The present invention is in relation to a process for preparing calcium phosphate-based sulfated adsorbents that capture mercury in gas streams, comprised of the steps of synthesis of the precursors, incorporation of a transition metal, and sulfation of the material. These adsorbents present high efficiency both for removal of low concentrations of mercury, such as in natural gas, and for stabilization of this pollutant. The adsorbents obtained in the invention may be used in the Mercury Removal Units (MRUs) present in natural gas processing plants, which mercury removal units may be located either upstream or downstream of the dehydration and H.sub.2S removal units, due to the adsorbents obtained showing resistance to H.sub.2S poisoning, and maintaining their performance in the presence of water.

A permanently porous vanadium(II)-containing metal-organic framework (MOF) with vanadium(II) centers and methods for synthesis of such MOF frameworks are provided. Methods for using such compounds to selectively react with N.sup.2 over CH.sub.4 are provided. In the synthetic methods, a vanadium source, such as VY.sub.2(tmeda).sub.2, where Y is a halogen and tmeda is N,N,N′,N′-tetramethylethane-1,2-diamine and a H.sub.2(ligand) are reacted in the presence of acid in a solvent at between 110° C. and 130° C. to form an intermediate product. The intermediate product is collected and washed with a washing agent, such as DMF and acetonitrile, and the vanadium(II) based MOF is activated by heating the washed intermediate product to at least 160° C. under dynamic vacuum.

Subject of the invention is a process for producing a biofuel from fatty acid methyl esters (FAMEs) obtained by transesterification of vegetable oils, comprising the steps of: (a) ethenolysis of the fatty acid methyl esters in the presence of ethylene and an ethenolysis catalyst, and (b) isomerizing metathesis in the presence of an isomerization catalyst and a metathesis catalyst. The invention also relates to biofuels obtainable by the inventive process and to uses of ethylene for adjusting and optimizing biofuels.

A process for selectively separating H.sub.2S from a gas mixture which also comprises CO.sub.2 is disclosed. A stream of the gas mixture is contacted with an absorbent solution comprising one or more amines, alkanolamines, hindered alkanolamines, capped alkanolamines, or mixtures thereof. The H.sub.2S/CO.sub.2 selectivity of the absorbent solution is preferably greater than about 4.0 for an acid gas loading [mol(CO.sub.2+H.sub.2S)/mol(amine)] between about 0.2 and about 0.6, and is achieved by reducing pH of the absorbent solution.

Embodiments of the present disclosure provide systems, apparatuses and methods for the use of deep vacuum for the regeneration of desiccant in compressed gas desiccant dryers. Through the use of a vacuum pump operably coupled to a gas dryer, the systems and methods described herein allow for a gas dryer system to reach a deep vacuum pressure, inducing liquid within the desiccant in a gas dryer tower to reach a boiling point induced by the low pressure and lower boiling point of water or liquid, allowing the water or liquid to change from a liquid to a gas. This phase change allows the liquid to separate from the desiccant. The vacuum pump is then able to remove or pull the vapor that has been released from the desiccant from the system.

The invention relates to an improved apparatus and methods for managing and utilizing light hydrocarbons utilized and created during the hydroprocessing of biological feedstocks in the making of middle distillate fuels.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

Methods for separation of oxygenates or other chemical components from fuels using chemical processes and separations including, but not limited to, onboard applications in vehicles. These separations may take place using a variety of materials and substances whereby a target material of interest is captured, held, and then released at a desired location and under desired conditions. In one set of experiments we demonstrated an enhancement in the separation of diaromatics by >38 times over gasoline and aromatics by >3.5 times over gasoline. This would give an advantage to reducing cold-start emissions, or emissions during transient conditions, in either gasoline or diesel.

In a device for separating methane from a gas mixture containing methane, carbon dioxide and hydrogen sulfide, comprising a gas compressor, two or three membrane separation stages downstream of the compressor and a hydrogen sulfide adsorber, comprising a bed of activated carbon having catalytic activity for oxidizing hydrogen sulfide with oxygen, arranged upstream of the membrane separation stages, oxygen content and relative humidity can be adjusted for optimum adsorption capacity of the hydrogen sulfide adsorber by recycling permeate from the second membrane separation stage, which receives the retentate of the first membrane separation stage, to a point upstream of the hydrogen sulfide adsorber.

In an aspect, a method is disclosed that includes contacting a composition with an aqueous solution to yield a mixture, where the composition includes one or more of animal fats, animal oils, plant fats, plant oils, vegetable fats, vegetable oils, greases, and used cooking oil, about 5 wt. % or more of free fatty acids, about 10 wppm or more of total metals, about 8 wppm or more phosphorus, about 20 wppm or more of nitrogen, and the aqueous solution includes ((NH.sub.4).sub.2H.sub.2EDTA, (NH.sub.4).sub.4EDTA, a monoammonium salt of diethylenetriaminepentaacetic acid, a diammonium salt of diethylenetriaminepentaacetic acid, a triammonium salt of diethylenetriaminepentaacetic acid, a tetraammonium salt of diethylenetriaminepentaacetic acid, (NH.sub.4).sub.5DTPA, a combination of citric acid and Na.sub.4EDTA, a combination of citric acid and Na.sub.2H.sub.2EDTA, a combination of citric acid and a monosodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a disodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a trisodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a tetrasodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and Na.sub.5DTPA, or a combination of any two or more thereof, where the method further includes centrifuging the mixture to yield a first treated composition, wherein the first treated composition has less total metals and less phosphorus than the composition.