Separation of some paraffin wax grades using solvent extraction technique

Solvent extraction technique has been used to separate paraffin wax grades; with different characteristics; from El-Ameria light, middle and heavy slack waxes. The wax deoiling has been done by solvent extraction at different extraction temperatures and different solvent feed ratios (S/F by weight). The extraction solvents used are furfural, N-methyl-2-pyrrolidone (NMP) and N, N, dimethylacetamide (DMA). The wax products are evaluated according to TAPPI-ASTM equation and petroleum wax specifications. The data revealed that DMA and NMP are suitable extracting solvents for isolating of semi- and scale-refined grades of paraffin waxes from light and middle slack waxes. But furfural solvent can separate only semi-microcrystalline waxes from heavy slack wax.     

Production of lubricating base oil from slop wax by different subsequent refining techniques

Different subsequent refining techniques including solvent dewaxing and solvent extraction have been used to produce lubricating base oil from slop wax waste by-product. The solvent dewaxing technique was performed using two different solvent mixtures of methyl ethyl ketone and toluene with and without benzene at different dilution solvent ratios and at different dewaxing temperatures. The solvent extraction technique was carried out using N-methyl-2-pyrrolidone solvent at 90 °C and at constant dilution solvent ratio of 3:1 by weight. The resulting data revealed that the highest yield of lubricating base oil having the lowest pour point (−6 °C) and the highest iso- and cyclo-paraffins to n-paraffins ratio (5.11) is obtained by solvent dewaxing process only. While the lowest yield of lubricating base oil having the highest pour point (−1 °C) and the lowest iso- and cyclo-paraffins to n-paraffins ratio (4.08) is obtained using solvent dewaxing followed by solvent extraction process. These lubricating base oil products, especially the one that having the lowest pour point (−6 °C) matches the principal characteristics of AX 973853 type of premium low viscosity textile machinery oils obtained by Mobile Velocite Oil Company.     

用神经网络对石蜡无催化剂氧化反应行为的研究

在自制的石蜡氧化装置上对石蜡进行了无催化剂氧化 ,并利用人工神经网络将氧化蜡的酸值和酯值与石蜡氧化条件 (反应温度、空气流量和反应时间 )进行关联。建立了石蜡无催化剂氧化的神经网络模型 ,并用该模型对石蜡的无催化剂氧化规律进行了预测。结果表明 ,该模型不但具有较高的计算精度 ,而且具有满意的预测能力     

利用NIRS和RI技术测试石油流体析蜡温度新方法

析蜡温度是重要的石油流体性质参数,得到准确的析蜡温度是保证含蜡原油管道安全输送的前提。提出了近红外光谱温度扫描测试法和折射率测试法,改进了近红外光谱波长扫描测试法,并从可靠性、灵敏性和稳定性等方面与常用的偏光显微镜法和差示扫描量热法进行比较。结果表明,近红外光谱法和折射率法可以得到可靠的测试结果,并具有较高的灵敏性和稳定性;实验操作和数据分析方法简单,测试结果不易受到制样过程影响,尤其适合挥发性较强的油样。此外,近红外光谱法测试时油样处于运动状态,可有效减小过冷度的影响,但与实际管输条件仍存在一定差别。     

Separation characteristics of acetic acid–water mixtures using poly(vinyl alcohol‐g‐4‐vinyl pyridine) membranes by pervaporation and temperature difference evapomeation techniques

The separation of acetic acid–water mixtures was carried out using pervaporation (PV) and temperature difference evapomeation (TDEV) methods. For the separation process, 4‐vinyl pyridine was grafted on poly(vinyl alcohol). Membranes were prepared from the graft‐copolymer by casting method and crosslinked by heat treatment. The effects of feed composition on the separation characteristics were studied and the performances of the separation methods were compared. Permeation rates were found to be high in PV whereas separation factors were high in TDEV method. Membranes gave permeation rates of 0.1–3.0 kg/m²h and separation factors of 2.0–61.0 depending on the composition of the feed mixture and the method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1385–1394, 2006     

Separation characteristics of acetic acid–water mixtures by using poly(vinyl alcohol‐g‐4‐vinyl pyridine) membranes by pervaporation and temperature difference evapomeation techniques

The separation of acetic acid–water mixtures was carried by using pervaporation (PV) and temperature difference evapomeation (TDEV) methods. For the separation process 4‐vinyl pyridine was grafted on poly(vinyl alcohol). Membranes were prepared from the graft‐copolymer by casting method and crosslinked by heat treatment. The effect of feed composition on the separation characteristics was studied and the performances of the separation methods were compared. Permeation rates obtained in PV were found to be high, whereas separation factors were high in TDEV method. Membranes gave permeation rates of 0.1–3.0 kg/(m² h) and separation factors of 2.0–61.0, depending on the composition of the feed mixture and the method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2030–2039, 2006