Method for Reclaiming Usable Products from Biosolids

摘要

The method of reclaiming usable products from sludge is disclosed. A predetermined level of solvent within an extractor is heated, below boiling point, and dried sludge is immersed within the headed solvent. The solvent is a non-polar or polar aprotic solvents, such as ethyl acetate. The non-solid products, an oil/solvent mixture, within the sludge are separated and transferred to at least one evaporator with a concentration of between 5-25% oil in the solvent. The oil and solvent are is separated in one or more evaporators to remove approximately 80%-90%, and preferably 70%-95%, of the solvent. The solids are moved to a desolventizer for removal of the residual solvent and are then dried to a moisture content of below 25%, and preferably between 10 to 15%.

主权项

1. The method of reclaiming usable products from sludge comprising the steps of:
a. transferring dewatered sludge from a wastewater treatment plant to a dryer; b. drying said sludge; c. heating a solvent; d. transferring said sludge to an extractor containing the heated solvent; e. In said extractor, separating non-solid products from said sludge using said solvent; f. transferring said separated non-solid products to at least one evaporator, g. removing residual solvent from sludge that is separated from said non-solid products in step (d); and h. recycling solvent from said at least one evaporator and step f, to said extractor.