Product compositions and kinetics in the rapid pyrolysis of milled wood lignin

Journal Article · Tue Jan 01 00:00:00 EST 1985 · Ind. Eng. Chem. Process Des. Dev.; (United States)

DOI:https://doi.org/10.1021/i200030a054· OSTI ID:5541293

Nunn, T R; Howard, J B; Longwell, J P; Peters, W A

Yields, compositions, and rates of evolution of major products from batch pyrolysis of predried milled wood lignin from sweet gum hardwood were measured for the temperature range 600-1400 K under 5 psig of helium at heating rates and residence times at final temperature of 1000 K/s and 0 s, respectively. Approximately 100-mg layers of 100 ..mu.. m or less thick lignin flakes, thinly spread on a hot stage, were heated so that volatiles residence times at elevated temperatures were minimized. Total weight loss increased strongly with temperature to an asymptote of 86% at 1050 K. Tar is the major pyrolysis product above 800 K. Its yield exhibits a maximum of 53 weight % at 900 K and declines to 47 weight % at 1150 K. The latter represents 57% of the energy of the dry lignin. Secondary cracking of the tar contributes to the yields of CO, CH/sub 4/, C/sub 2/H/sub 4/, and other light gases above 950 K. Carbon monoxide dominates the gas yield above 850 K and attains a yield of 19 weight % at 1440 K. A single reaction first-order decomposition model describes well the global rates of evolution of most major products, except tar. However, the data imply that most products are evolved by more complex reaction pathways.

• Research Organization: Massachusetts Institute of Technology, Cambridge
• OSTI ID: 5541293
• Journal Information: Ind. Eng. Chem. Process Des. Dev.; (United States), Vol. 24:3
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
LIGNIN
PYROLYSIS
PYROLYSIS PRODUCTS
CHEMICAL COMPOSITION
CARBON DIOXIDE
CARBON MONOXIDE
CHEMICAL REACTION KINETICS
CRACKING
DATA
DRYING
ENERGY
ETHYLENE
GAS YIELDS
HEATING
HIGH TEMPERATURE
METHANE
PRESSURE CONTROL
TAR
VERY HIGH TEMPERATURE
VOLATILE MATTER
WEIGHT MEASUREMENT
WOOD
ALKANES
ALKENES
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CONTROL
DECOMPOSITION
HYDROCARBONS
INFORMATION
KINETICS
MATTER
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLYSACCHARIDES
REACTION KINETICS
SACCHARIDES
THERMOCHEMICAL PROCESSES
YIELDS
090122* - Hydrocarbon Fuels- Preparation from Wastes or Biomass- (1976-1989)
140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)