Energy efficiency project

Service: Energy efficiency in industrial systems and plants Service area:Technical consultancy

Sector: The oil and gas industry Specialist area:Oil & Gas products

Energy Efficiency Project

Basis:

Recent decades have seen a spectacular increase in worldwide energy consumption. This fact, along with environmental-type factors, has led industry in general to lean towards energy savings and efficiency.

The 'energy optimisation' of a set of systems and facilities implicitly brings about an improvement in the quality of services offered, as well as a longer useful life for equipment, without sacrificing production standards.

Conscious of this reality, Repsol is asking Applus+ to do an energy efficiency study of its Co-generation II, Gas Stripper, Compressed Air, Steam Network and Cooling Tower facilities located in La Pobla de Mafumet, Tarragona, one of the largest petrochemical complexes in Europe.

Almost fifteen years ago, Applus+ made a bid towards placing energy efficiency as one of the cornerstones of its development. The Applus+ ITA Industrial Processes and Technologies business unit is equipped with some 40 professionals dedicated to industrial energy efficiency and process engineering and automation.

Applus+ solutions for this new challenge

In the field of industry, we have developed our own methodology, which allows for the systematic identification of improvements in industrial processes consumption. This methodology is the fruit of the experience of a multi-disciplinary technical team, certified in all industrial sectors.

We start the project by gathering technical information from each of the facilities under study, for the purpose of determining aspects such as operating features, operational yardstick, the typology of the fuels used, inventory, technical specifications, etc.

In this phase we also gather the records of parameters indicative of the operation of each of the facilities, because, in our judgment, these are determining factors when calculating energy yield and modes of operation (pinch point, fouling, approach).

A fundamental part of our energy-analysis work on facilities relates to carrying out visual inspections and taking mesurements of the level of consumption of operation equipment. In this way, we obtain a comparison between actual and nominal consumption, and we identify differences that later translate into energy-saving possibilities.

Our field work includes inspection of the facilities (leaks, regulation systems, instrumentation, etc.) measurement of their electrical consumption and thermographic analysis.

Combining the information initially gathered with the results of the field work, a detailed diagnostic of each facility is made, determining the energy condition of the part of the plant under study.

An energy-consumption distribution diagram (Energy Sankey) is created for each of the facilities, which allows us to highlight the plant's greatest consumers.

At the end of this process, we draw up optimisation recommendations and estimate a savings/investment ratio for each of the facilities.

Benefits for our client

It is estimated that the energy-saving proposals put forth by the Applus+ audit team will allow for an annual reduction of 19,000 tons of CO2 emissions into the atmosphere and 74 GWh in the audited plant's energy consumption-the equivalent of the annual electricity consumption of 12,000 homes.

The savings measures proposed can be grouped into three main categories:

• Improvements in energy management and control.

As a result of the audit, each facility's performance was reviwed and its statistical follow-up indicators verified. In this way, the company has at its disposal a tool able to monitor each facility and its internal components on an ongoing basis and to act on significant divergence in the follow-up indicators. Similarly, maintenance plans can be drawn up for the primary facilities. There are resultant savings in primary fuel consumption.

• Optimisation of key processes.

This measure centres onthe proposal to increase process automation. Increased automation and improved control of all operations that affect energy consumption will lead to improvements in both heat and electricity efficiency.

• Re-engineering and use of residual process energy.

The energy audit carried out by Applus+ highlighted the possibility of using residual heat energy generated during the production process, in the pre-heating of other processes using primary sector energy sources, leading to potential savings.

The success of this project, combined with Repsol's commitment to the ongoing improvement of its production processes, offers the possibility of collaborations between Repsol Group and Applus+.