Production of gypsum wallboards

The production of gypsum wallboards is highly energy demanding due to the need to evaporate the excess water from the wet gypsum board. Sika provides the gypsum industry with tailor-made additive solutions for a cost-effective wallboard production based on innovative technologies like ViscoCrete® and Retardan®. A substantial water reduction is accompanied by reduced energy consumption (and CO2-emissions) during the board drying process and thus leads to a reduced energy and CO2 footprint of the gypsum industry.

Producing a wallboard using a high range water reducer like Sika® ViscoCrete® allows a substantial water reduction when compared to using a conventional water reducer, e.g. naphthalene based.

Case Study: Optimization of Gypsum Wallboard Production

To evaluate the benefits of using Sika® Viscocrete® in the production of gypsum wallboards, such two scenarios were analysed using a Life Cycle Assessment (LCA). The LCA is from cradle to gate, which means the potential environmental impacts from raw material acquisition to production are investigated.

The Cumulative Energy Demand (CED) and the Global Warming Potential (GWP) were calculated. CED accounts for the consumption of energy resources, namely the primary energy from renewable and non-renewable resources. GWP measures the potential contribution to climate change, focusing on emissions of greenhouse gases, such as carbon dioxide (CO2).

The overall environmental and economic performance of gypsum wallboards produced with Sika® ViscoCrete® vs. a reference with a conventional water reducer are compared. A relative comparison was carried out for the main sustainability drivers in gypsum wallboard production: material and energy costs, GWP, CED and formaldehyde release (which may be present during application of conventional plasticizers).

Result of the sustainability analysis
Result of the sustainability analysis

Relative comparison of wallboard manufactured with Sika® ViscoCrete® vs. a reference wallboard using a conventional water reducer. The reference wallboard is taken as benchmark (1=100%).

High performance wallboard production

Applying the Sika solution results in the best overall performance. To quantify the benefits for the yearly production in a wallboard plant, an example is given for a modern plant producing approx. 30 million m2 wallboards annually. There, the savings would amount to:

  • no formaldehyde release
  • 28’000 GJ (Cumulative Energy Demand)
  • 1’500 tons CO2-eq
  • 334’500 Euros (considering average European energy price 0.04 Eur/kWh).

These figures are related to an existing factory which was originally designed for conventional water reducer application. Taking high-range water reducers already into account during planning phase of a new plant, the economic gains can even be higher. These additional savings are mainly due to the downsize potential of the dryer units. Higher cost savings occur in regions and/or times of higher energy prices.

The Sika solution not only brings a relevant quantitative contribution to a sustainable high performance wallboard production, but it also helps fulfill the customer requirements from an economic and technical point of view.