Catalytic Ethanol Steam Reforming in Brazilian Sugarcane Industry
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
This work aims to study energetic, economic and ecological aspects of the steam reforming of ethanol for production of hydrogen in a sugar-alcohol plant.
The distillery Pioneers, a sugarcane industry with a cogeneration system, where its main products are: sugar, anhydrous and hydrated ethanol and sale of surplus electrical power, is taken as reference for the study. The maximum amount of hydrogen that could be produced in this distillery is 5126 Nm3/h requiring for this, 4081 l/h of anhydrous ethanol or 4407 l/h of hydrated ethanol and 6305 kg/h bagasse. The production of 1500 Nm3/h hydrogen by ethanol steam reforming in this sugarcane industry is studied. For the production of 1500 Nm3/h of hydrogen, it is required 0.5 kg/s of bagasse and 1194 l/h of anhydrous ethanol or 1290 l/h of hydrated ethanol. The production of 1500 Nm3/h of hydrogen by steam reforming of ethanol will reduce the electric power generation in 900 kW. The cogeneration yield of the plant is determined in reference to the amount bagasse used for steam reforming process. The cogeneration yield of the plant increases with the amount bagasse used for hydrogen production. A hydrogen production of 1500Nm3/h will increase the cogeneration yield of the plant in 4.36% from 67.9% to 70.86%.
The ecological efficiency of the plant increases with the amount bagasse used for stem reforming. A hydrogen production of 1500Nm3/h will increase ecological efficiency of the plant in 0.77 % from 0.795 to 0.8011
The ecological efficiency of the stem reforming (0.7083 for anhydrous ethanol and 0.7111 for hydrated ethanol) is lower than the ecological efficiency of the cogeneration process (0.8011).
Although the anhydrous ethanol has higher lower heating value and demanded less ethanol amount to produce 1 [Nm3/h] of hydrogen, the results of economic analysis have shown that hydrated ethanol is the best option for this purpose. The main reason for this result was the cost difference between anhydrous and hydrated ethanol. In this specific situation, the hydrated ethanol cost was adopted as being 70% of production cost of anhydrous ethanol. The hydrated ethanol presents higher thermodynamic yield for producing hydrogen as well as better ecological efficiency.
Place, publisher, year, edition, pages
Biomass, entrained-flow gasifier, gasification, synthesis gas, torrefaction
IdentifiersURN: urn:nbn:se:kth:diva-146312OAI: oai:DiVA.org:kth-146312DiVA: diva2:723783