A useful substance is extracted from botanical feedstock by mechanically compressing the feedstock and pumping a solvent through the compressed feedstock at high pressure while applying compressive mechanical force against the feedstock. Movement of pressurized solvent through the compressed feedstock may increase the volume of solvent in contact with the feedstock. Flow of solvent under pressure may also present a shearing force that facilitates dissociation of the useful substance from the feedstock.

A method for extraction of desirable comounds from cannabis provides for high-cannabinoid full spectrum (HCFSE) extractions, using CO.sub.2 at low temperature to extract the compounds in an extraction vessel. The CO.sub.2 with extracted compounds is transferred to a heated vessel which converts the CO.sub.2 to a gas, allowing the desired compounds to drop out and be removed.

A method for extraction of desirable compounds from cannabis provides for high-cannabinoid full spectrum (HCFSE) extractions, using CO.sub.2 at low temperature to extract the compounds in an extraction vessel. The CO.sub.2 with extracted compounds is transferred to a heated vessel which converts the CO.sub.2 to a gas, allowing the desired compounds to drop out and be removed.

A system and method of extracting essential oils from plant material through the use of a low pressure alcohol-based closed system that includes a solvent chamber connected to a material column that is, in turn, connected to a kettle. Plant material in the material column and the solvent in the solvent chamber are cooled using a cooling liquid, such as nitrogen. A vacuum pump connected to the kettle creates a vacuum in the kettle to draw the cooled solvent through the cooled plant material and extract essential oils, which are collected in the kettle.

A system and method for extraction of cannabis oil from cannabis plant materials by further reducing the temperature of the extraction system effluent, which may be a mixture of solvent, the desired cannabinoids, and/or the undesired non-polar extracted waste from the plant material. This invention improves the extraction process by: 1) enhancing the rapid filtering of the waste material from the process stream, speeding up the overall process, and 2) improving the quality of the product, yielding a purer extract as evidenced, in part, by its lighter (yellow/gold) color as compared to less-pure green/brown extracts.

A proppant slurry for fracturing a subterranean formation is prepared by preparing a mixture comprising the proppant and a transfer fluid and transferring the proppant from the mixture to a base fluid, such as a liquefied gas or an acid. The proppant can be mixed with the transfer fluid to form a transfer slurry, the transfer slurry and the base fluid can be introduced into a proppant exchange device, and the proppant can be transferred from the transfer slurry to the base fluid to form the proppant slurry. The base fluid and the proppant slurry can be maintained in a closed system, out of contact with the surrounding environment, while the proppant can be added continuously to the base fluid. A proppant exchange device for use in the method is also provided.

A system and method of extracting essential oils from plant material through the use of a low pressure alcohol-based closed system that includes a solvent chamber connected to a material column that in turn is connected to a kettle. Plant material in the material column and the solvent in the solvent chamber are cooled using a cooling liquid, such as nitrogen. A vacuum pump connected to the kettle creates a vacuum in the kettle to draw the cooled solvent through the cooled plant material and extract essential oils, which are collected in the kettle.

An apparatus for the extraction of compounds from botanical material using a condensable gas solvent includes an extraction chamber wherein the feedstock is extracted while in a frozen state.

A plant oil extraction apparatus may include a volatile solvent tank, an oil bearing plant material container for receiving at least some of the volatile solvent, a chiller for cooling volatile solvent to a liquid state in contact with the oil bearing plant material, a vessel for collecting at least some of the mixture of volatile solvent and plant material, a heater for heating at least liquid state volatile solvent to a gas state, a compressor for compressing volatile solvent gas to a higher pressure, and a heat exchanger to cool and condense at least part of the compressed solvent gas to a liquid state and to return at least part of the condensed liquid volatile solvent to the solvent tank. The cycling of the apparatus may at least in part be controlled by an electronic controller and a human machine interface may be used by an operator to input data to the electronic controller.

A system and method of extracting essential oils from plant material through the use of a low pressure alcohol-based closed system that includes a solvent chamber connected to a material column that in turn is connected to a kettle. Plant material in the material column and the solvent in the solvent chamber are cooled using a cooling liquid, such as nitrogen. A vacuum pump connected to the kettle creates a vacuum in the kettle to draw the cooled solvent through the cooled plant material and extract essential oils, which are collected in the kettle.