延迟焦化深度裂解技术研究与工业应用

基于延迟焦化工艺本质与炉管结焦机理，采用焦化加热炉管内外过程模拟技术，以控制炉出口介质裂解深度为目标，对1.6 Mt/a延迟焦化装置焦化加热炉进行改造。在加热炉总体结构不变的条件下，采用多项创新专利措施对在役设备进行改造与操作参数优化，提高生焦反应焦化加热炉给热量，结合深度裂解技术，改善产品分布。设备改造后的工况过程模拟结果表明，介质炉出口裂解深度得到提高，生焦反应焦化加热炉给热也明显增加。工业应用结果表明，焦化加热炉采用深度裂解技术后，加热炉的处理能力提高了，达到1.85～1.90 Mt/a；改造后的炉管表面温度比改造前低约80 ℃；烧焦后运行周期从改造前的9个月延长到15个月以上；在原料残炭上升的情况下，石油焦收率和焦炭产率系数均下降，增加了液体产品收率，经济效益明显。改造后该装置可以适应因原料重质化，对扩大焦化装置处理能力和改善产品结构的要求。

RESEARCH AND COMMERCIAL APPLICATION OF DEEP CRACKING DELAYED COKING TECHNOLOGY

Based on studying the reaction characteristics of delayed coking and coking mechanism in furnace tubes,a technical revamping of the coking furnace of a 1.6 Mt/a delayed coking unit was carried out in order to control the cracking severity of feedstock leaving furnace,a software simulating process happened inside and outside of the furnace tube was adopted.Several novel technical measures and patents were involved in the revamping,as well as operating parameters optimization to enhance the heat provided for coking reactions by furnace and improve product distributions.The simulation results post to furnace revamping showed that the cracking severity of feedstock leaving furnace was deepened and the heat provided for coking reactions was enhanced significantly.Commercial running results showed that by adopting deep cracking technology in coking furnace,the processing capacity of the furnace increased and reached 1.86—1.95 Mt/a;the external surface temperature of furnace tube was about 80 ℃ lower than that of prior to revamping,and the operation period after coke burning was prolonged from 9-month to more than 15-month.After revamping,although the carbon residue in feed was higher,the coke yield/coke yield coefficient both decreased and the liquid yield increased with good economic benefit,which indicated that this delayed coking unit could meet the requirements of processing inferior feedstock with high processing capacity and improved product distributions.