Simulation study of improved biomass drying efficiency for biomass gasification plants by integration of the water gas shift section in the drying process. (October 2015)

• Record Type: Journal Article
• Authors: Haarlemmer, Geert
• Is Part Of: Biomass and bioenergy. Volume 81(2015:Oct.)
• Page Start: 129
• Page End: 136
• Publication Date: 2015-10
• Subjects: Biomass -- Gasification -- Drying -- Water gas shift; Biomass energy -- Periodicals; Biomass -- Periodicals; Energy-Generating Resources -- Periodicals; Bioénergie -- Périodiques; 333.9539
• DOI: 10.1016/j.biombioe.2015.06.002
• Languages: English
• ISSNs: 0961-9534

Abstract

Abstract: This paper examines thermochemical biomass conversion plants that produce synthesis gas that can be converted into synthetic fuels. Biomass requires forced drying before torrefaction or gasification to increase the heating value of the feed, an energy consuming step that weighs heavy in the energy balance of the plant. This paper shows that decreasing the humidity of the admitted drying air greatly improves the efficiency of the biomass drying. It is possible to reduce the humidity of the air by passing the air on a water adsorbent solid such as activated alumina. The alumina loaded with water can then be regenerated with waste heat, but more efficiently by using synthesis gas and convert the adsorbed water to hydrogen in the water gas shift section. The energy saved in the improved drying step amounts to 2–8% of the total fuel consumption of the plant, depending on the ambient conditions. Highlights: Drying is a crucial step in a biomass gasification plant. A new process scheme is proposed to reduce heat requirement of biomass drying. A new application of the water gas shift reaction is proposed. Up to 8% of the total heat load can be saved with the new process scheme.