This Revolutionary Reactor by DOPS Transforms Waste Back Into Gas and Other Valuable Raw Materials

The startup has a laboratory-scale reactor at Investa in Alkmaar, a center for gasification technologies. DOPS has proven its technology works, processing 6 kilograms of waste per hour. In Q1 of 2025, DOPS plans to build a pilot plant that can process between 50 and 100 kilograms per hour. The next factory will be even larger, capable of handling 1,000 kilograms per hour for its first customer. “We’re making it possible for the circular economy to make economic sense,” say co-founders Roeland Jan Dijkhuis and Michiel Spits.

Addressing the waste problem

Each year, the Netherlands burns approximately 7.6 million tons of waste. Most waste processing plants generate energy from waste, but they emit more CO₂ than other power plants. Moreover, these incinerators fuse all solid waste into slag, leaving behind a waste residue from which metals are painstakingly recovered—a process that requires substantial energy. DOPS Recycling Technologies offers a solution to reduce both the loss of valuable raw materials and emissions. The startup can reuse 70-80% of the waste while keeping energy consumption relatively low.

Breaking it down

DOPS’ reactor gasifies and heats waste or biomass to 900-1,200 degrees Celsius without oxygen. This breaks down everything that isn’t metal or mineral, enabling the recovery of valuable raw materials from waste. “It’s as if you’re breaking down all molecules into their smallest components—carbon into C atoms and CO molecules, and hydrogen into H₂ atoms,” explains Michiel Spits. “To us, waste is still a collection of valuable atoms and molecules.”

All types of waste

The reactor can process various types of waste, including household, industrial, and agricultural waste. From plastic to mayonnaise, ketchup, trees, diapers, clothes, chicken bones, and electronics—only construction and demolition waste containing concrete and rebar are unsuitable. Waste must contain hydrocarbons, a bond between a C- and an H-atom, which are then cracked at high temperatures in the reactor. “We can use these hydrocarbons for other purposes, while the metals and minerals remain usable. We haven’t found the limit yet because we simply haven’t reached it,” says Dijkhuis. “Unlike in an incinerator, our solid materials don’t fuse together—glass remains glass, and metal remains metal—making post-sorting much easier.”

Electronic waste

DOPS technology, called Direct Carbon Immobilization, allows for more valuable materials to be recovered from waste, contributing to the circular economy. The Netherlands aims to be fully circular by 2050, where all waste is reused as raw material. The byproducts of DOPS’ process depend on the waste input. “Take electronic waste, for example—it’s a mix of metals, minerals, and plastics. At the top, syngas (a mix of carbon monoxide and hydrogen gas) is produced, while solid carbon, metals, and minerals settle at the bottom,” Dijkhuis explains.

Closing the loop

A mix of minerals and metals is essentially an ore, similar to what is extracted in mining. Companies that process ore can also handle the raw materials from DOPS’ reactor, albeit on a smaller scale. Syngas is already used in the petrochemical industry to produce ethanol, methanol, or naphtha—the base raw materials for most plastics. The two sectors can turn ore and syngas into consumer products. “You’re separating waste into two components that the mining and petrochemical industries can use to create new products,” says Dijkhuis.

Their technology is ideal when mechanical or chemical plastic recycling is not possible, such as when waste is too contaminated.

Combining two ideas

The startup was founded in 2021, originating from the separate ideas of its four founders. In the summer of the COVID pandemic, Michiel Spits and Wiebe Pronker had an idea for waste gasification, while Roeland Jan Dijkhuis and Harmen Oterdoom had a business case to recover metals from electronics, hindered by plastic content. That summer, they joined forces.

Proven technology

Over the years, DOPS has further developed its technology, with its reactor now at TRL 5 (Technology Readiness Level) and aiming for TRL 6, which represents the final stage for this type of reactor. “TRL 6 shows that the technology and process are proven to work,” they explain. The next step is testing in an industrial environment that simulates customer use.

Gasifying waste wood

In the next step, TRL 7, a small pilot plant will be built outside Investa’s site, with DOPS securing funding. “We want to demonstrate that the reactor is industrially applicable and scalable, which is crucial for large-scale deployment of this type of technology,” says Spits. DOPS aims to build its first industrial factory at a client’s site in 2026. “That will be our demo plant,” Spits adds. “The client will gasify waste wood to replace natural gas with syngas.”

Not a producer

The client uses the technology to recover energy from waste, but it can also be used to recover raw materials. The residual carbon, for example, forms black chunks resembling coal, suitable for various applications, from activated carbon to an alternative for fossil carbon used in steel melting. In addition to chemical companies interested in purchasing the gas, there’s high demand for the remaining metals and minerals.

DOPS plans to license its technology, potentially to plantations with large biomass waste. “We see all the potential applications of the technology but don’t plan to become waste processors ourselves. Our clients will ultimately develop business cases with our technology,” says Dijkhuis.

Scaling up

At Investa’s expertise center in Alkmaar, DOPS has proven the technology works at lab scale. The lab reactor was funded with €90,000, and DOPS participates in several research programs, including ReBBloCS. In this program, a consortium of companies and Wageningen University explores waste reuse as raw material for chemical products. To scale up further, DOPS is seeking additional capital.

Green Chemistry Accelerator

DOPS Recycling Technologies was one of five participants in this year’s Green Chemistry Accelerator (GCA) program by Groene Chemie Nieuwe Economie (GCNE). GCNE aims for circular chemistry by 2050, using innovative technologies without fossil fuels or CO₂ emissions. The GCA program, established with Invest-NL and regional development organizations (ROMs), helps startups scale up to a full-fledged company capable of building pilot plants, entering the market, and ultimately producing thousands of tons of recycled or biobased plastic raw materials.

The program helped DOPS prepare for investors, uncovering blind spots in their business case and identifying initial target markets. “One of those markets consists of companies seeking alternatives to natural gas, for whom hydrogen is still too expensive,” says Spits. DOPS also learned from other startups in the same field. “We discovered that we’re not the only ones with ambitious industrial plans,” say the co-founders.

This article was also published on Change Inc. by editor André Oerlemans. It is part of a series on Groene Chemie, Nieuwe Economie.