Influence of calcium content of biomass-based materials on simultaneous NOx and SO{sub 2} reduction

Journal Article · Tue Apr 01 04:00:00 EDT 2008 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es0719430· OSTI ID:21049829

Pisupati, Sarma V; Bhalla, Sumeet ^[1]

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1. Pennsylvania State University, University Park, PA (United States). Energy and Mineral Engineering Department

Pyrolysis products of biomass (bio-oils) have been shown to cause a reduction in NOx emissions when used as reburn fuels in combustion systems. When these bio-oils are processed with lime, calcium is ion-exchanged and the product is called BioLime. BioLime, when introduced into a combustion chamber, pyrolyzes and produces volatile products that reduce NOx emissions through reburn mechanisms. Simultaneously, calcium reacts with SO{sub 2} to form calcium sulfate and thus reduces SO{sub 2} emissions. This paper reports the characterization of composition and pyrolysis behavior of two BioLime products and the influence of feedstock on pyrolysis products. Thermogravimetric analysis (TGA) and {sup 13}C-CP/MAS NMR techniques were used to study the composition of two biomass-based materials. The composition of the pyrolysis products of BioLime was determined in a laboratory scale flow reactor. The effect of BioLime composition on NOx and SO{sub 2} reduction performance was evaluated in a 146.5 kW pilot-scale, down fired combustor (DFC). The effect of pyrolysis gas composition on NOx reduction is discussed. The TGA weight loss curves of BioLime samples in an inert atmosphere showed two distinct peaks corresponding to the decomposition of light and heavy components of the BioLime and a third distinct peak corresponding to secondary thermal decomposition of char. The study also showed that BioLime sample with lower content of residual lignin derivatives and lower calcium content produced more volatile compounds upon pyrolysis in the combustor and achieved higher NOx reduction (15%). Higher yields of pyrolysis gases increased the NO reduction potential of BioLime through homogeneous gas phase reactions. Calcium in BioLime samples effectively reduced SO{sub 2} emissions (60-85%). 36 refs., 6 figs., 3 tabs.

• OSTI ID: 21049829
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 7 Vol. 42; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION CONTROL
BIOMASS
CALCIUM
COMBINED SOXNOX PROCESSES
CONCENTRATION RATIO
FLASH HEATING
LIGNIN
LIMESTONE
NITROGEN OXIDES
PYROLYSIS
PYROLYSIS PRODUCTS
PYROLYTIC GASES
REDUCTION
STAGED COMBUSTION
SULFUR DIOXIDE
THERMAL GRAVIMETRIC ANALYSIS
VOLATILE MATTER