**5. Conclusions**

208 Renewable Energy – Trends and Applications

arrangement covering useful heat sources i.e. condenser duty, hot water from the bottom of the distillation column, and hot air of cathode recirculation is considered in this study. In the

c. Heat exchanged between hot water from the bottom of column and bioethanol inlet

All the system configuration studies are illustrated in Figure 13. The basic heat exchanger

Fig. 13. Process diagram of SOFC system integrated with distillation column: a) No-HX, b)

Scenario case study Overall electrical efficiency (%) CHP efficiency (%) No-HX 15.79 76.45 CondBio 16.26 78.73 HW-Bio 16.21 78.48 Cond-Air 16.95 81.74 CathRec 21.67 79.87 CondBio-CathRec 22.53 74.71 Table 6. Performance of SOFC system integrated with distillation column with different

With regard to preheating the bioethanol inlet stream, CondBio can offer both overall electrical efficiency and CHP efficiency higher than those of HW-Bio. Thus, CondBio case is chosen for preheating bioethanol inlet stream. For preheating the air inlet stream, there are two options: Cond-Air and CathRec. Since the condenser has already been used for a bioethanol inlet stream, CathRec has to be selected although its CHP efficiency is slightly less than that of Cond-Air. Afterwards, the CondBio and CathRec are then combined to become a new case: CondBio-CathRec, and its result as shown in Table 6 provides the

CondBio, c) HW-Cond, d) Cond-Air, and e) CathRec (Source: Jamsak et al., 2009)

earlier study, system configurations are divided into 5 cases as follows:

b. Heat exchanged between the condenser and bioethanol feed stream (CondBio)

d. Heat exchanged between the condenser and air inlet stream (Cond-Air)

network was employed in all cases and the results are shown in Table 6.

a. Base case (No-HX)

stream (HW-Cond)

e. Hot air cathode recirculation (CathRec)

configurations (Source: Jamsak et al., 2009)

This chapter has presented the important use of bioethanol applied as a renewable fuel for producing electricity by Solid Oxide Fuel Cell (SOFC) system. Bioethanol must be upgraded by purifying and reforming into hydrogen rich gas which can be further applied as a clean fuel for direct combustion or electrical power generation by the fuel cell. The later option is chosen as it was realized that bioethanol was worthily utilized in an effective way. The performance development of this system was proposed through our research and the other related scientific literature reviews. Macro level of physical structure design is taken into account for initially guiding a right path for system improvement. Process modification of the system is divided into two main scopes; SOFC and Balance of Plant. The Balance of Plant as a supporting part consists of fuel processing section, bioethanol pre-treatment section, and heat recovery section. All of these are necessary in the concept of process integration and cogeneration to reduce high energy consumption and difficulties within each unit. Bioethanol pretreatment section which is an essential part has been the focus in this chapter. Our evolution of the purification process improvement was proposed. Membrane technology is a promising alternative to be applied in this section and the outcome of SOFC system performance after using this technology is in good agreement with primary mathematical simulation and the criterion of no external energy demand condition. However, an economic assessment and practical experiment in term of investigating working life time should be taken into account for the further study.
