Exergy and environmental analysis of black liquor upgrading gasification in an integrated kraft pulp and ammonia production plant
by Meire Ellen Gorete Ribeiro Domingos; Daniel Flórez-Orrego; Moisés Teles Dos Santos; Hector Ivan Velásquez; Silvio De Oliveira Junior
International Journal of Exergy (IJEX), Vol. 35, No. 1, 2021

Abstract: The black liquor is a byproduct of the kraft pulping process that contains more than half of the exergy content in the total woody biomass fed to the digester, representing a key supply of renewable energy to the pulping process. In this work, the conventional scenario of the black liquor use (i.e., concentration and combustion) is compared with the black liquor upgrading (via) gasification process for ammonia production in terms of economics, exergy efficiency and environmental impact. The combined energy integration and exergy analysis is used to identify the potential improvements that may remain hidden to the energy analysis alone, namely, the determination and mitigation of the process irreversibility. As a result, the exergy efficiencies of the conventional and the integrated cases average 40% and 42%, respectively, whereas the overall emission balance varies from 1.97 to −0.69 t_CO2/t_Pulp, respectively. The negative CO₂ emissions indicate the environmental benefits of the proposed integrated process compared to the conventional kraft pulp mill.

Online publication date: Tue, 18-May-2021

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Exergy (IJEX):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com