SORPA’s production - Landfill and gas collection at Álfsnes.
In all landfills, landfill gas, a mixture of CO2 and methane (CH4), is formed. The landfill gas forms when natural bacteria break down organic material in the landfill, forming a landfill gas compound. The methane in the landfill gas is very rich in energy but is also a high-impact greenhouse gas, having approximately 21 times greater impact than carbon dioxide. It is better to burn the gas than allow it to emit into the atmosphere, as burning methane produces carbon dioxide and water vapours. The greenhouse effects of the Álfsness landfill are therefore minimal.
The chemical content of the landfill gas in Álfsnes is usually around 57% methane (CH4), 41% CO2 and 2% other gases.
Waste is buried in a highly systematic manner.
The landfill area is divided into 40-metre-wide strips which are then filled with waste, one at a time. Baled waste is placed in these strips before being covered with a layer of soil 1.5–2 metres thick. When several strips have been filled, grass seeds are planted in the soil.
The landfill is drilled every 1 ½ – 2 ½ year after each strip has been filled. Around 25 gas holes are drilled every year and slotted plastic pipes are placed in the holes. At the top of the pipe is a pipe that connects to a collection pipe. There are six collection pipes that connect with the main pipeline leading to the pumping plant, where the landfill gas is pumped from the slots. A pipe from the pumping plant leads to the SORPA treatment plant and a burner.
Methane production at Álfsnes in 2014 corresponded to 2.2 million litres of petrol.
Plans are afoot to plant trees in the landfill area in the future.
SORPA is collaborating with the Agricultural University of Iceland at Hvanneyri on a project called “Utilisation of Organic Waste”.