Lignosulfonates degradation

Lignosulfonate muds can be used efficiently at a pH of 9 to 10, and have a temperature limitation of about 350°F, above which lignosulfonates show severe thermal degradation. The recommended range of rheological properties of freshwater-base muds is shown in Figure 4-111 [29]. 

Modem concretes often incorporate a mixture of chemical and mineral admixtures, each of which may interact with the various constituents of cements and influence cement hydration reactions. The admixture-cement interactions may in fact be viewed as the reaction between two complex chemical systems - the multicomponent, multiphasic inorganic materials in the cement and the organic compounds of multicomponent admixture systems. For example, lignosulfonate water-reducers are intrinsically complex mixtures of chemical compounds derived from the chemical degradation of lignin, while synthetic admixtures such as superplasticizers contain species with a broad distribution of molecular weights, reaction products, or other chemicals added for a specific purpose [125]. The performance of an admixture in concrete is highly dependent on many... 

In addition to lignosulfonates and hemicelluloses and their degradation products, sulfite spent liquors contain small amounts of uronic acids, methyl... 

Another category of lignin-based chemicals is obtained when lignosulfonates are degraded to low molecular weight products. The commercially most important product is vanillin, which is obtained by alkaline oxidation... 

The RUP estimates were 42, 68, 62, and 65%, respectively, indicating that all treatments were effective at decreasing the amount of soy protein degraded in the rumen relative to solvent-extracted soybean meal. Ipharraguerre et al. (2005) also showed that lignosulfonate treatment and screw press treatment resulted in increased passage of feed protein to the small intestine. 

Another important source of hydrogen sulfide is the thermal degradation of lignosulfonates (that may be contained in the mud) that starts at about 330°F (165°C) and increases gradually until a major decomposition occurs at450°F (232°C). The rate of degradation is reduced at a pH of about 10. Reaction products are hydrogen sulfide, carbon dioxide, and carbon monoxide (Skelly and Kjellstrand 1966). 

SkeUy, W. G. and Kjellstrand, J. A. (1966) The Thermal Degradation of Modified Lignosulfonates in Drilhng Muds, API Paper 926-1106. 

It is difficult to describe a detailed degradation pathway for lignosulfonates for several reasons. Firstly, the chemical structure of lignosulfonates is complex, which complicates a mechanistic understanding of the degradation process. Secondly, lignin and... 

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