Computer Control of a Syngas Complex at LaPorte, Texas

Abstract

Air Products and Chemicals has successfully implemented a mini-computer monitoring and control system at its LaPorte Syngas Complex as an integral part of its energy management strategy.

The production complex consists of two separate plants at LaPorte, producing hydrogen and carbon monoxide, and a hydrogen producing plant at Battleground, six miles away. The combined facilities have a capacity of over 8 MMSCF/D of carbon monoxide and over 34 MMSCF/D of hydrogen product. The products are supplied to approximately fifteen customers via a pipeline system. The overall complexity of the multi-plant facility necessitated the implementation of a computerized control system to achieve maximum energy efficiency.

The paper describes a computer system based upon a DEC PDP 11-34 mini-computer with a software package developed specifically for Air Products' application. The monitoring, direct digital control, and optimization strategy which was developed and written by Air Products personnel is reviewed. More than 250 process signals are measured and plant and equipment performance are calculated on-line for continuous logging, alarming and operator reference. In order to obtain 'rock steady' operation, over forty loops are under direct digital control and all- product ion changes are implemented on a feed forward basis. The total installed cost of the system was $950,000 and savings in excess of $750,000 have been achieved in the first year of operation in energy consumption improvement alone.