摘要:
A method for forming multi-metallic sites on a substrate is disclosed and described. A substrate including active groups such as hydroxyl can be reacted with a pretarget metal complex. The target metal attached to the active group can then be reacted with a secondary metal complex such that an oxidation-reduction (redox) reaction occurs to form a multi-metallic species. The substrate can be a highly porous material such as aerogels, xerogels, zeolites, and similar materials. Additional metal complexes can be reacted to increase catalyst loading or control co-catalyst content. The resulting compounds can be oxidized to form oxides or reduced to form metals in the ground state which are suitable for practical use.
摘要:
Ceria-coated aerogels can include an aerogel support material having a stabilized ceria coating thereon. The ceria coating can be formed by solution or vapor deposition of alcogels or aerogels. Additional catalytic metal species can also be incorporated into the coating to form multi-metallic compounds having improved catalytic activity. Further, the ceria coated aerogels retain high surface areas at elevated temperatures. Thus, improvements in catalytic activity and thermal stability can be achieved using these ceria-coated composite aerogels.
摘要:
Methods and apparatus relate to catalysts and preparation of the catalysts, which are defined by sulfides of a transition metal, such as one of molybdenum, tungsten, and vanadium. Precursors for the catalysts include a metal ion source compound, such as molybdenum trioxide, and a sulfide ion source compound, such as thioacetamide. Once the precursors are dissolved if solid and combined in a mixture, homogenous precipitation from the mixture forms the catalysts. Exemplary uses of the catalysts include packing for a methanation reactor that converts carbon monoxide and hydrogen into methane.
摘要:
A process of modifying a zeolite catalyst to produce a modified zeolite catalyst wherein the modified zeolite catalyst has blocked pore sites. An oxygenated feed is flowed over the modified zeolite catalyst, wherein the oxygenated feed comprises hydrocarbons, methanol and dimethyl ether or a mixture thereof. The hydrocarbons, methanol and dimethyl ether in the oxygenated feed react with the modified zeolite catalyst to produce cyclic hydrocarbons, wherein the cyclic hydrocarbons produced has less than 10% durene and a median carbon number is C8.
摘要:
A single pass direct conversion of biomass derived oxygenates to longer chain hydrocarbons is described. The longer chain hydrocarbons include higher naphthene content which is quite useful in the distillate range fuels or more particularly, the jet and diesel range fuels. Naphthenes help the biomass derived hydrocarbons meet product specifications for jet and diesel while really helping cold flow properties.
摘要:
An ECG recorder and playback unit which includes software-implemented digital signal processing filters which compensate for phase and magnitude distortion occurring when an ECG signal is recorded on a Holter recorder and played back. This permits "tuning" a recorder and playback unit which may be unrelated, as when made by different manufacturers. An impulse or step signal is recorded and played back to provide a system frequency response measurement. Coefficients for a digital correction filter are derived from the discrete Fourier transform of the impulse or step response and a desired system response. When recorded ECG data is played back, it is filtered on a substantially real-time basis with the digital correction filter to compensate for phase and magnitude distortion. Prior to recording, the high frequencies of the ECG signal are boosted to compensate for high frequency losses inherent in the recording and playing back of ECG signals. A calibration pulse and a system characterization pulse are derived by statistically selecting from a plurality of pulses and averaging the selected pulses in order to minimize the effects of noise and tape defects in the pulses. High frequency components of the ECG signal can be amplified prior to recording the signal. This results in decreased amplification, and therefore noise, when the recorded signals are played back. Cardiac pacer pulse detection is performed prior to the step of filtering the played back signal to optimize pulse detection.
摘要:
A single pass direct conversion of biomass derived oxygenates to longer chain hydrocarbons is described. The longer chain hydrocarbons include higher naphthene content which is quite useful in the distillate range fuels or more particularly, the jet and diesel range fuels. Naphthenes help the biomass derived hydrocarbons meet product specifications for jet and diesel while really helping cold flow properties.
摘要:
Enhanced mixed metal catalysts are provided which allow high conversions of carbon dioxide to methane, in some cases up to about 100% conversion. Methods of preparing enhanced mixed metal catalysts comprise a series of steps involving combining nickel and chromium salts with a nucleation promoter in a base environment to form a gel, allowing the gel to digest to form a solid and a mother liquor, isolating the solid, washing the solid, drying the solid, and thermally treating the solid to form a nickel-chromium catalyst. Methanation processes using the catalysts are also provided. The enhanced mixed metal catalysts provide more efficient conversion and lower operating temperatures for carbon dioxide methanation when compared to conventional methanation catalysts. Additionally, these enhanced catalyst formulations allow realization of higher value product from captured carbon dioxide.
摘要:
A process of modifying a zeolite catalyst to produce a modified zeolite catalyst wherein the modified zeolite catalyst has blocked pore sites. An oxygenated feed is flowed over the modified zeolite catalyst, wherein the oxygenated feed comprises hydrocarbons, methanol and dimethyl ether or a mixture thereof. The hydrocarbons, methanol and dimethyl ether in the oxygenated feed react with the modified zeolite catalyst to produce cyclic hydrocarbons, wherein the cyclic hydrocarbons produced has less than 10% durene and a median carbon number is C8.
摘要:
Enhanced mixed metal catalysts are provided which allow high conversions of carbon dioxide to methane, in some cases up to about 100% conversion. Methods of preparing enhanced mixed metal catalysts comprise a series of steps involving combining nickel and chromium salts with a nucleation promoter in a base environment to form a gel, allowing the gel to digest to form a solid and a mother liquor, isolating the solid, washing the solid, drying the solid, and thermally treating the solid to form a nickel-chromium catalyst. Methanation processes using the catalysts are also provided. The enhanced mixed metal catalysts provide more efficient conversion and lower operating temperatures for carbon dioxide methanation when compared to conventional methanation catalysts. Additionally, these enhanced catalyst formulations allow realization of higher value product from captured carbon dioxide.