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Title: System and process for efficient separation of biocrudes and water in a hydrothermal liquefaction system

Abstract

A system and process are described for clean separation of biocrudes and water by-products from hydrothermal liquefaction (HTL) product mixtures of organic and biomass-containing feedstocks at elevated temperatures and pressures. Inorganic compound solids are removed prior to separation of biocrude and water by-product fractions to minimize formation of emulsions that impede separation. Separation may be performed at higher temperatures that reduce heat loss and need to cool product mixtures to ambient. The present invention thus achieves separation efficiencies not achieved in conventional HTL processing.

Inventors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1281062
Patent Number(s):
9,404,063
Application Number:
14/534,010
Assignee:
Battelle Memorial Institute (Richland, WA) PNNL
DOE Contract Number:
AC05-76RL01830
Resource Type:
Patent
Resource Relation:
Patent File Date: 2014 Nov 05
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 54 ENVIRONMENTAL SCIENCES

Citation Formats

Elliott, Douglas C., Hart, Todd R., Neuenschwander, Gary G., Oyler, James R., Rotness, Jr, Leslie J., Schmidt, Andrew J., and Zacher, Alan H. System and process for efficient separation of biocrudes and water in a hydrothermal liquefaction system. United States: N. p., 2016. Web.
Elliott, Douglas C., Hart, Todd R., Neuenschwander, Gary G., Oyler, James R., Rotness, Jr, Leslie J., Schmidt, Andrew J., & Zacher, Alan H. System and process for efficient separation of biocrudes and water in a hydrothermal liquefaction system. United States.
Elliott, Douglas C., Hart, Todd R., Neuenschwander, Gary G., Oyler, James R., Rotness, Jr, Leslie J., Schmidt, Andrew J., and Zacher, Alan H. 2016. "System and process for efficient separation of biocrudes and water in a hydrothermal liquefaction system". United States. doi:. https://www.osti.gov/servlets/purl/1281062.
@article{osti_1281062,
title = {System and process for efficient separation of biocrudes and water in a hydrothermal liquefaction system},
author = {Elliott, Douglas C. and Hart, Todd R. and Neuenschwander, Gary G. and Oyler, James R. and Rotness, Jr, Leslie J. and Schmidt, Andrew J. and Zacher, Alan H.},
abstractNote = {A system and process are described for clean separation of biocrudes and water by-products from hydrothermal liquefaction (HTL) product mixtures of organic and biomass-containing feedstocks at elevated temperatures and pressures. Inorganic compound solids are removed prior to separation of biocrude and water by-product fractions to minimize formation of emulsions that impede separation. Separation may be performed at higher temperatures that reduce heat loss and need to cool product mixtures to ambient. The present invention thus achieves separation efficiencies not achieved in conventional HTL processing.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 8
}

Patent:

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  • A combined hydrothermal liquefaction (HTL) and catalytic hydrothermal gasification (CHG) system and process are described that convert various biomass-containing sources into separable bio-oils and aqueous effluents that contain residual organics. Bio-oils may be converted to useful bio-based fuels and other chemical feedstocks. Residual organics in HTL aqueous effluents may be gasified and converted into medium-BTU product gases and directly used for process heating or to provide energy.
  • For operating control and safety, a variable-speed close-coupled pump is direct connected to the underflow of the primary separation vessel (PSV). The desired discharge density of the PSV is 70--80% solids in order to minimize bitumen losses. For a good pumping system, the pump discharge density should be less than 65% solids to avoid settling out of the solids in the downstream conduit. Therefore it is necessary to dilute the PSV underflow before it reaches the pump. Secondary flotation tailings, a dilute stream containing a high proportion of fine solids, is used for this purpose. The solids content of themore » PSV underflow is monitored by one of two alternative systems: a torque recorder on the PSV rake shaft or a density gage on the PSV underflow conduit. The former is used when the PSV is being fed low fines tar sand, the latter when it is treating high fines tar sand. The close-coupled pump speed is adjusted relative to the solids content measurement to keep it at the desired 70--80% level. The density of the stream at the pump discharge is also monitored and the measurement is used to control the amount of secondary flotation tailings added. By the use of the controlled-speed, close-coupled pump, a closed system for controlling underflow density is provided. By using secondary tailings as diluent, water requirements for the process are reduced and a pumpable mixture is provided from which the solids do not readily settle out.« less
  • For operating control and safety, a variable-speed close-coupled pump is directly connected to the underflow of the primary separation vessel (PSV). The desired discharge density of the PSV is 70--80% solids in order to minimize bitumen losses. For a good pumping system, the pump discharge density should be less than 65% solids to avoid settling out of the solids in the downstream conduit. Therefore it is necessary to dilute the PSV underflow before it reaches the pump. Secondary flotation tailings, a dilute stream containing a high proportion of fine solids, is used for this purpose. The solids content of themore » PSV underflow is monitored by one of two alternative systems, a torque recorder on the PSV rake shaft or a density gauge on the PSV underflow conduit. The former is used when the PSV is being fed low fines tar sand; the latter, when it is treating high fines tar sand. The close-coupled pump speed is adjusted relative to the solids content measurement to keep it at the desired 70--80% level. The density of the stream at the pump discharge is also monitored and the measurement is used to control the amount of secondary flotation tailings added. By the use of the controlled-speed, close-coupled pump, a closed system for controlling underflow density is provided. By using secondary tailings as diluent, water requirements for the process are reduced and a pumpable mixture is provided from which the solids do not readily settle out. 1 fig.« less
  • Production of a low mineral content fuel by a coal liquefaction process utilizing a hydrogenated coal solvent having been hydrogenated to remove at least about 80% of the asphaltenes which yields as the primary product a mixture of liquid and solids, a part of which is suspended in the liquid. The suspended solids are effectively removed with minimum loss of desired product by means of a light aromatic solvent in combination with a hydrogenated coal solvent.
  • Production of a low mineral content fuel by a coal liquefaction process utilizing a hydrogenated coal solvent having been hydrogenated to remove at least about 80% of the asphaltenes which yields as the primary product a mixture of liquid and solids, a part of which is suspended in the liquid. The suspended solids are effectively removed with minimum loss of desired product by means of a light aromatic solvent in combination with a hydrogenated coal solvent.