Biofuels made from cannabis waste

Transforming residues from industrial hemp crops into biomass and raw materials… That is the objective of a new research project in Argentina, called “Thermochemical conversion processes for the treatment of Cannabis sativa cultivation waste and the manufacture of therapeutic products” and launched by the Grupo de Investigaciones en Aplicaciones Catalíticas, or Research Group in Catalytic Applications (GIAC), related to the INCAPE, or Research Institute in Catalysis and Petrochemistry, an organization under the Consejo Nacional de Investigaciones Científicas y Técnicas, or National Scientific and Technical Research Council, (CONICET) and the Litoral National University in the city of Santa Fe, one of the largest public universities in Argentina.

This new government-funded research project research aims, on the one hand, at promoting the production of green energy and, on the other, at providing a solution for the proper management of waste resulting from the cultivation of medicinal cannabis, since national laws requires government to control the entire production process of this plant when there is a presence of THC, as a controlled substance. The research project is led by Melisa Bertero, an associate researcher at the CONICET, a government organization that created the Medical Cannabis Network for Cannabis (or RACME) in 2019, a workspace for researchers and professionals who work jointly on cannabis research at Research Council.

In an interview published on the Argentine newspaper El Litoral, Bertero explains that one of the lines of investigation conducted within the framework of this project is the treatment of cannabis waste using thermochemical processes such as pyrolysis —a thermal decomposition in the absence of oxygen at elevated temperatures between 500 ºC and 600 ºCthat converts waste into fuel and raw materials— or gasification —a treatment with oxygen that transforms waste into fuel gas—. These processes of conversion of unwanted plants to biofuels are already being used with other crops residues but had not been contemplated in the hemp industry until now.

As the associate researcher explained to El Litoral, at the beginning the Argentine National Institute of Agricultural Technology (or INTA) was allowed to grow their own hemps crops in order to get the necessary raw material for investigation. As a second option, the Association for Medical Cannabis Users of Santa Fe could provide researchers with the their medical cannabis waste. This association, born in 2016, promoted an city ordinance in June 2020 to allow public communal growing of cannabis, and that was finally approved two months later.

Bertero explained that transformed cannabis residues can be used for multiple purposes such as the production of asphalt mixtures or antioxidants, in addition to biofuels.

“The use of these transformation processes to value cannabis waste is a topic of global interest that has not yet been developed in our country”, the researcher declared to El Litoral.

Argentina approved Law 27350 allowing the use of medical cannabis in 2017, but it was not until 2020 when the draft of a new regulation to lower the government controls on the consumption and cultivation of this plant, was finally approved in November. By February 2020, the only cannabis cultivation license for medicinal purposes in Argentina was held by the public company Cannava and occupied 35 hectares in the province of Jujuy for 2,000 cannabis plants. After the approval of this new regulation, it is expected that the crops of this plant will increase in the short term. As researcher Melisa Bertero finally stated.

“We do hope to contribute to the development of national protocols for the proper treatment and disposal of cannabis-derived waste, considering the prospects of massive production of this crop in the next few years in our country”.