«Development of scientific bases for hydrogen production, storage and use in autonomous energy supply systems»

Development of autonomous cogeneration hydrogen power plants with solid organic waste conversion

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The principle of autonomous operation of cogeneration plants with solid organic waste conversion using equipment of Coal Energy Technology Institute of the NAS of Ukraine

Area of application

Autonomous plants for heat and electricity production with solid organic waste conversion can be used for independent energy supply in the municipal power and chemical industries, hospitals, food industry, educational institutions, farms, private houses, shops, hotels, mobile homes, power systems of special devices and tools, etc.

Brief description

Hydrogen-rich synthesis gas and, if necessary, pure hydrogen are produced in the CETI NASU gasifier, which can be transformed for the various solid organic waste conversion in the different modifications of moving and fluidized beds. The gasifier start is carried out using plasma torches (steam or air). The gasifier can operate both with and without the use of plasma torches depending on the solid organic waste properties.
A parallel-series circuit of operation of heat and electricity generation units was used for the construction of cogeneration power plants. Depending on need in the cold season, only heat can be produced in the boiler using hydrogen-rich synthesis gas or pure hydrogen. In order to achieve autonomy, energy efficiency improvement, and the plant operation in the mode of heat load change, the hot water obtained in the boiler is fed into the heat accumulator that provides the possibility of boiler periodic operation with continuous independent heat supply from heat accumulator for heating.
In the case of heat and electricity generation, heat from an electric generator with an internal combustion engine (ICE), fuel cell electrochemical generator (FC ECG) or a gas turbine unit (GTU) is fed into the heat recovery unit. In the cogeneration power plant circuits, FC ECG can be involved, for example, with Bloom Energy or Rolls Royce planar solid oxide fuel cells; Mitsubishi Hitachi Heavy Industries, Bosch Thermotechnology/Aisin Seiki tubular solid oxide fuel cells or others.
In order to achieve autonomy, energy efficiency improvement, and the plant operation in the mode of electrical load change, electricity generated by power generators is fed through the charger to the electric accumulators, from which electricity is fed through the inverter to the consumer. Thus, cogeneration plants are hybrids for generating both electricity and heat using accumulators. In these plants, both periodically operating power units and batteries are used to achieve autonomy. This is done to reduce the load on the main equipment (gasifier, plasma torches, boiler, electric generators, and fuel cells) and to increase the life time of power plants, which operate intermittently with continuous supply of electricity and heat from batteries to the consumer.
For further energy efficiency improvement, cogeneration plants may contain metal hydride hydrogen accumulators (to store hydrogen in the warm season and to use it in the cold season in a hydrogen boiler), solar cell panels without the use of electrolyzers and with the use of electric accumulators for power supply and for the operation of electric heaters built into the heat accumulator, and with electrolyzers (with the production of hydrogen for the FC ECG operation and oxygen for the gasifier operation), as well as heat pumps.

Expected results

As a result of complex research, a new autonomous cogeneration plant with heat capacity up to 20 kW will be created using a gasifier, boiler, and an electric generator driven by an internal combustion engine. The technology will be developed and the units of the cogeneration plants for the conversion of solid organic waste into gas, suitable for use in electrochemical generators on solid oxide and polymer fuel cells, will be tested.

Advantages

Improvement of the efficiency of the use of solid organic waste due to the simultaneous generation of electricity and heat, the use of heat and electricity accumulators and fuel cell electrochemical generators. An increase in the life time of plants due to a decrease in the load on the main equipment, the mobility of the plants due to the use of heat and electricity accumulators, and possibility to work on different types of solid organic waste. A decrease in the cost of electricity and heat generated due to the use of cheap organic raw materials (solid organic waste) and power equipment.

Competitor

State of development

The gasifier-transformer was developed for the further use as part of cogeneration power plants. The gasifier was tested on different types of solid organic waste (SOW). The main equipment for the operation of the cogeneration plant, a boiler and electric generators, was identified, selected, and purchased. The boiler is Kolvi Euroterm KTK standard solid fuel-fired boiler with thermal capacity up to 18 kW with anthracite, coal, briquettes, and wood combustion for autonomous heating of rooms up to 200 m2. The boiler was transformed for combustion of synthesis gas and hydrogen obtained in the gasifier (the way from carbonization to decarbonization). The electric generator with ICE Endress ESE 3200P with nominal electric power of 2.35 kW, which was modified to operate on hydrogen-rich synthesis gas, was used in the power supply circuit. The electric generator with different carburetors can also operate autonomously on gasoline, propane-butane and natural gas.
Optimization of the operation of the gasifier, boiler and electric generator with internal combustion engine for heat and electricity production has been started. Gasifier has been tested using various types of SOW. There were determined optimal parameters of gasification of different SOWs depending on their composition and consumption of oxidants (air and steam) in order to use the obtained gas for the operation of cogeneration and trigeneration power plants. Tangential two-stage air supply to the zones of partial oxidation and carbonization of the gasifier was used to increase the gasification efficiency. There were determined the regularities of increasing the molar ratio of H2/CO compounds in the gas obtained after gasification due to the use of high-temperature steam. The temperature of gases at the outlet of the carbonization zone depends on the type of SOW and, for their effective conversion, should be 300 to 500 °C, and the temperature of gases at the outlet of the gasifier should be above 600-650 °C. It was found that the use of a reactor with a regenerated Ni-catalyst is the best option for use in cogeneration plants to reduce the content of high-molecular compounds in the gas before electric generators.
It is determined that for full autonomous climate control in rooms needs the use of autonomous trigeneration power plants for the production of electricity, heat and cold. In this case, the maximum energy efficiency of the SOW energy use is achieved when changing both the daily load and the load at different times of the year. The use of the trigeneration principle provides the highest fuel efficiency at different times of the year. The principle circuit of the installation for obtaining cold with use of solid organic waste has been developed.
The principle circuit of a hybrid power plant with an electric power of 250 kW with pressurized gasifier, 9I120 gas turbine unit, and electrochemical generator on solid oxide fuel cells has been developed.
It is established that the use of SOW as a fuel in cogeneration and trigeneration power plants reduces the cost of the obtained products in comparison with the use of traditional fuels by 1.5-2.0 times.
The analysis was carried out and proposals were prepared on the possibility of using the by-product of SOW conversion – carbon dioxide for the operation of polygeneration cogeneration hydrogen power plants for the production of electricity, fertilizers, plastics, third generation biofuels, construction materials, nanocarbon, etc.

Intellectual property

Contact information

Institute of Heat and Power Technologies, National Academy of Sciences of Ukraine

Project 3 "Development of autonomous cogeneration hydrogen power plants with solid organic waste conversion"

Project leader:

Tel. +38 044 425-04-19

Е-mail: aldudnyk2018@gmail.com