Catalysts for hydrogen rich syngas production from pyrolysis of non-recyclable plastic waste materials

PYH2

Proposing Institution: University of Modena and Reggio Emilia

Name of the project’s Scientific Coordinator: Luca Montorsi

E-mail address of the project’s Scientific Coordinator: luca.montorsi@unimore.it

Other ECOSISTER partners involved in the project: Laboratorio Energia Ambiente Piacenza S.C.a R.L. - LEAP Politecnico di Milano - POLIMI Consiglio Nazionale delle Ricerche-CNR

Coordinating Spoke: Spoke 5

Other Spokes involved in the project: Spoke 2, Spoke 3

Name of partners based in the South: CNR – ISMN (Palermo), CNR IC (Bari)

Project duration (in months): 13

Starting TRL: 4

End TRL: 6

ATECO/industrial sector of potential reference: Electricity, gas, steam and air conditioning supply

Smart Specialization Strategy: Energy and sustainable growth

EU Taxonomy: Transition to a circular economy

Abstract

The project aims at developing a nano-structured environmentally friendly catalyst for the production of hydrogen-rich syngas from the pyrolysis of non-recyclable plastic waste materials.

The catalyst will be integrated into a lab-scale prototype for the analysis of the pyrolysis process, designed in D5.2.13, W2 of SPOKE 5 of the ECOSISTER Project.

Key activities include:

Modification of the pyrolyzer prototype to test an ad-hoc developed catalyst for H₂-rich gas production.
Sensor integration: development and specification of sensors required to control and monitor the pyrolysis process, with connection to a data acquisition system at industrial level.
Experimental campaign with the retrofitted prototype (green catalytic reactor) to define optimal operating conditions and system configuration for maximizing hydrogen yield.

Expected outcomes:

Definition of the best catalyst option for specific plastic waste feedstocks.
Conceptual design of an industrial-scale system for H₂-rich syngas production via pyrolysis, integrated with nano-structured green catalysts.
Identification of best operating parameters for maximizing syngas quality and hydrogen content.

Industrial case-study:

Utilization of syngas in off-road internal combustion engines.
Development of a realistic simulation model to estimate syngas consumption and pollutant emissions based on combustion properties.

Environmental sustainability assessment:

Well-to-Wheel analysis to evaluate primary energy consumption and fossil CO₂ emissions of the proposed technology.

Impact:

The research activity on off-road syngas engines will generate guidelines for standardization of key components required for this alternative fuel, supporting the transition towards greener energy solutions and the circular economy in plastic waste management.

Expected Results

Development and Catalytic Assessment of La-Based Perovskites for Hydrogen-Rich Syngas Production from Plastic Waste
(DESIGN OF PRODUCTS, SERVICES, DEVICES, MATERIALS)
The activity carried out at CNR-ISMN aims at developing a nano-structured environmentally friendly catalyst for hydrogen-rich syngas production from the pyrolysis of non-recyclable plastic waste materials. Three powders with perovskite structure ABB’O₃ were synthesized by solution combustion synthesis (SCS): LaNi₀.₂₅Mn₀.₇₅O₃, LaNi₀.₇₅Mn₀.₂₅O₃ and LaNi₀.₇₅Co₀.₂₅O₃. Preliminary XRD characterization, TPR reduction property studies, and DRM catalytic tests were carried out.
The composition LaNi₀.₂₅Mn₀.₇₅O₃ emerged as the best catalyst in terms of activity and stability against coke poisoning during a 25 h lifetime test at 700 °C. This material, with relatively low Ni content, represents an environmentally friendly candidate to be tested in a lab-scale pyrolysis prototype for H₂-rich syngas production.

Ab-Initio Structural Analysis and Rietveld Refinement of La-Based Perovskites: Correlating Crystal Structure with Catalytic Performance
(DESIGN OF PRODUCTS, SERVICES, DEVICES, MATERIALS)
In-depth structural characterization of the three perovskites (LaNi₀.₂₅Mn₀.₇₅O₃, LaNi₀.₇₅Mn₀.₂₅O₃, LaNi₀.₇₅Co₀.₂₅O₃) was performed by X-Ray Powder Diffraction (XRPD) using the EXPO software package. Ab-initio structure solution and Rietveld refinement were conducted to determine:

unit cell parameters
peak shape/background
atomic coordinates and isotropic displacement factors
site occupancy factors (SOF) for shared cation sites

The objective was to correlate structural parameters with catalytic performance, supporting material optimization.

Development and Test of a Catalytic Reactor for Hydrogen Production from Pyrolysis Products
(PROTOTYPING OF PRODUCTS, SERVICES, DEVICES, MATERIALS)
At CNR-ISSMC, a catalytic reactor was developed to couple with the pyrolyzer for H₂-rich syngas production. The catalyst, LaMn₀.₇₅Ni₀.₂₅O₃, synthesized at CNR-ISMN and further characterized at CNR-IC (Bari), was deposited on alumina carriers to obtain a structured catalyst.
The reactor:

is made of AISI 316 (1” tube)
has an internal volume of 50–100 mL
is filled with the structured catalyst and placed inside a radiating furnace for operation up to 800 °C

Expected results: determination of gas composition at reactor exit under both simulated (lab-scale) and real (prototype) pyrolysis conditions.

Integration of the Catalytic Reactor in the Pyrolyzer Prototype to Demonstrate Hydrogen Yield from Different Non-Recyclable Plastics
(PROTOTYPING OF PRODUCTS, SERVICES, DEVICES, MATERIALS)
The pyrolysis prototype was modified to integrate the catalytic system. The experimental campaign evaluates how waste composition, temperature, and residence time affect hydrogen yield.

