Plants Thirst for Energy Efficiency

The rapid drop in energy costs from historic highs and a growing recession aren’t blunting the chemical industry’s efforts to reduce energy consumption. “We regularly survey our customers to find out what their main issues are. In the chemicals industry, the focus is still very much on energy management and efficiency,” says Vikas Dhole, vice president engineering product management for AspenTech, Burlington, Mass.

“Feedstock and energy make up about 70% of costs in the bulk chemical processes and the monthly energy bills for these companies are still huge. So any saving will have a very big impact,” adds Elinor Price, the company’s director of product marketing.

AspenTech has identified three different energy-improvement opportunities for the chemical industry: real-time optimization, utilities and design.

“Real-time optimization allows operators to be more agile. They are able to continuously maximize margins, which improves the overall business and makes it more robust,” says Dhole. He points to a long-term project with Dow’s North American operations that has yielded $175 million in savings over the last four years. Each plant typically is getting an energy benefit of 3% to 5%.

“Dow regard this as a differentiator for their whole business. They are getting an incredible return. So in terms of optimized technology, this is definitely best practice,” notes Price.

The massive DSM/Sabic site at Geleen, The Netherlands, provides a potent example of a recent success in utilities management. Here, a centralized utility system generates the energy needed for the site’s processes. The challenge was to reduce a nine-figure annual energy bill in a country where energy is one of the most expensive commodities for chemical producers.

“Our AspenUtility suite allowed fundamental modeling and optimization of the utilities system, a holistic site-wide approach that made it much easier for the company to better understand its different processes and improve long-term optimization,” explains Dhole.

Figure 1 -- Success Story: DSM Geleen has increased production capacity and reduced emissions while achieving steam energy savings. Source: DSM.

DSM Geleen reported benefits of €2.5 million in the first year of operations and, since then, a 3%-to-4% reduction in site-wide energy bills on an ongoing basis (Figure 1).

A project for the Samsung Total Aromatic Complex in Daesan, Korea, illustrates the third point. Or, as Dhole puts it, “The scope for energy savings is very much greater when you move from optimization to design.”
Here the company’s modeling and energy analysis software played an important role, particularly for studying the complex’s energy-intensive distillation columns. It led to 12 projects, producing savings equivalent to about $12 million per year — including a more than 20% cut in energy costs.

Seconding the Opinion
The industry’s quest to boost energy efficiency isn’t flagging, agrees Brendan Sheehan, senior marketing manager for chemicals and energy for Honeywell Process Solutions, Phoenix, Ariz. “Although feedstock is cheaper now, we are not seeing a falloff in interest in improving energy efficiency. This is because margins are very tight at chemical plants and the big fall in demand means that people are not pushing throughput as hard. Bear in mind that the cost of natural gas accounts for more than 80% of the operating cost of an ammonia plant. So anything you can do to reduce energy use is important,” he explains.

“We commonly hear from customers that they expect energy prices to pick up as the global economy picks up. They don’t think it will go to the $140/bbl that we saw last year but the perception is that $60–$70/bbl may not be unexpected. On top of this, the continued focus on carbon emissions in Europe — the regulations for which are certainly going to get tighter — really drives the need for improved energy efficiency,” he adds.

Its strategy involves capturing energy data from plants to create energy models that demonstrate the difference between what plants are doing and what they could be doing. This performance assessment serves to identify possible solutions.