The chemical industry is among the most energy-intensive sectors. In Germany alone, it uses around 20% of all the power consumed by industry. Thus, efficient use of energy plays a key role in keeping companies competitive in the world market, while contributing to climate protection.
In 2008, higher global production volumes increased WACKER’s electricity consumption to 2.4 TWh (2007: 2.1 TWh; 1 TWh = 1 million MWh). Due to production increases and full consolidation of sites acquired from Air Products, heat consumption also rose to 2.8 TWh groupwide (2007: 2.5 TWh).
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Energy | |||||||
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TWh |
2008 |
2007 |
2006 | ||||
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Electricity consumption |
2.4 |
2.1 |
1.9 | ||||
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Heat consumption |
2.8 |
2.5 |
2.5 | ||||
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Primary energy1 |
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Natural gas |
5.4 |
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Heat (supplied by third parties)2 |
0.2 |
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Fuel oil |
0.01 |
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At WACKER’s Burghausen and Nünchritz sites, steam and electricity are produced in cogeneration systems – combined heat and power (CHP plants with 80% fuel efficiency (twice as high as that of conventional oil, gas or coal-fired power plants). In Burghausen, we also use hydro power to generate electricity. Together, the two CHP plants and the hydro-power plant generated 1.4 TWh electricity in 2008. This means that, at WACKER, we produce just under 60% of our total electricity needs ourselves.
Many chemical reactions generate heat, which can be used in other production processes. In Burghausen and Nünchritz, we have been implementing integrated heat recovery systems for years and are continually improving them. In this way, we can reduce the amount of primary energy (normally natural gas) that our power plants use. This results in lower emissions of carbon dioxide a greenhouse gas.
To manufacture one metric ton of product, our Nünchritz site now requires 60% less electricity and 80% less process steam from its CHP plant than ten years ago, when WACKER took over the site. The Nünchritz power plant has converted fully from heavy fuel oil to more climate-friendly natural gas. The following overview describes the key heat utilization measures during the reporting period:
Nünchritz Site:
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Since 2007, the incinerator’s waste heat has been used to generate process steam. Savings: 11,000 tons of CO2 emissions/year.
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When we expanded the methylchlorosilane distillation facility in 2007, we hooked up pairs of columns to form a heat-recovery system. Savings: 28,000 tons of CO2 emissions/year.
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Thanks to a new integrated heat-recovery system in the basic silicone production process, the starting material – chloromethane – can be evaporated without the use of primary energy. Savings: 5,000 tons of CO2 emissions/year.
Burghausen Site:
In 2007 and 2008, the waste heat from several high-temperature processes was made available for use in upstream production plants. This reduces the site’s carbon dioxide emissions by some 120,000 tons per year – at 40%, a bigger reduction than the one achieved in 2006.
Many of the heat-utilization measures came from the POWER PLUS project. WACKER initiated this project in 2007 to increase the energy efficiency of our plants. The aim is to reduce the specific (referenced to production output) energy consumption at Burghausen and Nünchritz by 10% by the end of 2009 (based on 2006). The two sites consume around 80% of the energy needed groupwide. The project receives input from Idea Management’s Employee Suggestion Scheme.
By the end of 2008, WACKER energy experts had inspected a total of 36 plants. 150 measures were drawn up and are being implemented stepwise. Once all the measures are in place, the Burghausen site will be saving some 178,600 MWh of electricity (a 14.3% saving) and 525,000 tons of steam (a 22.8% saving) per year. For Nünchritz, the potential savings through POWER PLUS measures add up to 18,100 MWh of electricity (a 18% saving) and 325,000 tons of steam (a 50% saving) per year.
We are also working on boosting energy efficiency at our sites outside Germany. Siltronic’s Portland site (Oregon, USA) equipped its cooling-water supply with higher-performance cooling pump units and a heat-recovery system. As a result, power consumption was cut by 3 million KWh and natural gas demand by around 15% per year.