Chris Higman reports from the Gasification Technologies Conference 2014*

About 400 delegates assembled in Washington, DC to attend the 2014 Gasification Technologies Conference, 26-29 October. While in recent years there has been much discussion of project development, the 2014 conference saw much more focus on construction and commissioning. All in all presentations of projects in this phase of realisation amounted to an estimated 14 000 MWt of synthesis gas (syngas) production outside China. If Chinese projects were included this number would more than double.

Construction and commissioning

The largest gasification project presented at the conference is that of Reliance Industries in Jamnagar, India. The basic plan is to use petroleum coke generate on the site, which is the world’s largest oil refinery, to produce syngas as a replacement for current LNG imports. Of course in detail, the project is more complicated than this. The two main products are fuel for the cogen power and steam generation system and hydrogen for the refinery. Additionally some gas will be methanated to provide substitute natural gas (SNG) fuel for existing process heaters. New process heaters will be designed to use unconverted syngas. This major fuel replacement project will also release ethane and ethylene from the refinery fuel gas system for use as petrochemical feedstock. The overall syngas production from the ten large CB&I E-Gas gasifiers amounts to about 11 000 MWt. Engineering and procurement are essentially finished and construction is about 20% complete. Start up is scheduled for 2015.

A second E-Gas project is that of POSCO in Gwangyang, South Korea. This 1600 MWt coal-to-SNG project is also motivated by the high prices of LNG in the Asian market. Construction on this project is nearly 90% complete and start up is scheduled for early 2015. The engineering, procurement and construction is being performed by POSCO’s own E&C company. POSCO E&C is also following up a number of other projects of this sort. In Korea this includes a plant of similar scope for Korean Southern Power, which would use it to refuel existing LNG-fired NGCC plants. Further from home are a coal-to-liquids plant in coal-rich but oil-poor Mongolia and an SNG plant in Brazil to produce four times the amount of SNG as the Gwangyang plant.

Despite (or in one case perhaps because of) the new-found abundance of natural gas in North America there are three projects under construction there. During the year Mississippi Power’s Ratcliffe (Kemper County) lignite-fired 582 MWe IGCC power plant, to be equipped with 65% CO2 capture, started producing power from the combined cycle unit with natural gas fuel. The project has seen considerable cost and schedule overruns and commercial operation on syngas is now scheduled for 2015. The boom caused by the availability of cheap natural gas has reached the construction industry (with welders costing over $100/hour) and this has been an important contributor to these overruns. The impact on some newer projects has been simpler. They have just been cancelled before any site activity began.

Cheap natural gas is not a hindrance to some projects however. An example is the Linde Gas project to expand the capacity of its La Porte, TX, syngas plant. The facility will use GE’s partial oxidation technology to generate a high pressure product gas as feedstock for nearby petrochemical plants. The process, operating with virtually no steam addition, produces a gas much richer in carbon monoxide that the traditional steam reforming technology. The new air separation unit (ASU) will come on stream in December 2014 with the gasifier following on in Q1 2015.

Although site activities for the third North American project, North West Redwater’s Sturgeon Refinery near Edmonton, Canada have been underway for a year, the start up is only scheduled for 2017. This project is much larger than just the gasification and syngas treatment units. It is essentially a grass-roots refinery, upgrading oil-sands bitumen to low-sulphur diesel and similar high quality products. The function of the gasification unit is to convert refining residues to the hydrogen needed for the product hydrocracking and desulphurisation. At the same time carbon dioxide is captured for use in enhanced oil recovery (EOR). Climatic conditions in Alberta are such that unhindered construction activities are only possible for seven months in the year. Much of the gasification plant will be modularised.

China has seen three technically interesting start ups during 2014, which were discussed in presentations at the conference. The first was Shell’s long-awaited quench gasifier. The Shell Coal Gasification Process has been well-known for its high efficiency and high cost. Major cost contributors are the steam-generating syngas cooler, the recycle gas quench and the dry gas filtration. These have all been eliminated in the water quench version now demonstrated at the 1000 t/d feed scale for Wison in Nanjing (see illustration on previous page). Other important features of the existing process, such as dry feed burners and water wall, which contribute both to the efficiency and fuel flexibility, have been retained. The demonstration plant was first started in October 2013 and has been under demonstration and test operation for the last year. Four coals have been tested with ash content varying between 8 and 25%.

