Gasification Combined Heat and Power from Coal Fines

The overall objective of this project is to complete a front-end engineering design (FEED) study for a 5 MWe equivalent polygenerating unit to be located at the Coal Fields Regional Industrial Park in Hazard, Eastern Kentucky. The plant will utilize waste coal fines and biomass, one of which has secondary environmental improvement impacts. This project will develop a cross industry synergy in a rural, remote area that will serve as a model for future economic development in depressed regions. The gasification unit will generate electricity, provide heat and power for the building and process operations for a private company, and generate a high value liquid fuel for the transportation sector with an attached Fischer-Tropsch (F-T) skid as a load-following alternative to minimize the impact of frequent startups and shutdowns on the gasifier operability and refractory lifetime. Fuel for the gasification unit will consist of recovered coal and sawdust supplied by a nearby coal fines impoundment and lumber company, respectively. There are several supporting goals to meet the main objective. 1) The design basis will be completed, including feed characterization of the coal fines and biomass and site visits. 2) The preliminary design of the polygeneration unit will be completed. 3) The capital and operational costs will be estimated and compared them with a commercial scale unit to determine economic viability. 4) Environmental, health and safety (EH&S) and social and economic assessments will be completed. 5) The impact of application of this unit and the impact if applied throughout Eastern KY will be assessed. There are three results that are expected to be realized through this proposed project. 1) A template will be developed for site determination, economic, environmental and social assessment and technology selection for niche applications of small, modularized polygeneration units that also recover waste coal and/or sawdust, thereby reducing local environmental impact, meeting local energy demands and producing new value-added products in Eastern Kentucky, an area suffering from a decline in the coal industry. 2) Identify a method for deployment of small-modularized energy conversion units throughout Eastern Kentucky that is environmentally sound, supported by local governments and motivates private business participation. 3) Establish a procedure to select technologies relating to gasification, acid gas cleanup, F-T synthesis, and combined heat and power (CHP) production that appropriately addresses the regional demands of Eastern Kentucky. Proposed Technology The process flow, consisting of 4 blocks, of the proposed 5 MWe polygeneration unit with one optional block 1) a feed preparation unit, 2) a coal/biomass gasifier for syngas production, 3) an aqueous-based absorber/stripper and activated carbon bed system for sulfur removal (main target) with beneficial CO2 reduction, 4) a micro-channel reactor for F-T synthesis, 4) a commercially available (Cat®, Cummins, etc.) reciprocating engine for combined heat and power (CHP) generation. To adapt to the local, remote power load change, an micro-channel F-T unit for chemical and fuel production can be installed prior the power generation unit, with the synthesis tailed gas acting as a fuel source for the CHP engine, rather than being recycled within the F-T skid. To vary the syngas conversion rate in the F-T unit while gasifier is operated at constant load for refractory lifetime management, operations can be switched between liquid hydrocarbon production and electricity generation, while the hydrocarbons can be temporarily stored on-site to be transported for upgrading. The required auxiliary components will be determined as part of the FEED study, but may include a feed preparation system, nitrogen generator, air compressor, chiller system, oxygen tank, crane, natural gas supply or fuel oil for system startup, flare system, and control room. The three products will be value-added liquid hydrocarbon from the F-T unit, power and heat in the form of low pressure, and saturated steam for facilities and process needs.