Simulation-Based Study of a Novel Integration: Geothermal–Biomass Power Plant (original) (raw)

An Improved Hybrid and Cogeneration Cycle for Enhanced Geothermal Systems

Geothermal energy is one of alternative energies that should be used as optimally as possible. Conversion of geothermal energy to be electric energy plays important role in saving energy resource due to advantages of utilization of electric energy. Energy state of steam before entering turbine significantly influence in specific output power. Shortcoming of steam quality from geothermal well is one factor causing most geothermal direct expansion power plant produces low thermal efficiency. A hybrid system is proposed to enhance geothermal system. Modification of a conventional geothermal power plant is conducted by combining with a gas turbine, a refrigerationheat pump, and organic Rankine cycles. Quality of steam from the geothermal well should be heated before entering the steam turbine. Organic Rankine cycle is included to utilize low thermal energy of exhaust gas to generate power. A refrigeration and heat pump system is introduced to cool inlet air into gas turbine and as an additional heat source of working fluid in an organic Rankine cycle. Most evolved parameters are investigated such as temperature, pressure, working fluid, and pressure ratio. The hybrid system can improve significant efficiency from 19.85% to be 35.83%. Fossil fuel utilization factor of the hybrid system is up to 63.81%. Increment of net output power and efficiency of the direct expansion cycle in the hybrid system are 42.70% and 15.98%, respectively, compared to the conventional geothermal power plant. The best working fluid from thermodynamic aspect for organic Rankine cycle and vapor compression cycle is R-600.

Alternative Systems for Enhancing Geothermal Power Plant

Geothermal energy is one of alternative energies that is currently used in Indonesia around 3% for power generation should be used as optimally as possible. Electric energy utilizations are very convenient so that the electric energy generation is chosen to be priority energy. This motivates to converse geothermal energy into electric energy forms by developing geothermal power plant. Lower steam quality generated from geothermal wells are most remaining problems in most world geothermal wells since this condition causes lower thermal efficiency of the system. Therefore, finding efficient thermodynamic systems of the geothermal power plant is important to be conducted. Several alternative systems with basis of geothermal energy sources are investigated in this paper. Three main different systems which are independent geothermal heat source, i.e. direct expansion steam turbine, binary cycle (Organic Rankine Cycle, ORC) and heat pumped geothermal power plants are compared. Two systems with combining fossil fueled system are also compared. ORC with working fluid R-134a and R-600a have better performance than direct expansion cycle when operated at lower geothermal source temperature. Especially working fluid of CO2 has significantly different characteristics due the fluid should operate at supercritical region. Direct expansion cycle will perform better when steam temperature is higher 150oC. Including a gas turbine system into geothermal power plant can improve significant efficiency of the system. Adding by a vapor compression cycle operated as heat pump and cooling systems can give better efficiency and fuel utilization than most recent technology of combined cycle power plants.

Experimental Tests and Modeling on a Combined Heat and Power Biomass Plant

Energies

Renewable energy sources can help the countries to achieve some of the Sustainable Development Goals (SDGs) provided from the recent 2030 Agenda, allowing for clean, secure, reliable and affordable energy. Biomass technology is a relevant renewable energy to contribute to reach a clean and affordable energy production system with important emissions reduction of greenhouse gases (GHG). An innovative technological application of biomass energy consisting of a burner coupled with an external fired gas turbine (EFGT) has been developed for the production of electricity. This paper shows the results of the plant modelling by Aspen Plus environment and preliminary experimental tests; the validation of the proposed model allows for the main parameters to be defined that regulate the energy production plant supplied by woodchips.

A Technical and Economical Analysis of Combined Heat and Power Production from Biomass

Even at small scale combined heat and power production from biomass can achieve high overall efficiencies referred to the fuel power input. In the present work, six technologies are evaluated; conventional combustion based technologies, like steam turbine, steam engine, ORC-process (Organic Rankine Process) or Stirling engine on the one hand and gasification-based technologies, like fixed and fluidized bed gasification combined with gas engines on the other hand. Plant data are collected to assess the different technologies and to calculate their electricity production costs. To obtain comparability for each plant the costs are calculated using a reference case. The influence of scale is considered in order to compare electricity production costs for plants of different sizes. Furthermore, variations are carried out to show the influence of different parameters. Finally, learning curves are applied to calculate electricity production costs for future plants. Revenues from heat sales...

The development of geothermal energy as a renewable power plant

Journal of Earth Energy Engineering

Geothermal energy is a sustainable and ecologically beneficial energy source, it is believed that Indonesia alone has 40% of the world's geothermal energy reserves of roughly 28.000 MW. The Indonesian government expects the geothermal power plant installed capacity to reach 10.000 MW by 2025. However, the installed capacity remained at 1.739 MW until 2014. Aside from that, the Indonesian government has made significant investments to expand the geothermal sector through different current rules. This research aims to determine the absorption of geothermal energy as an alternative to power generation and many elements of the associated hurdles, such as natural and human resources. In addition, this paper also creates new model parameters that significantly improve model performance. Analysis of system dynamics methods and modelling and simulation methods are used for fast and accurate results. According to a literature analysis done by collecting secondary data from journals and a...