Systems and methods for converting biomass to biocrude using hydrothermal liquefaction

A method comprising:

• flowing a biomass slurry into a top of one or more tubing positioned inside a casing of a well, the well having a well depth, a top positioned at a surface location, and a bottom portion positioned at a subterranean location, the well comprising a casing and one or more tubing positioned therein, forming an annulus there between, the casing and the one or more tubing defining a hydrothermal liquefaction (HTL) reaction zone in the bottom portion of the well and a heat transfer and separation zone above the HTL reaction zone;
• heating the biomass slurry while flowing turbulently downward through the HTL reaction zone employing a cable comprising an electric heating element positioned in one or more of the one or more tubing in the HTL reaction zone;
• converting at least a portion of the biomass slurry into biocrude oil by HTL in the HTL reaction zone, the biomass slurry entering into the tubing at the top of the well at a first temperature and a first pressure, the well depth and the electrical heating element sufficient to produce a second temperature and a second pressure in the HTL reaction zone sufficient to form sub-critical water but insufficient to form supercritical water, and produce a product fluid comprising the biocrude oil;
• flowing the product fluid comprising the biocrude oil upward through the annulus between the casing and the one or more tubing;
• and
• transferring heat between the product fluid and the biomass slurry in the heat transfer and separation zone.