Ammonia by-product to provide feedstock for Pupuk’s new facilities

State-owned industrial conglomerate, Pupuk Indonesia (Persero), plans to build two soda ash plants each with a 300tpy capacity to supply the domestic glass and ceramic industries. One will be built in Bontang, East Kalimantan and the other in Gresik, in East Java, under two new subsidiaries, PT Pupuk Kaltim and PT Petrokimia Gresk respectively.  The new plants will be built in stages with construction commencing towards the end of 2024.

The soda ash will be produced using salt and carbon dioxide, which will be sourced from emissions captured from ammonia production. With the new soda ash facilities in place, the CO₂ footprint of the ammonia production will be reduced. Pupuk has an ammonia capacity of up to 6.5Mtpy and is developing blue and green ammonia technology to reduce carbon emissions. Currently by-product CO₂ is used in the urea fertiliser plant and in liquid CO₂ as a raw material for carbonated drinks, welding gas, fire extinguishers and food preservation, but these applications do not account for all the CO₂ produced.

The soda ash process is likely to be based on the Hou process (also known as the ammonium chloride co-production or dual process). This was developed in China and has lower energy requirements and produces less waste than the Solvay process, as over 90% of the sodium content of the salt is converted into soda ash. Outside of China, only a handful of plants have used this process to produce synthetic soda ash.

Demand for soda ash is estimated by Pupuk to be around 1Mtpy in Indonesia, with all of it currently imported, so the new plants will fill a need from the domestic glass and ceramics industries. Soda ash imports in 2022 and 2023 were 920kt and 790Kt respectively.

Indonesia is already a significant salt importer, with imports of 2.8Mt in 2023, with three-quarters of that source from Australia and the balance largely from India. These soda ash plants will create further demand for imports into the country.