Local manUre and agri-food waste treatment for bioGAs and biofertiliZers production from Zero waste and circular economy perspective

Introduction

LuGaZ aims to create a sustainable zero-waste facility that manages organic and non-hazardous wastes generated primarily in the dairy sector value chain, and to create the opportunity for other agri-food industries in the area to manage their residues. The project proposes an ambitious facility that combines a biogas plant with an innovative low-scale upgrading system, a liquid treatment of digestate for water recovery at low cost, and a solid treatment for fertiliser production across industrial symbiosis.

Waste Collection and Biogas Generation

Nearly 55,000 tonnes/year of residues will be collected in the facility to generate biogas containing methane which will be captured, cleaned, upgraded, and injected into the natural gas grid. The digestate will be separated into:

1. A solid fraction to generate a stabilised organic fertiliser for the primary sector to compensate for the manure sent to the LuGaZ plant.
2. A liquid fraction which will be treated to recover reusable water in industrial applications.

The relative greenhouse gas (GHG) emissions avoidance due to LuGaZ operations during the first 10 years amounts to around 85%.

Innovative Waste Treatment Technologies

LuGaZ goes beyond the commercial and technological state-of-the-art, bringing to the table a first-of-a-kind combination of waste treatment technologies for the agri-food production value chain:

• OPTIBLENDER: A specialised software for the online control of anaerobic digestion that ensures the stability and quality of the digestate produced through co-digestion mixtures optimisation.

• NIDUP: An upgrading system specifically designed for small-scale applications and is highly competitive due to its low operational costs, capability of coping with high hydrogen sulphide (H2S) concentrations, and potential to minimise reagents/consumables needs.

• DEPURGAN/AQUATEC: A low-cost solution for liquid treatment based on an electrocoagulation all-in-one solution.

Contribution to Climate Neutrality

LuGaZ contributes to achieving European climate neutrality by 2050 by producing high-quality biomethane to be directly injected into the natural gas grid. LuGaZ combines waste management with renewable energy production, which, with biogas and the reduction of methane emissions from open manure storage and landfills, helps make treatment affordable and energy efficient.

It is also possible to obtain an added value product (fertiliser) and preserve natural resources through water recovery.

Scalability and Regional Impact

LuGaZ has the potential to scale up by:

1. Increasing the size of individual integrating technologies (higher volumes of agri-food waste streams to be treated).
2. Replicating the Zero residue plant in new areas at Galician and Spanish level.
3. Applying this throughout Europe.

LuGaZ’s innovative integrated scheme will play an essential role in the dynamisation of the primary sector by creating employment in rural areas, while actively participating in creating an innovative regional model of circular economy based on waste-to-energy principles.

Additionally, it offers a practical waste treatment solution for rural areas, reducing transport costs and carbon footprint.