HAMBURG WASSER 

Description of the company

HAMBURG WASSER is the municipal company for water supply and wastewater disposal in Hamburg. It is Germany's second-largest municipal water supply and wastewater disposal company and combines over 170 years of expertise and competence in drinking water and wastewater. Water supply and sewage disposal are not just ordinary services. They belong to the elementary bases of life and are therefore part of the municipal services of general interest. As a municipal company with around 2000 employees, HAMBURG WASSER is primarily committed to the interests of the Free and Hanseatic City of Hamburg (FHH) and its citizens. In 2006, Hamburger Wasserwerke GmbH (HWW) and Hamburger Stadtentwässerung (HSE) were merged to form the HAMBURG WASSER (HW) group of equal status and offer their services not only in the city of Hamburg but also beyond it in the metropolitan region. The HW Group thus supplies around 2 million people with the best drinking water and purifies wastewater.

Situation

HAMBURG WASSER produces large quantities of digester gas at the Hamburg wastewater treatment plant, which is obtained from the residues of the biological wastewater treatment. The gas is similar in composition to other biogases and consists of approx. 60% methane and approx. 40% CO2. This gas can be used in a variety of energetic ways. At present, it is mostly used directly for the electricity and heat supply of the sewage treatment plant. In addition, part of it is fed into the natural gas network after the CO2 content has been separated in a chemical cleaning process.

For the supply of electricity, HAMBURG WASSER also operates wind turbines at the sewage treatment plant, which naturally have a strongly fluctuating production. This regularly results in considerable power surpluses, which are currently fed into the public power grid.

Problem

The CO2 content of the digester gas cannot be used to generate energy and escapes into the environment both during power generation and when it is fed into the grid. Although it is of biogenic origin and thus climate-neutral, HAMBURG WASSER is nevertheless looking for ways to reduce or better use the CO2 content.

At the same time, the financial revenue for surplus electricity fed into the public grid is below the electricity production costs. Furthermore, this feed-in occurs in windy periods, when there is a surplus of electricity in the grid anyway. HAMBURG WASSER therefore aims to make better use of the temporary overproduction of wind power.

Aims of the project

A promising way to make excess electricity storable or otherwise usable is the production of hydrogen gas by electrolysis (Power to Gas; P2G). However, hydrogen has various disadvantages that make its use in the existing gas network infrastructure more difficult. These disadvantages can be overcome if the hydrogen is further converted to methane with CO2 (methanisation).

HAMBURG WASSER has also already considered existing methanisation technologies. There are various approaches that do not process pure CO2 but the CO2 content in a biogas, which makes the application in the sewage treatment plant sector particularly interesting.

In the first step of the project, the known processes - especially for the methanisation of biogas - are to be researched and compared. For the most promising methods, the feasibility of implementation at the Hamburg sewage treatment plant shall be evaluated. The criteria for this are to be defined and should at least cover the areas of maturity of the technology, technical realisation, integration into the existing plant structure and economic efficiency. The aim is a well-founded recommendation of subsequent steps for technical implementation or for further investigations.

Scopes

• Research of existing technologies
• Comparison and evaluation according to technical and economic criteria
• Discussion & idea development for the implementation of a P2G plant with methanisation at the sewage treatment plant Hamburg
• Summary of the results and recommendation for further action

Target group (students)

Students of the TUHH who are interested and motivated to work independently and creatively on the content of the described task. Above all, enthusiasm for topics such as climate protection, sustainability, renewable energies, resource use/efficiency, innovative environmental and process engineering is important. The task requires interdisciplinary work in various fields of technology (biological/chemical processes, plant engineering, energy systems) and business administration (investment and operating costs).

Dates

Please reserve these dates: Fishing for Experience Termine

Registration

You can apply here for Fishing for Experience.