Process Comparison for Biomass Combustion: In Situ Gasification‐Chemical Looping Combustion (iG‐CLC) versus Chemical Looping with Oxygen Uncoupling (CLOU)

Abstract

Biomass is an interesting renewable fuel to be used in chemical looping combustion (CLC). If the CO2 generated during biomass combustion is captured, the negative‐CO2 emission concept is possible. This work evaluates the differences between biomass combustion under two CLC configurations developed for solid fuels: in situ gasification‐chemical looping combustion (iG‐CLC) and chemical looping with oxygen uncoupling (CLOU). The combustion efficiency, tar emission, and carbon capture efficiency obtained at different fuel reactor temperatures in a continuous 1.5 kWth CLC unit were compared. Higher carbon capture efficiencies were reached under the CLOU mode, with no tar emission. Although in the iG‐CLC mode tars were always present in the fuel reactor outlet gas, high carbon capture was reached by using CO2 as gasifying agent. Moreover, a simulation of the effect of the solid inventory necessary in the fuel reactor to reach certain carbon capture efficiency was performed for both processes. Lower solid inventories are needed in the CLOU configuration, but the cost for the oxygen carrier used in CLOU is higher than in iG‐CLC.

Chemical Looping Combustion of gaseous and solid fuels with manganese-iron mixed oxide as oxygen carrier

“…found when biomass was burned [29]. Traditionally, Cu-or Mn-monometallic oxides supported on an inert material have been proposed for their use in CLOU [30].…”

Process Simulation and Energy Analysis of Chemical Looping Combustion and Chemical Looping with Oxygen Uncoupling for Sawdust Biomass

“…Furthermore,t he difference between iG-CLC and CLOU operation using biomass as fuel was also investigated in terms of combustion efficiency and carbon capturee fficiency. [12] Thes tudies mentioned here have concluded that, in general, al ow oxygen carrier circulation rate is required for CLOU as compared to CLC to accomplish biomass combustion. Most of the experimental studies have provided ap ositive mandatet od evelop and scale-upt he CLC and CLOU process to an industrial level using biomass as fuel.…”

“…[2] CLOU does not involve the gasificationo f the fuel char;h ence the rate of combustion in the fuel reactor is high compared to CLC. [12] It shows that compared to CLC,t he residence time of oxygen carrier particles in the fuel reactor is also less.A saresult, the fluidizatione nergy cost is lower in CLOU compared to CLC.I th ad been reported that the fluidization agent does not have any influence on the decomposition of oxygen carrier particlesi nt he fuel reactor. [18] Hencei nt he present simulation, N 2 is useda s af luidization agent as per experimental worko fG ue tal.…”

Chemical looping combustion of biomass for renewable & non- CO2 emissions energy- status and review

“…Some research works have been concluded that direct CLC of solid fuels lead to the formation of unconverted char in the fuel reactor and burning of fuel in the air reactor [30]. Thus, to reduce the above mentioned difficulties a new technology named In-situ Gasification Chemical Looping combustion (IGCLC) was introduced where the gas released from the gasification of solid fuels will be used as a fuel in CLC process [31]. Adánez-Rubio I., et al demonstrated CLOU concept for the first time with biomass as fuel in a continuous CLC unit using milled pine wood chips with 60% of CuO contained oxygen carrier prepared by spray drying method where full conversion of biomass has been taken place [32].…”