At CEDER-CIEMAT the Thermal Conversion Processes Unit boasts a series of facilities that have varying power ratings and use different technologies. The purpose of these facilities is the development and implementation of advanced combustion and gasification systems for biomass and waste. These facilities are equipped with the necessary instrumentation and analytical equipment to study the optimal operating conditions, the emissions generated during combustion processes and the quality of the gas from gasification. Different systems for scrubbing flue gases are studied at the Unit with the aim of achieving compliance with the current legislation on emissions. Finally, researchers also study the different stages in the process of cleaning gas from gasification, in order to define the most suitable end use for the gas. In this way, the Unit is able to respond to the technological demands and environmental limitations of both today and tomorrow.
- Combustion Facilities
- Gasification facilities
- Sampling and gas analysis systems
1 MWt bubbling fluidized bed combustion plant
Pilot facility for combustion of biomass or other solid fuels in a bubbling fluidized bed, with two filtration options for particles abatement: namely, a bag filter and a hybrid filter (electrostatic precipitator and bag filter). The facility is set up to enable the study of operating conditions, efficiency, emissions, and problems associated with fuel characteristics, such as corrosion phenomena and the formation of deposits and agglomerates, as well as the measurement of emissions (gases and particles). It also enables the collection of fuel and ash samples for subsequent characterization in the laboratory, while enabling comparisons with tests conducted on other technologies (e.g. fluidized bed vs moving grate) and studying the behaviour of different gas filtration systems.
Technical specifications
Thermal capacity: 600 kW to 1 MW. The combustion chamber has a diameter of 1 m and a height of 4 m. Solid fuels with a particle size of up to 50 mm. Can be fed with mixtures of various fuels and allows for the continuous addition of inert via a series of connected hoppers..
Primary (fluidizing air), secondary and tertiary air inlets, each with the option to regulate the amount and proportion.
The facility has a blower to introduce air and an exhaust gases fan, which maintains a low underpressure inside the furnace.
Recording of process parameters (temperature, pressure, flow) and continuous analysis of gases (O2, CO2, CO, NOx, SO2, TOC, NH3, HCl, CH4, NO, NO2, N2O, among others) and particles in the flue gas. Particles abatement via bag filter or electrostatic precipitator and bag filter.
500 kWt moving grate combustion plant
Commercial facility with moving grate combustion chamber and fire tube boiler with hot water production. It is equipped with an ash-extraction system, while the tubes of the heat exchanger are cleaned via a flow of compressed air. The facility is set up to enable the study of operating conditions, efficiency, emissions, and problems associated with fuel characteristics, such as corrosion phenomena and the formation of deposits and agglomerates. There is also a multi-cyclone at the boiler outlet to remove the larger particles present in the flue gases. Emissions measurement (gases and particles) and possibility of the collection of fuel and ash samples for subsequent characterization in the laboratory, while enabling comparisons with tests carried out on other technologies (e.g. fluidized bed vs moving grate).
Technical specifications:
Thermal capacity: 350 kW to 500 kW. Primary air enters under the grate, while there are six ducts for secondary air at the sides of the combustion chamber. The amount and proportion of both primary and secondary air can be regulated. Solid fuels of very low density and different sizes can be used. Can be fed with mixtures of various fuels and allows for the continuous addition of inert additives via a series of connected hoppers. The facility has three blowers to introduce air and an exhaust gases fan, which maintains a low underpressure inside the combustion chamber. Recording of process parameters (temperature, pressure, flow) and continuous analysis of gases (O2, CO2, CO, NOx, SO2, TOC, NH3, HCl, CH4, NO, NO2, N2O, among others) and particles in the flue gas.
160 kWt cyclonic combustion plant
Pilot facility with cyclonic combustion chamber and fire tube boiler with hot water production. The facility is set up to enable the study of operating conditions, emissions, and problems associated with fuel characteristics, such as ash agglomeration. There is also a multi-cyclone at the boiler outlet and a bag filter to remove large and fine particles, respectively. Emissions measurement (gases and particles) and possibility of the collection of fuel and ash samples for subsequent characterization in the laboratory.
