Abstract

Background: Energy is the key for economic growth of every nation and as such life blood for civilization. The demand for energy is also increasing at an exponential pace. To meet this energy demand, a great need arises to search for alternative sources of energy, which can be used in place of fossil fuels. Many alternate renewable sources of energy which can be used in place of fossil fuels biomass is considered one of the best alternative sources of energy due to its large potential and economic viability. It has been estimated that by 2050 biomass could provide nearly 17% of the world’s energy. In the present study, a new biomass fuelled triple power cycle is proposed and assessed.

Methods: This paper presents the findings of a thermodynamic investigation of a biomass driven syngas fuelled triple power cycle. In order to utilise the waste heat from the exit of the steam turbine, an ejector is employed to improve the efficiency of the proposed cycle. A parametric study is conducted by investigating the effect of gas turbine inlet temperature and gasifier pressure on various energetic and exergetic efficiencies.

Results: It is found that both energetic and exergetic efficiencies of the triple power cycle increase with the increase in gas turbine inlet temperature but decrease with an increase in gasifier pressure. It is observed that with the employment of an ejector the energetic and exergetic efficiencies of the triple power cycle increase by 6.2% and 3.1%, respectively. Furthermore, sawdust is seen to be more effective for power generation in comparison to the use of rice husk.

Conclusion: This paper is based on the energetic and exergetic analyses of biomass integrated gasification for the combined production of power and refrigeration resulting in following concluding remarks:

• The energetic and exergetic efficiencies of biomass fuelled triple power cycle increase with the increase in gas turbine inlet temperature.

• There is an average 6.2% gain in energetic efficiency and 3.1% gain in exergetic efficiency after the employment of an ejector.

• Slight variation in both the energetic and exergetic efficiencies occur when the biomass is changed from sawdust to rice husk.

• Both energetic and exergetic efficiencies of the triple power cycle slightly decrease with the increase in steam turbine inlet pressure.

Keywords: Biomass fuel, ejector cycle, ORC, refrigeration cycle, steam turbine, natural energy.

Graphical Abstract