Biochemical methane potential of residual biomass for energy generation

ABSTRACT

World's energy consumption has doubled in the last four decades, this demand has been covered by the usage of fossil fuels; which are an important source of greenhouse gases emissions, entailing climate change. An efficient less polluting management alternative is the anaerobic digestion (AD) process which generates biogas derived from organic matter. The methane contained at the biogas is considered a biofuel that can generate electricity and heat through its combustion. Biochemical Methane Potential (BMP) essays are standardized methodologies carried out to estimate the energy potential of an organic residue. After performing a BMP test for 13 residual biomass samples, it can be concluded that fresh livestock rumen and manure were the best substrates to generate higher biogas yields; ranging from 1119–1669 ml/g VS_added, with high methane content (65%<CH₄<77%) doubling the results reported at literature (≈550 ml biogas/g VS_added). Results indicate that energy potential of these residual biomasses can be increased 23–25% by improving management (freshness) and environmental (higher temperature) conditions and, by reducing the nutrimental deficiencies (mineral medium) of microorganisms. Fresh swine manure also produced large volumes of biogas (1150 ml biogas/g VS_added); however, average methane content ranged 50–65% CH₄ v/v. The rest of the residual biomasses produced biogas and methane yields within the normal ranges (≈550 ml biogas/g VS_added); meaning that also can be used as substrate for bioenergy generation. Residues from aquaculture and fish based-industry produced low quantities of biogas (<250 ml biogas/g VS_added; CH4 < 20%); therefore, these cannot be recommended as substrates for bioenergy purposes.

GRAPHICAL ABSTRACT

KEYWORDS:

• Residual biomass
• anaerobic digestion
• Biochemical methane potential (BMP)
• biogas
• green electricity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Consejo Nacional de Ciencia y Tecnología: [grant number SENER-CONACYT 249773].