Embodiments of the present disclosure are directed towards methods for preparing mixed-metal oxide particles by heating adamantane-intercalated layered double-hydroxide (LDH) particles at a reaction temperature of from 400° C. to 800° C. to form mixed-metal oxide particles. The adamantane-intercalated LDH particles have a general formula [M.sub.1-xAl.sub.x(OH).sub.2](A).sub.x.mH.sub.2O, where x is from 0.14 to 0.33, m is from 0.33 to 0.50, M is chosen from Mg, Ca, Co, Ni, Cu, or Zn, and A is adamantane carboxylate, and an aspect ratio greater than 100. The aspect ratio is defined by the width of an adamantane-intercalated LDH particle divided by the thickness of the adamantane-intercalated LDH particle. The mixed-metal oxide particles comprise a mixed-metal oxide phase containing M, Al or Fe, and carbon.

Industrial waste derived adsorbents were obtained by pyrolysis of sewage sludge, metal sludge, waste oil sludge and tobacco waste in some combination. The materials were used as media to remove hydrogen sulfide at room temperature in the presence of moisture. The initial and exhausted adsorbents after the breakthrough tests were characterized using sorption of nitrogen, thermal analysis, XRD, ICP, and surface pH measurements. Mixing tobacco and sludges result in a strong synergy enhancing the catalytic properties of adsorbents. During pyrolysis new mineral phases are formed as a result of solid state reaction between the components of the sludges. High temperature of pyrolysis is beneficial for the adsorbents due to the enhanced activation of carbonaceous phase and chemical stabilization of inorganic phase. Samples obtained at low temperature are sensitive to water, which deactivates their catalytic centers.

The present invention generally relates to CO.sub.2-adsorbing, graphene-containing nanocomposites, methods of making the same, and methods of using the same.

A mixed salt composition adapted for use as a sorbent for carbon dioxide removal from a gaseous stream is provided, the composition being in solid form and including magnesium oxide, an alkali metal carbonate, and an alkali metal nitrate, wherein the composition has a molar excess of magnesium characterized by a Mg:X atomic ratio of at least about 3:1, wherein X is the alkali metal. A process for preparing the mixed salt is also provided, the process including mixing a magnesium salt with a solution comprising alkali metal ions, carbonate ions, and nitrate ions to form a slurry or colloid including a solid mixed salt including magnesium carbonate; separating the solid mixed salt from the slurry or colloid to form a wet cake; drying the wet cake to form a dry cake including the solid mixed salt; and calcining the dry cake to form a mixed salt sorbent.

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

Calcium silicate hydrate nanoparticles are combined with ammonia control materials (e.g. alum, aluminum chloride, ferric chloride, ferric sulfate, and/or sodium bisulfate) to create a phosphorus-binding composition. In the preferred embodiment, the composition is applied to poultry litter, poultry bedding or other non-aqueous substrates that are at least partially comprised of animal manure. The composition binds with phosphorus to at least reduce the amount of phosphorus in runoff water or in leachate from fields fertilized with treated manure. The combining of the calcium silicate hydrate nanoparticles with the ammonia control products has a surprising and unexpected result. The calcium silicate hydrate-ammonia control material mix reduces soluble phosphorus more than either component of the mix alone.

The present disclosure relates to hydrocarbon emission control systems. More specifically, the present disclosure relates to substrates coated with hydrocarbon adsorptive coating compositions and evaporative emission control systems for controlling evaporative emissions of hydrocarbons from motor vehicle engines and fuel systems. The hydrocarbon adsorptive coating compositions include particulate carbon having a BET surface area of at least about 1300 m.sup.2/g, and at least one of (i) a butane affinity of greater than 60% at 5% butane; (ii) a butane affinity of greater than 35% at 0.5% butane; (iii) a micropore volume greater than about 0.2 ml/g and a mesopore volume greater than about 0.5 ml/g.

The present description provides structures, atomic layer deposition methods for preparing the structures, and an apparatus preparing the structures. The described structures provide unexpected advantages as compared to currently available materials.

A hydrocarbon removal system according an embodiment of the present invention includes: a first area including a first hydrocarbon adsorption catalyst having a first pore size; and a second area including a second hydrocarbon adsorption catalyst having a second pore size, wherein the first pore size may be smaller than the second pore size, the first hydrocarbon adsorption catalyst may include CHA zeolite, and the second hydrocarbon adsorption catalyst may include ZSM-5 zeolite.

A methane production apparatus (200) includes: a holding unit (110) configured to hold any one or both of: a metal organic framework containing any one or a plurality of chromium, copper, and magnesium, and storing carbon dioxide; and potassium bicarbonate; and a hydrogen supply unit (140) configured to supply hydrogen to the holding unit (110).