A liquid-liquid extraction process has been developed for the hydrothermal liquefaction (HTL) process to separate biocrude produce from aqueous and solids coproducts. HTL is a general process to convert aqueous biomass to a mixture of hydrocarbon liquids, commonly referred to as 'biocrude" because it has physical properties similar to crude petroleum oil, as well as less desirable aqueous and solid byproducts. The product of the HTL reactor is a stable emulsion of the solid, oil, and aqueous phases that must be separated for downstream processing. The emulsion product generally does not phase separate at ambient conditions for several reasons. The density of the biocrude product is very similar to the aqueous phase, both with a specific gravity of approximately 1. The solids are extremely fine, with many particles less than 10 microns. The solid particles are hydrophilic and stabilize the oil/water mixture. The oil coats a portion of the solid particle and the solid keeps the oil droplet dispersed due to the solid's affinity for water. The biocrude is very viscous and makes freeing the solid particles from the oil suspension difficult. The aqueous phase contains many soluble organic species, which act as natural surfactants and stabilize the oil-water interface. A solvent extraction process was invented to overcome these challenges to efficiently separate the oil, aqueous, and solid phases. A solvent is mixed with the HTL product emulsion and the biocrude is dissolved into the solvent, which then phase separates from the water and solids by traditional gravimetric separation processes (see Figure 1). The extraction process can occur as a single stage, multi-stage, or continuous counter-current step. After the biocrude is extracted from the HTL product emulsion mixture, the solvent and biocrude stream is sent to a distillation tower to separate the more volatile solvent from the heavier biocrude product. The biocrude can then be exported for downstream processing. The aqueous and solids stream is sent to wastewater processing for further treatment. This invention is not limited to the use of a particular solvent, but the solvents presented here were chosen based on their affinity for the biocrude product relative to the aqueous phase, their commercial availability, their compatibility with the downstream fuels process infrastructure, and energy efficiency for purifying and recycling the solvent. Figure 2 illustrates the solvent extraction process design in more detail than Figure 1, however some equipment is still omitted for clarity. A two-stage solvent extraction process is shown in this example, but this invention is not limited to this exact process configuration. 'HTL emulsion product" enters the unit from the HTL reactor section. The emulsion composition can vary, but it is generally around 77% water, 13% biocrude, and 10% solids. The HTL reactor product is typically at an elevated temperature relative to the optimal temperature for the solvent extraction process, so the emulsion stream passes through a cooler to reach the target temperature. The emulsion is then mixed with the extraction solvent, which contains a small amount of residual biocrude. Note the extraction shown here is staged in a countercurrent fashion. This means the fresh solvent is introduced to the second extraction stage and cascaded to the first stage. Countercurrent flow was chosen to optimize extraction efficiency, but it is not a requirement of the invention. The combined solvent and HTL product emulsion stream then passes through a mixing device ('1st Stage Mixer") to ensure good surface area contact between the solvent and emulsion. The mixture enters a settling vessel, which provides residence time under calm conditions allow the oil (solvent+biocrude) and aqueous phases to settle. There may be internals inside of the settling vessel to enhance the settling process. The oil phase is less dense than the aqueous phase, which will rise and can be withdrawn near the top of the vessel. The aqueous phase and solids will sink to the bottom of the settling vessel and can be withdrawn from the bottom. The solvent must be separated from the biocrude so it can be recycled. The solvent is chosen to be more volatile than the biocrude to allow it to be separated by distillation. The design of the Solvent Recovery Tower is independent of this invention. Relatively few fractionation stages will be required in practice if there is a large volatility difference between the selected solvent and biocrude. A large volatility difference between the solvent and biocrude allows the solvent to be separated at a lower temperature, which has several advantages. Distillation at lower temperature saves energy and allows cheaper energy sources to be used for heating (low pressure steam, etc). More importantly, lower distillation temperatures reduce the temperature of the biocrude in the bottom of the tower. Biocrude can break down (crack) or leave fouling deposits at high temperatures. The cracking products are corrosive and degrade the biocrude quality. The solvent is boiled overhead and recycled. A small amount of makeup solvent is added to the recycle stream to account for the solvent that leaves the system. The recycled solvent is mixed with the aqueous + bottoms stream leaving the bottom of the 1st Extraction Stage. The purpose of adding the recycle solvent at this point is to extract any remaining biocrude in the aqueous stream. The mixture of solvent and Aqueous stream then enters another settling vessel, which functions the same as the 1st Stage settling vessel. Solvent with the extracted residual biocrude exits the top portion of the 2nd Stage settling vessel. Note that the oil stream exiting the 2nd Stage settling vessel is mostly solvent with only a very minor amount of biocrude present. Because the steam is mostly solvent in composition, it can be used for the 1st Stage extraction. The Aqueous + Solids stream leaving the bottom of the 2nd Stage Separator vessel is nearly free of biocrude. Some solvent will remain in this stream due to solubility in water or minor entrainment. A desirable solvent will have a low solubility in water to minimize the amount of solvent leaving the bottom of the 2nd Stage Separator. Solvent leaving the bottom of the 2nd Stage Separator is reclaimed in the Water Product Stripper. The design of the Water Product Stripper is independent of this invention. In practice, the tower will likely have simple internals that are resistant to fouling. A resistance to fouling will be important because of the high solids concentration of the feed stream ( >10%wt solids). The minor amount of solvent is boiled overhead and recycled to the extraction process. The ability to boil the solvent from the aqueous stream is another driver for a relatively high volatility solvent. Solvents with a low vapor pressure will not volatilize before water. Therefore, the boiling point of the selected solvent should not be significantly above the boiling point of water (100 degC). Figure 3 details a more specific application of the invention. This figure represents the application of this invention to the published 'State of Technology" business case detailing a 110 dry ton per day HTL plant (PNNL-32731) using toluene as the extraction solvent. The following information is available in the figure: Heat and Material Balance Auxiliary equipment required for reliable operation and energy efficiency Approximate stream compositions Process operating conditions Equipment sizing