Upgrading landfill gas to vehicle fuel

Transcription

1 Upgrading landfill gas to vehicle fuel Seminar on landfill gas Malmö, 24. May 2016 Björn H. Halldórsson, CEO SORPA bs.

2 SORPA bs SORPA is a not-for-profit company jointly owned by 6 municipalities in the capital area. SORPA runs: Second hand market for used household goods. 6 recycling centres. 84 drop-off centres. A receiving- and sorting plant. A landfill. SORPA services approx. 70% of inhabitants in Iceland.

3 Energy situation in Iceland 90% of homes are heated with geothermal power. 100% of electricity produced by hydropower or geothermal power. 99,7% of transportation fuel is imported. Natural gas has not been found in harvestable quantities in Iceland.

4 The landfill site at Álfsnes The landfill in question at Álfsnes commenced operation in Waste is baled before landfilling. Collection of landfill gas started in Flared in the beginning. In 2000 a small pilot plant was installed for cleaning the landfill gas. In 2000, 17 different bi-fuel vehicles where introduced by various entities.

5 Various vehicles running on methane In 2005 the public bus company decided to buy 2 buses that could run on methane. In 2005 Reykjavik City decided to change out waste trucks from diesel to methane. A new upgrading facility was installed in 2006.

6 The Upgrading Plant Both the pilot plant and new plant use the same technology water scrubber. Both the old pilot plant and the new plant operate at 20 bar pressure (even the new one slightly over 20 bar pressure): 20 bar pressure results in lower tower. Lower water consumption

7 The Upgrading Plant The new plant was designed by Mannvit Consultants, our own workforce and with a little help from Sweden. Constructed on site - tendering on main components (pumps, compressors, dryers etc). Towers built in Iceland. Constructed by Icelandic company. SCADA system designed by Mannvit.

8 The Landfill gas Upgrading Plant Runs 24/7. Two individual lines, each capable of processing 450 Nm 3 of landfill gas. Distributors (oil companies) can have the methane pumped into a 9 bar pipeline, or compressed to 200/250 bar on containers (bottles).

9 Upgrading plant

10 Experience Diverse technical challenges have risen during course of time. But most of the problems are related to the mine not the upgrading plant Climate/weather Settlements in the landfill Design of boreholes and collection system Difficult to secure low N 2 levels Problems related to the upgrading process Dew point Algae growth

11 Experience and main challanges Production of landfill gas is very difficult to control after waste has been placed in the landfill. Weather and climate have a big influence. Atmospheric pressure. Amount of rain. Technical layout and forming of gas collection system Top layer thickness. Top layer quality. Type of wells. The type of wellheads collection system.

12 Landfill system Hydrology Waste physiochemical character Weather conditions Landfill system Waste composition and gas potential Gas collection system Leachate

13 Water height from sea level (m) Conditions in the landfill 26,00 25,00 24,00 23,00 22,00 21,00 20,00 Average water level inside waste

14 Climate/weather

15 Conditions in the landfill

16 Borhole profile 50mm connection valve Borehole head Protective blue barel Connection hose Ø32mm Soil shield Main collection pipe Ø160 Intermediate collection pipe Ø50mm Soil cover Bentonite Soil cover Landfilled waste Landfilled waste Draining material Drainage pipe Leachate Compacted clay

17 Well head Artic conditions High quality components in a 4th generation system Water level, Tbottom and ph measurement Isolation / Wind barrier Gas quality and quantity measurement Linear flow valve, adjusted monthly Creep autoadjustment ~100 W from a good well (5 Nm 3 /h)

18 Gas collection system (~30 m grid, ~170 boreholes, negative pressure, pigging ) Collection of landfill gas at lowest point Collection and water cleaning at suction point

19 Experience and main obstacles Human factor Physical laws apply (!) Employee understanding and commitment. Planning. Despite many obstacles the upgrading facility has run without problems longest stop, resulting from failures in the upgrading plant, is 6 hours to this date. 2+ line system provides for redundancy which is necessary for a smooth operation and customer satisfaction! Model of landfill gas production, high quality of the landfill gas collection system and implementation of a strong and rigid policy on the landfill gas collection

20 Primary goal of landfill gas collection system adjustment Collecting landfill gas without oxygen and minimize nitrogen at a fixed production rate Adjust system according to measurement results. Plan and implement maintenance to keep mechanical system in optimal conditions. Develop knowledge on landfill gas generation and interaction with the collection system. Develop a model and a monitoring tool for daily operation.

21 Future projects Landfill ( the mine ) Drones used to record near-infrared pictures and heat pictures to find faults in the top layer. Drones for better monitoring of settling. Drones used for better monitoring of vegetation cover. A Biogs plant for precessing household waste is being projected and will be installed within the next two years -> higher quality biogas Installing larger, high pressure depot Investigating liquification of methane (LBG) and production from CO 2 and H 2

22 Thank you!