Technical specifications:
Thermal capacity: 160 kW. The chamber is divided into two parts: a cylindrical, thermally isolated section, and a cone-shaped section where heat is transferred to the water. In the cylindrical section the fuel is burned in suspension, while the cone-shaped section houses the combustion of volatile compounds, CO and particles. The feeding system consists of a hopper with a bridge-breaker and a screw conveyor, with a capacity of up to 40 kg/h. The facility has a blower for introducing combustion air and an exhaust gases fan. Recording of process parameters (temperature and flow) and continuous analysis of gases (O2, CO2, CO, NOx, SO2, TOC, NH3, HCl, CH4, NO, NO2, N2O, among others).
40 kWt moving grate combustion boiler
Commercial facility for biomass, with moving grate combustion chamber and fire tube boiler with hot water production. It is equipped with an ash extraction system, while the tubes of the heat exchanger are cleaned by a mechanical system. The facility is set up to enable the study of operating conditions, efficiency, emissions, and potential problems associated with fuel characteristics, such as corrosion phenomena and the formation of deposits and agglomerates. Emissions measurement (gases and particles) and possibility of the collection of fuel and ash samples for subsequent characterization in the laboratory.
Technical specifications:
Thermal capacity from 25 kW to 40 kW, depending on the fuel used (i.e. herbaceous or woody biomass, respectively). Primary air enters under the grate, while there is an inlet for secondary air in the combustion chamber. The proportion of both can be regulated in a number of set positions. The facility can burn milled or pelleted fuel from agricultural, industrial or forest waste. Continuous testing for long periods is also possible. Exhaust gases fan fitted. Recording of process parameters (temperature, pressure, flow) and continuous analysis of gases (O2, CO2, CO, NOx, SO2, TOC, NH3, HCl, CH4, NO, NO2, N2O, among others) and particles in the flue gas.
25 kWt commercial condensing boiler
Commercial condensing boiler for biomass, with delivery below the burner and fire tube boiler with hot water production. The heat exchanger is spiral and features automatic cleaning with water injectors. The burner also has an automatic cleaning function. The ash falls into the ash pit, where it is manually removed from the experimental boiler in order to prevent the mixing of ash between tests. The facility is set up to enable the study of operating conditions, efficiency, emissions, and potential problems associated with fuel characteristics, such as the formation of deposits and agglomerates. Emissions measurement (gases and particles) and possibility of the collection of fuel and ash samples for subsequent characterization in the laboratory.
Technical specifications:
Thermal capacity of 25 kW, with the option of working in automatic modulation mode or in one of the five pre-set power levels. The boiler can work under condensing or non-condensing conditions and will always provide a high level of efficiency owing to the low temperature of the flue gas at the outlet. The facility has a blower to introduce combustion air (primary and secondary air) and an exhaust gases fan, which maintains a low underpressure inside the combustion chamber. It is able to burn pelleted fuel or fuel with a similar particle size to pellets (6 mm diameter). Recording of process parameters (temperature, pressure, flow, efficiency) and continuous analysis of gases (O2, CO2, CO, NOx, SO2, TOC, NH3, HCl, CH4, NO, NO2, N2O, among others) and particles in the flue gaswith discontinuous sampling.
10 kWt commercial pellet and olive stone stove
Pellet and olive stone stove with fuel delivery above the burner and continuous ash removal. The heat-exchanger tubes are fitted with a manually operated cleaner. The facility is set up to enable the study of operating conditions, efficiency, emissions, and potential problems associated with fuel characteristics, such as the formation of deposits and agglomerates. Emissions measurements (gases and particles) and possibility of the collection of fuel and ash samples for subsequent characterization in the laboratory.
Technical specifications:
Thermal capacity of 10 kW, with the option of working in automatic modulation mode or in one of the four pre-set power levels. Hot air can be delivered to three different rooms. The built-in hopper has a capacity of fuel for one day. The system also has an exhaust gases fan, which maintains a low underpressure inside the combustion chamber. Pellets and olive pits can be used as fuel. Recording of process parameters (temperature, pressure, flow) and continuous analysis of gases (O2, CO2, CO, NOx, SO2, TOC, NH3, HCl, CH4, NO, NO2, N2O, among others) and particles in fumes, with discontinuous sampling.
