Vonovia, Ampeers Energy

Over the course of 2020, Vonovia and Ampeers Energy will be setting up an ‘energy centre of the future’ in the residen-tial district of Bochum-Weitmar, which has already been constructed.

The energy centre is planned to incorporate some highly innovative technologies: hydrogen, fuels cells and storage. The goals of the technology selection are reduced conversion losses, low system complexity and a high degree of autonomy for the neighborhood. Existing buildings dating from 1959/1976 are to be supplied, which will be insulated in accordance with KfW 100. PV systems are to be installed on the roofs. The locally generated electricity is to be consumed as completely as possible in the neighborhood. Electric vehicles can be supplied with electricity via charging stations. Decentrally generated green electricity, which cannot be used immediately to supply the residents with electricity and heat, will be converted into hydrogen by an electrolyser, stored and can be converted back into electricity and heat by a fuel cell. The nature of its research enables it to test various combinations of systems and different ways of optimising operational manage-ment strategies in the real-life application of an urban district. Of particular interest to them are the practicability and scalability of these approaches.

The newly decoupled industrial heat is generated in the so-called contact plant during the conversion of sulphur dioxide, which is obtained during copper refining, into sulphuric acid. The exothermic chemical reaction releases the CO2-free heat. However, in order to be able to use it for external heat supply, it was necessary to raise the temperature level of the process from the current 65 °C to 117 °C. The process is now being operated at a temperature of 117 °C. This is the temperature at which the heat is released. This necessitated process engineering changes as well as new materials and plant components.

Aurubis and enercity conduct most of the industrial heat generated via a specially constructed 3.7 km heat transport pipeline from the plant site to eastern HafenCity. Aurubis also uses a quarter of the industrial heat in its own processes, such as heating the electrolyte during copper electrolysis. This reduces the company's natural gas requirements by around 50 gigawatt hours per year, which corresponds to an annual CO2 reduction of over 14,000 tonnes. The heat extraction measures were implemented in spring 2018. The first use of heat in HafenCity took place in late autumn 2018.

Energy efficiency measures

  • Adaptation of the sulphuric acid process to increase the temperature level
  • decoupling of industrial heat by technical conversion of the contact system
  • Erection of an internal heat transport pipeline
  • Transmission of industrial heat to supply eastern HafenCity with district heating
  • Use of industrial heat for in-house processes
  • Savings of 12 million m3 of cooling water per year

jury assessment

The jury selects Aurubis AG as the winner of the Energy Efficiency Award 2018 in the Energy Transition 2.0 category. The waste heat is now also used outside the plant in addition to being used internally. The external use of the waste heat by enercity Contracting NordGmbH makes a significant contribution to the climate protection goals of the City of Hamburg. With the help of industrial heat, it is even possible to fall short of the ambitious emission targets for supplying heat to the new HafenCity Ost development area. By using part of the heat internally within the plant, Aurubis can also cover almost half of its heat requirements for copper electrolysis and electrolyte treatment. The project has already been awarded as a lighthouse project of dena for waste heat utilisation and is one of the first major projects to be supported by the KfW promotional programme "Waste Heat".

company profile

Aurubis AG is an international supplier of non-ferrous metals and one of the largest copper recyclers in the world. The company processes complex metal concentrates, scrap metals and metal-containing recycling materials into metals of the highest quality. Aurubis produces more than 1 million tonnes annually.

copper cathodes and uses them to manufacture various copper products such as continuous cast wire rod, shapes or special wires and copper alloys.

Aurubis employs around 6,500 people and has production sites in Europe and the USA.