Aquaculture Canada and WAS North America 2022

August 15 - 18, 2022

St Johns, Newfoundland, Canada


Vijaya Raghavan* and Brenda Alvarez Chavez

McGill University, Department of Bioresource Engineering, 21,111 Lakeshore Rd, Sainte-Anne-de-Bellevue, Quebec H9X 3V9,;


In response to accelerated climate change, global agreements have been signed to implement and establish the use of renewable energy with low or zero GHG emissions,. As a result, the global bioeconomy is moving towards processes that can offer not only traditional products, but also new advanced renewable fuels, chemicals and other value-added products. Owing to their low cost and easy availability, thermochemical conversion processes, such as pyrolysis and hydrothermal carbonization (HTC), are attractive methods for producing bio-oils and bio/hydro-chars that can be considered as second generation biofuels [1]. The properties and yields of these products and energy requirements depend on operating conditions. These thermochemical processes use a variety of raw waste materials from agriculture, forestry, and non-traditional sources, such as wet animal manure, human waste, sewage sludge, municipal solid waste, as well as aquaculture and algae residues. Fast pyrolysis result in two products, biochar and bio-oil, while HTC is mainly used to obtain hydrochar. However, HTC has the advantage of using raw material with a moisture content greater than 50% [2], thus there is no need for a drying pre-treatment step before the thermochemical process, which opens up the possibility of using aquaculture residues. The fish processing industry generates enormous amounts of waste, approximately 45% of the live weight of fish, which could be used for HTC processing. Several studies have shown that the hydrochar quality of fish waste is largely comparable to conventional hydrochar [3, 4]. Both biofuels, bio-oil and hydrochar have great potential to mitigate GHG emissions and, at the same time, have other economic and environmental benefits. Bio-oil can be used as fuel in existing industrial burners for heating applications and for chemical extraction with high economic value. The advantage of using bio-oil is that it produces significantly lower emissions than fossil fuels. Hydrochar can be used in different applications, such as feedstock in gasification processes [5], as soil amendment [2], as adsorbent, as raw material for carbon production [6], hydrogen storage or electrochemical energy storage [7]. The use or storing of biochar in soils is a way of mitigating climate change through carbon sequestration, while providing energy and increasing crop yields.

This presentation will show that the use of waste generated by the aquaculture industry by either pyrolysis or HTC processes represents a sustainable option for biofuel production. It also provides the possibility of developing new lines of products and extra income from the sale of waste to companies that are dedicated to the production of biofuels.


[1] F. Cherubini. 2010. Energy Conversion and Management, 51(7): 1412-1421.

[2] J.A. Libra et al., 2011. Biofuels-Uk, 2(1): 71-106.

[3] S. Kannan et al. 2018. Biomass Conversion and Biorefinery, 8(3):563-576. 

[4] A. Funke & F. Ziegler. 2010. Biofuels, Bioproducts and Biorefining, 4(2): 160-177.

[5] D. Castello, et al. 2017. Energies 10(11), Art. no. 1734.

[6] L.L. Wang et al. 2014. Colloids and Surfaces A, 447: 183-187.

[7] E. Unur, et al. 2013. Microporous and Mesoporous Materials, 174: 25-33.