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

2. Production site in Linköping Production started in 1997. 54 000 tones of organic materials processed annually. 50 000 tones of certified biofertilizer sold annually on a regional market. Total sales of 4,5 million Nm 3 biogas (97 % CH 4 )

3. The biogas process

4. Substrates treated at the plant ProductAmountShare of total amount tons(%) Slaughtery industry28 30075% Food industry5 80015% Pharmaceutical industry6002% Alcohol1 2003% Manure2 0005%

5. 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.

6. 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)

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

8. 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

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

10. 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.

11. Results – gas production 0 2 4 6 8 10 12 14 16 -303691215182124273033363942454851545760636669 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 7.5 + 4 pH 7.8

12. 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 -6-226101418222630343842465054586266 Day Acetate (mg/l) Results – acid production ♦ 1a normal ■ 1b post-digestion normal ▲ 2a normal ● 2b post-digestion pH 7.5 x 3 pH 7.5 + 4 pH 7.8

13. Amount of organic acids at the Linköping biogas plant 0 2500 5000 7500 10000 12500 15000 17500 20000 22500 25000 27500 30000 32500 1999-06-191999-07-091999-07-291999-08-181999-09-071999-09-27 1999-10-171999-11-061999-11-261999-12-162000-01-052000-01-252000-02-142000-03-052000-03-252000-04-142000-05-04 2000-05-242000-06-13 2000-07-03 Concentration of organic acids (mg acetate/L) Rk1 (mg/l) Rk2 (mg/l)

14. 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.).

15. For further information: Lina Vallin lina.vallin@tekniskaverken.se Thank you for your attention!!