Study on the Carbon and Silicon Co-Production Technology of Rice Husk Based on the New Ammonia Carbon Capture Method and its Comprehensive Benefits

Abstract

Biomass with carbon capture technologies is essential to achieving net-zero CO2 emissions. In this paper, we innovatively proposed a new cogeneration technology for producing porous biochar and nano silica from rice husk using KOH and K2CO3 as silica solubilizers based on the ammonia-based carbon capture method. This technology route's energy value and economic analysis model are established, and its comprehensive benefits are further investigated. The results of the energy value analysis show that the technology is environmentally friendly, especially when the reaction reagent is K2CO3, the environmental loading rate is reduced from 1.19 to 0.19, and the sustainability index is increased from 1.40 to 5.32. The economic evaluation results show that applying this technology route leads to higher NPV and IRR of the system with solid profitability and self-solvency. When KOH is selected as the reaction reagent, the NPV increases from 34,253,700 RMB to 119,637,600 RMB, the IRR increases from 40.84% to 59.70%, and its profitability and self-solvency reach the optimum. This route meets the requirements of low environmental load, high sustainability index, and good economy.

Keywords: Biochar, Silica, Cogeneration, Energy value analysis, Economic evaluation