Light hydrocarbon liquids from dry raw sewage sludge
- Univ. of Toronto, Ontario (Canada)
Technology has been developed outside our group for the direct liquefaction of dry raw sewage sludge. However, the product is a fairly viscous, unpleasant-smelling liquid which contains up to 8% nitrogen and 2.5% sulphur, precluding its use as a fuel. Polar groups associated with these elements and oxygen also cause emulsification with pyrolytic water. We have identified that most nitrogen and sulphur-free oil derives from the lipid fraction and that nitrogen and sulphur-containing oil derives from the protein. Toluene extraction of a raw sewage sludge gives 18 wt % of lipid, and rejects 99% and 84% of the nitrogen and sulphur respectively. The extract contains 14--16% oxygen. The lipid contains 65% carboxylic acids, 7% glycerides and 28% unsaponifiables. Catalytic pyrolysis of the lipid over activated alumina at 450{degrees}C at a weight hourly space velocity less than 0.6 yields a light hydrocarbon liquid which contains 25% of the original carbon in the sludge. There is a fairly uniform distribution of compounds across the C6 to C20 range with a preference for unbranched compounds. The catalytic pyrolysis results in deoxygenation of carboxylic acids, esters and possibly some intermediate ketones.
- Research Organization:
- National Renewable Energy Lab., Golden, CO (United States)
- OSTI ID:
- 140212
- Report Number(s):
- NREL/CP--200-5768-Vol.2; CONF-9308106--Vol.2; ON: DE94000435
- Country of Publication:
- United States
- Language:
- English
Similar Records
Algae Biofuels Collaborative Project (CRADA Final Report)
Sewage sludge additive