摘要:
In the process of removing heavy metals from aqueous solutions (groundwater) by precipitation of a salt thereof, an oxidizing agent is optionally used to increase the valence of said metal, and a precipitation-enhancing agent is added to maximize particle size of the precipitate and to facilitate its separation from said solution.
摘要:
A process is disclosed for the removal of dissolved heavy metals from aqueous solution contaminated therewith wherein at least one of said heavy metals is reacted with a water-soluble inorganic sulfide or hydrosulfide at a defined elevated temperature and a controlled pH of between about 2 to about 3.5 to thereby precipitate heavy metal sulfide, and thereafter separating the precipitate from the filtrate.
摘要:
A highly dispersed platinum ZSM-5 catalyst used in hydrodewaxing lube stock yields a product with improved overnight cloud performance and lighter ASTM color.
摘要:
The present invention relates to a process for the removal of solvent from a polymer emulsion or suspension, by use of a decanter centrifuge (10). The decanter centrifuge (10) provides an efficient thickening method. The process is especially useful for emulsion or suspension polymer compositions having high levels of solvent (low polymer solids) that could benefit from a thickening or dewatering step prior to drying in a dryer (14).
摘要:
Hydrocarbon lubricating oil feedstocks are dewaxed by passing the waxy feedstock over a catalyst bed containing a mixture of medium pore zeolite and large pore zeolite catalysts havig a Constraint Index less than 2 and having hydroisomerization activity in the presence of a hydrogenation component.
摘要:
Sulfur-laden liquid organic phase dimethyl polysulfide (DMPS) is caused to rise from a sour gas well by reaction of the gaseous sulfur component within the well with a sulfur solvent, typically dimethyl disulfide (DMDS). The DMPS is contacted by an extraction or stripping liquid in a vertical column continuous multistage countercurrent flow extractor especially designed to promote high interfacial area contact between the liquids while flowing in opposing directions within the column.
摘要:
Hydrocarbon feedstocks are dewaxed in a dual catalyst cascade process by passing the waxy feedstock over a crystalline silicate zeolite catalyst having a Constraint Index between 2 and 12, and then over a different crystalline silicate zeolite catalyst having a Constraint Index no less than 2.
摘要:
A catalytic dewaxing process is improved by the use of a mixed zeolite catalyst which combines the following components: a first zeolitic catalyst having a Constraint Index not less than 1, a second, different, catalytic component of specified characteristics, and a hydrogenation component. This process for preparing the catalyst is also disclosed. Examples of specific combinations of dewaxing catalysts include ZSM-5 and Dealuminized Y, ZSM-5 and ZSM-12, and ZSM-5 and TEA Mordenite.
摘要:
The invention relates to a process that results in a fluoropolymer composition with improved chemical, thermal and color stabilities, and a reduced level of residual surfactants (both fluorosurfactants and non-fluorosurfactants. Such improvements, as indicated by total oxidizable carbon (TOC) and pellet yellowness index (YI), can be accomplished in a cost-effect manner through the use of a dewatering extruder. The dewatering extruder combines several typical unit operations into a single operation, producing solid fluoropolymer having a significantly reduced total oxidizable carbons, a lower yellowness index and minimal amounts of surfactants.
摘要:
In the process of removing heavy metals from aqueous solutions by precipitation of a salt thereof at increased pH, multiple stage precipitation by upward stepwise pH adjustment and solid separation at each stage is used to facilitate the manufacture of a product of high purity.