Occurrence and distribution of valuable metals in fly ash from Puertollano IGCC power plant, Spain

Division of Natural Sciences, CTG, University of Hertfordshire, College Lane, AL10 9AB Hatfield, UK. KEYWORDS: fly ash, coal gasification, germanium, nickel, vanadium INTRODUCTION In 1992 an Integrated Gasification in Combined Cycle (IGCC) plant in Puertollano (Spain) was launched as a THERMIE Targeted Project to demonstrate the feasibility of the European IGCC technology. Now that this plant is running in commercial operation, it proves the use of coal with high efficiency in an environmentally friendly manner. The Puertollano IGCC plant design innovative features focus on two main targets: improved efficiency (45% net, ISO conditions) and reduced emissions. The design concept is arranged at the maximum integration level (specially, the air streams and nitrogen network) and large capacity components (2600 t/day gasifier and 200 MW gas turbine rating) were selected. Works started at the site in April 1993, and mechanical erection of the Combined Cycle Plant began in June 1994. The first gas turbine operation with natural gas was carried out in April 1996 and in September 1996, the combined cycle 100 hours test was undertook. The first gasifier firing on design feedstock took place in December 1997, in August 1999 the IGCC 100 hours test was undertook. Between February and March 2000, ELCOGAS proved the flexibility of the gasification process by carrying out four tests using different coal/coke mixtures (respectively 54/46, 58/42, 42/55 and 39/61 in weight) over 525 operating hours. Until May 2001, 7537 h of operating gasifier have been accumulated. The net electricity production with coal gasification is currently 1379442 MWh and the Gas turbine maximum achieved load on coal gas operation has been 197.6 MW. The annual production of IGCC by-products from the Puertollano power plant is 12000 tonnes of fly ash and 90000 tonnes of slag. Due to the geochemical peculiarities of the Puertollano coal