Towards a Fossil Fuel Free Tissue Production

Introduction

The TFFFTP project replaces liquefied natural gas (LNG) used to dry the paper at a paper production facility with bio-syngas generated in a new on-site gasification plant using wood wastes. The direct connection of the bio-syngas production plant to paper production facilities is a first-of-a-kind integration. The project strongly contributes to the overall site’s decarbonisation, covering the Paper Machines Air Systems heat needs for 69,000 tonnes of annual paper production.

Innovation in Bio-Syngas Use

The use of bio-syngas in the paper industry is innovative in several respects.

1. Unique Setup: The setup whereby both a syngas production plant and a tissue paper production facility (that does not process the syngas) are operational on the same site makes it the first installation of its kind in the world to date.
2. Flexible Syngas Burners: The syngas burners have to be very flexible to ensure constant heat supply to the air system.
3. Dynamic Monitoring: Due to the expected variation in heat value, a unique dynamic monitoring and air-to-gas ratio adjustment is essential for efficient combustion.
4. Novel Heating Method: Using syngas combustion to indirectly heat an air system that is in direct contact with the product for the customer is novel. Although the different parts are well known in the industry, the integration in tissue is an absolute novelty.

Environmental Impact

The gasification plant substitutes 51,400 MWh of the LNG used for hot air needed in the tissue paper production process.

• GHG Emissions Reduction: Using locally produced bio-syngas is expected to avoid 72% more of the GHG emissions associated with the current process.
• Circular Economy Principles: In line with circular economy principles, the feedstock used to produce the bio-syngas is sorted wood waste collected from local industries and municipalities.

Alternatives Explored

A number of alternative fuels and/or energy sources were explored:

1. Hydrogen: The option of replacing LNG with hydrogen was discarded because of its limited availability and high costs, as well as its embrittlement tendency at high temperatures.
2. Electric Heaters: Electric heaters were also discarded due to the temperature thresholds of electric hood systems (300°C max) and related fire risks.
3. Bio-Oil: Lastly, the use of bio-oil was deemed unacceptable because of potential residues (i.e., ash) and impurities, which directly affected the final paper product.

Replication Potential

The technology could be replicated at around 10 of the 40 production facilities of the company, particularly on sites with high local availability of biomass by-products, such as wood chips or forest residues.

• Extension to Other Sources: The bio-based gasification process could also be extended to other sources such as agricultural waste, industrial residues, animal residues, municipal solid bio-based waste, sewage, and even other non-edible low-value biomass sources such as straw, grass, and algae.