Energy efficiency in the PVC production chain

For the Netherlands’ chemical industry, PVC and PVC feedstocks are important products. Their production requires substantial energy inputs, however: including the energy content of the raw materials, around 35 PJ a year.

In the project “Energy efficiency in the chlorine/PVC production chain” CE Delft has quantified current energy consumption in this chain and identified options for reducing it. The project, carried out in close cooperation with five companies active in the chain (Air Products, AkzoNobel, Huntsman, Shin-Etsu and Wavin) focused on measures in the supply chain, i.e. measures that can be implemented through inter-company collaboration. The study was conducted in the framework of the Dutch Multi-Year Agreement on Energy Efficiency at EU ETS companies and was commissioned by NL Agency.

The following steps in the PVC chain were considered: production of chlorine, vinyl chloride, PVC powder and the end product PVC tubing. Based on the actual production technologies used by the project partners, ‘energy flow charts’ were drawn up, which were then used in brainstorming sessions with the producers to identify concrete options for energy savings. This led to 25 potential measures, which were then worked up with the partners into factsheets detailing costs, savings, investments and technical feasibility.

Five of the measures have been given priority status. In a formal meeting on 25 October 2011, management representatives of the five companies signed a statement of intent that these would be seriously taken to hand. Some of the measures can already be implemented, while others are mainly relevant when capacity is expanded (as is anticipated). The five priority measures are:
–     using waste heat to heat demineralised water for chlorine production;
–     bringing in waste steam from adjacent companies via the ‘steam pipe’;
–     greater use of recycled PVC in end products;
–     recycling the waste brine stream from the Huntsman plant;
–     increasing the supply of hydrogen as a commodity to Air Products.

These measures have a combined energy savings potential of around 1,500 TJ, some 4.3% of overall energy consumption in the PVC production chain. This is equivalent to the energy consumption of approx. 20,000 households.

The energy flow charts and detailed information on the 25 measures identified have been set out in a confidential background report. The present report summarises the main results. An article published in the Dutch trade journal Chemie magazine describes the companies’ experience with the project.