PT Badak NGL Trains-A/B/C/D Debottlenecking Project
Badak LNG Plant in Bontang, East Kalimantan, started with only two trains called Train-A and Train-B. Both trains had production rate 460 m3/hour of LNG. They were started in 1977. I was still studying in the university at that time. In 1980 – 1982 both trains were debottlenecked by revamping the absorber section and increased the production capacity 640 m3/hour at density of 453 kg/m3. This is about 140% of original design capacity and equivalent to 2.5 million tons of LNG per year per train. In 1982 – 1983 Train-C and Train-D were built at this new design capacity.
Further study shows that the propane chillers and the main cryogenic heat exchanger still have extra capacity. The plant uses steam turbine driver for the refrigerant compressors.
The manufacturer offers a more efficient engine. The turbine could drive more power with same amount of steam rate. The compressor performance can also be upgraded with minimum cost. Hence, all we need is to increase the pipe size to reduce pressure drop upstream of the main cryogenic heat exchanger.
We also gain reduction of pressure drop by adding one drier bed which allows 2 beds in service and one on standby or in regeneration. Further reduction in pressure drop we gain by reducing the mercury removal bed by half the height based on historical data of low mercury content in the feed gas.
However, we faced a new problem which is propane carryover from the chillers to the compressor suction drums due to high velocity. I was involved personally with the debate in Bechtel office, Houston during the debottlenecking study.
I am a proponent to installing flash drums to allow liquid propane to settle down and knocked before entering the compressor suction drum. I did not agree that we only add pump at the compressor suction drum since it still introduce a risk of getting some liquid droplets into the compressor if the pump fails. I was happy when finally it was agreed by management.
The debottlenecking project successfully increased the production capacity of Train-A/B/C/D from 640 to 700 m3/hour or equivalent to 2.75 million tons per year (mtpa) each train. Train-E/F/G/H was built based on this study with capacity of over 3.0 million tons per year of LNG.