A major refinery in Northern California has, for the past 15 years or more, been gradually moving towards greater use of high purity hydrogen as part of its process. This is intended to help the refinery work with a greater variety of crude oil, as well as boost the facility’s environmental performance through greater use of “green” energy. The overall purpose of the refinery modernization is to make greater use of high purity hydrogen throughout the refining process. To make this happen, many systems in the plant need to be adjusted and modified, including the updating of key aspects of the process control system.
Personnel now with Verus have been working alongside the refinery’s management team since 2000 as they complete this transition. Of paramount importance is the need to get the work done in a way that avoids shutdowns. This is partly because of the high financial cost that would come if production stopped, but also due to the potential safety issues that could be involved in shutting down and then restarting elements of the plant. The overall plant management is done through a Distributed Control System, and this is managed by the software manufacturer. However, the role of Verus employees has been to support and maintain several hundred smaller Programmable Logic Controllers (PLCs) that manage the individual processes within the refinery as a whole. Many of the PLCs in the plant need to be adjusted to support the high purity hydrogen environment. A large number of the PLCs at the plant are legacy equipment, and one of the challenges lies in sourcing spares, parts and personnel with the right skills. There are also difficulties in the performance and expandability of the older PLCs, where performance is about at the maximum for the equipment, particularly with regards communication with the central data system. That aspect of the modernization dovetails with a parallel project Verus is undertaking, to modernize the data networks throughout the facility.
The result of these projects is expected to be higher performance for the plant as a whole, leading to higher productivity – plus the environmental and financial benefits of maximizing the application of high purity hydrogen.