漂白桉木硫酸盐浆厂ECF与TCF漂白技术经济分析

Techno-economic analysis on ECF bleaching and TCF bleaching for a bleaching eucalyptus kraft pulp mill

对比分析了漂白桉木硫酸盐浆厂无元素氯(ECF)漂白工艺流程(OOD_0[EOP]D_1P与新提出的全无氯(TCF)漂白工艺流程(OOA[ZEO]_1[ZEO]_2P)技术经济指标,两种漂白流程的运营成本(ECF=465$/ADt,TCF=468$/ADt)与内部收益率(ECF=16.5%,TCF=16.4%)接近。虽然TCF漂白方案剩余蒸汽少而利润稍低,但节约NaCIO_3、CH_3OH等化学品可抵消高电耗的成本。评估与化学品、用电价格波动相关的财务风险概率分析表明:NaOH、NaCIO_3的价格波动对内部收益率(IRR)概率分布影响最为明显。尽管仅在实验室阶段完成测试并表明TCF漂白工艺新技术具有潜在优势,且需进一步扩大规模测试证明其技术先进性;但其技术经济分析表明所提出的TCF漂白工艺流程在未来工业化生产中应用具有潜在优势。

An early stage techno-economic analysis was performed to compare a traditional element chlorine free (ECF) sequence (OOD0[EOP]D1P) with the proposed totally chlorine free (TCF) sequence (OA[ZEO]1[ZEO]2P) for a bleached eucalyptus kraft mill. Similar operating cost (ECF=465US$/ADt, TCF=468US$/ADt) and similar internal rate of return (ECF=16.5%, TCF=16.4%) were obtained. Although the TCF case has lower revenue with surplus steam, saving with chemicals (NaOH, NaCIO3) pays the higher consumption of electricity. Probabilistic analyses were also performed to evaluate the financial risks associated with of sodium hydroxide and sodium chlorate have significant impact on the probability distribution of the internal rate of return (IRR). Despite its promising potential, the new TCF sequence has only been tested in laboratory scale and further scale up has to be performed to validate the technology. However, the techno-economic analysis shows that the proposed TCF technology has promising potential for future industry application.