In the pulp and paper industry, black liquor, which is a biomass resource, is burned to produce electricity. Black liquor is concentrated to 21 wt% water through an evaporator before being burned in a boiler. For the evaporator, a multiple-effect evaporator (MEE) is mainly used, but it requires a large amount of energy and cost. Therefore, it is crucial to reduce energy and cost of evaporation process. Hence, this study suggested a novel process model that integrated mechanical vapor recompression (MVR) with MEE to increase the energy efficiency. The suggested MVR-assisted evaporation process was composed of preheating and evaporation processes to effectively concentrate black liquor. In addition, it reduced the steam consumption of MEE by using MVR, which uses relatively inexpensive electric energy in the pre-evaporation process. In the simulation results, the steam, electricity consumption, and the latent heat recovered from the secondary vapor of the suggested process were quantitatively analyzed to verify the energy efficiency. The results indicate that the proposed process increases substantial energy efficiency compared to the conventional process. Then, the appropriateness of the suggested process was evaluated by the techno-economic analysis. The total annualized cost (TAC) is determined for both current and potential future economic benefits. TAC of the MVR-assisted MEE configuration can be reduced by up to 77.54%.
|Number of pages||19|
|Journal||International Journal of Energy Research|
|Publication status||Published - 2022 Mar 10|
Bibliographical noteFunding Information:
This study has been conducted with the support of the Korea Institute of Industrial Technology as “Development of hybrid model and software to optimization of as removal system in recovery boiler for power generation (kitech JH-21-0006)” and “Development of Global Optimization System for Energy Process (kitech EM-21-0022, IR-21-0029, IZ-21-0052).”
© 2021 The Authors. International Journal of Energy Research published by John Wiley & Sons Ltd.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering
- Fuel Technology
- Energy Engineering and Power Technology