efficient approach for collecting, monitoring, analysing and managing information and resources via the SGMS will not only lead to organisational sustainability, but also have the potential to save ample resources, remove significant redundancies, promote cleaner production and enhance the profitability and efficiency of an organisation. An application of the proposed SGMS framework is demonstrated on a facility management case study that uses a unified GI as an indicator for an organizational sustainability. [ABSTRACT FROM AUTHOR]

Abstract: Many countries have organised energy awards as an instrument to promote energy efficiency (EE), to contribute towards energy sustainability and to provide a mechanism for organisations to continuously search, benchmark and acknowledge initiatives and best practices in EE. To be effective, an award system must be tailored towards the needs, the level of readiness and the acceptance of a nation. This paper presents a framework for implementation of a national EE award in the context of Malaysia. The current energy scenario and energy issues relevant to Malaysia are first highlighted to establish the premise for organising a national energy award. Models and success stories of EE awards in other countries are discussed as possible benchmarks for implementation. The results of a survey conducted on various energy stakeholders in Malaysia confirmed the needs, readiness and acceptance for a national EE award. A framework for the implementation of a Malaysian EE award is proposed based on the survey conducted, and on various models of energy award implementation worldwide. [Copyright &y& Elsevier]

This paper presents a new technique for simultaneous minimisation of water and energy in process plants through a combination of numerical and graphical tools. The technique consists of three steps, namely, setting the minimum water and wastewater targets; design of minimum water utilisation network, and finally, heat recovery network design. This technique offers two key advantages over current state-of-the art techniques. Firstly, it is applicable to mass transfer based and non-mass transfer based water-using operations. Secondly, it introduces a new graphical visualisation tool through a plot of temperature versus stream flowrate, termed as heat surplus diagram to guide water and energy reduction simultaneously. The heat surplus diagram provide insights on the energy demand as well as on stream matching scenarios during design of a maximum water and energy recovery network. A case study on a paper mill plant demonstrates that significant reductions in water and energy consumption can be achieved using this approach. [ABSTRACT FROM AUTHOR]

The hybrid power system (HPS) that integrates diesel/biodiesel plant with renewable energy (RE) technologies has become increasingly popular to alleviate greenhouse gases emissions issue of the sole diesel/biodiesel power system. Integrated diesel-RE power system offers cleaner power supply while minimising cost of diesel fuel and diesel system maintenance. The use of Power Pinch Analysis (PoPA) method for the integration of diesel plants and RE systems into HPS with the objective to minimise fuel requirement and operational time of diesel generator has been presented. This work aims to achieve the same objective via probability theory utilisation, to simplify the PoPA procedure involving the matching of various routes for power flows. The extended technique called the Probability-Power Pinch Analysis (P-PoPA) can give accurate results as those established from the PoPA method within a shorter analysis time because it replaces the tedious manual matching step with correction factors. All probable routes of power from RE and diesel generators to demands are considered in computing the correction factors, in order to target the minimum diesel power in the integrated system. The result of a Case Study demonstrates that 19% saving in diesel fuel consumption can be realised if the present diesel station is supported with renewable solar power in an HPS. The result of the P-PoPA method is accurate with a very minor deviation to that from the conventional PoPA technique. [ABSTRACT FROM AUTHOR]