In order to obtain pipeline quality gas the biogas

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: njection into the natural gas grid, and transport as “Green Gas” to customers, would be more advantageous. In order to obtain pipeline quality gas, the biogas must pass through two major processes[7]: (1) A cleaning process, in which trace components (hydrogen sulphide, water, particles, halogenated hydrocarbons, ammonia, oxygen, and organic silicon compounds) harmful to the natural gas grid, appliances, or end-users, are removed. (2) An upgrading process (basically separation of methane and carbon dioxide), in which the calorific value, Wobbe-index and other parameters are adjusted in order to meet the pipeline specifications (furthermore, the gas must be odourised before it is added to the natural gas grid). In 2001, 27 landfill projects in the Netherlands delivered 2*107 Nm 3 natural gas equivalent to the gas distribution net, while the contribution of biogas from digestion projects was about 3*107 Nm 3 natural gas equivalent. Compared to annual Dutch gas consumption of 4*1010 Nm3, the contribution of landfill gas and digestion gas was, therefore, 0.1%. Taking into account the additional potential for digestion gas, a total contribution of about 0.5% of the annual Dutch gas consumption can be achieved. Although very limited, the short-term exploitation of this potential, as “Green Gas” would be interesting[8]. If biogas is distributed in a closed biogas network or in a town gas network, only cleaning of biogas is necessary. This option has been demonstrated in Sweden and Denmark[7]. Utilisation of the natural gas grid, as a transporting system for biogas, plays an important role in promoting the use of biogas as a vehicle fuel, as it will be possible to produce biogas in any place along the gas grid, with the possibility to trade 100% of the gas as vehicle fuel. In Switzerland gas as a fuel for vehicles is becoming more and more popular. Both natural gas and biogas are utilised as vehicle fuel. Also in ECN-RX--04-085 5 Sweden biogas has become very popular as a fuel for vehicles (end 2000 about 4000 vehicles operated on biogas[5]). During the last years many upgrading...
View Full Document

Ask a homework question - tutors are online