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Title: Hydrotreating Pyrolytic Lignin to Produce a Refinery Feedstock (Poster)

Fast pyrolysis of biomass followed by water separation to produce pyrolytic lignin and hydrotreating of the lignin could be used to produce a stable volatile low-oxygen intermediate liquid. Such a liquid could be converted into a finished motor-fuel in a refinery, taking advantage of the existing infrastructure and economies of scale of refineries. Hydrotreating just the lignin would consume less hydrogen while preserving about half of the energy of the original oil. The aqueous by-products could be reformed to produce the needed hydrogen and would contain much of the unwanted acids and unstable oxygenates. To assess such intermediate liquids, several pyrolytic lignins were prepared by mixing pyrolysis oil with water at 1:1 and 3:1 ratios. The carboxylic acidity in the pyrolytic lignin was reduced to 24 and 10 mg-KOH/g-lignin compared to 81 in the whole oil. These lignins were hydrotreated using Ni-Mo(S)/alumina, Pt/char, or Pd/C(activated) in a semi-batch 1 L stirred autoclave. The oil was stabilized under hydrogen at 150-280 degrees C, then water and light organics were removed by partial depressurization. Hydrodeoxygenation was then performed at 340-400 degrees C. Total pressure was controlled at 70 or 170 bar with hydrogen gas. Organic liquid yields of 39-56% were obtained. Formore » many experiments the organic oxygen content was <7%, acidity was < 7 mg-KOH/g-oil, the volatility was greater than or equal to 94% and, on a carbon basis, the total yield of organic products miscible in hydrocarbons at a 1:10 ratio was over 50%. These properties are probably acceptable to a refinery.The residual liquids left in the reactor at the end of the experiment comprised 60-85% of the organic-phase product while the rest was condensate. 13C-NMR of the residual liquids showed that they were 50-80% aliphatic. 13C-NMR coupled with GC-MS identified phenolic compounds as the main oxygenates in most residual liquids.« less
Authors:
Publication Date:
OSTI Identifier:
1114045
Report Number(s):
NREL/PO-5100-60256
DOE Contract Number:
AC36-08GO28308
Resource Type:
Conference
Resource Relation:
Conference: Presented at the TC Biomass 2013, 3-6 September 2013, Chicago, Illinois; Related Information: NREL (National Renewable Energy Laboratory)
Research Org:
National Renewable Energy Laboratory (NREL), Golden, CO.
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 59 BASIC BIOLOGICAL SCIENCES BIOMASS; PYROLYSIS OIL; LIGNIN; HYDROTREATING; ACIDITY; MISCIBILITY; CATALYST; NICKEL; PLATINUM; PALLADIUM