The present disclosure relates to an apparatus and a method for measuring miscibility in oil using back titration. The apparatus includes: a flocculation solution storage unit; a flow cell including a UV transmitting member; a dissolving agent storage unit; a UV irradiation unit; and a measurement unit, wherein: a flocculation solution is stored in the flocculation solution storage unit; the flocculation solution circulates between the flocculation solution storage unit and the flow cell; the measurement unit measures the UV transmittance of the flocculation solution while the dissolving agent in the dissolving agent storage unit is supplied to the flocculation solution storage unit; the miscibility in the oil is calculated from the amount of dissolving agent supplied and a change in the UV transmittance measured by the measurement unit; and the miscibility is calculated based on a time point when the slope of increase in the UV transmittance changes.

Food for human consumption is smoked by providing smoke, removing one or more polycyclic aromatic hydrocarbons (PAHs) from the smoke and contacting the food with the treated smoke, or smoking the food and then removing the PAHs from the smoked food. PAH removal is selective, to remove the PAHs that contain 4 or more benzene rings, in particular without significantly changing the volatile profile of the smoked food. A selective filter is provided, as is apparatus comprising a smoke generator, a chamber in which to smoke food, and the selective filter, disposed between the smoke generator and the chamber.

System and method for removing molecular contaminants from an air stream are disclosed. The system includes first, second and third filter. The first filter removes organic contaminants from an air stream passing through the first filter. The second filter is downstream of the first filter, is physically and chemically exchangeable with the first filter and removes organic contaminants from the air stream output of the first filter. The third filter, downstream of the second filter, is not exchangeable with the first filter or the second filter. The first position filter can be replaced by the second filter in the second position when the first filter in the first position becomes depleted as detected. A new filter in the second filter position is inserted. Replacing the depleted first filter with the second downstream filter reduces costs and waste while inserting the new filter in the second position ensures removing organic contaminants.

The present invention relates to an improved process and system for purifying a gas, preferably an energy gas, containing aromatic compounds and isolating a fraction of aromatic compounds from said gas. In the process according to the invention, the gas is contacted with a washing liquid in step (a), at a temperature of 15-250° C., to obtain a purified gas, which is depleted in aromatic compounds, and a spent washing liquid wherein the aromatic compounds are dissolved. The spent washing liquid is stripped in step (b) with a stripping gas comprising at least 50 vol. % steam, to obtain a stripped washing liquid which is advantageously reused in step (a) and a loaded stripping gas comprising the aromatic compounds. The aromatic compounds are separated from the loaded stripping gas in step (c) by condensation of the steam and/or the aromatic compounds comprised in the loaded stripping gas to obtain an immiscible composition and isolating the aromatic compounds therefrom. The cleared stripping gas which is advantageously reused in step (b).

A graphene material coating and a preparation method thereof pertain to the technical field of air filtration, and relates to an air filtration device and system based on the graphene material coating. The preparation method of the graphene material coating includes the following steps: S1), preparing a slurry dispersion stock solution: adding a dispersant and a binder to a solvent, and stirring to form the slurry dispersion stock solution; and S2), forming a graphene surface coating: adding a graphene powder to the slurry dispersion stock solution, and after being homogenized by stirring, coating a homogenate on a surface of a carrier, and drying to obtain a finished product of the graphene material coating. This technique can increase the adsorption rate of harmful substances in the gases and avoid secondary pollution caused by unstable adsorption.

The invention discloses a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst, a preparation method and use thereof. The preparation method comprises the steps of: dissolving an organic ligand and Ti(OC.sub.3H.sub.7).sub.4 in a mixture of methanol and DMF at a certain ratio, performing a hydrothermal reaction, centrifuging and drying to obtain a Titanium-based metal organic framework (Ti-MOF); pyrolyzing the obtained Ti-MOF under an inert atmosphere, and oxidizing the same for etching to obtain a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst. The obtained composite photocatalyst not only facilitates the adsorption, enrichment and mass transfer of low concentration VOCs, but also efficiently degrades VOCs under sunlight. It has high degradation activity and stability when performing photocatalytic removal of VOCs in the presence of visible light, is simple in synthesis, low in preparation cost, and has strong potential for the use in environmental protection.

A method of recovering paraxyiene in a pressure swing adsorption unit with varying hydrogen purge pressures. The pressure swing adsorption zone is adapted to adsorb and desorb paraxyiene based on the cycling of partial pressure in the zone. A first hydrogen purge fed to the zone is within 50 psi of the adsorption pressure of paraxyiene in the zone. A second hydrogen purge fed to the zone is within 50 psi of the desorption pressure of paraxyiene in the zone. The overall amount of hydrogen necessary to operate the pressure swing adsorption zone is reduced and heat may be recovered from the effluent leaving the pressure swing adsorption zone.

A method for retrofitting a system for recovering paraxylene. The system is retrofitted with a pressure swing adsorption unit and a second isomerization reactor. The retrofit lowers the variable cost of the plant, while providing the opportunity to maintain existing equipment and furnace and refrigeration duty.

A graphene adsorbing material, a preparation method therefor and application thereof, and a cigarette filter tip and a cigarette are provided. The graphene adsorbing material comprises a fiber carrier, graphene and doped elements wherein the graphene and the doped elements are loaded on the fiber carrier and the doped elements comprise at least one of Al, Si and Fe. The graphene adsorbing material is obtained by contacting the fibers with the graphene material to load the graphene material on the fibers. By introducing the graphene and the doped elements in the fiber carrier, harmful substances with a type of fused aromatic hydrocarbons such as benzopyrene in smoke can be specifically adsorbed, filtered and removed; while nicotine and the other harmless substances are retained, and thus the smoking taste of a cigarette is not affected. The cigarette filter tip can effectively adsorb cancerogenic substances with a type of fused aromatic hydrocarbons such as benzopyrene in smoke to reduce harm of smoking; meanwhile, the pleasure of smoking and the mellow taste of the smoke are not affected. Besides, the graphene adsorbing material can also prevent the phenomenon that a cigarette holder gets mildewed due to humid environment and the other factors.

The invention is directed to a process to convert a sulphur compound to bisulphide by direct or indirect transfer of electrons from a cathode of a bio-electrochemical cell to the sulphur compound under anaerobic conditions and in the presence of mixed culture comprising methanogens and suitably also a anaerobic or facultative anaerobic bacteria. The sulphur compound may be a thiol like methanethiol or ethanethiol or a polysulphide, like dimethyl disulphide.