The other Chinese start ups of technical interest use ECUST (East China University of Science and Technology) technologies. The 3000 t/d feed ECUST OMB gasifiers for Rongxin Chemicals in Ordos, Inner Mongolia, operating at 65 bar, are currently the largest in the world. ECUST’s OMB technology uses a coal-water-slurry feed and multiple, side- mounted burners. In co-operation with Sinopec it has now developed a dry-feed, top-fired gasifier with single burner. The 1000 t/d feed SE (Sinopec-ECUST) demonstration plant at Sinopec Yangzi Petrochemical site was taken on line in January 2014. The full acceptance test was performed in October. More of these units are planned for other Sinopec sites.

Biomass and waste

Significant real-world activity has also been taking place in the field of biomass and waste gasification. The first of two 1000 t/d waste gasifiers located at the Tees Valley Renewable Energy Facility near Billingham, UK, is currently in commissioning. These are the largest Westinghouse Plasma gasifiers ever built, with a diameter of 9 m and a height of 25 m. Each of the two lines is coupled to a combined cycle unit that will generate 50 MWe. Westinghouse Plasma Corp has also supplied a turnkey unit to gasify hazardous waste in Shanghai, which was taken into service in Q1 2014.

The size range of biomass technologies is considerable. The smallest commercial unit presented at GTC 2014 was a 12 t/d downdraft gasifier built by PHG Energy in Covington, TN. The syngas generated from a mixture of sewage sludge and waste biomass is used to power a small organic Rankine cycle unit, generating 120 kWe, half of which is used internally. The balance is used in the adjacent waste water treatment plant, which is the source of the sewage sludge. Waste heat in the flue gas is used for drying the 55% moisture feedstock.

Other interesting presentations included that of Royal Dahlman, which described technology proposed for a 7 MWe (net) power plant in Grimsby, UK, which is in the running for support from the UK’s Energy Technologies Institute. The technology offered is an ECN MILENA dual fluid bed biomass gasifier using steam as gasifying agent, coupled with ECN OLGA tar removal technology (see pp 18-20).

Research and development

An important development reported on at this and and previous conferences is RTI’s warm (250-600°C) desulphurisation process. The demonstration unit at Polk power station in Florida, which takes about 20% of the raw syngas from the 250 MWe IGCC power plant there was taken into service in early 2014. By the time of the conference the plant had over 2000 hours of operation. The sorbent attrition rate has so far proved to be less than design. Sulphur removal is 99.8-99.9% including COS, a difficult component for many solvent-based systems. And there is to date no indication of sorbent deactivation. Desulphurised gas is already fed back into the main plant as gas turbine fuel. The demonstration period is planned to last one year and will come to an end in late 2015. RTI is now seeking a partner to commercialise the technology.

A technology that is much earlier on its development path is the Allam Cycle, which, put simply, is a semi-closed Brayton cycle operating with carbon dioxide as the working fluid. An important result of the process is that excess carbon dioxide is available pure and at pressure. A first 50 MWt demonstration of the cycle with natural gas as fuel in a turbine especially developed by Toshiba is planned for a site in Texas. Commissioning is expected to begin in 2016 with completion in 2017. The GTC presentation focused on the use of the Allam Cycle with syngas, so as to make it usable with solid fuel feedstocks.

Significant activity

There continues to be significant activity in the gasification market – and not only in China. This has motivated the Gasification Technologies Council (organiser of GTC) to move its database from a three-year update cycle to an annual update. Despite the decommissioning of a considerable number of oil-fired gasifiers for economic reasons (prior to the recent fall in oil prices), the net gasification capacity has increased during the year by 12 000 MWt. A further 80 000 MWt is under construction, much of which is related to the Chinese SNG and coal-to-chemicals programmes. The growth can be seen from the graph below, which was presented at the conference by your correspondent.