Biogas production/storage for lessened dependency on oil
Who are we looking for?
The department for wastewater- and drinking water treatment in Oskarshamn are looking for a student with a background/knowledge in biogas storage and optimization for an exciting project looking into the energy demand at Ernemar wastewater treatment plant. The project will focus on trying to meet the energy demand for heating of the facilities by utilizing the available in-house digestor, where optimization by either separation of gas, increased overall biogas production or storage of biogas are possible alternatives to achieve this goal.
Project background
Ernemar wastewater treatment plant is the central and largest treatment plant in Oskarshamns municipality with a capacity around 20 000 pe. The treatment plant operates as an active sludge treatment plant with demand on both phosphor and nitrogen reduction before final release into the Baltic sea.
A mesophillic digestor exists at the site were processed sludge is used for biogas production. Before being put into the digestor, water is removed from the sludge until a dry weight of around 4-8 % is achieved through a de-watering process using a special kind of polymer. Removal of water is critical to make sure that as little energy as possible is required to heat the material to an appropriate temperature for digestion (~ 37 C °). It is preferable to have a high level of digestion as it leads to less digested sludge that needs to be transported away off-site which in turn helps us to cut costs.
Once the sludge has been digested, methane and carbon dioxide is formed and transported away to a small gasometer (gasholder, for storage) before it is used in the boiler for heating of water which in turn heats the facility buildings and the digestor. In the case were not enough gas is produced to satisfy the heating demand of the buildings and the digestor a second boiler is used where oil is used as fuel.
Over a year the biogas production is around 650 Nm3/day and over a year around 237 340 Nm3. Oil usage is around 1,5 m3 per year. The current gas production is enough to cover the needs over the warmer months of the year but not enough during the colder ones (Nov-Mar).
Project goal
The goal of the project is to lessen the dependency and need for oil during the colder months of the year, this either through increasing our storage capabilities and/or through optimization of the biogas production. What we are looking for is someone who can investigate what options we have to achieve our goal of reducing our use of oil for heating and can estimate investment costs of said options in the form of a list ranking (most expensive to least expensive) and deliver this in written form for us to use further down the line in potential, future projects.
Supervisor at KTH
If this sounds interesting to you or if you would like more information about the project, please contact Marcus Westholm or through 010-35 60 716.