摘要:
Crosslinked cellulose beads or lignocellulose beads (referred to as beads for short), wherein at least 50% by weight of the beads have a particle diameter greater than 800 μm (21° C., 1 bar, determined by sieve analysis).
摘要:
Methods and systems are disclosed for providing incremental backup and restore operations for a file system having a large number of files. A file system accessing a mass storage device is augmented by including an enhanced directory services component (EDSC) that has an associated EDSC database that contains file system information regarding contents of the file system including file attributes. Accordingly, high-performance backup and restore operations can be performed by directly or indirectly querying the EDSC database to obtain fill attributes rather than traversing the file system's native file attribute data structures. This enables the file system to provide more consistent response to applications requesting file status independent of the number of files stored in the file system.
摘要:
C4-dicarboxylic acids or derivatives thereof are hydrogenated in the gas phase in a fluidized-bed reactor. It is possible to use catalyst compositions known per se.
摘要翻译:C 4 N 4 - 二羧酸或其衍生物在气相中在流化床反应器中氢化。 可以使用本身已知的催化剂组合物。
摘要:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated. It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
摘要:
A process for polymerizing cyclic ethers over a heterogeneous catalyst comprises using a heterogeneous catalyst comprising one or more pillared interlayered clays (PILCs).
摘要:
Polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers are prepared by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer on a heterogeneous carrier catalyst which contains on an oxidic carrier material as active mass a catalytically active amount of at least one oxygenous molybdenum and/or tungsten compound and, when the precursor compounds of the active mass have been applied to the carrier material precursor, has been calcined at temperatures of between 500° C. and 1000° C. The catalyst used contains a promotor which comprises at least one element or a compound of an element of the 2nd, 3rd including the lanthanides, 5th, 6th, 7th, 8th or 14th group of the periodic system of elements.
摘要:
A process for working up by distillation the crude products obtained in the process according to DE-A 196 07 954 and containing 1,6-hexanediol (HDO), 1,5-pentanediol (PDO) or caprolactone (CLO) in order to obtain the corresponding pure products, the working-up by distillation being carried out in each case in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper common column region (1), a lower common column region (6), a feed section (2, 4) having a rectification section (2) and stripping section (4), and a take-off section (3, 5) having a stripping section (3) and rectification section (5), with feeding of the respective crude product HDO, PLO or CLO in the middle region of the feed section (2, 4) and removal of the high boiler fraction (C) from the bottom of the column, of the low boiler fraction (A) via the top of the column and of the medium boiler fraction (B) from the middle region of the take-off section (3, 5), or in thermally coupled columns.
摘要:
A system for making presentations to audience clients in a computer network. The presentation is made by a presenter client via a Web server connected to one or more audience client units. Each audience client unit has a browser for linking to the network. The system comprises a receiver for receiving and processing page requests from at least one presenter client; a transmitter for transmitting requested pages to the presenter client; and a server siphon for intercepting composed pages and sending copies of each composed page to at least one connected audience client.
摘要:
A process for preparing cyclopentanone by reacting adipic esters of the formula R1OOC—(CH2)4—COOR2 I where R1 and R2 are each alkyl having from 1 to 12 carbon atoms, cycloalkyl having 5 or 6 carbon atoms, aralkyl or aryl and R2 may additionally be hydrogen, in the presence of oxidic catalysts comprises reacting adipic esters of the formula I having less than 5% by weight of by-products other than adipic esters in the gas phase in the presence of water, a carrier gas and a) from 0.01 to 10% by weight of at least one metal oxide selected from the first or second main group of the periodic table or from the group of the rare earth metals on titanium dioxide or zirconium dioxide as catalyst support, or b) from 0.01 to 50% by weight of at least one metal oxide selected from the second main group of the periodic table on zink oxide as catalyst support.
摘要:
A process for producing 1,6-hexanediol by hydrogenation of adipic esters and/or 6-hydroxycaproic esters in the gas phase at elevated temperature and elevated pressure in the presence of chromium-free catalysts comprises hydrogenating a) over a catalyst comprising copper, manganese and aluminum as essential constituents or over Raney copper, b) at a temperature of from 150 to 230° C. and a pressure of from 10 to 70 bar, c) at a molar ratio of hydrogen to ester to be hydrogenated within the range from 150:1 to 300:1, and d) at a catalyst space velocity of from 0.01 to 0.3 kg of C6 ester per liter of catalyst per hour.