Customer case:

APP's OKI Pulp and Paper Mill - record breaking key technology

Oct 14, 2019

APP’s OKI Pulp and Paper Mill in Indonesia had its start-up in late 2016. Being one of the largest in the world, the mill has hit several pulp production world records ever since. Valmet’s delivery scope comprised of key technology, including pulp drying and baling, evaporation, ash treatment, biomass drying and gasification, a lime kiln, green liquor handling, mill wide NCG collection and biomass boilers. Both pulp dryers, as well as the ash crystallizer, are the largest machines ever built, with the largest production capacity.

David Kerr, General Manager of OKI Pulp and Paper Mill
APP has partnered with Valmet on major projects in the past, and we expected and received the same good level of cooperation in all areas of the project.
David Kerr, General Manager of OKI Pulp and Paper Mill


Location South Sumatra, Indonesia
Customer challenge Meet the growing demand for pulp with a cost-efficient and sustainable new production line.

New pulp mill with key technology from Valmet: 

Pulp drying and baling:

  • Pulp dryers largest ones in the world - 10.6 meters wide
  • No capacity limitations on dryers
  • Production record for both machines combined 8,630 tonnes in one day
  • Pulp drying line featuring several new technologies
  • Baling lines with extensive safety features


  • The largest evaporation plant in the world with design capacity of 2,900 tons of evaporated water per hour
  • Exceptionally high dry solids
  • The condensate treatment system is designed to enable 100 percent reuse of condensates in mill processes

Ash treatment:

  • World's largest ash crystallization plant
  • Fully energy-integrated in the evaporation plant, optimizing the steam balances

Biomass dryer and gasification

  • Biomass dryer utilizes mill waste heat
  • Two CFB Gasifiers - producing product gas from acacia bark with capacity of 110 MW each

Lime kiln

  • Two lime kilns with a length of 140 meters each
  • Using biogas (gasified acacia bark) as fuel

Green liquor handling

  • Green liquor from the lime kiln is cleaned in Valmet OptiClear high rate clarifiers to increase the efficiency of the recausticizing process

Mill wide NCG collection

Biomass boilers


The project was a success, with highly skilled specialists from across the globe working closely together as a team - regardless of any language barriers. The mill has an annual production of 2.8 million tonnes of bleached hardwood pulp.

Keywords Chemical pulping, Complete pulp mills, Greenfield project, New lines, Indonesia, Asia Pacific