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Industrial Ecology for Waste Minimization, Utilization, and Treatment
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Organic chemicals may also be treated by hydrolysis. For example, toxic acetic anhydride is hydrolyzed to relatively safe acetic acid:
Surface Treatment of Natural Fibers (Chemical Treatment)
Published in Shishir Sinha, G. L. Devnani, Natural Fiber Composites, 2022
Acetyl-treated flax fiber–reinforced composite, tensile, and flexural properties increase until 18%. Acetylation treatment of natural fiber reduces the hydroscopic nature, increases dimensional stability, and roughness. Acetylation-treated bamboo fiber changes properties. The matrix may be different for different fibers and it is discussed in Table 4.9. Acetic anhydride and acetic acid did not react with cellulosic fiber directly so first it is treated with acetic acid and then treated with an acetic anhydride solution. This will accelerate the reaction. This will provide roughness with less void content to promote better bonding between the fiber and matrix. Acetylated fiber shows increments in mechanical properties like acetylated-treated flax fiber increase tensile and flexural strength by 25% (Kabir et al., 2008).
Chemical Modification Processes
Published in Dick Sandberg, Andreja Kutnar, Olov Karlsson, Dennis Jones, Wood Modification Technologies, 2021
Dick Sandberg, Andreja Kutnar, Olov Karlsson, Dennis Jones
In the commercial acetylation process, wood is impregnated in a pressurised autoclave, so that the reagent penetrates through the porous wood and further into the wood cell wall. The removal of moisture from the wood before the introduction of acetic anhydride is crucial, as water will consume reagent and produce acetic acid in a reaction that is enhanced by a high temperature. As can be seen in Figure 2.2, acetic acid can to a certain extent help the acetylation by swelling the wood, making it easier for the reagent to reach reactive groups (Rowell et al., 1990). It is considered to be important to impregnate a thicker solid wood with the anhydride under cold conditions to prevent the early formation of large amounts of acetic acid which will dilute the reagent (Rowell, 1986). It should be noted that, under dilute aqueous conditions, the content of acetic anhydride was reduced to half within 5 minutes at 23°C (Kovac Kralj, 2007).
Design and optimization of an acetic acid recovery system via extraction–distillation using an isopropyl acetate + isopropanol mixed solvent
Published in Chemical Engineering Communications, 2020
Peng Fang, Chao Yu, Zuoxiang Zeng, Weilan Xue
The recovery of industrial wastewater has a major impact on reducing environmental impacts and economic costs (Park et al. 2013). Acetic acid (HAc), one of the most common organic acids, is a good solvent for the oxidation reaction, such as the oxidation of p-xylene to produce terephthalic acid. It is also an important raw material in the organic synthesis industry, such as the production of acetic anhydride, aspirin, etc. However, a large amount of dilute acetic acid solutions (less than 40 wt%) is produced in these processes (Kürüm et al. 1995). Therefore, the dehydration of HAc from dilute aqueous solutions becomes an important industrial problem.