• Energy Research

AbstractPalm oil mill is rich with biomass and biogas resources. Thus the resources can be utilised to power a green DEG energy system for an eco-community comprising of the POM itself as well as a local residential community in Iskandar Malaysia. Solar energy systems are also integrated to the DEG system to supply additional energy to ensure the system is fully RE operated, to drive the realisation of a low carbon society in Iskandar Malaysia. Thus in this work, a model that incorporates load shifting feature is developed, with the aim to design an optimal biomass and biogas power generation system, solar energy system, and energy storage system, with consideration of the variation of electricity and thermal energy requirement due to weekday/weekend profiles and operation status of palm oil mill.

Renewable distributed energy generation (DEG) system plays an important role in future power developments and is one of the options to reduce energy consumption. It is envisaged that energy efficiency of DEG systems can be improved via load shifting (LS). This study proposed a heuristic-based numerical approach to perform LS analysis on renewable stand-alone DEG systems. The technique is an extension from a method known as the Electric System Cascade Analysis (ESCA). The new technique, which focuses on efficient electricity utilisation is able to determine the optimal: (i) load profiles, (ii) capacity of power generator, (iii) capacity and power of energy storage (ES) and (iv) charging/discharging schedule of ES. The stage-wise technique allows user to compare and determine the optimal design in a flexible way while having a better understanding of the selection of options. The application of ESCA-LS on a case study revealed that after incorporation of direct LS (load manipulation) in addition to LS by ES (supply manipulation), the power generators and ES capacity can be further reduced. While reduction of 3.1 % for solar-PV installation area and 3.9 % for biomass power generator is recorded, ES power-related capacity and energy-related capacity managed a higher reduction of up to 19.0 and 13.2 % for the main case study

AbstractMalaysia is considered as a major palm oil producer in the world. Therefore, it is vital to utilize an environmentally friendly and inexpensive method to treat palm oil mill effluent (POME) in Malaysia. Nowadays, the use of microalgae to remove pollutants from POME has gained a lot of attention. The main objective of this research was to investigate the effect of POME as a nutrient on the microalgae growth and analyze the removal rate of pollution. In this study, a pure culture Chlamydomonas incerta was aseptically transferred to an Erlenmeyer flask containing POME. The effect of POME as a high nutritional substrate, different cultivation scales, carbon total nitrogen (C:TN) ratio, and the lipid productivity of microalgae C. incerta were assessed. C. incerta was grown at room temperature under continuous illumination with the intensity of ± 15 (μmol/m2/s) for 28 days, followed by the measurement of chemical oxygen demand (COD) reduction at different substrate concentrations. The results of this study demonstrated that organic carbon was removed by C. incerta for the ratio of 100:7, 100:13, and 100:31 respectively within the second day of cultivation. Fast growth of microalgae was observed in organic and inorganic substrates for adoption within the second day of experiment. The optimum achievement rate of nutrient removal with C. incerta was about 67.35% of COD for 250mg/L of POME concentrations in 28 days. The significance of this study is regarding the introduction of a new microalgae strain with a high ability to remove nutrients from POME, which can contribute to the effort in finding an efficient and economic technology for improving our environment.

Abstract Palm oil mill effluent (POME) is recognised as one of the biggest sources of pollution due to its eutrophying nature and methane emitting treatment. Although biogas recovery and utilisation are promoted through government initiatives, the motivation and support from mills still reported low in Malaysia. This paper aims to discuss the benefits and drawbacks of POME utilisation in the palm oil supply chain based on environmental, social and economic concerns to review the favourability of POME elimination. A zero effluent approach is introduced based on POME evaporation technique, undiluted clarification practice and water recycling strategy as an alternative for conventional POME management approaches. An integrated palm oil complex concept is proposed which includes new palm oil processing approach that eliminates POME and provides industrial symbiosis possibilities within palm oil upstream and downstream sectors to promote sustainability of palm oil industry with balanced economic and environmental advantages. A comparative study between POME utilisation (Case 1 and 2) and POME elimination (Case 3) in different perspectives is included in this work. In the economic view, the payback period of Case 3 is shorter (4 y) compared to Case 1 and 2 (4.3–8.3 y). In comparison, POME elimination technology is more environmentally friendly due to smaller water and land footprint, zero methane emission and minimum waste generation. Approximately 0.3% improvement in oil extraction rate can be potentially achieved by the proposed mill configuration in Case 3. One of the challenges in POME elimination implementation is the additional 0.25 kg steam requirement associated with evaporation of 1 kg water. The study provides insights on the feasibility of the proposed sustainable concept in Malaysia with consideration of government policies and programmes. The suggested POME elimination-based complex provides alternative option to mill owners who are uninterested to invest in biogas capturing facilities.

