A carbon dioxide adsorbent including silica gel and an amine compound carried by the silica gel. The silica gel has a spherical shape, a particle size ranging from 1 mm to 5 mm inclusive, an average pore diameter ranging from 10 nm to 100 nm inclusive, a pore volume ranging from 0.1 cm.sup.3/g to 1.3 cm.sup.3/g inclusive, and a waterproof property N that is defined by an expression (1) and that is not lower than 45%,
N=(W/W.sub.0)×100  (1) where N is the waterproof property in percentage (%) of the silica gel, W.sub.0 is a total number of particles of the silica gel immersed in water, W is a number of particles of the silica gel not subjected to breakage out of W.sub.0.

Methods and systems for recovering terpenes and controlling the composition of terpenes collected from wood drying processes are provided. In particular, a sorbent having adsorbed materials, including terpenes, from a wood drying process can be desorbed in a desorber, resulting in a gaseous stream containing terpenes, which can be condensed and collected from the gaseous stream. The conditions of desorption can be controlled to ensure a desirable amount of alpha-pinene and beta-pinene relative to other terpenes, such as dipentene and camphene, in the collected terpenes.

Methods and systems for recovering terpenes and controlling the composition of terpenes collected from wood drying processes are provided. In particular, a sorbent having adsorbed materials, including terpenes, from a wood drying process can be desorbed in a desorber, resulting in a gaseous stream containing terpenes, which can be condensed and collected from the gaseous stream. The conditions of desorption can be controlled to ensure a desirable amount of alpha-pinene and beta-pinene relative to other terpenes, such as dipentene and camphene, in the collected terpenes.

Disclosed are a VOC treatment rotor system and a VOC treatment method. The system comprises: a rotor having a first adsorption zone and a second adsorption zone; a gas intake pipeline communicated with an inlet of the first adsorption zone; a gas outlet pipeline comprising a gas outlet main pipe, a gas outlet branch pipe and a first clean gas outlet pipe; a second clean gas outlet pipe, communicated with an outlet of the second adsorption zone. The treatment method comprises: making VOC-containing waste gas enter the first adsorption zone through the gas intake pipeline for adsorption treatment by the first adsorption zone, then enter the gas outlet main pipe, and then enter the second adsorption zone through the gas outlet branch pipe or be discharged from the first clean gas outlet pipe.

Disclosed are a VOC treatment rotor system and a VOC treatment method. The system comprises: a rotor having a first adsorption zone and a second adsorption zone; a gas intake pipeline communicated with an inlet of the first adsorption zone; a gas outlet pipeline comprising a gas outlet main pipe, a gas outlet branch pipe and a first clean gas outlet pipe; a second clean gas outlet pipe, communicated with an outlet of the second adsorption zone. The treatment method comprises: making VOC-containing waste gas enter the first adsorption zone through the gas intake pipeline for adsorption treatment by the first adsorption zone, then enter the gas outlet main pipe, and then enter the second adsorption zone through the gas outlet branch pipe or be discharged from the first clean gas outlet pipe.

A system and method for passive collection of atmospheric carbon dioxide is disclosed. The system includes a harvest chamber having a first opening and a sorbent regeneration system. The system also includes a capture body coupled to and movable by a support structure. The capture body includes a sorbent material and is movable by the support structure to be in a collection configuration wherein at least a portion of the capture body is in contact with a natural airflow outside the harvest chamber such that atmospheric carbon dioxide is captured by the sorbent material, and a release configuration wherein at least a portion of the capture body holding captured carbon dioxide is operated upon by the regeneration system inside the harvest chamber such that captured carbon dioxide is released to form an enriched gas.

A system and method for passive collection of atmospheric carbon dioxide is disclosed. The system includes a harvest chamber having a first opening and a sorbent regeneration system. The system also includes a capture body coupled to and movable by a support structure. The capture body includes a sorbent material and is movable by the support structure to be in a collection configuration wherein at least a portion of the capture body is in contact with a natural airflow outside the harvest chamber such that atmospheric carbon dioxide is captured by the sorbent material, and a release configuration wherein at least a portion of the capture body holding captured carbon dioxide is operated upon by the regeneration system inside the harvest chamber such that captured carbon dioxide is released to form an enriched gas.

Systems and methods are provided for separation of CO.sub.2 from dilute source streams. The systems and methods for the separation can include use of contactors that correspond radial flow adsorbent modules that can allow for efficient contact of CO.sub.2-containing gas with adsorbent beds while also facilitating use of heat transfer fluids in the vicinity of the adsorbent beds to reduce or minimize temperature variations. In particular, the radial flow adsorbent beds can be alternated with regions of axial flow heat transfer conduits to provide thermal management. The radial flow structure for the adsorbent beds combined with axial flow conduits for heat transfer fluids can allow for sufficient temperature control to either a) reduce or minimize temperature variations within the adsorbent beds or b) facilitate performing the separation using temperature as a swing variable for controlling the working capacity of the adsorbent.

Systems and methods are provided for separation of CO.sub.2 from dilute source streams. The systems and methods for the separation can include use of contactors that correspond radial flow adsorbent modules that can allow for efficient contact of CO.sub.2-containing gas with adsorbent beds while also facilitating use of heat transfer fluids in the vicinity of the adsorbent beds to reduce or minimize temperature variations. In particular, the radial flow adsorbent beds can be alternated with regions of axial flow heat transfer conduits to provide thermal management. The radial flow structure for the adsorbent beds combined with axial flow conduits for heat transfer fluids can allow for sufficient temperature control to either a) reduce or minimize temperature variations within the adsorbent beds or b) facilitate performing the separation using temperature as a swing variable for controlling the working capacity of the adsorbent.

A method for manufacturing a carbon dioxide adsorbent includes: forming a kneaded product containing a hydrophilic fiber, a powdery porous material, and an aqueous hydrophilic binder dispersion into particles and drying the particles to generate porous material particles containing the hydrophilic fiber and the powdery porous material combined by the hydrophilic binder; and preparing an aqueous amine solution having an amine concentration of 5% or more and 70% or less and a temperature of 10° C. or higher and 100° C. or lower, impregnating the aqueous amine solution into the porous material particles, and aeration-drying the porous material particles impregnating the amine. The carbon dioxide adsorbent contains the porous material particles and the amine carried by the porous material particles, the porous material particles containing the hydrophilic fiber and the powdery porous material combined by the hydrophilic binder.