Renewable and sustainable biofuel production from algal biomass has been explored vigorously due to the owing potential of overcoming the limitations of first and second-generation biofuel feedstocks. Thermochemical conversion technologies are considered promising routes for bioenergy production from algal biomass and have been extensively investigated over the last few years. This paper aims to review the various pyrolysis (slow, fast, and microwave -assisted) processes and hydrothermal liquefaction (HTL) techniques. The fast pyrolysis is involving a higher heating rate and shorter residence time compared to slow pyrolysis. Microwave-assisted pyrolysis (MAP) is considered a highly efficient process due to uniform heating. Due to a high moisture feedstock, the HTL process is considered the most energy-efficient processing option for algal biomass. In all these processes, the process temperature is considered the most critical parameter affecting product yield. This paper provides a detailed analysis and discussion on the effect of temperature and heating rates on the product (biochar, bio-oil, and syngas) yields for various microalgal species. The process details, different approaches, and process conditions investigated, challenges and recent advancements achieved in both technologies have been discussed in detail that provides useful insights to design a sustainable process and understand the process feasibility.
Bibliographical noteFunding Information:
The research was supported by the Natural Science Foundation of Jiangsu Province (BK20200775), National Research Foundation of Korea (NRF) grant funded by the Korean Government (Ministry of Science and ICT) (Nos. NRF-2019M3E6A1103839 and NRF-2020R1A2B5B02001757). The authors would like to thank IGPRED (www.igpred.com) and Advanced Analysis and Test Center of Nanjing Forestry University for providing insight and expertise on the research topic and for the assistance that greatly improved the manuscript.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Organic Chemistry