Grass Biorefinery

Most dairy farms grow more grass than they use efficiently.
Grass biorefineries turn excess grass into high-value protein, and lower supply chain emissions.

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The Climate Issue

Grass is a useful and renewable resource. But most of it goes straight from the field to the cow. A lot of its protein is lost during digestion or turned into methane, a strong greenhouse gas.

At the same time, Europe imports millions of tonnes of soy and other protein feeds every year. This causes deforestation, adds to global emissions, and makes feed prices less stable for farmers.

We have plenty of grass. But we’re not using its full value as a local, climate-friendly protein source. Using it better could cut imports and lower emissions.

The Solution: Grass Biorefinery

A grass biorefinery extracts protein from fresh grass before it’s fed to livestock. The process presses and separates the grass into fibre, juice, and a concentrated protein product, ideal for feeding pigs, poultry, or as a milk replacer.

This creates a circular, plant-based protein source from local biomass. The remaining grass fibre can be fed to cattle, used for bedding, or further processed into biogas or biofertiliser. It’s a new way to unlock more value and fewer emissions, from every hectare of grassland.

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Key Benefits of a Grass Biorefinery

Local Protein

Biorefineries replace imported soy with protein extracted from locally sourced grass, supporting food sovereignty and reducing reliance on global supply chains.

Lower Emissions

Using grass protein can cut feed-related emissions by 40–70 %, especially in systems where soy footprints are high.

Revenue Stream

Grass processing creates multiple co-products, protein, fibre, juice, opening up markets for food, feed, and fertiliser inputs.

Impact of a Grass Biorefinery

Grass biorefineries convert local grass into Grass Protein Concentrate (GPC), a sustainable alternative to imported soy. They reduce emissions, enhance nutrient circularity, and support regional feed autonomy.

Research from Farm Zero C and Teagasc highlights key benefits:

250–350 kg of digestible protein per hectare of intensively managed grass
Up to 1.5 tonnes of soy protein replaced per farm/year
€300–€600 per tonne in potential feed cost savings
4–7% reduction in whole-farm GHG emissions

While benefits are significant, setup and processing infrastructure costs must be considered separately, as the table below illustrates only the potential impacts of protein replacement based on Irish dairy system modelling.

Scenario	Grass Protein Use	Feed Cost Savings	GHG Emissions	% GHG Reduction
0% Protein Replacement	-	-	0.960 kg CO₂-eq/kg milk	0%
50% Protein Replacement	Partial grass protein	€1,500	0.919 kg CO₂-eq/kg milk	4.3%
100% Protein Replacement	Full grass protein for target animals	€3,000	0.875 kg CO₂-eq/kg milk	8.9%

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Considerations

Processing Infrasctruture

Biorefineries require capital investment and grass processing equipment. Clustered regional models may be more viable than on-farm units for most.

Protein Quality & Use

The protein is ideal for monogastric animals and young stock. It’s not a full substitute for all feed types but can replace a significant portion of imported protein.

Harvest Timing

Grass must be harvested young and fresh to maximise protein content and extraction yield. This affects rotation and harvesting logistics.

Implementation

Grass biorefineries are still emerging, but they offer strong potential for farms and feed producers. Below are practical steps to help you start exploring the opportunity. These actions support early adoption and informed decision-making.

1. Start with feasibility. Assess local grass supply, distance to potential processing sites, and possible users of grass protein and co-products like fibre or juice.

2. Link with processors. Join or help form regional biorefinery pilot groups. Shared infrastructure can reduce upfront costs and open doors to co-investment options.

3. Run small trials. Test early-cut grass in collaboration with researchers or tech providers to measure protein yield, digestibility, and logistics in real conditions.

Behind the Research

ODOS Tech was founded by Cian White and Alejandro Vergara, two sustainability specialists with deep expertise in agricultural climate action.

Alejandro (left), a PhD in environmental engineering from University College Dublin, helps farmers measure their carbon footprint and implement mitigation strategies to reduce their impact. Cian (right), a researcher at Trinity College Dublin with a PhD in ecology, works on restoring nature to increase biodiversity on farms using satellite imagery to monitor habitats.

Together, they helped lead the carbon and nature-based work for the Farm Zero C project at Shinagh Farm, one of Europe’s first net-zero dairy pilots. In 2020, they launched ODOS, a platform that built smart, science-based tools to help agri-food businesses protect the environment and restore nature.

Research

Grass Pilot Projects

In the Netherlands, Grassa has piloted biorefineries that yield high-quality protein from grass with up to 40 % soy replacement potential in pig diets.

Farm Zero C Evaluation

At Shinagh Farm, grass biorefinery potential was explored to add value to excess grass growth and produce local feed protein. Integration with biogas and fertiliser strategies was also assessed.

EU Protein Strategy

Grass-based protein supports EU goals for strategic autonomy and sustainable agriculture. It aligns with Green Deal ambitions for low-carbon, circular bioeconomy systems.