Abstract Petroleum coke (petcoke) contains high carbon and low ash qualities, but often with an undesirably high sulfur content. High-temperature (>1000 K) calcination produces a coke, suitable for many industrial uses, with an acceptable S content. Here the sulfur removal behavior during high-temperature pyrolysis was evaluated by combining high-temperature thermogravimetric analysis with product gas mass spectrometry (TG-MS), and reactive molecular dynamics (ReaxFF) simulations. From the TG-MS data the pyrolysis temperature of >1000 K significantly affected the S rejection. Three petcokes under 1273–1773 K in six different particle sizes (≤6 mm) were pyrolyzed to determine the desulfurization initiation temperature and desulfurization extent. A non-uniform behavior across the particle size ranges was obtained. Six Qingdao petcoke samples with cut sizes of 1673 K. However, considerable variability was shown in larger particles (1.18–0.88 and 5.00–6.00 mm) for Qingdao, Zhenhai, and Qilu petcoke between 1473 and 1773 K. The products included water (presumably from coke quench, 350–410 K), volatiles (430–550 K), CO2 and H2 (>800 K, mainly), CO and SO2 (>1200 K, mainly), and trace quantities of CS2 (>1400 K). The stable sulfur-containing products of this petcoke during high-temperature pyrolysis were SO2 and trace amounts of CS2. However, COS and H2S pyrolysis products were absent or below the detection limits. The pyrolysis behavior was explored using ReaxFF on a macromolecular petcoke structure with the S atoms in thiophene-like functional groups. The mechanism of S loss, under the simulation conditions, involved molecular rearrangement and thermolysis into intermediate states (C2S and CNS) and COS. These were explored for 250 ps for 3000, 3500, and 4000 K with the constant volume/temperature (NVT) ensemble. The sulfur removal transformation during pyrolysis is generally followed: thiophene sulfur → COS, C2S, or CNS → HS → SO2 or CS2.

中文翻译：

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在高温热解过程中从石油焦中脱硫。来自 TG-MS 数据和 ReaxFF 模拟的分析

摘要 石油焦（petcoke）含有高碳和低灰分，但通常硫含量高得令人不快。高温 (>1000 K) 煅烧产生的焦炭适用于许多工业用途，其 S 含量可接受。在这里，通过将高温热重分析与产品气体质谱 (TG-MS) 和反应分子动力学 (ReaxFF) 模拟相结合，评估了高温热解过程中的硫去除行为。根据 TG-MS 数据，>1000 K 的热解温度显着影响了 S 去除率。在 1273-1773 K 下，对六种不同粒径 (≤6 mm) 的三种石油焦进行热解，以确定脱硫起始温度和脱硫程度。获得了跨越粒度范围的非均匀行为。六个青岛石油焦样品的切割尺寸为 1673 K。然而，青岛、镇海和齐鲁石油焦在 1473 至 1773 K 之间的较大颗粒（1.18-0.88 和 5.00-6.00 毫米）中表现出相当大的变异性。产品包括水（推测为来自焦炭淬火，350–410 K)、挥发物 (430–550 K)、CO2 和 H2（主要是 >800 K）、CO 和 SO2（主要是 >1200 K）以及痕量 CS2（>1400 K） . 这种石油焦在高温热解过程中的稳定含硫产物是 SO2 和痕量 CS2。然而，COS 和 H2S 热解产物不存在或低于检测限。使用 ReaxFF 在大分子石油焦结构上探索热解行为，其中 S 原子位于类噻吩官能团中。S loss的机理，在模拟条件下，涉及分子重排和热解成中间态（C2S 和 CNS）和 COS。这些在 3000、3500 和 4000 K 下进行了 250 ps 的探索，并具有恒定体积/温度 (NVT) 合奏。热解脱硫转化一般遵循：噻吩硫→COS、C2S或CNS→HS→SO2或CS2。