Renewcell is based in Sweden, and produces the world’s first 100% waste-textile-derived dissolving pulp (Circulose®) for MMCF production. Its first commercial scale textile recycling plant – Renewcell 1 – was opened in October, 2022. Circulose is recyclable, with no loss of fibre quality.
Points of technical and aesthetic difference
Circulose matches the characteristics of virgin MMCFs. It has no discernible performance, tactile or visual difference to virgin wood-derived MMCF. It is neither better nor worse — it is exactly the same.
Points of impact reduction
The feedstock for Circulose is 100% textile waste of 95% or higher cotton content. This requirement is expected to reduce to 90% cotton in the near term, once full scale is reached in the first recycling facility. The waste textiles are either from post-industrial waste (including offcuts from garment manufacturers) or post-consumer waste (clothing that is no longer in a wearable condition). In both cases, this waste would otherwise be incinerated or landfilled, or to a lesser degree, mechanically recycled and thereby downgraded in quality. Renewcell’s offcut waste feedstock is currently sourced from denim factories in Bangladesh and Turkey. The unwearable garments are sourced from second hand clothing companies and via clothing sorting facilities, either in the south of Sweden or in India.
In terms of the processing of the waste, the inputs are chemical and mechanical, requiring the addition of water and powered by 100% renewable energy. Renewcell has not had a LCA conducted on the dissolving pulp from its newly established commercial recycling plant. Instead they have provided comparative impact data from an SCS recycling study conducted in 2017, that was peer reviewed. The study: ‘Life Cycle Assessment Comparing Ten Sources of Manmade Cellulose Fiber’, was commissioned by Stella McCartney and followed the ISO 14044 standard for LCAs. It was intended to be published publicly to help the evaluation of these MMCF feedstocks: wood from various forest regions, bamboo pulp, cotton linter, flax by-products and recycled clothing.
The scope of the LCA was cradle-to-gate – meaning raw material to the staple fibre (ie. excluding use of the fibres in yarns/textiles/products and the end-of-life phase). The scope, therefore, extends beyond the Renewcell pulp process to include the fibre spinning process (which is conducted by mills external to Renewcell). For full clarity, Renewcell makes only the pulp, which is supplies to mills which spin it into fibres for yarn then textile production.
The Renewcell data in the study was gathered during the development phase and the pulp was not yet in use by MMCF mills, so a hypothetical scenario where the pulp was spun by a mill in Germany was modelled. Now that the commercial Renewcell recycling facility is up and running, the actual supply chain is established, and the majority of Circulose pulp is transported to a mill in China for MMCF production.
Therefore, the study’s LCA impact results are only a modelled scenario based on estimates – not the actual scenario based on current data from Renewcell 1. Furthermore, the energy mix in Germany is weighted towards renewables, whilst in China it is primarily fossil-powered; and sea freight from Europe to China should also be factored in. Therefore, the actual impact of Circulose as it is processed in to fibres today is likely to be different than what is reported in the LCA. Additionally, the pulp data estimates could not encompass the efficiencies achieved now at commercial scale, so whilst some aspects of the hypothetical model likely underestimated the impacts, others probably overestimated them.
The 2017 LCA1 concluded that Circulose’s comparative Global Climate Change impact was -2 kg CO2e/kg (mostly due to using waste as the feedstock and non-disturbance of biogenic carbon storage in wood). By comparison, Indonesian Rainforest pulp spun into fibres in China was calculated at 13kg CO2e/kg.
*The negative emissions score is difficult to reconcile in practice, because of course there are emissions generated during the creation of Circulose®. However, due to the comparison methodology of the study and inclusion of biogenic carbon storage as a factor, Circulose was given a comparatively negative score.
Disruption potential and route to disruption
Since Circulose is a 100% recycled feedstock that feeds into existing fibre production infrastructure it is a seamless circular solution in both current and future MMCF production processes. Circulose-derived materials are only limited to the extent that the cellulose molecule itself is limited.
The likely route to disruption is firstly to demonstrate 1-to-1 substitutability in MMCF applications, then partial replacement for cotton (for example, in denim), and finally where polyester is used in composite natural and synthetic materials.
Route to commercialisation
Circulose capacity is 60,000 metric tonnes per year, with expansion to 120,000 tonnes feasible in the near term. Capacity is expected to reach 360,000 metric tonnes by 2030, representing 0.5% of today’s MMCF market (7.2M metric tonnes in 2021).
A key limitation for commercial expansion is facility construction (Renewcell 1, in Sundsvall, is a decommissioned paper pulp factory which reduced the facility construction and fit-out time from years to months, and significantly reduced the CapEx for facility set-up).
The output pulp is an exact match for virgin pulp sources for MMCFs, so there are no technical or performance limitations – it is like for like. In terms of the circular business model, waste sourcing and procurement has some price and logistics challenges compared to well-established supply chains for virgin feedstocks.
Barriers to success
Renewcell has limited Circulose (relative to demand) even at the current scale of 60,000 tonnes per year. Renewcell’s scale-up strategy is to sign off-take agreements with fibre producers and brands that, in turn, can be used to secure funding for CapEx investment in facilities expansion.
“Technically, we could replace all viscose (11M tonnes) by 2030, and we think Circulose can [also] replace 30% of cotton and 15% of polyester”
Patrik Lundström, CEO, Renewcell