-clean energy supply for a sustainable society Lina Vallin David Kvick Jörgen Ejlertsson Anna Karlsson

Production site in Linköping Production started in tones of organic materials processed annually tones of certified biofertilizer sold annually on a regional market. Total sales of 4,5 million Nm 3 biogas (97 % CH 4 )

The biogas process

Substrates treated at the plant ProductAmountShare of total amount tons(%) Slaughtery industry % Food industry % Pharmaceutical industry6002% Alcohol1 2003% Manure2 0005%

Biofertilizer Provides routines for the production plant in respect to get a valuable and stable biofertilizer. Insurance of quality for the farmer. Confidence in the product for the customers to the farmer e.g. food processing industries.

Biogas in Sweden EU’s goal for 2020 means every fifth car. Great focus on market expansion with a common goal of 100 filling stations before 2010 (34 st 2003  ~50 st 2004) Svensk Biogas filling stations 2005/2006 (13 in total): Linköping (4) Norrköping (1+1) Katrineholm Nyköping Mjölby Örebro Västervik (+1) Motala (+1)

Progress of the production Gas production today: 155 Nm 3 /ton substrate

Process development Increased knowledge of the microbiological process in the digester Optimization of the process at the current production plant in Linköping New concepts for biogas production

Lab scale reactors Mesophilic digestion, 37 degrees Volume 3 L Volumetric gas meters Analysis of: substrates process parameters biofertilizer

Lab scale experiments Addition of iron chloride and hydrochloric acid Experimental plan: –Controls (1a & 2a) –Post-digestion of the control reactors (retention time 12.5 days) –Reactors (3 & 4) with adjusting of pH (7.5 respectively 7.8) Substrate : from the full scale plant.

Results – gas production Day Production of biogas (L/(day and 4Lreactor)) ♦ 1a normal ■ 1b post-digestion normal ▲ 2a normal ● 2b post-digestion pH 7.5 x 3 pH pH 7.8

Day Acetate (mg/l) Results – acid production ♦ 1a normal ■ 1b post-digestion normal ▲ 2a normal ● 2b post-digestion pH 7.5 x 3 pH pH 7.8

Amount of organic acids at the Linköping biogas plant Concentration of organic acids (mg acetate/L) Rk1 (mg/l) Rk2 (mg/l)

Conclusions The experiment resulted in an increase of 30 % gas production when pH was adjusted to 7.5 and 7.8. The amount of organic acids were decreased by 50 %, which indicates a stabilization of the process. The product was implemented at the plant in Linköping with good results. The composition of the product and the amount added must be optimized in regard to the substrate fermented. The product has been developed in cooperation with Kemira, and will soon be available on the market. The product has been patented by Tekniska Verken i Linköping AB (publ.).

For further information: Lina Vallin Thank you for your attention!!