Recent trends in biochar integration with anaerobic fermentation: Win-win strategies in a closed-loop

A. Naresh Kumar, Pavani Dulanja Dissanayake, Ondrej Masek, Anshu Priya, Carol Sze Ki Lin, Yong Sik Ok, Sang Hyoun Kim

Research output: Contribution to journalReview articlepeer-review

22 Citations (Scopus)


Anaerobic fermentation (AF) is a widely used process for the transformation of organic waste into biogas. However, despite its ubiquitous use, it has several limiting factors, including low yield, redox imbalance, high concentration of inhibitors, and a long retention time. Integration of pyrolysis with AF improves efficiency and facilitates effective biomass utilization in a closed-loop approach. Research trends emphasize the inclusion of biochar derived from biomass to improve the stability and efficiency of AF and facilitate biogas up-gradation (H2S removal). However, there is a lack of consolidated scientific understanding regarding the complex interactions of biochar and AF microbial communities, in addition to its potential amendment advantages. Therefore, this review summarizes biomass utilization for biochar production using various pyrolysis methods and its use as an effective inclusion material to improve AF performance. Specifically, the influence of biochar amendments in AF is discussed in terms of microbial colonization, direct interspecies electron transfer, minimization of organic load, and buffering maintenance. Moreover, the role of AF digestate biochar in nutrient recycling and utilization as a soil conditioner is elaborated. The progressive integration of pyrolysis and AF offers the complete decoupling of biomass, enhances AF performance, and promotes the establishment of a sustainable bioprocess by inducing the circular bioeconomy.

Original languageEnglish
Article number111371
JournalRenewable and Sustainable Energy Reviews
Publication statusPublished - 2021 Oct

Bibliographical note

Funding Information:
This work was supported by the Korea Environment Industry & Technology Institute ( KEITI ) through a project for developing innovative drinking water and wastewater technologies, funded by the Korea Ministry of Environment (MOE) ( ARQ202001174001 ) and the Cooperative Research Program for Agriculture Science and Technology Development (Effects of plastic mulch wastes on crop productivity and agroenvironment, Project No. PJ01475801 ), Rural Development Administration, Republic of Korea and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1A2C2011734 ). A. Naresh Kumar duly acknowledges the NRF for providing the Korean Research Fellowship (KRF) with grant number: 2019H1D3A1A01102655 .

Publisher Copyright:
© 2021


  • Anaerobic digestion
  • Bioeconomy
  • Biogas
  • Nutrient cycling
  • Organic waste
  • Sustainable waste management

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment


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