Category New developments in renewable energy

Research scope and application

This research was performed with the objective to determine the combustion efficiency of the existing coal-fired combustor during co-firing agricultural residue with coal. The effi­ciency is calculated mainly based on the carbon monoxide and carbon dioxide emissions. Furthermore, this works also to demonstrate the technical feasibility of a fluidized bed as a clean technology for burning agricultural residues. In addition, the effect of biomass proper­ties such as such as particle size, particle density and volatility as well as influences of oper­ating parameters such as excess air, fluidizing velocity on axial temperature profile, the combustion efficiencies and CO emissions are also being investigated.

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Problem statement

Although there are many potential benefits associated with co-combustion, there are several combustion related concerns associated with the co-combustion of coal and biomass. Utiliza­tion of solid biomass fuels and wastes sets new demands for boiler process control and boil­er design, as well as for combustion technologies, fuel blend control and fuel handling systems. For example, the different mineral matter composition (high alkali levels) and mode of occurrence (mostly mobile forms) in biomass results in concerns over enhanced fouling and slagging of pulverized coal boilers, particularly when firing agricultural resi­dues or herbaceous materials. The economics of co-combustion in pulverized coal boilers are closely tied to the biomass preparation costs (i. e...

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Combustion studies

Fluidized bed combustion of alternative solid fuels (including biomass) are attractive as a result of the constantly increasing price of fossil fuels, the presence of high quantities of wastes to be disposed of and global warming issues. Extensive experimental investigation has been carried out to date on the feasibility and performance of different biomass fuels FB combustion such as rice husk [1013], animal waste [1415], municipal solid waste (MSW) [1619] and Refuse Derived Fuel (RDF) [5]. In whatever form biomass residues are fired (loose, baled, briquettes, pellets), a deeper understanding of the combustion mechanisms is required in order to achieve high combustion efficiency and to effectively design and oper­ate the combustion systems...

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Fluidised Bed Combustion (FBC) technology

Fluidised bed combustion technology is one of the most significant recent developments in both coal and biomass incineration over conventional mass burning incinerator designs. This technology has been accepted by many industries because of its economic and favoura­ble environmental consequences.

The major advantages of fluidized bed combustors are [8,9]:

• Uniform temperature distribution due to intense solid mixing (no hot spots even with

• strongly exothermic reactions

• High combustion efficiencies

• FBC systems have a very short residence time for their fuels (making these systems

• highly responsive to rapid changes in heat demand).

• Large solid-gas exchange area by virtue of the small solids grain size

• High heat-transfer coefficients between bed and the heat exchangi...

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Biomass as potential renewable resources

A recent study shows that Malaysia has been one of the world’s largest producers and ex­porters of palm oil for the last forty years. The Palm Oil industry, besides producing Crude Palm Oil (CPO) and Palm Kernel Oil, produces Palm Shell, Press Fibre, Empty Fruit Bunch­es (EFB), Palm Oil Mill Effluent (POME), Palm Trunk (during replanting) and Palm Fronds (during pruning). Almost 70% of the volume from the processing of fresh fruit bunches (FFB) is removed as waste. Malaysia has approximately 4 million hectares of land under oil palm plantation. Over 75% of total area planted is located in just four states, Sabah, Johor, Pahang and Sarawak, each of which has over half a million hectares under cultivation...

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Sustainable Power Generation Through Co­Combustion of Agricultural Residues with Coal in Existing Coal Power Plant

Wan Azlina Wan Ab Karim Ghani and Azil Bahari Alias

Additional information is available at the end of the chapter http://dx. doi. org/10.5772/52566

1. Introduction

Waste-to-energy is gaining more and more attention as landfill costs and environmental concerns increase in many developed countries including Malaysia. Biomass from agricul­tural residues is one of the most important sources of renewable energy in Malaysia. The Na­tional Biofuel Policy, launched in 2006 encourages the use of environmentally friendly, sustainable and viable sources of biomass energy. Under the Five Fuel Policy, the govern­ment of Malaysia has identified biomass as one of the potential renewable energy...

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Hybrid power system simulation results

The load’s power, diesel genset’s power and wind generators power are shown respectively in Fig. 8, Fig. 9 and Fig. 10. The diesel genset operates with minimum load of 35% of the rated power (Fig. 9). Three 80 kW alkaline electrolyzers are used as dump load. The surplus power is absorbed bythe electrolyzers (Fig. 11, Fig. 12, Fig. 13) which contribute to balance the load demand and power production (Fig. 14). Electrolyzers contribute to maintain the frequency of the autonomous power system (Fig. 15).

Hybrid power system simulation results

Hybrid power system simulation results

Figure 9. Diesel genset power

 

Hybrid power system simulation resultsHybrid power system simulation results

Hybrid power system simulation results

Подпись: Figure 11. Power absorbed by Electrolyzer 1

Hybrid power system simulation results

Подпись:

Hybrid power system simulation results

Figure 15. AC-Bus frequency

3. Conclusion

This chapter is devoted to a large scale wind diesel Hybrid Power System (HPS)...

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Alkaline electrolyzer

The decomposition of water into hydrogen and oxygen can be obtained by passing a direct electric current (DC) between two electrodes separated by a membrane and containing an aqueous electrolyte with good ionic conductivity. The electrodes are immersed in an alka­line aqueous solution.

The electrolyzer model is composed of several modules (F. J. Pino et al., 2011). Powered by the DC electrical sources and pure water, an electrolyzer can effectively split water into hy­drogen and oxygen. Since it is difficult to obtain analytically the inverse of the equation (34), linear models are used generally in literature (R.Takahashi et al. 2010).

Alkaline electrolyzer Alkaline electrolyzer Подпись: (34)

In this paper, the electrolyzer model takes into account the ohmic resistances and cell over­voltages (equation 34) (O. Ulleberg, 1998).

V...

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