Factsheet summary now available for Task Force 5’s analysis of the state of the art of biomethane pretreatment technologies

Brussels, 4^th of June. Today the Biomethane Industrial Partnership releases an accompanying factsheet to the Task Force 5’s analysis of the state of the art of biomethane pretreatment technologies. This analysis is part of their report “Innovative technologies for biomethane production – review of the current state of the art”.

The factsheet summarises the state of the art of biomethane preatreatment technologies. These are technologies that can be applied in the upstream processing steps of biogas & biomethane production to optimise biogas quality, enhancing the methane yield from organic materials.

The pretreatment technologies analysed by Task Force 5 are enzymatic and acid hydrolysis and lignocellulose steam explosion. The factsheet includes the description of each technology, pros, TRL, and the recommendations indicated by Task Force 5. It also includes plant examples for each technology, where available.

Enzymatic hydrolysis: It is used as a pre-treatment step in biomethane production, in order to increase the methane output of anaerobic digestion. Advantages include not requiring inorganic chemicals and operating at mild conditions compared to acid hydrolysis. The technology readiness level (TRL) ranges from 6 to 9. Recommendations for improvement include:

• Reducing high CAPEX and OPEX;
• Researching new enzymes with lower cost and higher resistance;
• Optimising the process through pre-treatments like milling, grinding, or steam explosion.

Acid hydrolysis: Similar to enzymatic hydrolysis, acid hydrolysis aims to boost methane yield. One benefit over the enzymatic method is its faster processing time. The TRL for acid hydrolysis also ranges from 6 to 9. Task Force 5 recommends:

• Utilising equipment with high corrosion resistance to handle acidic environments.
• Developing methods for chemical recovery and reuse to minimise environmental impact.
• Using microorganisms less sensitive to inhibitory compounds produced during the process.

Lignocellulose steam explosion: This technology breaks down lignocellulosic biomass, unlocking new feedstock types for anaerobic digestion. Key advantages include low capital and operational costs, especially if digestate is used as an energy source for steam generation; reduced energy use if digestate or another on-site energy source powers the steam generation; and little to no environmental impact particularly if digestate is used as soil enhancer, acting as a carbon sink. The TRL for lignocellulose steam explosion in biogas applications is 6. Recommendations include:

• Evaluating the effectiveness of steam explosion across various feedstocks.
• Continuously improving the technology’s effectiveness and mobilization of feedstock.