Methane and Nutrient Salts from Waste Biomass:
Development of a Catalytic Conversion Process in Supercritical Water
Andrew Petersona,b,#, Maurice Waldnerb,c, Morgan Frolinga, Frédéric Vogelb, Jefferson Testera
bPaul Scherrer Institut, Villigen, Switzerland.
cSwiss Federal Institute of Technology, Zurich (ETH-Zurich), Switzerland.
aMassachusetts Institute of Technology, Cambridge, MA, USA.
Vision
Synthetic natural gas (SNG) can potentially be produced from biomass (liquid manure, wood) by a hydrothermal process. The hydrothermal route carries two major ad- vantages over conventional gasification:
1. Drying is unnecessarry.
2. Nutrient salts are recovered.
Experimental
240 mm
ID:
14 mm
•Solids content ≤30%.
•Batch reactor, Raney nickel catalyst.
•400°C, 300 bar. Supercritical.
Results
Complete conversion to gases and water
Gas composition achieved:
0 10 20 30 40 90 100
0 5 10 15 20 25 30 35 40 45 50 55
CH4 / vol%
time (T > 374 °C) / min.
HB400R05 HB400R04 HB400R06 HB400R07 HB400NC1
thermodynamic equilibrium
nickel catalyst
no catalyst
#Corresponding author. aap@mit.edu. Andrew Peterson, 77 Massachusetts Ave 66-053, Cambridge, MA 02139. 1-617-253-0070.
Ongoing Work
¾Salt separation studies in supercritical water.
In-situvisualization
using neutron radiography.
Finite-element modeling of fluid flow and heat transfer.
¾Environmental systems analysis.
Chemical process simulation (ASPEN+) and life-cycle assessment will be used to optimize the environmental performance of the process in a systems perspective.
¾Realization of continuous process.
Gasification of liquid model systems with same C-H-O composition in biomass in continuous test rig.
Pumping of real biomass slurry, up to 20% solids, ground to xD≤100 microns.
Salt separation in continuous fashion, preliminary design.
Global Warming Potential per 1000 kg Biomass Example of preliminary results for manure feed.
-120 -100 -80 -60 -40 -20 0 20
Catalyst Production Electricity Burner Fan Electricity Grinder 1 Electricity Grinder 2 Electricity Pump 1 Turbine Emissions Avoided Natural Gas Production Avoided Natural Gas Use Total
kg CO2 equivalents
