DOE issues new analysis on coal-fueled Texas Clean Energy Project

The U.S. Department of Energy (DOE) on Feb. 24 issued a supplement analysis (SA) to the coal-fueled Texas Clean Energy Project’s (TCEP) Final Environmental Impact Statement (EIS) that had been issued in 2011.

The new analysis is based on the changes made to the coal gasification project after the record of decision (ROD) was issued in September 2011. The ROD announced DOE’s decision to provide $450 million, in accordance with the terms and conditions of the cooperative agreement, in cost-shared Clean Coal Power Initiative funding to Summit Texas Clean Energy LLC. This funding would support the planning, design, construction and operation of the TCEP in Ector County, Texas.

Since the ROD was published, the plant configuration and associated resource requirements, plant processes, and by-products have been modified; six new delivery options from three new water supply sources and two new backup water supply sources for the TCEP’s process water supply have been identified; and, additional information gathered from an exploratory well and nearby production wells to support planning for the TCEP’s deep well injection option for brine disposal has been obtained.

The TCEP would be located approximately 15 miles southwest of the city of Odessa in Ector County, Texas. It would demonstrate the full integration of CO2  capture and geologic sequestration with a commercial, coal‐based polygeneration plant.

While the purpose and need for Summit’s project has not changed since issuance of the final EIS, the polygen plant design has been modified. Specifically, the polygen plant configuration has been altered to use one larger gasifier, instead of two smaller gasifiers, and to use a larger gas combustion turbine‐generator. These changes increase the efficiency of the polygen plant, decrease its costs, and improve the project’s return on investment. As a consequence, the plant’s availability, resource requirements, by‐products, emissions and waste streams change slightly.

In general, Summit’s purpose and need for the TCEP is to continue and expand its business strategy of developing low‐ and zero‐carbon power projects. Specifically, the purpose of the TCEP is to add low CO2 emissions base‐load power to the nation’s electricity generation mix, to provide supply stability to offset the irregular nature of West Texas wind generation, and to store captured CO2 geologically, in this case by using it to boost production of oil wells in the Permian Basin. There also is a national‐level need for urea‐based fertilizers. Granulated urea produced at the plant would support the farming industry and reduce annual imports of foreign‐produced urea by approximately 10%. There are now two newly identified by‐products, ammonium sulfate and liquefied nitrogen gas, that have potential for local sales.

Project cut from two Siemens gasifiers, to one

Summit has reconfigured the plant to replace two Siemens SFG‐500 entrained flow, oxygen‐blown gasifiers with a single larger SFG‐850 gasifier. There will be a corresponding change in combustion turbine‐generator from an SGT6‐5000F3 combustion turbine‐ generator to an SGT6‐8000H combustion turbine‐generator. While the gross generating output will remain approximately the same at 400 MW, the reconfiguration will result in an increase in the electrical output to the grid from 130 MW–213 MW to 140 MW–262 MW on average.

The reconfiguration will require a reduction in coal feed from 5,800 tons  per day as stated in the EIS to 4,611 to 5,097 tons per day. No significant changes to the transportation intervals (e.g., two 150‐car trains per day and two to three 150‐car trains per week) of coal to the polygen plant are expected as a result of the polygen plant reconfiguration. However, on an annual basis, there will likely be fewer 150‐car trains overall as arrivals are expected to be less frequent in nature and less at the regular intervals anticipated in the EIS. In addition, no changes to the storage of coal are expected; storage will remain at 45 days of total capacity with approximately 9 days of active storage and 36 days of inactive storage.

The  reconfiguration will have an overall lower amount of syngas production as a result of the new single SFG‐850 gasifier having a lower capacity than the two SFG‐500 gasifiers combined. The total amount syngas produced by the SFG‐850 gasifier is distributed through two syngas streams: one to the ammonia/urea synthesis unit and the other to the power block. The amount of syngas required to operate the ammonia/urea synthesis unit will increase by approximately 18%  from 1,077 million British Thermal Units (MMBtu) per hour under the old configuration to 1,273 MMBtu per hour to achieve higher ammonia/urea production. This increase to the ammonia/urea synthesis unit, combined with the decreased gasifier capacity, allows for an even smaller amount of syngas available to the power block. Syngas available to the power block will decrease between 10% and 43% from 1,718 MMBtu per hour as identified in the EIS to 1,205 to 1,559 MMBtu per hour. This decrease, however, will be supplemented with natural gas to maintain approximately the same amount of gross power generation output.

As a result of the polygen plant reconfiguration, the natural gas required for coal drying, and gasifier and flare pilots will be reduced or at the same levels as what was identified in the EIS. The polygen plant reconfiguration will now use the low pressure steam for pre‐drying coal, then natural gas and tail gas for subsequent drying, thereby reducing the amount of natural gas compared to the original configuration, even with the use of natural gas to supplement syngas in the power block. The polygen plant would typically require between 1,012 to 1,111 MMBtu per hour of natural gas, but has the potential to require 1,998 MMBtu per hour (or 17.5 trillion Btu per year), which is the same or less than was identified in the EIS.

The project is controlled by Summit Power Group LLC, which develops all types of energy projects, including carbon capture projects for enhanced oil recovery, natural gas, coal, wind, solar projects and other energy-intensive industrial projects using proven technologies.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.