Renewable Energy
predominantly generated from landfill gas – a trend driven by the high amount of waste the UK produces every year and the shortfall of space to house it.
Outside the EU, the opportunities to transform waste to energy are vast. Many initiatives are already underway in the Middle East, for example, with Qatar currently generating 30MW of electricity. Meanwhile Saudi Arabia and the UAE are setting production capacity targets to help improve their waste management. Whereas in Africa, there is still more work to be done to enable efficient use of waste. Although some urbanised cities have started to implement effective waste management techniques, including recycling and composting, more education is needed to promote the benefits of waste management and the technologies to do so need to be made readily available.
The climate change factor One of the strongest cases for generating energy from waste is its potential contribution to climate change. It has a valuable role to play in both diverting waste from landfill and in power generation. Converting this waste into gas can help reduce emissions that would otherwise be released into the atmosphere as the waste decomposes in landfill sites or on farmland. However it’s not without challenges. The biggest issue is how we can use this waste safely and efficiently to generate power.
The composition of landfill gas, in particular, typically has methane concentrations of around 45 to 60% and it can also contain a number of harmful contaminants including halides, volatile organic compounds and siloxanes. These siloxanes are used in the manufacture of personal hygiene and healthcare products such as deodorants and shampoos, and as a result of their widespread use, are often found in landfill sites.
It is these contaminants that pose one of the biggest challenges for the waste to energy sector. They can accelerate wear and scuffing in engines, resulting in the need for more frequent maintenance procedures and limiting engine availability.
Due to the contents of the gases used, pre- treating is required. This helps to reduce the extremely corrosive nature of these contaminants, such as sulphur compounds, which can lead to engine damage.
Lubricants are also vital in protecting gas engines but this becomes particularly important in those running on aggressive gases. As these gases are particularly corrosive, operators need to consider a lubricant that can help mitigate the risks and still maintain performance. There are a number of points that should be taken into account when selecting an effective lubricant that will extend oil drain intervals, reduce the frequency of maintenance and ultimately improve power output.
One important factor when selecting a lubricant for an engine running on biogas is its total base number (TBN), which identifies its acid-neutralising capacity. Alkaline additives used in higher TBN lubricants can help protect engines by absorbing and neutralising the corrosive properties of sulphuric acid. As a result, component and equipment life can be extended, reducing the risk of unscheduled downtime and engine failure.
To improve the productivity of waste to energy power plants, regular oil analysis should also be conducted. Examining changes in the oil analysis data over time is necessary to assess the condition of the oil. Conducting regular used oil analysis can help operators anticipate oil drain intervals, reduce maintenance and, in turn, improve safety.l
Jarmo Vihersalo is with ExxonMobil.
www.exxonmobil.com
www.engineerlive.com 23
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25