Renewtec has made an inventory of techniques related to gasification of Shredder Light Fraction (SLF) to a client who wants to remain confidential.
According to Swedish legislation shredder products containing more than 10% of organic carbon is not allowed to be deposited, it should be recovered (material or energy). End-of-Life products such as cars undergo a shredding process which result in shreeder light fraction containing plastic parts, textile, rubber etcetera.
SLF contains metalls, including heavy metals, but also substances that normally aren’t associated with gasification feedstock, such as bromine originating from flame retardants. SLF has normally a high content of ash and chlorine resulting in an increased risk for agglomeration, sintering, fouling, build up of depositions and corrosion.
International Conference on Renewable Energy Gas Technology, REGATEC 2014, takes place 22-23 May 2014 in Malmö, Sweden.
REGATEC has a technical and industrial focus and is directed towards thermo-chemical and microbial conversion of biomass and waste to biomethane.
In addition to plenary and parallel sessions with presentation, there will be a poster session and an exhibition. 250 participants and up to 40 exhibitors are expected.
REGATEC is organized by prof. Frank Scholwin, Institute for Biogas, Waste Management & Energy and dr. Jörgen Held, Renewable Energy Technology International AB.
In Germany CNG (Compressed Natural Gas) costs approx. 1 euro/kg (which is about half of the cost in Sweden) and there are no instruments targeted for the use of biomethane in the transportation sector. However, there are instruments (feed-in tariffs) that promote the use of biogas for production of renewable electricity. Approx. 30 % of the energy content in the biogas becomes electricity when used for electricity production while 100 % of the biogas is utilized when it replaces fossil fuels in the transportation sector. The above indicates that there are market possibilities in Sweden for upgraded German biogas.
In a study ordered by Nawaro AG the costs and conditions for different types of biogas distribution were investigated by Renewtec and several distributors of biomethane and operators of filling stations as well as one trading company were contacted for further discussions.
In a study financed by the Swedish Energy Agency and the industrial gasification group at the Swedish Gas Technology Centre (SGC) Renewtec has reviewed promising gasification techniques for small and medium scale (5-30 MWth) biomethane production.
Small plants are normally associated with a high specific investment cost but by changing to a gasification and gas cleaning technique adopted for smaller plants this problem may be circumvented.
Even if small plants often are associated with a somewhat lower conversion efficiency there are several advantages to build plants in the smaller scale. The economic risk is lower, it’s easier to secure the feedstock supply and to integrate excess process heat with the local heat demand.
On the gas cleaning side techniques related to catalytic tar reforming are under development which implies that the rather costly tar separation based on wet scrubbing techniques can be avoided. When it comes to carbon dioxide separation the thermo-chemical biomethane route based on gasifcation and methanation profits from the development within the anaerobic digestion sector.
The report can be downloaded through the following link Small and medium scale technologies for bio-SNG production
In the report the specific investment cost is investigated.