Siemens Sees Technology Upgrades Aiding Gasification Projects

San Francisco – Ever since Siemens acquired the former Future Energy gasification technology from Sustec 15 months ago, it has been undertaking investigations on how to improve gasification for future applications.“We need a 15-20% cost reduction to get the ‘third wave’ of IGCC [integrated gasification combined cycle] going,” Siemens IGCC business development manager Harry Morehead told the Gasification Technologies Council 2007 conference here.Unfortunately, energy-project engineering, procurement & construction (EPC) costs are “skyrocketing,” which has put a damper on several proposed IGCC projects, he noted.Meantime, development of “reference plants” (now underway) will help to trim the cost differential between IGCC and conventional pulverized-coal plants, he showed.

But government incentives and stakeholder risk-sharing also are needed to push IGCC forward in the near-term, he added.What’s more, carbon capture & storage (CCS) “has become a given for IGCC – a significant challenge,” he said, since governments have yet to define a legal framework for CO2 storage. Nor has the real market cost/value of CO2 been well-defined, world-wide.

But while many IGCC projects may be snagged by cost and CO2 issues right now, non-IGCC gasification projects are moving ahead, he noted. Among the newer projects in which Siemens is involved: a resid gasifier at the Sokolovska refinery in Czech Republic (now in start-up); two coal-to-chemical gasification projects in China (Shanxi Lanhua ammonia plant, and Shenhua Ningxia, a propylene project); the proposed Secure Energy coal to synthetic substitute natural gas (SNG) project in Illinois; and the in-development Dodds Roundhill coal gasification project in Canada (for Sherritt, to produce syngas for IGCC and hydrogen for industrial users).

Currently, Siemens has nine 500-megawatt (thermal) gasifiers on order or being manufactured, Morehead said. The company’s Freiburg, Germany, test center used for feedstock studies and pre-FEED studies is “booked solid” thanks to growing commercial interest, he added.

As for front-end engineering & design (FEED) projects, Siemens has three FEEDs for proposed IGCC plants underway. However, “the challenge is addressing the cost increase” of such energy projects, he said.This year, Siemens has completed combustion testing of high-percentage hydrogen feed to its SGT6-5000F gas turbine, employing a “new combustion system for IGCC based on existing Siemens diffusion-flame technology,” he said. The scheme allows use of the existing access port for air extraction and integration with an IGCC plant’s air-separation unit.In future, Siemens aims to go beyond its current SFG-500 class gasifier (500-MW) to even larger gasifiers (one shown with a triple burner here) in order to improve over-all plant economics, he said.

This bigger gasifier would enable matching the requirements of Siemens “F-class” turbines, he explained.Also under R&D starting this year: a new gasifier with partial quench and waste heat recovery steam generator system. This scheme, if commercialized, would enable “efficient use of the high temperature heat in the steam generator” for high-pressure or intermediate-pressure steam; water quench of raw syngas and slag; optimization of the reactor; and optimization of partial-quench system, he said.

The idea is to boost plant efficiency without sacrificing reliability and availability, he added. But while the scheme holds promise, “it’s not a given that we’ll commercialize it,” Morehead said in response to a question here. “Adding new technology can add risk.”