ECN publication
OLGA Optimum - Improving the economics of integrated biomass gasification plants by extension of the functionalities of the OLGA tar washer
Boerrigter, H.; Bolhár-Nordenkampf, M.; Deurwaarder, E.P.; Erikson, T.; Könemann, J.W.; Rauch, R.; Paasen, S.V.B. van; Palonen, J.
Published by: Publication date:
ECN Biomass, Coal and Environmental Research 20-11-2006
ECN report number: Document type:
ECN-E--06-048 ECN publication
Number of pages: Full text:
49 Download PDF  

The main technical challenge in the implementation of integrated biomass gasification plants is the removal of tar from the product gas, e.g. with the OLGA tar removal technology. OLGA requires cooling of the gas to below 320-340°C and de-dusting of the product gas. The economy of gasification plants can be improved when the OLGA is suitable for combined tar and dust removal (i.e. then the hot gas filter is superfluous) and when the risk of tar fouling is minimised. In this study the impact of OLGA extensions addressing the system efficiency and economic potential were assessed for eight selected systems, based on circulating fluidised bed (CFB) or fast internally circulating fluidised bed (FICFB) gasification. The use of an OLGA for combined dust and tar removal increases the system efficiency, while changing the cooler temperature has no efficiency effect (although it is desired for operational point of view). The total fuel utilisation in the CFB systems is more than 80%, while the standard FICFB case has a 4% point lower utilisation. Installation of an OLGA unit to replace the standard FICFB tar scrubber has little effect. However, the OLGA allows the reduction of the steam consumption in the gasifier and this results in an increase of the fuel utilisation to 79%. The IRR of the FICFB reference case is 8.1%; the economic viability can be increased to 8.8% when an OLGA unit and an air-cooled fire-tube cooler are installed. The highest IRR of 9.8% is realised in the system based on a CFB gasifier with an OLGA (and fire-tube product gas cooler). The cost-effectiveness of integrated biomass gasification CHP plants can be improved when an OLGA unit for combined tar and dust removal is part of the system.

Back to List