中文摘要：

在单一工业气相流化床反应器内,提出以氢气振荡为操作手段制备双峰聚乙烯树脂的方法.研究了3种对氢敏感程度不同的茂金属催化剂Cp2^＊ZrCl2、（Ind）2ZrCl2和Cp（Ind）ZrCl2在反应器中的聚合动力学行为,以Flory分布函数描述单活性中心的相对分子质量分布.模拟结果表明,在氢气的振荡操作下可获得相对分子质量呈双峰分布的聚乙烯树脂;振荡的可操作性与催化剂的氢转移速率常数ktrH和相对氢转移速率常数（氢转移速率常数ktrH和链增长速率常数kp之比）密切相关,ktrH/kp和ktrH越大,树脂相对分子质量分布越容易通过改变氢气浓度来调节;氢气浓度切换所需时间越短,振荡操作生产双峰聚乙烯越容易实现.

英文摘要：

A novel technology was presented to produce bimodal polyethylene in a gas-phase fluidized bed through oscillating operation of hydrogen periodically. Three metallocene catalysts with different sensitivities to hydrogen were chosen to simulate their dynamic behaviors in the fluidized bed reactor. The Flory distribution function was adopted to simulate the molecular weight distributions （MWDs） of single-site activity. Bimodal polyethylene was obtained by oscillating hydrogen periodically for all of the three catalysts. Simulation results showed that the feasibility of oscillating operation depends on values of ktrH/kp （the ratio of the termination rate constant by chain transfer to hydrogen to the propagation rate constant） and ktrH （the termination rate constant by chain transfer to hydrogen）, and that the bi-MWD of polyethylene are easier to obtain by metallocene catalysts when values of ktrH/kp and ktrH are larger. It also showed that the changeover time from high to low hydrogen concentration in the fluidized bed reactor is the key factor for implementing oscillating operation, and that shorter transition time leads to easier oscillating operation.