Chemical-looping combustion of synthetic biomass-volatiles with manganese-ore oxygen carriers

Abstract

Carbon capture and storage of CO 2 from combustion of biomass, i.e., bio-energy carbon capture and storage (BECCS), makes it possible to obtain so-called negative emissions-the atmosphere is cleansed from carbon dioxide. The purpose of the present study was to investigate the suitability of different manganese ores as oxygen carriers in chemical-looping combustion of biomass fuels. For this screening study, a laboratory-scale, circulating fluidized-bed CLC system with a nominal fuel input of 300 W th was used. The primary focus was to investigate the reactivity of these oxygen carriers towards biomass fuels, and find a reactive oxygen carrier with sufficient mechanical stability that could be suitable for large-scale chemical-looping combustion of biomass. A synthetic "biomass volatiles" gas was used to study how the different gas components react with the oxygen-carrier particles. Additional experiments were conducted with methane and a syngas. Parameter studies concerning temperature and specific fuelreactor bed mass (bed mass per fuel thermal power in kg/MW th) were carried out. With the synthetic biomass volatiles, conversion of fuel carbon to CO 2 as high as 97.6 % was achieved. For a majority of the investigated ores, essentially all C2 and C3 hydrocarbons were converted, as well as a very high fraction of the CO. Reactivity towards CH 4 was generally lower, but improved at higher temperatures. The resistance of the oxygen carriers towards mechanical degradation was measured in a jet-cup attrition test rig. The measured attrition was estimated as "intermediate" for four of the five tested materials, while one of the ores displayed high attrition.

Oxygen‐Carrier Development of Calcium Manganite–Based Materials with Perovskite Structure for Chemical‐Looping Combustion of Methane

“…Here, the method was adapted and tested for the 10 kW unit. A similar method of determining solids circulation through injection of char batches had previously been applied in the 300 W chemical‐looping reactor …”

Developing Oxygen Carriers for Chemical Looping Biomass Processing: Challenges and Opportunities

“…CuO/olivine OC [31] Mg Cu-Fe OC [99] Fe Manganese ore (Morro da Mina) [188] ( Manganese ore (Tshipi) [188] (Mn, Fe) 3 O 4 , Mn 7 SiO 12 , SiO 2 , CaO, unidentified (Mn, Fe)O/CaO, Fe 2 O 3 , unidentified…”

“…Screening the manganese ores of different origins revealed that the ores from brazil, Australia and Gabon exhibit high reactivities and good fluidization properties. [ 187 ] These advantages, however, are compromised by the high attrition rates [ 188 ] and the low durability. [ 189 ] Depending on operation conditions, the lifetimes of Mn ores are estimated to be ≈100–400 h. [ 108 ] It is also reported that the chemical interaction with ash will severely deterioate the performance of manganese ores.…”

Flexible Carbon Capture and Utilization technologies in future energy systems and the utilization pathways of captured CO2

“…While CLC was originally proposed for use with gaseous fuels, particularly natural gas (NG), the scheme can also be used in BECCS systems. One option is to first gasify the biomass, and then to use the resulting volatile product in conventional CLC systems [112]. Direct use of particulate solid fuels in CLC has also been explored [113].…”