Powdered wheat straw

In the latter part of the 1950s, this author (Hayes, 1960) attempted to repeat the experimentation used by Waksman and Iyer (1932,1933). He exhaustively washed powdered wheat straw with boiling water, then with hot dilute hydrochloric acid, and extracted twice for 5h in an autoclave at 120 °C, each time with a 4% sodium hydroxide solution. The combined filtrates were acidified to pH 4 with hydrochloric acid and the precipitate formed was washed free of chloride and freeze-dried. A ligno-casein complex was formed by reacting three parts of the lignin extract and one part casein in a 0.1 M solution of sodium hydroxide and collecting the precipitate formed when the pH was adjusted to 4. This complex was washed free of chloride and freeze-dried. A 6 1 lignin-protein complex was formed in the same way. 

Two experiments (RSI, RS2) were performed with DC-II and Swedish wheat straw with particle size in the range of 1 to 2 mm. During these experiments the solids recovery system (cyclone and impinger, Figure 1) did not perform satisfoctorily with the very fragile straw char. The char, exposed to the very harsh envirorunent (fast moving sand particles) of the CFB reactor and atritted to very fine particles, almost submicTon powder, could not be collected by conventional solids recovery systems. Consequently, the char was either adhered with the liquids heavy fraction to the STHE inner tubes or readilly accumulated in the liquid recovery system. 

Powdered wheat (Triticum aestivum) straw has been modified with urea under the effect of microwave radiation and used for the removal of Cd(II) ions from aqueous solution in a batch process [102]. Dried straw from wheat was washed, ground, and screened to a particle size of less than 100 pm. The powder was soaked in distilled water for 2 days, then washed with distilled water, and dried at 80°C to constant mass. Wheat straw and urea were blended in a ratio of 1 2 by mass and were exposed to microwave radiation (2450MHz) for 12min. Then it was boiled in water for 300min and filtered while hot, washed with hot water, and dried at 80°C to constant mass. The chemical modification of wheat straw with urea through microwave radiation is illustrated in Figure 5.18. 

Wheat straw powder Urea-modified wheat straw 6.00 39.22 [102]... 

High-intensity ultrasonication can be considered as a mechanical method for producing cellulose nanofibers with hydrodynamic forces [72]. In this process, ultrasonic waves create strong mechanical stress because of cavitations, and therefore, cause the disaggregation of cellulosic fiber to nanofibers [73]. Several attempts have been made to isolate cellulose nanofiber by ultrasonication from various cellulose sources such as microcrystalline cellulose, regenerated and pure cellulose fibers [72], kraft pulp [74], flax, wood, wheat straw and bamboo [75] (Figure 11.5), para rubberwood sawdust [76], and poplar wood powders [15]. 

Xylans can be coextracted from wheat straw and bran in a twin-screw extruder. The best results for both the production yield and the extract properties are obtained with low alkali content, as the majority of the xylans conies from bran. The desired concentration of the extract solution can be achieved by ultrafiltration. The membrane configuration and molecular weight cut off (MWCO) must be adapted to each solution to limit fouling and concentration polarisation. A permeate flux of 20 dmVh.nr was obtained at a final concentration ratio of 2. Ultrafiltration allows for a partial demineralization of the solutions but does not change the properties of the final powder. 

Molasses Paraffin Peat Petroleum pitch Polyvinyl alcohol Potato starch Refined asphalts Resins (natural and synthetic) Rosin Sawdust Seaweed Slack wax Slaughterhouse refuse Straw (pulped) Sucrose Sugars Tanning liquors (tannic acid) Thermoplastic powders Vegetable pulp Water Wheat starch Wood pulp Water... 

The best results for both the extraction yield in the hemicellulosic powder and the sugar purity in the case of xylan extraction from wheat bran in a twin-screw extmder are obtained for a low NaOH ratio (bran/soda = 7) and a low straw content. 

After the precipitation stage, the final powder from twin screw extmsion (92% dry matter), contains 91% organic matter. The global yield of this process is about 24 % of the potential in hemicelliiloses of wheat bran, if it is considered that arabinoxylans represents 60 % organic matter 26% protein and 5.3% lignin (originating from straw) (table 111). These results should be compared with extraction conditions in the stirred reactor, where the best results are obtained with a molar soda and a L/S ratio of 50. The chemical charge is reduced by a factor of 14 and the L/S ratio by a factor of 15 when twin-screw extruder is used. 

Z. isolated from com gluten meal is a granular, straw- to pale-yellow, amorphous powder or fine flakes with properties similar to the gliadins of - wheat gluten. For composition - com gluten meal. 

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