title: CO₂ uptake performance and life cycle assessment of CaO-based sorbents prepared from waste oyster shells blended with PMMA nanosphere scaffolds.
abstract: In this paper, we demonstrate a means of simultaneously solving two serious environmental issues by reutilization of calcinated mixture of pulverized waste oyster shells blending with poly(methyl methacrylate) (PMMA) nanospheres to prepare CaO-based sorbents for CO2 capture. After 10 cycles of isothermal carbonation/calcination at 750°C, the greatest CO2 uptake (0.19 g CO2/g sorbent) was that for the sorbent featuring 70 wt% of PMMA, which was almost three times higher than that (0.07 g CO2/g sorbent) of untreated waste oyster shell. The greater CO2 uptake was likely a result of particle size reduction and afterwards surface basicity enhancement and an increase in the volume of mesopores and macropores. Following simplified life cycle assessment, whose all input values were collected from our experimental results, suggested that a significant CO2 emission reduction along with lesser human health and ecosystems impacts would be achieved immediately once waste is reutilized. Most importantly, the CO2 uptake efficiency must be greater than 20% or sorbents prepared from limestone mining would eventually produce a net positive CO2 emission.
authors.affiliation: Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Tsinghai
authors.initials: T
authors.lastname: Wang
authors.affiliation: School of Environment, Tsinghua University, Beijing, China.
authors.forename: Da-Cheng
authors.initials: DC
authors.lastname: Xiao
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Huang
authors.affiliation: Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Yi-Kong
authors.initials: YK
authors.lastname: Hsieh
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Chung-Sung
authors.initials: CS
authors.lastname: Tan
authors.affiliation: Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan. Electronic address: cfwang@mx.nthu.edu.tw.
authors.forename: Chu-Fang
authors.initials: CF
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D060105:Animal Shells; D000818:Animals; D017610:Calcium Compounds / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D057965:Carbon Sequestration; D054118:Nanospheres / Q000737:chemistry*; D010125:Ostreidae; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D059027:Recycling; D013499:Surface Properties; D018505:Waste Management / Q000379:methods; D014866:Waste Products
chemical_list: D000393:Air Pollutants; D017610:Calcium Compounds; D010087:Oxides; D014866:Waste Products; D002245:Carbon Dioxide; D019904:Polymethyl Methacrylate; C016538:lime
keywords: Calcium oxide-based adsorbents; Carbon dioxide capture and sequestration; Life cycle analysis; Poly(methyl methacrylate); Template; Three-dimensional ordered mesoporous (3DOM) materials