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Process optimization for terephthalic acid (PTA/QTA/CTA) production

The challenges of reducing PTA production costs and maximizing ROI

Samsung Petrochemical

Samsung Petrochemical is one of the Korean manufacturers investing in process improvement



terephthalic / PTA cost reduction

See the ICIS News interviews with PSE and Aspen Technology on enhancing process efficiency and reducing production costs




We chose to work with PSE because of the comprehensive set of industry-tested techniques that they bring to PTA process optimization, and the high level of expertise and experience of their core personnel.

— Mr. S.H. Park,
Managing Director, SPC





Until relatively recently, the challenge for purified terephthalic acid (PTA) manufacturers was to squeeze as much production out of their plants as possible.

With recent increases in capacity followed by the downturn in world demand, the challenge is now to reduce variable cost.

In addition, companies looking to the future are investigating the construction of much larger-capacity plants – for example 1000kTpa from a single reactor – in order to reduce unit capital cost.

Where does Model-based Engineering come in?

The new economic realities mean that there are two key drivers for manufacturers of PTA in the current market:

Cost optimisation of existing plants, using process improvement or process optimisation techniques to reduce variable cost primarily by reducing unnecessary consumption of raw materials.
Process development to optimise the design of next-generation plants. Economies of scale are driving manufacturers towards 1000 tpa single-train plants – but can these scales be achieved reliably?

PTA producers are adopting innovative techniques to maximize return on investment.

One key technology being applied widely is Model-Based Engineering, where detailed and experimentally validated mathematical models with a high degree of predictive accuracy are used to optimise design and operation as well as accelerate development of new processes.

Model-based engineering for terephthalic acid reaction processes

PSE has extensive experience in the modelling of PTA processes, including key units such as oxidation reactors.

This is embodied in PSE's Model-based Engineering solution for Terephthalic Acid (MBE:TA), a set of high-fidelity process models and advanced methodologies for the detailed modelling and optimisation of PTA processes.

PSE's MBE:TA technology is typically used to address the following aspects of operation and design of full-scale commercial PTA plants:

Reduction in paraxylene consumption. Reductions of the order of 1% can be achieved, saving $1m or more on a medium-sized plant over a year.
Reduction in acetic acid consumption. Reductions of the order of 15% can be achieved, saving a similar amount.
Optimisation of operating conditions. Conditions can be optimised regularly as raw material prices change relative to each other
Re-design of equipment for changing production. MbE is used to establish the optimal impeller design and nozzle placement for anticipated production requirements.
Due diligence for capital expenditure. MbE techniques are used for 'before the event' verification of the economics of potentially expensive capital expenditure decisions such as impeller replacement.
Optimisation of operating conditions for new impeller. Operating conditions are optimised to minimise raw material and energy consumption following equipment changes, with similar benefits to those listed above.

Payback on such projects is typically of the order of 6 to 12 months, depending on whether there is associated capital expenditure or not.

Example: Samsung Petrochemical Co.

Samsung Petrochemical and PSE signing the master collaboration agreement on purified terephthalic acid (PTA) process development and optimization

SPC and PSE signing the agreement

SPC and PSE press release on plant improvement and process optimization

Joint press release   

Korea's Samsung Petrochemical Co. (SPC), a leading producer of purified terephthalic acid (PTA) is working closely with PSE to optimize its current operations as well as to to accelerate development of new high-performance technologies for PTA production.

SPC is already a leader in PTA manufacture, with the lowest capital and variable costs of all the major processes licensors. The new developments will aim primarily at reducing operating costs and improving product quality, providing clear advantages over other licensed processes on the market.

PSE's technology and expertise will be applied to accelerate the development of SPC's brand new high-performance PTA Process, optimizing its performance and commercial advantage.

In addition, PSE's advanced Model-based Engineering techniques are being combined with SPC's PTA process know-how and expertise to develop a range of advanced process optimization services to be offered to PTA manufacturers around the world.

Mr. T.H. Her, President of SPC, said "We aim to strengthen the distinctive technology differentiators for SPC's PTA processes by using the most advanced methods available to optimize design and operations." The agreement with PSE is a key step in this strategy.

Mr. S.H. Park, Managing Director of SPC, adds "We chose to work with PSE because of the comprehensive set of industry-tested techniques that they bring to PTA process optimization, and the high level of expertise and experience of their core personnel."