摘要:
An oxidative coupling catalyst composition for converting methane to a higher hydrocarbon comprising a mixed oxide of: a) a Group IIIB metal selected from the group consisting of yttrium, scandium and lanthanum; b) a Group IIA metal selected from the group consisting of barium, calcium and strontium; and c) a Group IVA metal selected from the group consisting of tin, lead and germanium and wherein the cationic species are present in the approximate ratio of 1:0.5-3:2-4, respectively, and an improved process employing same.
摘要:
Exhaust gas emissions from an internal combustion engine are controlled through the use of a heat exchanger, a sulfur oxide absorbent, and a catalytic converter. The exhaust gas is contacted with the sulfur oxide absorbent before it is passed to the catalytic converter, and the heat exchanger is used to extract heat from the exhaust gas before the exhaust gas is contacted with the sulfur oxide absorbent. The heat extracted from the exhaust gas by the heat exchanger is then used to heat the catalytic converter. In a preferred embodiment, the exhaust gas is also contacted with a hydrocarbon adsorbent which: (1) adsorbs organic compounds, such as hydrocarbons, from the exhaust gas at the low temperatures which are typical of an engine cold-start, and (2) desorbs them at the higher temperatures which are reached after sustained engine operation.
摘要:
Exhaust gas emissions from an internal combustion engine are controlled through the use of a heat exchanger, a sulfur oxide absorbent, and two catalytic converter zones. The exhaust gas is passed sequentially through: (1) a first catalytic converter zone, (2) the sulfur oxide absorbent, and (3) a second catalytic converter zone. The heat exchanger is used to transfer heat from the first catalytic converter zone to the second catalytic converter zone.
摘要:
Processes are disclosed for production of value-added products from fluid admixtures of hydrocarbon compounds at least one of which is an aromatic hydrocarbon compound, by means of one or more devices using perm-selective polymeric membranes. More particularly, processes of the invention comprise separations using aromatic-selective polymeric materials comprising long-chain polymeric molecules in which recurring amide and imide linkages are part of the main polymer chain. Processes of the invention advantageously employ aromatic-selective membranes to separate an aromatic enriched stream from gaseous and/or liquid mixtures comprising one or more aromatic hydrocarbon compounds thereby producing a stream comprising the remaining compounds which may include alkenes and/or alkanes containing 3 or more carbon atoms, and/or alicyclic hydrocarbons. Processes of the invention are particularly useful for recovery of meta-xylene and para-xylene products from liquid mixtures even containing ethylbenzene as well as the three xylene isomers.
摘要:
A product of reduced sulfur content is produced in a multiple stage process from a feedstock which is comprised of a mixture of hydrocarbons and includes sulfur-containing aromatic compounds as unwanted impurities. The first stage involves: (1) subjecting the feedstock to alkylation conditions which are effective to convert a portion of the impurities to higher boiling sulfur-containing products, and (2) separating the resulting products by fractional distillation into a lower boiling fraction and a higher boiling fraction. The lower boiling fraction is comprised of hydrocarbons and is of reduced sulfur content relative to the feedstock. The higher boiling fraction is comprised of hydrocarbons and contains unconverted sulfur-containing aromatic impurities and also the higher boiling sulfur-containing products. Each subsequent stage involves: (1) subjecting the higher boiling fraction from the preceding stage to alkylation conditions which are effective to convert at least a portion of its content of sulfur-containing aromatic compounds to higher boiling sulfur-containing products, and (2) separating the resulting products by fractional distillation into a lower boiling hydrocarbon fraction and a higher boiling fraction which contains higher boiling sulfur-containing alkylation products. The total hydrocarbon product of reduced sulfur content from the process is comprised of the lower boiling fractions from various stages.
摘要:
A process for separating solids from liquids in a filtration zone defined by a higher concentration zone and a lower concentration zone separated by a filter. The process includes the steps of directing a slurry feed comprising a liquid and solids into the higher concentration zone, directing a displacement fluid to the higher concentration zone and passing at least a portion of the liquid through a filter to the filtrate zone, producing a filtrate.
摘要:
A product of reduced sulfur content is produced from an olefin-containing hydrocarbon feedstock which includes sulfur-containing impurities. The feedstock is contacted with an olefin-modification catalyst in a reaction zone under conditions which are effective to produce an intermediate product which has a reduced amount of olefinic unsaturation relative to that of the feedstock as measured by bromine number. The intermediate product is then contacted with a hydrodesulfurization catalyst in the presence of hydrogen under conditions which are effective to convert at least a portion of its sulfur-containing impurities to hydrogen sulfide.
摘要:
A method is provided for putting a fresh bed of solid phosphoric acid catalyst into service to catalyze a hydrocarbon conversion process. The method involves establishing hydrocarbon conversion conditions of temperature and pressure in the catalyst bed while it is immersed in a hydrocarbon liquid which is substantially free of water and compounds which can yield water upon contact with the catalyst. Thereafter, the catalyst bed is used to catalyze the conversion of a hydrocarbon feedstock which contains a minor amount of a hydrating agent which is effective to provide a desired level of catalyst hydration. The method permits the catalyst to be rapidly brought to an optimum level of activity for the specific hydrocarbon conversion process.
摘要:
A method for converting methane to higher molecular weight hydrocarbons wherein hot oxidative coupling reactor effluent is briefly contacted with a C.sub.2 to C.sub.20 alkane quench material to remove part of the heat contained in the raw reactor effluent, and is then further quenched by thermal quenching means to achieve a temperature which discourages retrograde reactions.
摘要:
Compositions and processes are disclosed for economical separation of fluid mixtures. Broadly, the present invention discloses ionic polymer compositions that are useful for perm-selective membrane separations. More particularly, ionic polymers of the invention comprise a plurality of repeating structural units having as a constituent part thereof organic ionic moieties consisting of nitrogen containing anions and/or cations. In the form of non-porous membranes, ionic polymers of the invention facilitate recovery of purified organic and inorganic products from fluid mixtures by means of perm-selective membrane separations. The present invention also provides methods for forming the ionic polymers, for example by treating selected nitrogen-containing organic polymers with acids, or treating a polymeric material comprising a plurality of carboxylate groups with an amine. Ionic polymer compositions of the invention are particularly useful for simultaneous recovery of a permeate product of an increased concentration, and a desired non-permeate stream, from a fluid mixture containing at least two compounds of different boiling point temperatures.