Small scale anaerobic digestion using agricultural waste: when technology and science team up for the environment!

Small scale anaerobic digestion is a true solution to help the Canadian agricultural and agri-food industry to fight against climate change and manage their waste. Generally, anaerobic digestion is a process aiming to convert organics into biogas containing methane using a digester. How can you make anaerobic digestion projects more profitable for farms? Slurry is the most common feedstock in farms, but it has a low energy production potential. To address this challenge, Bähler Biogas built a digester able to process agricultural waste for the Sherbrooke Research and Development Centre at Agriculture and Agri-Food Canada (AAFC).

Bähler Biogas, a leading biogas company in Canada specialized in designing and building projects, has recently finished their on-farm small-scale bioreactor project. Indeed, a real laboratory for farmers is being created in this research and development centre in Canada. It will help on-farm biodigester project developers to adopt best practices and optimize their anaerobic digestion process.

Small-scale anaerobic digestion for agricultural waste: An efficient solution

Small-scale anaerobic digestion helps farmers and small communities to become more energy self-sufficient by using renewable energy and manage their waste. Small-scale anaerobic digestion can produce from 100 up to 300 kW in agricultural environment, lower output as compared to industrial facilities that can produce more than 1000 kW.

Small-scale anaerobic digestion for agricultural waste offers various benefits:

• Savings because they produce their own renewable energy (heat, fuel or even electricity)
• Switch to greener (environmentally friendly) activities
• Less strong smell coming from treated manure used in the field as fertilizer
• Less transportation needed for agricultural waste

Small-scale anaerobic digestion for agricultural waste has a lot of potential from energy and environmental perspectives for the agricultural and agri-food industries that represent two major business sectors in Canada.

This research infrastructure built by Bähler will help the Sherbrooke Research and Development Centre to continue their scientific work. The agricultural and agri-food sectors will certainly grow and become more durable thanks to this initiative.

Bähler’s laboratory bioreactor, a technological showcase for the industry

The small-scale bioreactor will act as a laboratory for the agricultural industry. The Agriculture and Agri-food Canada’s researchers will test a variety of processes and feedstock mixes. The goal is to find mixes that will maximize methane production for a given quantity of organics.

Agriculture and Agri-food Canada wants to build a strong technological showcase to highlight the best practices for the valorization and small-scale anaerobic digestion of agricultural waste in Canada.

On the technical side, the bioreactor is a small-scale concept that includes:

• A digester with a capacity of 275 m³ with 7 m in diameter and 6.5 m in height
• A double membrane gasometer that is installed above the digester with a capacity of 80 m³
• A flare and a boiler customized to meet the requirement of the project

Bähler has the necessary expertise to play a main part in developing this reference project in the agricultural industry. Bähler supplied state-of-the-art equipment, designed, built, and will commission the digester. The bioreactor is very  important to Bähler as it is located in Sherbrooke, near its own facilities.

Bähler Biogas, a biogas company in Canada and experts in anaerobic digestion facilities

Over the years, Bähler Biogas has developed a unique expertise in designing, building and installing anaerobic digestion facilities. In the last few years, Bähler was trusted to build most of the existing anaerobic digesters in the East of Canada. As of today, Bähler is a known biogas company in Canada and has worked on more than 20 anaerobic digestion projects.

Bähler’s high degree of excellence helped them build this reputation and attract to their team the most qualified industry experts in the country. Bähler has also developed the capacity to negotiate strategic alliances with world-known manufacturers to provide high-quality products.

Bähler Biogas offers to project developers turnkey solutions to satisfy their requirements, budget and delivery time. The new bioreactor is built to meet the needs of the Sherbrooke Research and Development Centre’s scientific team. It will ensure the success of the research for the agricultural and agri-food industries.

A Research Center specialized in anaerobic digestion to improve best practices

The Sherbrooke Research and Development Centre at Agriculture and Agri-food Canada has been working on anaerobic digestion since the late 1990s. Their first research on anaerobic treatment of manure (without oxygen), produced in collaboration with Bio-Terre Systems Inc already allowed them to convert pig manure into energy. They thus obtained three bioproducts with an interesting economic value: biogas, an odorless concentrated liquid fertilizer and solid digestate that could be reused on the farm as a litter.

The Sherbrooke Research and Development Centre chose to build their own biodigester to push their research further. This is where Bähler Biogas came into play: they built a biodigester able to support this scientific work.

A technological platform to meet the needs of the agricultural industry

This technological platform will help the teams collaborate to develop the best practices possible about anaerobic digestion. The Sherbrooke Research and Development Centre aims to maximize economic and environmental potential. They want to extend the use of anaerobic digestion to other livestock effluents such as dairy cattle manure.

The scientific teams will test methods and practices of anaerobic digestion that meet the needs of a medium-sized farm. The research has the following goals:

1) Reduce the environmental impact of farm activities by reducing methane emissions, a powerful greenhouse gas (GHG).

2) Increase the value of residual matters by converting manure into bioenergy (biogas) and bioproducts. For example, they could convert solid residues coming from the biodigester into high-quality biofertilizers or biocharbon (BioChar), which have multiple applications.

3) Find answers to the problems that are encountered by agricultural producers when it comes to managing manure or slurry on their farm.

Meeting these goals will help the agricultural and agri-food industries to benefit from the advantages of small-scale anaerobic digestion of agricultural waste.

Innovative technology within AAFC

Compared to other existing approaches to treat livestock effluents, the anaerobic digestion technology created by AAFC has many forward-thinking, unique and promising benefits for agricultural waste:

• Operation at low temperature (20-25 °C), which makes it possible to reduce energy consumption required for the process
• Reliable and stable process that is ideal for agricultural applications
• Possibility to use a variety of livestock effluents and other organics such as agri-food residual materials
• Purification of biogas by the removal of hydrogen sulfide
• Removal of pathogens in the digestates
• Simple process, easy to integrate into the farm’s activities

In the next years, research will allow AAFC to develop an optimal biodigester that meets the needs of Canadian livestock farms. This biodigester will help medium-sized farms to reduce their ecological footprint. It will also help using purified by-products generated by the anaerobic digestion and produce renewable energy.

Innovation and anaerobic digestion to fight climate change

Today, all industries need to act to reduce their carbon footprint. The agricultural and agri-food industries are no exception. Anaerobic digestion can become an unparalleled ally because it is based on a circular economy approach, especially when it comes to managing agricultural waste.

Bähler’s technical expertise in building a small-scale bioreactor, combined with the scientific expertise of the Sherbrooke Research and Development Centre will allow Agricultural and Agri-Food Canada to develop anaerobic digestion facilities that are more profitable and advantageous for the agricultural and agri-food industries. This is an excellent way to make anaerobic digestion attractive and accessible to this industry.

Visit the website of Bähler Biogas or the Sherbrooke Research and Development Centre at Agriculture and Agri-Food Canada (AAFC) to learn more.

Sources

What is the future of small-scale anaerobic digestion plants? BiogasWorld

Research projects, Agriculture and Agri-Food Canada