Instrumentation: pressure and temperature sensors, with in-line gas composition monitoring for real-time analysis.
Goals: optimize catalyst performance and ensure accurate control of the pyrolysis process.
Results will guide the scale-up to industrial applications.

Numerical Simulation of the Conversion of a CNG Engine to H₂-Rich Syngas Operation: Performance, Emissions, and Design Insights
(DESIGN OF PRODUCTS, SERVICES, DEVICES, MATERIALS)
A Heavy Duty CNG internal combustion engine was virtually converted to operate with syngas (45% H₂, 55% CO). Simulations accounted for laminar flame speed and burned gas composition.

Results:

Feasible syngas operation without major setup changes
~16% reduction in maximum torque and efficiency
Increase in NOx emissions due to higher combustion temperatures
Higher CO and CO₂ emissions due to syngas composition

Design insights: performance can be improved with an increased compression ratio, although this may require a dedicated combustion chamber design.

Final Results

Rietveld Refinement and Literature Correlation of LaNi–Mn Perovskites: Structural Insights for Catalytic Design
(DESIGN OF PRODUCTS, SERVICES, DEVICES, MATERIALS)
The activity focused on developing La-based perovskite catalysts for hydrogen-rich syngas production from non-recyclable plastic waste.

Synthesis: three compositions (LaNi₀.₂₅Mn₀.₇₅O₃, LaNi₀.₇₅Mn₀.₂₅O₃, LaNi₀.₇₅Co₀.₂₅O₃) obtained via solution combustion synthesis with metal nitrates, citric acid as fuel, and ammonium nitrate as oxidizer control. Powders calcined at 900 °C for 5 h.
Characterization: XRD and Rietveld refinement confirmed rhombohedral perovskite structures (R-3c space group).
- Crystal size: LaNi₀.₇₅Mn₀.₂₅O₃ ~90 nm; LaNi₀.₂₅Mn₀.₇₅O₃ ~250 nm; LaNi₀.₇₅Co₀.₂₅O₃ ~500 nm.
- BET surface area inversely proportional to crystal size: LaNi₀.₇₅Mn₀.₂₅O₃ highest (11 m²/g); LaNi₀.₇₅Co₀.₂₅O₃ lowest (5.5 m²/g).
TPR: two reduction steps—below 500 °C (partial Ni/Mn reduction) and above 500 °C (complete reduction). In LaNi₀.₇₅Co₀.₂₅O₃, Co reduced alongside Ni at lower temperatures.
Catalytic DRM tests (700 °C, 25 h):
- LaNi₀.₂₅Mn₀.₇₅O₃ showed the best stability and coke resistance.
- LaNi₀.₇₅Mn₀.₂₅O₃ slightly lower activity but stable.
- LaNi₀.₇₅Co₀.₂₅O₃ deactivated after 3 h due to coke, confirmed by TGA.
Outcome: LaNi₀.₂₅Mn₀.₇₅O₃ selected as most promising eco-friendly catalyst. A 20 g batch was synthesized for scale-up: part tested for reproducibility, remainder sent for further catalytic evaluation.

Ab-Initio Structure Determination and Rietveld Refinement of LaNi–Mn Perovskites: Structural Insights for Catalyst Design
(DESIGN OF PRODUCTS, SERVICES, DEVICES, MATERIALS)

Ab-initio structure solution performed with EXPO for LaNi₀.₂₅Mn₀.₇₅O₃ and LaNi₀.₇₅Mn₀.₂₅O₃.
Structures consistent with literature; rhombohedral symmetry confirmed.
Due to similar X-ray scattering of Ni and Mn, site occupancies not refined—literature comparisons used for expected ratios.
Rietveld refinements showed good agreement.
Analysis of LaNi₀.₇₅Co₀.₂₅O₃ ongoing to complete dataset.
These results strengthen the correlation between crystal structure and catalytic performance.

Development and Test of LaNi₀.₂₅Mn₀.₇₅O₃-Based Structured Catalyst in a Tubular Reactor
(PROTOTYPING OF PRODUCTS, SERVICES, DEVICES, MATERIALS)

A structured catalyst was developed using LaNi₀.₂₅Mn₀.₇₅O₃ powder, deposited onto alumina carriers.
The catalyst was tested in a tubular reactor (AISI 316 steel, volume 50–100 mL), placed in a radiating furnace capable of operation up to 800 °C.
Expected results: determination of gas composition at reactor outlet under simulated lab conditions and real prototype conditions.

Next Steps

Further developments and future collaborations

Further collaboration with CNR colleagues of ISSMC and IC aiming to investigate the catalytic performances in the DRM and the structural modifications occurring on the LaNi₀.₂₅Mn₀.₇₅O₃ catalyst deposited over gamma-alumina pellets.

Perovskite samples post-DRM treatment and after reduction at 800 °C (for La–Ni–Mn) or 700 °C (for La–Ni–Co). Qualitative and subsequently quantitative phase analyses will be carried out to identify and quantify the phase transformations induced by these treatments. These investigations will refer to the XRD patterns of the treated samples and are expected to provide deeper insight into the evolution of perovskite phases under realistic operating conditions, contributing to the optimization of catalyst stability and long-term performance.

Further collaboration with CNR colleagues of ISMN and IC for the optimization of the structured catalyst and operation of the catalytic reactor. Subsequently, the integration of the catalytic reactor with the UNIMORE pyrolizer will be done.

The catalyst reactor will be tested using the modified pyrolysis prototype. The experimental analysis will study the effects of the main pyrolysis process parameters on the performance of the catalyst. Additionally, various compositions of non-recyclable plastic waste will be investigated to determine the hydrogen yield.