Zecomix

ZECOMIX (Zero Emission of CarbOn with MIXed Technologies) research infrastructure reported in figure 1, is a very flexible facility in which, a number of low carbon technologies, can be tested separately or connected together.

Figure 1 ZECOMIX research infrastructure

The main objective of the facility is to test the decarbonisation of power and industrial (e.g. steel and cement) sectors based on high temperature CO2 capture with CaO-based solid sorbent (Calcium Looping, CaL) for the production of H₂-rich syngas. Several processes such as synthetic fuel gas production, steam methane reforming, clean-up of syngas, CO₂ capture by means of CaL process have been investigated.

Latest experimental results obtained in ZECOMIX are published in peer reviewed journals as Energy 103 (2016) 697-708 and Fuel Processing Technology 139 (2015) 204–215, Chemical Engineering Journal 220 (2013) 383–394.

Figure 2 shows the main components of the Research Infrastructure.

The coal gasifier is a 500 kWth bubbling fluidised bed reactor. The coal feed system has been designed to feed a nominal load of 60 kg/h of coal. The system is equipped with a 2 m³ coal storage, which permits stationary operation up to about 40 hours. Steam and oxygen are fed at different points of the reactor, in order to control the hydrodynamics of the fluidised bed (made up of olivine sand) and the reaction rate all throughout the reactor. A syngas mainly composed of H₂, CO, CO₂, and steam is obtained at temperature of 800°C. This syngas is sent to a regenerative heat exchanger reducing its temperature to around 700-600 °C. It can then be fed into the carbonation reactor, or alternatively to a liquid based scrubbing device, after a second cooling step down to 350°C.

The five-meter high CO₂ capture module has been conceived as a fluidised bed with a 1 meter internal diameter. In the fluidised bed, the reforming of CH₄ coupled with CO₂ capture by means of solid sorbents can also be carried out, in order to produce high H₂ rich gas in a single step.

Figure 2 Main components of ZECOMIX

In the CaL process it is desirable to produce a concentrated CO₂ stream during regeneration, and in this case, the calcination will be carried out in a CO₂ atmosphere. This puts requirements on the sorbent, e.g. the sorbent must withstand a high CO₂ concentration during its regeneration for an extended number of cycles. Efforts are being made to synthesise a high regenerable solid sorbent to be used in a cycling CO2 capture.

The power block is a 100 kWe micro-turbine test bench, in which significant modifications to the combustion chamber have been made to make it able to burn H₂-rich syngas in air.

Research activities are carried out under the joint programme between ENEA and the Italian ministry of economic sustainable development and in agreement to international EU funded projects (ASCENT www.ascentproject.eu) and European initiatives (Joint programme CCS of the European Energy Research Alliance).

The multipurpose platform ZECOMIX is included in the database of MERIL (Mapping of the European Research Infrastructure Landscape) as a Research Infrastructure of great importance in Europe in the field of CCS (Carbon Capture and Storage).