Recycling and regeneration of carbonaceous and porous materials through thermal or solvent treatment

Tanushree Dutta, Taejin Kim, Kowsalya Vellingiri, Daniel C.W. Tsang, J. R. Shon, Ki Hyun Kim, Sandeep Kumar

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)

Abstract

Recyclability is a prerequisite for successful commercialization of new adsorbent materials. For the recycling, adsorbents should have high desorption efficiency at low economic and energy costs. Here, a comprehensive review is offered to describe the strategies for thermal or solvent-assisted (chemical) regeneration of carbonaceous materials derived from diverse bioresources (e.g., activated carbon, biochar, and hydrochar) along with other common or novel adsorbents (e.g., natural/synthetic zeolites and metal-organic frameworks). Our study reveals thermal regeneration as the most common recycling manoeuvre due to the simplicity of reactor design. However, the use of high temperatures during thermal treatments perturbs key surface attributes of adsorbents through oxidation, polymerization (of functional groups/entities), or framework breakdown. In contrast, solvent-assisted methods generate waste solvents and causes chemical degradation. The polarity of the solvents plays a pivotal role in performance of regenerated sorbents or regeneration potential due to strong adsorbate-adsorbent interaction (e.g., electrostatic and π-π interaction). Note that, for the selection of any adsorbent, there is inherently contradictory structural requirement between selective adsorption (favored by smaller pore space) and efficient desorption (favored by larger pores). Nonetheless, recent introduction of 'smart adsorbents’ strikes the right balance between such opposing characteristics. Overall, a vast assemblage of adsorbents and hybrid regeneration techniques developed in recent times (2012–2018) signals the emergence of application-directed synthesis, self-assembly, and desorption-degradation coupling to make adsorptive removal process environmentally benign and scalable.

Original languageEnglish
Pages (from-to)514-529
Number of pages16
JournalChemical Engineering Journal
Volume364
DOIs
Publication statusPublished - 15 May 2019

Keywords

  • Adsorptive removal
  • Cumulative heel formation
  • Desorption performance
  • Regeneration scale-up
  • Sorbent recycling

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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