Production of Green Hydrogen via Pyrolysis of Biomass and MSW
Presentation of TXP Energy
My name is Liberty Gura, co-founder and principal engineer of TXP Energy, a US-based company focused on green hydrogen technology. Our work centers on pyrolyzing waste streams — municipal solid waste (MSW), biomass, waste tires and plastics — into various valuable products. Our core mission is to contribute to a greener future for coming generations by producing clean energy from waste.
What is Pyrolysis?
Pyrolysis is a thermochemical process in which waste material is placed in a reactor in an oxygen-free chemical environment and heated to high temperatures — approximately 950°C. This produces a synthetic gas (syngas) rich in hydrogen, which is then converted to pure hydrogen via a PSA (Pressure Swing Adsorption) unit.
A key advantage of our system is that it is self-powered: a portion of the syngas is used to run the system, enabling off-grid operation.
The basic process flow is as follows: waste enters the reactor, is pyrolyzed into biochar and syngas, and the char drops out. If liquid oil is the target product (as with tires), the gas is condensed. If syngas or hydrogen production is the goal, the gas bypasses condensation, passes through a gas cooling system, and is collected as syngas or hydrogen.
The reactor can be heated using natural gas or electricity, depending on the configuration.
Products of Pyrolysis
Biochar
Biochar is the most common solid output. When produced from pure biomass, it can be used as an agricultural soil amendment, a livestock feed additive or a carbon credit source. Research is ongoing into converting biochar to graphene, though this requires significant refinement given that graphene requires near-pure carbon. Future applications in fertilizers are also being explored.
Biochar from MSW contains contaminants and is harder to valorize commercially — it is typically used as a fuel within the plant.
Syngas
The typical syngas composition from biomass pyrolysis includes CO₂, carbon monoxide (CO), hydrogen (H₂), light hydrocarbons such as ethane and methane, and a small amount of nitrogen.
Liquid products
Tires and plastics can be pyrolyzed to produce pyrolysis oil, which is then refined into diesel and naphtha. Companies such as Maersk and Alfa Laval are actively exploring green methanol produced via this route to power their ships.
Process Streams by Waste Type
— MSW: shredded and steamed in an autoclave to remove pathogens, then dried and pyrolyzed
— Plastics: crushed and fed into the reactor, producing pyrolysis oil as the primary product
— Biomass: chipped into small particles, fed into a silo reactor, producing syngas and biochar
— Waste tires: fed whole into a dedicated reactor — no pre-shredding required. As the tire travels through, it is progressively pyrolyzed, yielding carbon black, steel rings and syngas
Pyrolysis vs Electrolysis: A Comparison
A common concern about pyrolysis is energy efficiency — specifically, that more energy is put in than is extracted as hydrogen. This is a valid challenge for grid-powered electrolysis as well, where the cost of electricity is the dominant variable.
Our approach addresses this differently: we use waste as feedstock, operate off-grid, and the energy input is significantly lower than the energy content of the hydrogen produced.
For a production target of 500 kg of hydrogen:
— TXP pyrolysis system: ~974 kWh of energy input required
— Solar-powered electrolysis: ~26,000 kWh required
In addition, our system has a physical footprint approximately one-tenth that of an equivalent solar panel installation. From energy efficiency, productivity and capacity perspectives, pyrolysis offers a compelling case compared to water electrolysis — particularly in regions where fresh water is scarce or expensive.
Scale and Technology Readiness
Our reactors are modular and scalable, with capacity up to 30,000 kg of hydrogen per day depending on configuration and investment level.
The technology is at TRL 9 — fully commercialized. TXP Energy has installed operational systems in the United States (California, Colorado), South Africa (Johannesburg), the United Kingdom (Ireland and Wales). Fabrication is handled by a partner in South Africa; TXP manages installation.
Hydrogen Quality
Using our PSA purification system, the hydrogen produced achieves a purity of 5.0 grade — 99.999% — which is high-quality hydrogen suitable for fuel cell and industrial applications. Final purity depends on the quality of the syngas feedstock and the waste type used.
