Design and optimization of solar-assisted conveyer-belt dryer for biomass

Document Type: Research Paper


School of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran


Biomass, as a renewable source of energy, can be used in many industries to reduce their dependence on fossil fuels. However, due to the significantly high and varied moisture content of biomass, its use has several drawbacks, such as low total efficiency and process instability. Drying biomass before combustion or gasification can eliminate these drawbacks. Besides these benefits, there are several environmental advantages of removing moisture from organic materials before disposal. In this study, a solar-assisted conveyer-belt dryer was designed to remove moisture from biomass. Economic optimization was conducted under different economic conditions to find the optimum performance of the designed dryer. The results indicated that depending on the economic condition, drying biomass with the designed dryer costs between 4 and 7 cents per kilogram of biomass. Under optimum economic operation, the solar fraction is less than 6% in both scenarios. On the other hand, by ignoring economic constraints and reducing the dryer’s capacity, solar fraction increases to more than 55%, and in this case, the drying cost will be about 11 cents per kilogram of biomass.


[1]  Verma M., Loha C., Sinha A. N., Chatterjee P. K., Drying of Biomass for Utilising in Co-Firing with Coal and Its Impact on Environment–A Review, Renewable & Sustainable Energy Reviews (2017).

[2]  Alamia A., Ström H., Thunman H., Design of an Integrated Dryer and Conveyor Belt for Woody Biofuels, Biomass and Bioenergy (2015)77: 92–109.

[3]  Cummer K. R., Brown R. C., Ancillary Equipment for Biomass Gasification, Biomass and Bioenergy (2002) 23(2): 113–128.

[4]  Castleman J. M., Gottschalk C., Vincent R. Q., Fluidized Bed Combustion and Gasification, A guide for Biomass Waste Generators, Western Regional Biomass Energy Program, Reno, NV (United States)(1994).

[5]  Amos W. A., Report on Biomass Drying Technology (1998).

[6]  MacCallum C., Blackwell B. R., L. Torsein, Cost Benefit Analysis of Systems Using Flue Gas or Steam for Drying of Wood Waste Feed Stocks (1981).

[7]  Drucker S. J., The Industrial Wood Energy Handbook, New York Van Norstrand Reinhold Co (1984).

[8]  Young G. C., Municipal Solid Waste to Energy Conversion Processes, Economic, Technical, and Renewable Comparisons. John Wiley & Sons (2010).

[9]  Kreith F., Handbook of Solid Waste Management (1999).

[10] Hoornweg D., Bhada-Tata P., What a Waste, A Global Review of Solid Waste Management, Urban Development Series Knowledge Papers (2012) 15:1–98.

[11] Patil R., R. Gawande, A Review on Solar Tunnel Greenhouse Drying System, Renewable and Sustainable Energy Reviews (2016) 56:196–214.

[12] Lutz K., Mühlbauer W., Müller J., Reisinger G., Development of a Multi-Purpose Solar Crop Dryer for Arid Zones, Solar Wind Technology (1987)4(4): 417–424.

[13] Condorı M., Echazu R., Saravia L., Solar Drying of Sweet Pepper and Garlic Using the Tunnel Greenhouse Drier, Renewable Energy (2001)22(4):447–460.

[14] Perea-Moreno A.-J., Juaidi A., Manzano-Agugliaro   F.,   Solar  Greenhouse Dryer System for Wood Chips Improvement as Biofuel, Journal of Cleaner Production (2016)135: 1233–1241.

[15] Hawlader M. N. A., Jahangeer K. A., Solar Heat Pump Drying and Water Heating in the Tropics, Solar Energy (2006) 80(5) 492–499.

[16] Şevik S., Experimental Investigation of a New Design Solar-Heat Pump Dryer under the Different Climatic Conditions and Drying Behavior of Selected Products, Solar Energy (2014) 105: 190–205.

[17] Ceylan İ., Gürel A. E., Solar-Assisted Fluidized Bed Dryer Integrated with a Heat Pump for Mint Leaves, Applied Thermal Engineering (2016) 106: 899–905.

[18] Maroulis Z. B., Saravacos G. D., Food Process Design (2003) 126.

[19] Perry R. H., Green D. W., Perry’s Chemical Engineers’ Handbook, McGraw-Hill Professional (1999).