My transnational access within BRISK2 project titled “Data gathering of updraft gasification and subsequent hydrogen enrichment for process modelling” took place in ENEA Trisaia research centre under the mentorship of Dr. Francesco Zimbardi. The objective of work was to gather data from updraft gasifier (PRAGA) equipped with hydrogen enrichment module (HENRI) for developing mathematical models of updraft gasification process.
In the performed work the focus was put on tuning syngas composition as a desirable feature of biomass gasification. Gasification was carried out in a pilot facility able to treat 20-30 kg/g of lignocellulosic feedstock using almond shells that maintain a good gas permeation when loaded as bulk. The main component of the system is a fixed bed, autothermal, updraft gasifier, operated slightly above atmospheric conditions. The gasifier has a cylindrical shape with a height of 2.4 m and diameter of 0.5 m. The inner wall of the gasifier is coated with 0.1 m of refractory material. Air, oxygen, steam or mixtures of these can be used as the gasifying media. The flow of the gasifying media is introduced into the lower part of the gasifier below the grate.
A new inserted mobile probe was employed that allowed to assess syngas quality (incondensable and tar) at different positions of the reactive biomass bed. This was achieved by drafting syngas streams directly from the core and analyzing it onsite to measure the content of H2, CO2, CO, CH4, CnHm, N2, O2. The chemical composition was correlated to the temperature profile provided by in bed measurements of 7 thermocouples, plus 4 in freeboard.
Besides the gasification section, the plant is also equipped with catalyst section for Water Gas Shift (WGS) to increase the H2 yield. It is based on a catalytic reactor loaded with 1 dm3 of Pt on Cerium oxide that in the tests was feed by 20Nm3 of syngas produced by the updraft gasifier. Before entering the catalyst syngas was cleaned by 1 m3 of biodiesel in the scrubber and filtered through coalescence filters.
The tests were carried out without significant problems and the process was effective and stable. The use of steam increased the hydrogen content and positively affected the molar ratio H2/CO that reached the steady value of 1 by using air and steam as gasifying medium. In the tests, the biomass was completely converted into gaseous and liquid energy carriers with a cold gas efficiency (CGE) ranging from 61% to 75%. With WGS the level of H2 in gas reached 37%vol (53%vol on nitrogen free basis) corresponding to a new increased H2/CO ratio of 9. Thee diagrams with measurements results are attached to this report.
Experimental data acquired during the visit are going to be used in future mathematical modelling of the updraft gasification and hydrogen enrichment process. It can be concluded that this transnational access has been successful with respect to the objectives defined at the application stage.