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This study presents an investigation for comparing the regeneration process of two activated carbons saturated with Basic Blue 9 (BB9) and Acid Blue 93 (AB93) using conventional (250-500 °C) and microwave heating (100-300W). The effect of the textile dye used on the regeneration performance was analyzed by determining their dielectric properties using the perturbation cavity method from 20 to 600 °C and by TG/DTG analysis. The efficacy of the regenerated carbons was investigated by their physical properties characterized by pore structural analysis using N 2 adsorption isotherms. Results showed only 3 min are required by microwaves to achieve similar textural parameters obtained by conventional heating at 190 min. The results indicate that the adsorbate plays a determining role on the regeneration efficiency as results of their interaction with the adsorbent, being easily regenerated when AB93 is the adsorbate. The adsorption capacity of microwave regenerated samples for AB93 and BB9 was 192-240 and 154-175 mg/g, respectively. Additionally, the equilibrium isotherms were simulated using the Langmuir and Freundlich isotherms models and the results suggest the textile dye removal is achieved on multilayer adsorption.

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Background: In this work the impact of grinding and chopping on the rheological properties of four switchgrass materials (panicum virgatum) is investigated, comparing physical characterization to previously published feeding performance in bulk equipment in a high-tonnage facility, in which chopped materials exhibited dramatically better handling performance than corresponding ground materials. Results: Physical characterization included sieve analysis, automated digital image analysis of particle size and shape distributions, microscopy of particle microstructure, shear tests using two different sizes of ring shear testers, flow tests in a custom hopper with an adjustable outlet, and uniaxial compression and spring back tests. Shear tests failed to demonstrate consistent statistically significant differences between the shear strengths of the chopped and ground materials subjected to uniaxial compression. However, in laboratory-scale hopper flow tests, the chopped materials exhibited substantially better flow performance than the ground materials, in agreement with the previously published bulk handling tests. Conclusion: Chopped switchgrass materials exhibit substantially better flowability properties in large-scale bulk equipment and in laboratory-scale hopper feeding tests; however, shear tests were not able to reliably predict the flowability properties of bulk switchgrass particles, likely because uniaxial-compression shear tests do not capture the effects of compressibility and elasticity in multi-dimensional flow streams.

Highlights Conventional and microwave-assisted extraction of “hairy” pectin from sugar beet. Determined effect of heating method, temperature, time & pH on yield & composition. No difference between microwave and conventional extraction under conditions tested. Strong alkaline is favoured in rhamnogalacturonan-I “hairy” pectin extraction. Hydrothermal water extraction can be an alternative to strong alkaline extraction.