Integrated Production – Our Greatest Strength

The highly integrated material loops at its major sites in Burghausen, Nünchritz and Zhangjiagang are one of WACKER’s key competitive advantages. Basically, integrated production involves using the byproducts from one stage as starting materials for making other products. The auxiliaries required for this, such as , are recycled in a closed loop. Waste heat from one process is utilized in other chemical processes. Integrated production not only cuts energy and resource consumption, but also improves the use of raw materials in the long term, and integrates environmental protection into our processes.

Our integrated production system is primarily based on salt, , methanol, acetic acid and as starting materials. In our integrated processes, we optimize material efficiency by purifying byproducts and reusing them or making them available for external use. Examples:

  • In our integrated ethylene production system, we use ethylene to obtain organic intermediates, which we then turn into dispersions and .
  • Our integrated silicon production system operates along similar lines. Although comprising only a small number of raw materials – silicon, methanol and salt (sodium chloride) – this system enables us to manufacture over 2,800 different products, as well as and .

Integrated Hydrogen Chloride System

Integrated Hydrogen Chloride System (graphic)

A further focus of our integrated production is to minimize consumption. Hydrogen chloride is an essential auxiliary deployed in the production of reactive intermediates from energy-poor natural materials. We then use these intermediates to make our end products.

Hydrogen chloride production requires a lot of energy. In our integrated material loop, we recover both hydrogen chloride and some of the energy in the form of heating steam during the conversion of the chlorine-containing intermediates to chlorine-free end products (such as silicones, hyperpure silicon or pyrogenic ). We then return the recovered hydrogen chloride to the production loop and reuse it. This closed material loop reduces emissions and, due to lower raw-material consumption, shipment journeys.

Integrated Hydrogen Chloride System

We use a chlor-alkali membrane process to supply chlorine, hydrogen, caustic soda and hydrogen chloride as starting materials to our Burghausen site. This membrane electrolysis has enabled us to stop using mercury-based chlorine electrolysis and simultaneously cut energy consumption by around 25 percent per year. Thus, WACKER has fulfilled the chemical industry’s voluntary commitment to phase out mercury-based processes by 2020 at the latest well ahead of schedule. In 2017, we increased energy efficiency by a further 8 to 10 percent by using new electrolysis cells.

Examples of savings potential for resources through our integrated production system:

  • We recycle 93 to 96 percent of the that we use in the production loops at our Burghausen and Nünchritz sites. During the reporting period, we again worked on closing our material loops as much as possible and reducing the loss rate by means of optimization projects.
  • In 2018, our integrated hydrogen chloride system in Burghausen prevented the of over 495 kilotons (kt) of CO2 equivalents (CO2e) (2017: 719 kt). The CO2e effect dropped from 2017 to 2018, because we equipped our chlor-alkali electrolysis with more efficient membranes. These require less energy specifically to generate chlorine and, from it, hydrogen chloride. Due to the high reutilization rate, we save on fresh hydrogen chloride and, consequently, on raw materials and energy.
  • We optimized the hydrogen loops in our integrated polysilicon production system and thus significantly lowered the consumption of hydrogen extracted from natural gas. This has led to a reduction in emissions of 8,000 metric tons per year compared with 2016.

Zhangjiagang in China – alongside Burghausen (Bavaria) and Nünchritz (Saxony) in Germany – is our third major integrated production site. We employ state-of-the-art environmental technology in China, too, where we operate facilities according to stringent national and WACKER EH&S standards.

This also applies to our new site in Charleston in the USA, where we are further optimizing our system of integrated polysilicon production. We have erected a new production plant for HDK® pyrogenic silica there. This constitutes an important addition to the supply chain at the Charleston site, because the main byproduct of polysilicon manufacturing is tetrachlorosilane, which we can either convert and feed back into the production loop or we can use it to create added value by processing it further into HDK®. As already operated by WACKER at its Burghausen and Nünchritz sites in Germany, an integrated production system that combines polysilicon and HDK® facilities permits maximum flexibility in the processing of tetrachlorosilane, avoids the disposal of waste products and thereby enhances the viability of integrated production as a whole.

Silanes are used as monomers for the synthesis of siloxanes or sold directly as reagents or raw materials. Typical applications include surface treatment, agents (medically active substances) in pharmaceutical synthesis or coupling agents for coatings.
After oxygen, silicon is the most common element on the earth’s crust. In nature, it occurs without exception in the form of compounds, chiefly silicon dioxide and silicates. Silicon is obtained through energy-intensive reaction of quartz sand with carbon and is the most important raw material in the electronics industry.
A colorless, slightly sweet-smelling gas that, under normal conditions, is lighter than air. It is needed as a chemical starting product for a great many synthetic materials, including polyethylene and polystyrene. It is used to make products for the household, agricultural and automotive sectors, among others.
A polymer is a large molecule made up of smaller molecular units (monomers). It contains between 10,000 and 100,000 monomers. Polymers can be long or ball-shaped.
Dispersible Polymer Powders
Created by drying dispersions in spray or disc dryers. VINNAPAS® polymer powders from WACKER are recommended as binders in the construction industry, e.g. for tile adhesives, self-leveling compounds and repair mortars. The powders improve adhesion, cohesion, flexibility and flexural strength, as well as water-retention and processing properties.
General term used to describe compounds of organic molecules and silicon. According to their areas of application, silicones can be classified as fluids, resins or rubber grades. Silicones are characterized by a myriad of outstanding properties. Typical areas of application include construction, the electrical and electronics industries, shipping and transportation, textiles and paper coatings.
Silica, Pyrogenic
White, synthetic, amorphous silicon dioxide (SiO2) in powder form, made by flame hydrolysis of silicon compounds. Variously used as an additive for silicone rubber grades, sealants, surface coatings, pharmaceuticals and cosmetics.
Hyperpure polycrystalline silicon from WACKER POLYSILICON is used for manufacturing wafers for the electronics and solar industries. To produce it, metallurgical-grade silicon is converted into liquid trichlorosilane, highly distilled and deposited in hyperpure form at 1,000 °C.
Hydrogen Chloride (HCl)
The chemical industry uses HCl to generate valuable intermediates from organic and inorganic raw materials. The colorless gas dissolves in water to form hydrochloric acid.
Collective term for compounds with the general formula SiO2 nH2O. Synthetic silicas are obtained from sand. Based on their method of production, a distinction is made between precipitated silicas and pyrogenic silicas (such as HDK®).
Hydrogen Chloride (HCl)
The chemical industry uses HCl to generate valuable intermediates from organic and inorganic raw materials. The colorless gas dissolves in water to form hydrochloric acid.
Substance outputs, noise, vibrations, light, heat or radiation emitted into the environment by an industrial plant.
Carbon Dioxide
Chemical name: CO2. This gas naturally constitutes 0.04% of air. Carbon dioxide is generated during the combustion of coal, natural gas and other organic substances. As a greenhouse gas in the atmosphere, it contributes to global warming. Since the start of industrialization in 1850, its concentration in air has risen from approx. 300 to 390 ppm (parts per million). This value is increasing by around 2 ppm every year. Other greenhouse gases are represented as CO2 equivalents (CO2e) based on their greenhouse effect.