Title:
Empirical Indices to Forecast Adverse Effects of Biomass Co-Firing: The Analysis of 200 Full-Scale Experiences
Author(s):
García-Galindo, D., Royo, F.J., Sebastián Nogués, F., López, E.
Document(s):
Paper
Abstract:
The present work aims to utilize experimental indices (EIs) to define ceilings for co¬firing. The novel methodology pursues finding a correlation between co¬firing effects described in full¬scale experiences and EIs. Technical reports, R&D papers have been reviewed and interpreted in order to quantify the impacts of co¬firing. Consulting with several companies and R&D centres has also been carried out for that purpose. Co¬firing effects have been classified into five impact categories (IC), from IC=1 when no effects were noticed, to IC=5 for cases where co¬firing caused a shutdown. More than 200 full¬ scale co¬firing experiences reported in 130 pulverized coal power plants (PF CPPs) from 12 countries have been compiled. Among them fuel has been characterized for 176 PF CPPs. An IC has been assigned to the effects of co¬firing on slagging, fouling, corrosion, particulate matter emissions, efficiency and gas cleaning systems whenever reports or personal communications provided sufficient information. Traditional, biomass specific and new EIs based on fuel composition have been calculated for each experience. Values of EIs and ICs have been analysed aiming to find evidences of correlations. Through a multiple regression analysis it was found that several EIs were significant p<0.05) to explain the ICs. Correlations were mostly under R2= 50 and therefore regression curves were not produced. Even though the goodness of the fit was low, the values indicate that EIs were able to explain a relevant part of the IC. The visual analysis of the EI vs IC plants has been useful to propose zones of secure operation based on EIs. The utilization of the proposed EIs indices has been exemplified to estimate the co¬firing ceilings achievable when co¬firing straw with three types of coal: black lignite, bituminous and anthracite. According to different criteria, ashy coals with important sulfur contents are more convenient to buffer the effects of biomass during co¬firing. Straw co¬firing ceilings above 17% for all coals. When utilizing the most restrictive criteria, straw co¬firing is restricted to less than 10% for all types of coal.
Keywords:
biomass, co-combustion, co-firing, fouling, model, ashes, coal co-firing
Topic:
R&D on Biomass Conversion Technologies for Heating, Electricity and Chemicals
Subtopic:
Solid biofuel combustion for large utility
Event:
20th European Biomass Conference and Exhibition
Session:
2CO.1.4
Pages:
814 - 826
ISBN:
978-88-89407-54-7
Paper DOI:
10.5071/20thEUBCE2012-2CO.1.4
Price:
FREE
