2 edition of Low-molecular weight lignosulfonates from spent sulfite liquor found in the catalog.
Low-molecular weight lignosulfonates from spent sulfite liquor
Written in English
|Statement||by Cheng-fan Lo.|
|The Physical Object|
|Pagination||, 145 leaves, bound :|
|Number of Pages||145|
Disclosed herein is a process for preparing sulfonated lignins by selectively isolating lignins having molecular weights greater than 5, and subsequently reacting the lignin with sodium sulfite and an aldehyde. The resulting sulfonated lignins are useful as dispersants for disperse dyes and vat dyes. tion through lignin sulfonation and the low molecular weight lignin is always ﬁrst solubilized before dissolving large molecular weight lignin. D, from sulﬁte pulping of softwood, was supplied by LignoTech USA, the M w of which Da, almost fold of LSs from SPORL. SXP, SAL, and LS had a normal curve with a small.
CHENG-FAN LO AN ABSTRACT OF THE THESIS OF for the Doctor of Philosophy (Name of student) (Degree) Forest Products in (Wood Chemistry) presented on March 6, Title: LOW-MOLECUL. USA USA USDA USA US A US A US A US A US A US A US D A USD A US DA US A US A US A Authority US United States Prior art keywords lignosulfonate lignin thionyl thionyl halide product Prior art date Legal status (The legal status is an assumption and is .
Plate polymeric membranes were tested for each type of process, however the low molecular weight of lignosulfonates, make more suitable the use of NF. In other work, Fernández-Rodríguez et al. () performed a study of the splitting of spent sulfite liquor in different fractions with three UF membranes (15, 5, and 1 kDa). A cascade fractionation process led to generate a permeate stream enriched in . Kontturi AK, Sundholm G The extraction and fractionation of lignosulfonates in spent sulfite liquors. Acta Chem Scand – CrossRef Google Scholar Kosyukova LV, Galyanova NV [Determination of volatile acids C 1 -0 5 in black liquors].
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Low-molecular weight lignosulfonates from spent sulfite liquor: isolation, purification and identification Public DepositedAuthor: Cheng-fan Lo.
Membrane filtration has been recognized as a commercial process for recovering lignosulfonates from spent sulfite liquors because lignosulfonates have a higher molecular weight than that of other components in the spent liquors, and the difference in molecular weights allows for effective separation.
3, 13, 54, 56 Ultrafiltration has been commercially applied in a calcium bisulfite pulping process 57 in Cited by: Lignosulfonates consist of a mixture of sulfonated lignin, sugars, sugar acids, resins, and inorganic chemicals.
Most lignosulfonates are obtained from the spent pulping liquor of sulfite pulping operations; some are also produced by postsulfonation of lignins obtained by. The spent liquor of sulfite pulping process contains a significant amount of lignocellulosic materials, which can be converted to various value-added products.
Such a process can fit into the. Abstract In this study, a novel approach for isolation and purification of lignosulfonates from spent sulfite liquor was established. Low-molecular weight lignosulfonates from spent sulfite liquor book This approach involves sorption onto macroreticular non-ionic poly (methyl methacrylate) beads (XAD-7 resin) and subsequent desorption with organic solvents to obtain lignosulfonates of high purity.
Alternative methods to produce lignosulfonates from spent sulfite pulping liquors and kraft lignin from black liquor of kraft pulping process are critically reviewed herein.
Furthermore, options to increase the sulfonate contents of lignin‐based products are outlined and. Sulfite spent liquor, a side stream of the pulping process, is an abundantly available source for bio-based platform chemicals. Lignosulfonates can be separated from the other organic components and pulping chemicals by ultrafiltration.
After distillation, the fermented spent sulfite liquor contains about 12% total solids, of which 5% are high molecular weight lignin compounds and the remainder are low molecular weight lignins plus pentose sugars and inorganic salts.
In this review paper, alternative methods to produce lignosulfonates from spent sulfite pulping liquors and kraft lignin from black liquor of kraft pulping process are critically reviewed. The molecular weight of lignosulfonates ranges from 10 3 –10 6 g/mol. A schematic drawing of part of the structure of a lignosulfonate is given in Fig.which shows possible bonds and substitution pattern in.
Lignosulfonates are recovered from the spent pulping liquids (red or brown liquor) from sulfite pulping. Ultrafiltration can also be used to separate lignosulfonates from the spent pulping liquid.
A list of CAS numbers for the various metal salts of lignosulfonate is available. Lignosulfonate is a major component of the spent liquor of the sulfite pulping process. molecular weight compounds to low molecular weight compounds, promoted cracking reactions of oxygenated.
Membrane filtration performance during the filtration of spent sulfite liquor (feed temperature = 60 °C, CFV = 6 m•s −1, Re = 12, τw = Pa, TMP = 3 bar). (a) nm ceramic hollow. Typical spent sulphite liquor from Eucalyptus globulus contains lignosulphonates, from 60 to 80 g/L, and sugars, from 35 to 45 g/L, from hydrolysed hemicelluloses, mainly xylose.
Recovery of Lignosulfonates from Spent Sulﬁte Liquor Using Ceramic Hollow-Fiber Membranes as different molecular weight cut-offs (1 kDa– m [5,19–22,24,25]) were also well described in the kg, again with the feed and filtration system preheated to 60 °C. Unfiltered spent sulfite liquor was added when a volume reduction of.
Lignosulfonates consist of a mixture of sulfonated lignin, sugar acids, sugars, inorganic chemicals, and resins. Most of the lignosulfonates are obtained from the spent pulping liquor of sulfite pulping processes but some are also produced by postsulfonation of lignins obtained by sulfate pulping (kraft process).
Recovered coproduct lignosulfonates can be used with little or no additional treatment or they can be. Sulfite liquors, however, may contain besides about 14% lignosulfonates, additionally humic acids, low molecular weight electrolytes and carbohydrate degradation products (e.g.
furfural). It was reported that precipitates of polyacids with polybases are cleavable by alteratibh of the pH or by addition of neutral salts (Thiele and Langmaack, ). USA USDA USA US A US A US A US D A USD A US DA US A US A US A Authority US United States Prior art keywords liquor sugars digestion sulfite spent sulfite Prior art date Legal status (The legal status is an assumption and is not a legal conclusion.
Alternative methods to produce lignosulfonates from spent sulfite pulping liquors and kraft lignin from black liquor of kraft pulping process are critically reviewed herein. Furthermore, options to increase the sulfonate contents of lignin-based products are outlined and the industrial attractiveness of them is evaluated.
Calcium lignosulfonate () is an amorphous light-yellow-brown powder obtained from the sulfite pulping of softwood. The organic framework of the additive is a sulfonated random polymer of three aromatic alcohols: coniferyl alcohol, p-coumaryl alcohol, and sinapyl alcohol, of which coniferyl alcohol is the principle unit.
Spent sulfite liquor from the acidic magnesium-based sulfite pulping of beech has a pH ofa lignosulfonate concentration of 92 gL −1 and was withdrawn before entering the evaporation unit. A detailed analysis of the spent sulfite liquor from a different charge (but .Lignosulfonate obtained from sulfite pulping spent liquor or prepared from sulphonation of alkali lignin at low cost can be used as a water reducer in the construction field.
But the low water reducing capability (water reducing rate usually around 8%) hinders its large-scale application (Ouyang et al. ). Also, most of water reducers.Relatively little is known about the molecular weight distribution of lignosulfonate molecules in spent sulfite liquor.
This has been investigated by size-exclusion chromatography when the raw material for the liquor was beech wood, revealing an average molecular mass (Mw) of g∙moL−1and a polydispersity (Mw/Mn) of