SulROP™ ring-opening polymerization for PLA

Licensed processes for industrial bioplastics

Sulzer licenses end-to-end PLA production technology, from lactide synthesis (SULAC™) and purification to ring-opening polymerization (SulROP™), enabling agricultural and chemical companies and EPC contractors to build efficient, scalable polylactic acid plants. In SulROP™, purified lactide undergoes continuous ring-opening polymerization in Sulzer’s SMR loop and plug-flow reactor systems. Precise temperature control and efficient melt mixing enable a wide portfolio of PLA grades, from food packaging to durable engineering grades, on a single production line with minimal changeover downtime.

Download Brochure

Contact an Expert

30+ years

Experience in PLA polymerization process development

1,000 to 80,000+ tpa

Licensed plant capacities, from demonstration to world scale

All PLA grades on one line

Fast transitions between molecular weights and stereoisomer ratios without separate process trains

Main benefits

Grade flexibility on a single line Serve packaging, fiber, engineering and 3D printing grades from one plant

Low maintenance, high uptime Predominantly static equipment with no moving parts in key process units

Scalable capacity design Plants and individual lines licensed from 1,000 to 80,000+ tonnes per annum

Feedstock agnosticism Compatible with lactic acid from first- and second-generation feedstocks, including food waste, to minimize carbon footprint and supply risk

Full project lifecycle support Process design, equipment supply, installation, commissioning, start-up supervision and operator training from a single point of responsibility

Key characteristics

SMR loop and plug-flow reactors: Continuous ring-opening polymerization of purified lactide with precise temperature control and efficient melt mixing

Integrated value chain: SULAC™ lactide synthesis, distillation and crystallization purification, SulROP™ polymerization, DEVO™ devolatilization and pelletizing

Product scope: Bio-based, compostable and recyclable PLA for packaging, textiles, automotive components and 3D printing

Download our technical resources

Contact an expert

Our technical specialists are ready to help you find the optimal distillation solution for your specific application

Charlie Chou

Global licensing director

Contact us

Get detailed technical information and project consultation

Send an email

GT‑DWC is a unique distillation technique called dividing wall column, that produces three or more purified products in a single tower that otherwise in conventional way is done by 2-3 columns in series.

A vertical wall splits typically the mid‑section into two functional zones so the column can pre‑fractionate the feed on one side while the other side refines the middle cut (heart‑cut) from the top and the bottom cuts. Compared with a conventional in-series distillation columns, this integrated column reduces investment by half of the equipment count, and its internal arrangement reduces remixing that lower the utility consumption as well.

When comparing with the normal column with a side draw, GT-DWC produces the heart‑cut where it is most concentrated with contamination from top & bottom products, and achieves the same (or better) product specs as by the multi-column system.
A two‑column sequence inevitably wastes duty by splitting and then remixing components between shells, causing thermal inefficiency that drives up utility consumptions for reboiling and condensing. GT‑DWC® consolidates that work inside one shell, so the separation is done once without such thermal inefficiency, with one reboiler and one condenser. That means fewer separation efficiency losses, lower internal flows, and smaller overall duty. Where applicable, GT-DWC typically provide 20-30% energy saving comparing with two-column system with the same or better product separation quality.
Yes. GT‑DWC is often a revamp enabler because it replaces two columns with one shell, freeing plot space and reducing energy consumption. It can also be applied for revamping an existing column with sidedraw to greatly improve the middle heartcut purity/quality that benefit its value and downstream units. Sulzer high-efficiency tower internals and proprietary DWC design are key to guarantee the success of the revamp. Dynamic simulation is used to validate start‑up/shutdown procedures as well as the feed variation to prove controllability within your existing utility envelope.
Sulzer supplies the full set of trays or structured packings, along with distributors, collectors, and when needed, custom wall hardware. The internals are engineered to maintain pressure balance and uniform liquid/vapor distribution on both sides of the wall—this is critical to prevent maldistribution, channeling, or cross‑leakage that can degrade efficiency. Selection (trays vs. packing) depends on capacity, turndown, fouling tendency, and pressure drop targets; our design team sizes distributors/redistributors and sealing elements to keep performance stable across the operating range.
Yes. A single shell creates a clean condenser ↔ reboiler pairing that a heat pump can bridge: the overhead releases heat while condensing; VoltaSplit™ lifts that heat to the reboiler temperature replacing a large share of steam with electricity and reusing condenser heat that would otherwise be rejected.
GT‑DWC excels when there is a meaningful middle cut (heart‑cut) to recover, and when the alternative would be a two‑column arrangement. Typical examples include aromatics heart‑cuts, naphtha splitter, reformate splitter, iso/normal-separation column, and light/medium hydrocarbon fractionations where three product slates are needed. As a rule of thumb, if your feed has a clear light, middle, and heavy region—and the middle product purity/yield matters—GT‑DWC is a strong candidate.
We pair a standard temperature/reflux control structure with additional loops to maintain vapor/liquid splits around the dividing wall. It ensures high controllability, and robust operation even facing the feed variation. Dynamic simulation is used to test disturbances (feed swings, utility changes) and to finalize startup/shutdown sequences before commissioning.