skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Study of the Neutralization and Stabilization of a Mixed Hardwood Bio-Oil

Abstract

Fast-pyrolysis bio-oil that is currently produced from lignocellulosic biomass in demonstration and semicommercial plants requires significant modification to become an acceptable transportation fuel. The high acidity and chemical instability of bio-oils render them incompatible with existing petroleum refinery processes that produce gasoline and diesel fuels. To facilitate the use of bio-oil as a feedstock in a traditional refinery infrastructure, there is considerable interest in upgrading bio-oils through chemical pathways that include converting the carboxylic acids and reactive carbonyl compounds into esters and acetals using low-cost alcohols. In this article, we discuss our observations with different approaches to esterification and etherification chemistry using a crude bio-oil derived from mixed hardwoods. The high water content in crude bio-oils (ca. 20?30%) creates equilibrium limitations in the condensation reactions that hamper the upgrading process in that the neutralization and stabilization steps cannot easily be driven to completion. The lowest acid number that we were able to obtain without causing serious degradation of the flow properties of the bio-oil had a total acid number of about 20, a value that is still too high for use in a traditional petroleum refinery.

Authors:
; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
968451
DOE Contract Number:
AC36-99-GO10337
Resource Type:
Journal Article
Resource Relation:
Journal Name: Energy and Fuels; Journal Volume: 23; Journal Issue: 5, 2009
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; ACETALS; ALCOHOLS; BIOMASS; CARBONYLS; CARBOXYLIC ACIDS; CHEMISTRY; DIESEL FUELS; ESTERIFICATION; ESTERS; GASOLINE; INSTABILITY; MODIFICATIONS; PETROLEUM; PH VALUE; STABILIZATION; Bioenergy

Citation Formats

Moens, L., Black, S. K., Myers, M. D., and Czernik, S. Study of the Neutralization and Stabilization of a Mixed Hardwood Bio-Oil. United States: N. p., 2009. Web. doi:10.1021/ef8009266.
Moens, L., Black, S. K., Myers, M. D., & Czernik, S. Study of the Neutralization and Stabilization of a Mixed Hardwood Bio-Oil. United States. doi:10.1021/ef8009266.
Moens, L., Black, S. K., Myers, M. D., and Czernik, S. 2009. "Study of the Neutralization and Stabilization of a Mixed Hardwood Bio-Oil". United States. doi:10.1021/ef8009266.
@article{osti_968451,
title = {Study of the Neutralization and Stabilization of a Mixed Hardwood Bio-Oil},
author = {Moens, L. and Black, S. K. and Myers, M. D. and Czernik, S.},
abstractNote = {Fast-pyrolysis bio-oil that is currently produced from lignocellulosic biomass in demonstration and semicommercial plants requires significant modification to become an acceptable transportation fuel. The high acidity and chemical instability of bio-oils render them incompatible with existing petroleum refinery processes that produce gasoline and diesel fuels. To facilitate the use of bio-oil as a feedstock in a traditional refinery infrastructure, there is considerable interest in upgrading bio-oils through chemical pathways that include converting the carboxylic acids and reactive carbonyl compounds into esters and acetals using low-cost alcohols. In this article, we discuss our observations with different approaches to esterification and etherification chemistry using a crude bio-oil derived from mixed hardwoods. The high water content in crude bio-oils (ca. 20?30%) creates equilibrium limitations in the condensation reactions that hamper the upgrading process in that the neutralization and stabilization steps cannot easily be driven to completion. The lowest acid number that we were able to obtain without causing serious degradation of the flow properties of the bio-oil had a total acid number of about 20, a value that is still too high for use in a traditional petroleum refinery.},
doi = {10.1021/ef8009266},
journal = {Energy and Fuels},
number = 5, 2009,
volume = 23,
place = {United States},
year = 2009,
month = 1
}
  • An overview of the environmental impact assessment (EIA) for a mixed tropical hardwood integrated pulp and paper mill in Sabah, Malaysia, is presented. The EIA before the mill construction included, among other things, a detailed baseline study and also environmental impact predictions based on certain mill design and pollution abatement measures. Subsequent to mill construction (during the operational stage), data were gathered to determine the quality of the ambient air as well as the effluent and the receiving bay water quality. These post-construction monitoring results were then compared with the earlier impact predictions, and showed, in general, a good correspondence.
  • Removal of hemicellulose by acid pretreatment in a flow reactor followed by enzymatic hydrolysis of the neutralized slurry has resulted in glucose yields as high as 95% for mixed hardwood. For white pine, however, the maximum glucose yield is 65%. Although pine has a higher extractives content, removal of the extractives prior to enzymatic hydrolysis does not increase the glucose yield. Pore size measurements reveal that the increase in pore volume, in the size range of the cellulase molecule, following pretreatment for pine is only about one-half the value obtained with mixed hardwood. This suggests that pore volume is anmore » important determinant of substrate-enzyme reactivity. 18 references.« less
  • This report describes the results of the cementitious solidification/stabilization studies conducted on a mixed wastewater sludge generated from biodenitrification and heavy metals precipitation.
  • In studies on natural regeneration of Pinus taeda and P. echinata, mineral soil exposure, light intensity under residual stands and establishment of pine seedlings after one year were studied on 1-acre plots that had been harvested to remove stems greater than or equal to 4 inch or greater than or equal to 1 inch d.b.h. in winter and summer in mixed pine/broadleaved stands in Dawson Forest, Georgia, USA. Few seedlings became established after summer logging, but acceptable establishment followed winter harvesting. Removal of all woody biomass to 1 inch d.b.h. limit resulted in 94% stocking of pine seedlings. Harvesting tomore » a 1-inch limit exposed twice as much mineral soil and allowed more groundlevel points to receive high intensity insolation. 7 references.« less
  • The cellulase activity in cell-free broths from Clostridium thermocellum is examined on both dilute-acid-pretreated mixed hardwood (90% maple, 10% birch) and Avicel. Experiments were conducted in vitro in order to distinguish properties of the cellulase from properties of the organism and to evaluate the effectiveness of C. thermocellum cellulase in the hydrolysis of a naturally occurring, lignin-containing substrate. The results obtained establish that essentially quantitative hydrolysis of cellulose from pretreated mixed hardwood is possible using this enzyme system. Pretreatment with 1% H/sub 2/SO/sub 4/ and a 9-s residence time at 220, 210, 200, and 180/sup 0/C allowed yields after enzymaticmore » hydrolysis (percentage of glucan solubilized/glucan potentially solubilized) of 97.8, 86.1, 82.0, and 34.6%, respectively. Enzymatic hydrolysis of mixed hardwood with no pretreatment resulted in a yield of 10.1%. Hydrolysis yields of greater than 95% were obtained from 0.6 g/l mixed hardwood pretreated at 220/sup 0/C in 7 hours at broth strengths of 60 and 80% (v/v) and in approximately 48 hours with 33% broth. Hydrolysis of pretreated mixed hardwood is compared to hydrolysis of Avicel. The initial rate of Avicel hydrolysis saturates with respect to enzyme, whereas the initial rate of hydrolysis of pretreated wood is proportional to the amount of enzyme present. Initial hydrolysis rates for pretreated wood and Avicel at 0.6 g/l are greater for wood at low broth dilutions (1.25:1 to 5:1) by up to 2.7-fold and greater for Avicel at high broth dilutions (5:1 to 50:1) by up to 4.3-fold. Maximum rates of hydrolysis are achieved at less than 2 g substrate/liter for both pretreated wood and Avicel).« less