In a typical operation of palm oil mill, oil palm residues and palm oil mill effluent (POME) would be produced. While the oil palm residues have been well harnessed as biomass fuel, regional planning of efficient POME utilisation via biogas recovery and upgrading, coupled with possible biogas compressed natural gas (bioCNG) transshipment among the palm oil mill cluster, deserves more research and development. In this study, the objective is to design a modelling tool for optimising the oil palm biomass and POME utilisation pathway as well as bioCNG distribution network for a palm oil mill cluster with maximum simultaneous economic satisfaction level. Fuzzy optimisation approach was applied for this proposed multiple-objective modelling problem. Two case studies were simulated by the developed mathematical tool to examine the economic benefit of POME utilisation pathway in multiple-site palm oil processing complex (POPC) design. Moreover, the impact of feed-in-tariff (FIT) quota variation on POPC and bioCNG transshipment pathway designs was examined. From the simulation, it was found that POME utilisation pathway incorporation had increased the overall annual worth by MYR 15,049,096 per year due to additional revenues from bioCNG and biogas-derived electricity sales as well as utility saving.

Abstract Biofuel is an attractive vehicular fuel option for the transportation sector. Diverse biofuel blends can be produced from biomass. Complexity arises when optimum biofuel blends need to be designed to comply with fuel regulation standards as well as generate less emission. This paper discusses an integrated computational and experimental technique to design economically viable and environmentally friendly tailor-made biofuel blends from palm biomass that is abundant in Malaysia. An experimental based trial-and-error method is time consuming and uses up resources. Computational approaches adopt a systematic blend formulation methodology that assists focused experimental work. The biofuel design problem has been formulated as a Non-Linear Program to satisfy specified target properties such as density, kinematic viscosity, cetane number, gross calorific value, distillation temperature, and sulphur content. Target properties predicted through mixture property models were experimentally validated according to ASTM standard test methods. Five optimum tailor-made biofuel blend formulations were generated based on cost, gross calorific value and emission limitations. The result indicates that biofuel blends with butyl levulinate could increase the price of biofuel up to 80% from the retail price of B5 diesel. However, cleaner biofuel with less cost and highest calorific value can be achieved for biofuel blends that contain B5 diesel, butanol and ethanol. The application of this model yields about 26% CO 2 emission reduction and about 22% less sulphur content as well as comply with the EN590 fuel regulation standard.

Pinch analysis concept has been recently stepped into the realm of design and optimisation of power systems. One well-established pinch analysis that has been used in power systems design and optimisation is called Power Pinch Analysis (PoPA). In PoPA, both graphical and numerical approaches have provided an insight on the systematic approach to target and design various power systems. By only visualising the minimum amount of outsource energy required by the power system, the graphical PoPA method as a whole does not show the purchasing of outsource energy based on the exact time intervals. Using graphical PoPA, the objective of this study is to determine a proper strategy to buy and sell outsource electricity to improve the overall performance of a hybrid power system comprising renewable power generators and energy storage system. The strategies are made based on three design parameters: energy-related capacity, power-related capacity of energy storage and maximum grid power rating between centralised grid and hybrid power system. While deciding on the best strategy and heuristics to be implemented, the effects on system operation and economy are indirectly analysed. It is experimented that the output can benefit electricity consumers or producers.