5 questions about extracting organic material from waste

1. What are the primary solutions to extract organics from waste?

It all starts with the collection method. This includes source-separated organics (SSO), co-collection and mixed solid waste (MSW).

SSO is best suited to commercial and institutional environments, such as schools, restaurants, etc. As a separate collection route, they generate more tonnage and make the stops more sustainable for the hauler and the environment.

Co-collection is best for the residential space. It allows haulers to run fewer trucks, meaning reduced associated costs. There is far less environmental impact on the roads and from emissions, too. It also works well for the homeowner to simply tie up a bag and throw it in the trash, eliminating an extra container. In addition, co-collection works at commercial sites with space restrictions.

Any 2-inch-minus material extracted from the waste stream usually is the organics fraction that is missing from the MSW. Capturing this fraction is a great way to help hit aggressive diversion goals and provide feedstock for anaerobic digestion (AD) facilities.

Furthermore, we have to consider extraction methods. With SSO, a depackaging machine crushes and tears open the packaging , allowing the organic material to be squeezed out. For co-collection, the bags must be sorted out of the MSW stream before being opened to remove the organics separately from the rest of the MSW processing setup.

2. What are some conventional and developing technologies used to extract organics?

The short answer is technology such as optics, robots, various screens and air density separation equipment.

Since manufacturing its extensive sorting equipment line in-house, Machinex is able to truly engineer the solution that best fits the needs for a specific project. For example, a co-collection program would be best suited for optics or robots to sort the organic bags. The sorting technologies from our Mach Hyspec® optical sorter can be configured to recognize specific bag types and use air ejection to separate them. Alternatively, our SamurAI® sorting robot powered by artificial intelligence can recover the bags from a picking belt. Additional mechanical screening can be employed to collect any loose 2-inch-minus organic material.

For depackaging, the unit itself is one component of a fully integrated system that handles each step of the process from delivery through extraction. A depackaging line often needs to remove the organics from the packaging, and then—depending on the end market for the organic materials—liquids are frequently separated and sent to digester operators, while the solids typically are more suited for composters.

3. Can I retrofit an MSW system anytime to start extracting organics?

Retrofits are possible in almost every type of system; they are conducted to enhance the purity of the end material but often require detailed engineering to integrate the new equipment into an existing system.

Experience and expertise are critical to delivering a successful retrofit, whether it be in project management, installation or the start-up phase, so current operations are affected as little as possible.

4. What are the drivers that make an organics processing solution viable?

It truly varies from one location to another and from one business model to another. Factors can include local regulations, cost avoidance from landfill, tipping fees and available end markets for the organic fraction. It is common for our team to sit down with a client and help them model their business case to develop a viable project.

5. Where do you see organics processing going in the next decade?

I think this market is evolving along a trajectory similar to that of recyclables. I also believe SSO will always have a place in the world, though organics might eventually be extracted from one bin. Machinex has completed projects in all three types of collection and will be able to track residential customers’ behavioral tendencies.