Sep-2020

Remote management of hydrogen production

Remote monitoring and control can improve safety, detect problems early, and promote efficient operations through modelling and analysis of hydrogen production

BRIAN BUMGARNER, MARCO MÁRQUEZ and JEFFREY SWANSON
Matheson, a Taiyo Nippon Sanso Corporation company

Article Summary

The use of hydrogen in petroleum refining is essential to the production of clean burning, low sulphur fuels, the hydrotreating of heavy feedstocks to yield more desirable products, and also for the production of second generation renewable (green) fuels, an area which has received considerable recent attention in the marketplace. Hydrogen production has increased significantly in recent decades as the demand for transportation fuels increases and environmental regulations and product quality considerations have become more critical for lower allowable sulphur content in gasoline, diesel, marine fuel oil (IMO 2020), and maintenance of high cetane in diesel.

Hydrogen can be produced in several ways including steam reforming, partial oxidation, autothermal reforming, gasification, and electrolysis. Of all these routes, steam reforming of natural gas, commonly known as steam methane reforming (SMR), is the most widely used process, primarily due to the efficiency, reliability, and lower cost and evolved experience base with the technology. Even though natural gas has the lowest carbon content of conventional hydrocarbons, it is important to maximise the efficiency of its use and minimise emissions from a sustainability perspective.1 The importance of doing this is illustrated in Figure 1, which presents a simplified scheme with some actions that can be taken to minimise greenhouse gas emissions.2 Focusing on the central column of Figure 1, the efficient operation of hydrogen plants — via optimised consumption and energy monitoring systems — can significantly contribute to reducing costs and emissions.

Since the 1990s, many petroleum refiners have shifted the responsibility of hydrogen supply to industrial gas companies (IGC) through over-the-fence supply. Refiners understand that suppliers like Matheson own and operate multiple hydrogen plants worldwide and can benefit from their expertise and the associated advantages including a commitment to safety, guaranteed efficiency, improved reliability, infrastructure maintenance, and predictable and lower overall hydrogen cost. One of the many beneficial practices implemented by some suppliers is the use of remote monitoring and operations centres.
The role of remote process control and monitoring

Matheson’s SMR based hydrogen plants worldwide are data-linked to the HyCO (hydrogen, carbon monoxide and syngas) Remote Operations Center (ROC) in La Porte, Texas. The fundamental role of the centre is to support local operations and promote plant safety, reliability, and efficiency (see Figure 2). It also serves as a training platform for current, incoming, and future operators. From the ROC, hydrogen facilities can either be controlled or monitored remotely, thus providing expert advice and troubleshooting to operators sitting at any of the local plant‘s control panels. The remote monitoring system enables continual observation, analysis, evaluation, and control of what is happening, while in-house developed simulation tools visualise what should be happening. Matheson has developed proprietary models that predict in real time how a plant should be running and compare those results to how it is actually running. An example interface screen associated with one of Matheson’s models is shown in Figure 3. This tool is used to identify potential problems.

The advantages that the ROC can offer rely on the expertise leveraged by owning, monitoring, operating, and maintaining multiple sites over time. Operators and supporting engineering staff have monitored and operated multiple SMRs with various configurations for years, gathering experience and data from real and simulated scenarios. They are able to intervene before minor issues escalate to become major problems. This adds up to better safety, improved reliability, and enhanced energy efficiency.

Safety, training & operational modes
Safety is the first and most important objective of plant process design and operations. The primary commercial goal of a business can be short and long term profit optimisation. Sometimes these two objectives can appear to be at odds with each other. The implementation of a remote operating centre can help achieve better overall performance with respect to all objectives and goals.

A key element of process safety is having well-trained operators. The ROC provides virtual and actual training platforms for the operations staff. The centre is equipped with an in-house developed plant simulator that utilises the plant’s control system logic and a human-machine interface. This means the operator can be trained on a generic plant simulator, before moving on to an actual operating plant. In-house calculation simulations have been developed to give realistic feedback to the operators so they can learn the effects of their actions. Our simulator is dynamic, allowing operators to train for scenarios involving start-ups, shutdowns, process upsets, and mechanical failures.

With proper automation measures installed at the local plant (instrumentation and controls), remote operation centres can maintain a high degree of operational safety, while complementing the headcount at the local site. The centre’s support allows local staff to optimise plant operations on each shift.  The centre is staffed with a collection of expert operators with knowledge across sites, who a site employee can use as a ‘sounding board’ in the event of an unusual occurrence.

Annual plant reliability
Annual plant reliability can be defined as the fractional volume of hydrogen delivered to the customer versus the amount of hydrogen requested by the customer.

(*) exclude the periods of scheduled maintenance, force majeure, and any feedstock/utilities supply shortfalls.
A reliable supply of hydrogen is essential for refinery operation. Fuel processing, utilisation, and quality depend on hydroprocessing units to remove sulphur and other impurities and hydrocrack heavy feedstock. Days, or even hours, without hydrogen can represent significant monetary losses and operational and logistical challenges for a refinery. As such, IGCs typically guarantee high annual reliability of hydrogen supply to the end user.