Test stands for domestic stoves and boilers
The Unit has a number of test stands, where domestic stoves and boilers can be installed for laboratory testing. This allows for the installation of a stove with thermal power of up to 20 kW and two boilers with power ranging from 15 to 50 kWt, in order to study the behaviour of each device with different fuels under controlled operating conditions, following a protocol based on current standards (EN 303-5, EN 14785, EN 16510 and Eco-design). Separate exhaust stacks with monitoring of gaseous and particle emissions. Controlled water-cooling systems with recording of flow and temperature.
The facility is also equipped with all the necessary instruments for measuring all the parameters (temperature; flows of air, exhaust gases and water; heat transfer; pressure) and a central data-acquisition system for the stoves and boilers that are connected to the test stands.
500 kWt circulating fluidized bed gasification plant
Pilot plant for atmospheric circulating fluidized bed gasification, with a supplementary gas-cleaning system comprising a cyclone, heat exchanger, bag filter, low-temperature gas scrubbers and gas flare. The feeding system is sealed and consists of two hoppers and two screw conveyors. There is also a hopper for adding inert material to the bed. Ash is removed continuously using a refrigerated screw. Continuous analysis of gases is provided, with a number of sampling points. The plant is equipped with the necessary instrumentation for monitoring the operation of the gasification process, along with a data-acquisition system, and enables the collection of fuel and ash samples for subsequent characterization in the laboratory.
Technical specifications:
Thermal power: up to 500 kW. Able to burn granulated and milled solid fuel. Atmospheric gasifier with a diameter of 0.3 m and a height of 8.5 m. Initial heating with a propane burner until fuel ignition, after which the process is auto-thermal. Recirculation of solids is achieved using a cyclone, a return tube and a solids valve. Recording of process parameters (temperature, pressure, flow) and continuous analysis of gases (O2, CO, H2, CO2, CH4 y SH2, among others). Option of carrying out tar sampling with a protocol based on the CEN/TS 15439 technical specification, with subsequent characterization in the laboratory.
150 kWt bubbling fluidized bed gasification plant
Pilot atmospheric bubbling fluidized bed gasification plant with cyclonic particle retention system and gas flare. The feeding system is sealed and consists of two hoppers and two screw conveyors. There is also a hopper for adding inert material to the bed. Ash is removed continuously using a refrigerated screw. The gas outlet can be connected to testing systems for research on cleaning, scrubbing and cracking. Continuous analysis of gases is provided, with a number of sampling points. The plant is equipped with the necessary instrumentation for monitoring the operation of the gasification process, along with a system for the monitoring, management and acquisition of plant data. It also enables the collection of fuel and ash samples for subsequent characterization in the laboratory.
Technical specifications:
Thermal power: up to 150 kW. Able to burn solid fuels with a particle size of up to 30 mm. Fluidized bed chamber with a diameter of 0.3 m and a height of 3 m. Initial heating with a propane burner until fuel ignition, after which the process is auto-thermal. Recording of process parameters (temperature, pressure, flow) and continuous analysis of gases (O2, CO, H2, CO2, CH4 y SH2, among others). Option of carrying out tar sampling with a protocol based on the CEN/TS 15439 technical specification, with subsequent characterization in the laboratory.
Fixed flue gas analyser
- Non-dispersive infra-red (NDIR) analysers to detect CO, CO2, NO y SO2.
- Paramagnetic analyser to detect O2.
- Ultraviolet analyser to detect SO2.
- Flame ionization detector (FID) to detect total organic carbon (TOC).
Fixed analyser of gases from gasification
- Non-dispersive infra-red (NDIR) analysers to detect CO, CH4 and CO2.
- Thermal conductivity analyser for H2.
- Paramagnetic analyser for O2.
- Analizador láser para SH2.
- Fourier-transform infra-red (FTIR) analyser to detect H2O, CO2, CO, NH3, HF, CH4, C2H4, C2H6, C2H2, benzene and toluene (available in late 2020).
Portable FTIR flue gas analyser
Portable FIDs
PM2.5 and PM10 sampling impactor
The Unit has an isokinetic sampling impactor to determine the concentration of three particle fractions: bigger than 10 µm, smaller than 10 µm, and bigger than 2.5 µm. The device can be heated in order to avoid condensation in the filters, and has several nozzles to operate under isokinetic conditions, as stated in ISO 13721 and ISO 23210 norms.
Isokinetic sampling probe
Portable ELPI analyser



Tar sampling system

