The innovation uses the disparity between dry and wet conditions of the air, by storing the dryness or wetness in a hygroscopic material. When the surrounding air is drier or wetter than the hygroscopic material, the potential energy difference between moisture in the air and that in the material can be used as a way of transporting heat from the material to the air and vice versa. A simple way this energy can be used is for heating and cooling of a building. For example, a large storage of adsorbing material can be dried in the hot summer, and allowed to re-adsorb water in the cold winter, thus gaining heat that can be used for domestic heating.

A computerized process for controlling an air purification system comprises a bioreactor in particular, the system may include a photobioreactor for treating urban air, in particular for CO.sub.2 removal. The system may be connected to the sanitation network and/or to a (drinking and/or municipal) water supply network. The connection and the drainage system may in particular maintain a fluidic isolation between the two types of networks. The system may optionally be equipped with measurement sensors and/or actuators that make it possible to control the internal activity of the bioreactor. Various control modes of a grid of bioreactors are described. Data on the status of the connected networks (e.g. water, sanitation, cooling, heating networks) contribute to the control of a network of geolocalized bioreactors. The software aspects are described. The supervision of the grid of bioreactors may in particular be carried out remotely via onboard communication devices.

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

An air cleaning device is disclosed. A first opening and closing member opens and closes an inlet of a housing. A second opening and closing member opens and closes an outlet of the housing. A first filter unit collects and separates foreign substances from contaminated air in the housing A circulation tube has a first end portion disposed at the inlet to communicate with the housing and a second end portion disposed at the outlet to communicate with the housing. A third opening and closing member opens and closes the circulation tube. A first heater is installed inside the circulation tube to heat air in the circulation tube. A blower is installed inside the circulation tube to deliver air from the circulation tube into the housing.

A photocatalyst material (1A) in accordance with an aspect of the present invention includes a core particle (2) and a shell layer (3) with which a whole surface of the core particle (2) is covered. The core particle (2) contains at least a tungsten oxide, and the shell layer (3) is constituted by a titanium oxide.

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

The present invention provides an ohmic heating-type exhaust gas purification catalyst system. The ohmic heating-type exhaust gas purification catalyst system is configured to perform, based on information of temperature of a catalyst bed input from a temperature detector of an ohmic heating-type exhaust gas purification device, electric current pass control including controls of (1) causing an electric current to pass through a pair of electrodes when the temperature of the catalyst bed is equal to or lower than a first threshold temperature T1 set in a range of 350?25? C., (2) not causing an electric current to pass through the pair of electrodes when the temperature of the catalyst bed exceeds the first threshold temperature T1 and is equal to or lower than a second threshold temperature T2 set in a range of 450?25? C., (3) causing an electric current caused to pass through the pair of electrodes when the temperature of the catalyst bed exceeds the second threshold temperature T2 and is equal to or lower than a third threshold temperature T3 set to be equal to or higher than 550? C., and (4) not causing an electric current to pass through the pair of electrodes when the temperature of the catalyst bed exceeds the third threshold temperature T3.

A synthetic fuel production system and related techniques are disclosed. In accordance with some embodiments, the disclosed system may be configured to produce a liquid fuel using carbon dioxide extracted from the air and hydrogen generated from aqueous solutions by electrochemical means (e.g., water electrolysis). In production of the fuel, the disclosed system may be configured, in accordance with some embodiments, to react the carbon dioxide and hydrogen, for example, to form methanol. The disclosed system also may be configured, in accordance with some embodiments, to utilize one or more subsequent reaction steps to produce a given targeted set of hydrocarbons and partially oxidized hydrocarbons. For example, the disclosed system may be used to produce any one (or combination) of: ethanol; dimethyl ether; formic acid; formaldehyde; alkanes of various chain length; olefines; aliphatic and aromatic carbon compounds; and mixtures thereof, such as gasoline fuels, diesel fuels, and jet fuels.

The present disclosure relates to a UV- and visible-light photocatalytic titanium dioxide composite material. In particular, the disclosure relates to a 5 photocatalytic titanium oxide composite material for the decomposition of airborne pollutants.

The high temperature titanium-catalyst comprises a body, the body having a hot gas inlet and a hot gas outlet. The body comprises an array of titanium containing catalytic elements, wherein the array of titanium containing catalytic elements is arranged such that hot gas containing an amount of hexavalent chromium Cr(VI) may enter the body at the hot gas inlet, may pass through the array of titanium containing catalytic elements and may leave the body at the hot gas outlet. When the titanium-catalyst is in use, Cr(VI) in the hot gas containing an amount of Cr(VI) reacts with titanium oxide in a surface layer of the titanium containing catalytic elements, whereby the Cr(VI) is reduced to trivalent chromium Cr(III) thus reducing the amount of Cr(VI) in the hot gas containing an amount of Cr(VI).