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Title: Performance assessment of dilute-acid leaching to improve corn stover quality for thermochemical conversion

Lignocellulosic biomass is a sustainable energy source that can help meet the increasing demand for biofuels in the United States. However, the quality and availability of such feedstocks greatly affects their suitability for downstream conversion. This work reports the effects of dilute-acid leaching at various solid loadings, temperatures and acid loadings on the quality of a traditional biochemical feedstock, corn stover, as a potential feedstock for thermochemical conversions. At 5 wt% solids, dilute-acid leaching was observed to effectively remove 97.3% of the alkali metals and alkaline earth metals that can negatively affect degradation pathways during pyrolysis and result in greater yield of non-condensable gases. In addition, up to 98.4% of the chlorine and 88.8% of the phosphorus, which can cause equipment corrosion and foul upgrading catalysts, respectively, were removed. At 25°C in the absence of acid, only 6.8% of the alkali metals and alkaline earth metals were removed; however 88.0% of chloride was still removed. The ratio of alkaline/acidic ash species has been suggested to proportionately relate to slagging in biopower applications. The initial alkali/acid ratio of the ash species present in the untreated corn stover was 0.38 (significant slagging risk). At 5 wt% solids, this ratio was decreased tomore » 0.18 (moderate slagging risk) at 0 wt% acid and 90°C, and was decreased to 0.07, 0.08 and 0.06 at 0.5 wt% acid at 25°C, 50°C and 90°C, respectively (little or no slagging risk). Increasing the acid loading to 1.0% only slightly decreased the measured alkali/acid ratio of remaining ash species. Lastly, the results presented here show that a water wash or dilute-acid preprocessing step can improve corn stover quality for pyrolysis, hydrothermal liquefaction and biopower.« less
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  1. Idaho National Lab. (INL), Idaho Falls, ID (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0016-2361; PII: S0016236116307943
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 186; Journal Issue: C; Journal ID: ISSN 0016-2361
Research Org:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
09 BIOMASS FUELS; ash; biofuels; biopower; corn stover; hydrothermal liquefaction; leaching; pyrolysis; combustion
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1399041