Impact Analysis On Lignite's Chemical Looping Gasification Process Using Phosphogypsum Composite Oxygen Carrier

Under the pressure of environmental pollution and energy shortage,the development of clean new energy has aroused wide public concern all over the world.Chemical-Looping Gasification?CLG?was a novel combustion technology,which developed from the chemical looping combustion?CLC?technology.This technology was that the syngas was obtained by incomplete combustion of fuel though the direct contact between solid fuel and oxygen carrier.Phosphogypsum was a by-product of the process of wet process phosphoric acid.Its huge output and large amounts of accumulation can cause environmental pollution.However,the main component of phosphogypsum was Ca SO₄,which was suitable as an oxygen carrier.In this paper,the Chemical-looping combustion technology was applied to the resource treatment of phosphogypsum solid waste,and the phosphogypsum was used as the oxygen carrier for the Coal Chemical-looping combustion technology to realize the solid waste treatment.The main contents of the paper are as follows:1.Phosphogypsum as oxygen carrier was used for Chemical-Looping Gasification.Compared with pure gypsum,three substances,Fe ₂O₃,Si O₂and Al₂O₃,were added to the same proportion in CLG technology.The results showed that the reaction rat e of oxygen carrier with Fe₂O₃,Si O₂,Al₂O₃ and lignite was faster than that of phosphogypsum and lignite,but the initial reaction temperature decreased.The addition of pure gypsum with Fe₂O₃ was beneficial to the production of CO,and with Si O ₂ could promote the output of H₂,while with Al₂O₃ could improve the overall output of syngas.2.Nickelcompoundoxygencarrierwerepreparedwith phosphogypsum?Ni?NO₃?₂·6H₂O and?-Al₂O₃,using dip-molding method.The characteristic diffraction peaks of nickel and aluminum spinel?Ni Al ₂O₄?were not found in the reaction process,which indicated that the active components were stable.After adding Ni O,the carbon conversion rate of the reaction increased significantly,so did the activity of the carrier.The conversion rate of 10%PG-Ni O/?-Al₂O₃ was the highest,and the conversion time of carbon decrea sed with the increase of Ni O loading.3.Calcium and nickel compound oxygen carrier were prepared with phosphogypsum?Cu?NO₃?₂·3H₂O and?-Al₂O₃,using dip-molding method.There is no new inert component generated during the reaction of calcium copper complex carrier,which makes component inactivation,indicating that the crystal structure of active component is stable.The conversion rate of 8%PG-Cu O/?-Al₂O₃ was the highest.With the increase of Cu O content,the carbon conversion rate decreased,which might be due to sintering of oxygen carriers.