Regulatory Classification (EU)
Under EU regulations, hydrogen produced from MSW qualifies as green hydrogen, as MSW is classified as a non-biological waste source. Hydrogen produced from biomass does not currently qualify under EU taxonomy. Waste tires also fail to qualify due to the CO₂ emissions associated with their pyrolysis. At present, MSW is the only waste stream accepted under EU green hydrogen certification.
Carbon Footprint Calculation
The carbon footprint boundary starts at the point of waste collection — for biomass, from the moment the wood is harvested — and ends when hydrogen leaves the plant gate. All emissions from waste processing, transport to the plant and the production process itself are accounted for within this boundary. Post-plant emissions fall under the offtake agreement.
The CO₂ yield ratio (carbon in vs. carbon captured or emitted) varies between 2:1 and 3:1 depending on the waste type and operating temperature. A single fixed value cannot be given due to the variability of feedstock.
Key Operational Considerations
Feedstock consistency
Feedstock consistency is critical. Variations in the composition of biomass or MSW directly affect syngas quality and hydrogen yield. Best practice is to use a single type of biomass where possible and to maintain as homogeneous a feed as possible. MSW composition varies significantly by region — plastic-heavy streams yield differently from organic-heavy streams — with hydrogen yield typically ranging from 15% to 40%.
Sulfur in tires
Tire pyrolysis produces sulfur-containing pyrolysis oil. Our process includes a first distillation column to remove sulfur, followed by hydrogenation to remove residual sulfur as H₂S, before the oil is used or sold.
Water management
Unlike electrolysis, pyrolysis does not require fresh water as a feedstock. This is a significant advantage in water-scarce regions such as parts of Africa, where electrolysis projects must rely on wastewater treatment or desalination, significantly increasing both CAPEX and OPEX.
Hydrogen yield enhancement
To increase hydrogen yield beyond what direct pyrolysis produces, the syngas is passed through a water-gas shift reactor, which converts approximately 95% of the CO content into additional hydrogen. This step significantly improves overall hydrogen recovery.
OPEX and maintenance
Once operational, the system runs at approximately 95% capacity. The absence of moving parts keeps maintenance costs low. Once started, the system runs continuously with minimal intervention.
Current Pricing
Current hydrogen selling price from TXP systems: approximately $4.50/kg, with a CAPEX in the range of $9.00/kg equivalent.
Q&A Highlights
On coupling pyrolysis with electrolysis and methanol synthesis — This is a concept TXP has already explored with a UK refinery. The idea of coupling a pyrolysis reactor with an electrolyzer and a methanol synthesis unit is technically sound and creates interesting synergies — particularly the coupling of exothermic methanol synthesis with endothermic pyrolysis for heat integration. In the specific case explored, the CAPEX proved prohibitive, but the concept remains viable and worth pursuing.
On natural gas and coal as inputs — TXP has experience converting natural gas via an autothermal reformer (ATR) into syngas, from which a wide range of chemicals can be produced. This mirrors the approach used by Sasol in South Africa, which uses coal in an ATR to produce syngas for methanol, fuels and other chemicals.
On plastic pyrolysis and char yield — Pyrolyzing plastics at 500°C favors liquid oil production. At 950°C, more solid char is produced but at low yield. For high-quality, high-yield biochar production, biomass remains the preferred feedstock.
On funding challenges — Pyrolysis faces funding headwinds because many investors and project funders are more familiar and comfortable with electrolysis technology. This is gradually changing, particularly in the US and parts of the EU, but remains a challenge in some markets, including South Africa.
On waste stream sustainability in a circular economy — Even with aggressive recycling programs, complete elimination of MSW is practically impossible. Mixed waste streams in particular are extremely difficult to recycle to high purity. For the foreseeable future, sufficient MSW volumes will remain available as feedstock, making pyrolysis a durable pathway for green hydrogen production.
