What is a Small Anaerobic Digester? 

A small anaerobic digester is a compact and scaled-down version of a conventional large-scale anaerobic digestion system. It is designed to efficiently process organic waste on a smaller scale, making it suitable for residential communities, educational institutions, and commercial organizations. The anaerobic digestion process occurs in a sealed container, where microorganisms break down organic matter in the absence of oxygen, producing biogas and nutrient-rich digestate. The biogas can be utilized as a renewable energy source for heating, electricity generation, and cooking, while the digestate serves as a valuable biofertilizer to enhance soil fertility and promote sustainable agriculture practices.

How does a small digester work?

Chomp's digesters transform organic waste into renewable energy and biofertilizer by blending the feedstock into a smoothie-like mixture. An automatic system consistently feeds the digester based on its size and the type of feedstock. Microorganisms within the digester break down the organic matter, producing biogas (renewable energy) and digestate (biofertilizer) as byproducts.
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Learn more about biodigester systems

Top reasons to invest in a small anaerobic digester

Investing in a small anaerobic digester offers numerous environmental and financial benefits, including:

1. Sustainable Waste Management: Diverting organic waste from landfills reduces environmental impact and methane emissions.
2. Renewable Energy Production: Biogas generated can be utilized for heating, electricity, and cooking, reducing reliance on fossil fuels.
3. Cost Savings: Converting waste into valuable resources can lead to savings in waste disposal and energy expenses.
4. Nutrient Recycling: The biofertilizer produced improves soil health and enhances agricultural practices.
5. Community Engagement: Implementing biodigester systems fosters a sense of responsibility and ownership for sustainable waste management.

Case studies showcasing small anaerobic digesters

One noteworthy case study comes from Vashon Island, near Seattle, where Island Spring Organics faced unique waste management challenges. To overcome logistical complexities and expenses associated with food waste disposal, they partnered with Chomp to implement an on-site anaerobic digester connected to their facility. The digester efficiently transforms food waste from tofu production into biogas and biofertilizer, promoting a local circular economy and reducing landfill waste. Watch the Vashon Island digester tour.

Another significant case study involves National Grid, a utility company in the US. They have collaborated with Chomp to fund an anaerobic digester pilot program to enhance the energy grid's efficiency. This innovative project, based at Essex North Shore Agricultural & Technical School in Danvers, MA, uses food waste to produce renewable energy and biofertilizer for on-site use in greenhouses and agriculture. Notably, this project also serves as an educational opportunity, teaching students about carbon, energy, recycling, and climate change. Learn more about the benefits of anaerobic digestion for utility companies.

Composting VS small anaerobic digesters

While both composting and small anaerobic digesters are effective organic waste management methods, they differ in their outcomes and resource utilization. Composting breaks down organic matter aerobically, resulting in a nutrient-rich soil amendment, while anaerobic digestion produces biogas and biofertilizer. Choosing between the two depends on waste volume, available space, and desired end products.

Top small anaerobic digester manufacturers in the US

In the United States, there are prominent manufacturers of anaerobic digesters such as Chomp, Bioenergy Devco, Brightmark, and PlanET Biogas. While the industry is dominated by large-scale digesters, smaller on-site manufacturers like Chomp offer unique advantages that set them apart. One of the key distinctions lies in the cost factor. The substantial size and the associated high construction and installation expenses make large-scale digesters impractical for widespread use in urban areas.

Furthermore, large-scale projects entail greater upfront costs and longer installation times compared to their smaller counterparts. Adding to the complexity is the centralized nature of large-scale anaerobic digestion, which requires the transportation of organic waste from various sources, resulting in elevated transportation levels. Conversely, Chomp's small-scale solutions conduct all processes on-site, fostering a local circular economy, providing a zero waste solution, utilizing renewable energy locally, and contributing to the creation of local jobs.

6 Keys to operate a successful smaller biodigester

• Location: Secure an appropriate location with access to water, electricity, and sufficient space for effective biodigester deployment.
• Supply Management: The anaerobic digestion system handles regular organic waste volumes while flexibly managing fluctuations.
• Biogas Utilization: Plan various uses for biogas, including heating, electricity generation, cooking, and even as a propane substitute.
• Biofertilizer Strategy: Develop a plan for using the nutrient-rich biofertilizer on-site or within the community for sustainable agriculture.
• Funding: Plan for capital expenses and explore funding options such as tax incentives, carbon credits, and grants.
• Ongoing Operation: Determine responsible personnel or entities for consistent and efficient digester operation

How can you generate a ROI with a small anaerobic digester

Generating a return on investment (ROI) with a small anaerobic digester is achievable through various avenues. The primary source of ROI is derived from cost savings in waste disposal, as the biodigester diverts organic waste from landfills, reducing associated disposal expenses. Additionally, the produced biogas can be utilized as a renewable energy source for on-site heating, electricity generation, or cooking, offsetting conventional energy costs and further contributing to savings. Moreover, surplus biogas or nutrient-rich digestate (biofertilizer) can be sold to neighboring communities or industries, creating potential revenue streams. By effectively managing waste, producing renewable energy, and exploring revenue-generating opportunities, a small anaerobic digester can deliver a positive and sustainable ROI.

Small digester FAQs

• What is the timeline for installing a new system? Our systems are prefabricated and can be built and operational in as little as 3 months.
• Do you provide operational and maintenance support? Yes, we offer comprehensive packages that minimize your role in feeding the digester and performing daily housekeeping tasks, while we take care of larger maintenance needs. We can also support you in digester output optimization, liquid plant food management, and education and outreach support.
• Does the system smell? Chomp systems are specifically designed for urban settings. Not only do we use an advanced air scrubber system to eliminate odor from the digestion process, we also include a full enclosure for food waste and liquids handling. Our systems are designed so there is no nuisance odor associated with food waste, biogas, or digested organic matter.

How to get started with miniaturized anaerobic digestion? 

To get started with miniaturized anaerobic digestion, it’s key to research the technology and assess the waste generation. You also need to ensure feasibility by evaluating available space and resources while choosing the right system that aligns with capacity requirements. Next, you’ll need to secure funding through grants or financing and obtain necessary permits. Lastly, will be the installation and commission of the system, and the training of personnel for operation. Once the biodigester system is up and running you can educate stakeholders about the benefits and encourage community support.
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‍Contact Chomp to learn more.