Evaluation of Palladium-Based Sorbents for Trace Mercury Removal in Electricity Generation

• 作者: Christopher L. Munson Evan Granite Jenny Tennant Massood Ramezan Pradeep Indrakanti
• 来源期刊: 清洁煤炭能国际期刊(英文)
• 学科: 医学
• 关键词: PALLADIUM SORBENT MERCURY GASIFICATION Integrated GASIFICATION Combined CYCLE COST
• 年，卷（期）: 2014,（4）
• 页码范围: 65-76
• 页数: 12页
• 分类号: R73

摘要

The development of warm-gas cleanup (WGCU) systems for synthesis gas (syngas) cleanup in in- tegrated gasification combined cycle (IGCC) power plants has the potential to lower the costs of generating power. WGCU includes the removal of mercury (Hg), present in coal, from the syngas. Carbon-based sorbents used for Hg removal are not suitable for high-temperature Hg removal in conjunction with the WGCU. The US Department of Energy’s National Energy Technology Laboratory’s (DOE/NETL) Office of Research & Development (ORD) has been developing various sorbent alternatives to address the problem of high-temperature Hg removal. This study presents analysis of the capture of Hg from syngas streams as a polishing step to attain US Environmental Protection Agency (EPA) Mercury and Air Toxics Standards (MATS) requirements for Hg (0.003 lb/GWhgross for new IGCC plants) using palladium (Pd) adsorbent being tested by DOE/NETL in association with Johnson Matthey (JM). For the present study, it was assumed that syngas is already cleaned to 5 parts per billion by weight (ppbw) Hg, and the Pd sorbent technology is used as a polishing step to achieve the EPA MATS requirements (0.003 lb/GWhgross, equivalent to 2 ppbw given representative process configuration and material flows). The incremental cost of Hg polishing and the additional capital cost needed were estimated for several scenarios/cases. These cases were differentiated by variance in the following parameters, which are important because they have direct im- pacts on additional capital costs ($/kW), and in turn impacts on the levelized cost of electricity (LCOE): 1) Pd cost (varied from $4,000 to $12,000/lb Pd);2) Gas hourly space velocity (SV) (varied from 500 to 13,500 h-1);3) Pd loading (varied between 2 w/w% Pd and 5 w/w% Pd);4) Sorbent make-up rate (varied between 3%, 1%). The ranges were chosen in order to reasonably reflect, in the cases that are analyzed, the actual fluctuations that have been observed in past *Corresponding author. experience in these importan