Application of REC for Waste-to-Energy Supply Chain

The REC method has been extend for synthesising of Sabah (Borneo, Malaysia) Palm Oil Biomass supply chain under the collaboration between University of Pannonia, Hungary; University of Nottingham Malaysia Campus, and University of Technology Malaysia. The results are reported in Lam et al. (2010d). The main contribution of author of this Thesis is providing the methodology and solving the problem in GAMS.

Palm oil biomass (POB) residues such as palm empty fruit bunches (EFB), palm fibres and palm shell obtained from the milling process have good potential to meet the targeted share of renewable energy in Malaysia. After some simple pre-treatment processes (e.g. drying and densification), POB with high heating value may be used as the feedstock for combined heat and power (CHP) plant. The generated heat and power may be used by the local plant where CHP is based, while the excess power from the CHP can then be sent to the national grid system.

EFB is the most abundant and widely available POB residue in the mill (the other POB are normally burnt within the mill). In most cases, EFB are transported out from the mill by empty HDV that bring in fresh fruit bunches from the nearby oil palm plantation estates. Hence, the CO2 emission of these HDV is of concern in the planning of regional energy supply chain that is based on palm oil EFB.

Typical location of palm oil plantation are distributed in the rural areas, the relatively low energy density (energy per unit volume) and the distributed nature of the sources require extensive infrastructure and huge transport capacity for biomass supply. For POB supply chains, road transport is the usual mode for collection and transportation of

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the fuel. As a result the heavy road transport increases the CFP of the biomass energy supply chain. A Malaysian case study is used to illustrate the developed model presented in Section 3.1.

An illustrative case study is used here to illustrate the application of the proposed model.

Data of the case study is based on the actual palm oil mills, refineries and oleochemical plants in the northern part of Borneo Island Malaysia (Figure 3.7). However, actual names of the companies are not shown for business propriety reason.

Figure 3.7 Location of EFB suppliers and consumers (Lam et al., 2010d)

Table 3.5 shows the suppliers and consumers of the EFB. The former is a group of palm oil mills where EFB is produced. In most cases, these mills are owned by small enterprises without plantation estates that may utilise the EFB (as fertiliser). On the other hand, the EFB consumers are palm oil refinery (C1) and oleochemical plant (C3) that experience energy deficit. It is assumed that combined heat and power (CHP) plants are built in these plants to generate power for plant usage. Besides, a new CHP plant is also planned for an existing mill, i.e. C2. In other words, C2 is essentially the same plant as S8. The geographical location for these plants is shown in Figure 3.7;

while their distance from each other (suppliers and consumers) is given in Table 3.6.

Sandakan

Lahad Datu Kota

Kinabalu

67 Table 3.5 Data for EFB Suppliers and Consumers

Table 3.6 Distance between EFB suppliers and consumers (km)

C1 C2 C3

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Table 3.7 shows the parameter used for the calculation for the new CHP plant. Solving the objective function yield the minimum CO2 emission at 304,254 kg/y. The optimum allocation scheme is shown in Table 3.8.

Table 3.7 Parameter for CHP calculation Steam requirement for turbine

Average calorific value of dry solids Moisture in EFB

Table 3.8 Allocation of EFB between Suppliers and Consumers (t/y)

C1 C2 C3 Unutilised

69 3.5 Chapter Summary

A new procedure for regional energy clustering has been develop and demonstrated with a case study on CFP minimisation and regional energy management. A set of biomass transfer flows with minimum CFP is given as the solution of the supply chain.

The result is further analysed with graphical display which provides decision makers easier and faster solution rather than using mathematical calculation. After the optimised supply chain flows are obtained with the developed algorithm, a demonstration case shows that how the formation of energy clusters graphically represented by RESDC. This curve visually shows the grouping of energy cluster within the boundary of the supply and demand curves. This provides an opportunity to develop efficient energy planning and management strategies within a simpler supply chain compared to the whole region network. CFP Pay back analysis is applied to assess the suggestion of building alternative infrastructure in the cluster. The pay back period and the total saving of CFP and investment cost for construction can be used as the decision factors for regional planner. The REC algorithm has also been extended for waste-to-energy network synthesis under the collaboration within 3 universities namely (i) University of Pannonia, Hungary, (ii) University of Nottingham Malaysia Campus, Malaysia and (iii) University Technology Malaysia, Malaysia (Lam et al., 2010d).

The REC approach is going to be extended to into:

(i) The studied region by using RMC, see Chapter 4.

(ii) Synthesis of supply chain to manufacture biogas and liquid biofuel as alternative biomass products. A proposed efficient synthesis and optimisation tools is P-graph algorithms (Friedler et al., 1992) see Chapter 5.

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The exploitation of the energy potential in biomass in a specific geographical region is frequently constrained by high production costs and the amount of land required per unit of energy generated. In addition, the distributed nature of the biomass resource and its normally low energy density may result in large transportation costs.

Previous chapter on Regional Energy Clustering (REC) have been extended here to tackle simultaneously the issues of the biomass supply chain and transportation and land use. The Regional Resources Management Composite Curve, in this thesis it is shortened to RMC. This original research outcome is a tool for supporting decision making in regional recourse management. It provides a complete view of energy and land availability in a region, displaying their trade-offs in a single plot.

RMC can be obtained with two steps. The first step presents the Regional Energy Cascade Analysis, which estimates the energy target within regional supply chains and provides the result for energy exchange flows between zones, the quantity of energy required to be imported/exported, and the locations of the demands. In the second step, the initial results are analysed against potential measures for improving the energy and land use targets by using the RMC and a set of rules for its manipulation. The presented method provides the option to assess the priorities: either to produce and sell the surplus energy on the fuel market or use the land for other purposes such as food production. This extended approach is illustrated with a comprehensive case study, which demonstrates that with the RMC application it is possible to maximise the use land and to maximise the biofuel production for the requested energy demand.

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