Ž . Fuel Processing Technology 54 1998 95–108 Deposition and high temperature corrosion in a 10 MW straw fired boiler Hanne Philbert Michelsen a, ) , Flemming Frandsen a , Kim Dam-Johansen a , Ole Hede Larsen b a Department of Chemical Engineering, Technical UniÕersity of Denmark, Lyngby, Denmark b Fælleskemikerne, Elsam, 666 , Denmark Abstract Deposition and corrosion measurements were conducted at a 10 MW wheat straw fired stoker boiler used for combined power and heat production. The plant experiences major problems with deposits on the heat transfer surfaces, and test probes have shown enhanced corrosion due to selective corrosion for metal temperatures above 5208C. Deposition measurements carried out at a position equal to the secondary superheater showed deposits rich in potassium and chlorine and to a lesser extent in silicon, calcium, and sulfur. Potassium and chlorine make up 40–80 wt.% of the deposits. Mechanisms of deposit formation and selective corrosion are discussed based on the results of the practical measurements. Published by Elsevier Science B.V. Keywords: Deposition; Corrosion; Wheat straw 1. Introduction In recent years, much attention has been drawn toward the burning of biomass for power production. First of all a fairly large surplus of, e.g., wheat straw exists in certain parts of Denmark and the use of this for energy production could solve a waste problem and at the same time substitute coal. Secondly, the Danish Government has decided a Ž . 20% reduction of the carbon dioxide CO emissions before year 2005 with reference 2 to 1988. Biomass is considered CO neutral, which means that during growth it 2 accumulates the same amount of CO by photosynthesis as is released during combus- 2 tion. In 1993, the Danish power producers were enjoined to burn 1,200,000 metric tons of straw and 200,000 metric tons of wood chips every year beyond the year 2000. As a ) Corresponding author. 0378-3820r98r$19.00 Published by Elsevier Science B.V. Ž . PII S0378-3820 97 00062-3