Organically modified nano-clay facilitates pour point depressing activity of polyoctadecylacrylate

• Published in: Fuel (Guildford) Vol. 166; pp. 96 - 105
• Main Authors: Yao, Bo, Li, Chuanxian, Yang, Fei, Sjöblom, Johan, Zhang, Ying, Norrman, Jens, Paso, Kristofer, Xiao, Zuoqu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.02.2016
• Subjects: Nano-clay; Nanocomposite; POA; Pour point depressant; Waxy crude oil; Nano-clay; Nanocomposite; POA; Pour point depressant; Waxy crude oil
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2015.10.114

Introduction of nanomaterials constitutes a novel and efficient means to enhance the performance of polymeric pour point depressants (PPDs). Based on the specific layered structure and favorable cationic exchange characteristics of nano-clay particles in the presence of charged organic compounds, an original hydrophilic nano-clay is first modified by octadecyltrimethyl ammonium chloride (OTAC) and then bypolyoctadecylacrylate (POA). The modified nano-clay serves as an effective nanocomposite PPD. Compared to an identical content of POA, addition of POA/clay nanocomposite PPD to Changqing waxy crude oil improves the rheological properties while elevating the wax appearance temperature of the oil. Polarized microscope observation shows that POA/clay nanocomposites provide wax nucleation sites upon which wax molecules assemble and precipitate. Addition of POA/clay nanocomposite PPD results in larger and more compact crystal morphology, thus inhibiting the formation of a network structure, and further improving rheological properties of waxy crude oil. [Display omitted] •We introduce organic nanoclay to prepare nanocomposite pour point depressant.•POA/clay nanocomposite could further improve the rheological properties of crude oil.•The addition of nanoclay fosters the precipitation of wax crystals.•Adding nanocomposite PPD results in the formation of larger and compact wax crystals.•A possible heterogeneous nucleation mechanism for POA/clay nanocomposite is proposed. Introduction of nanomaterials constitutes a novel and efficient means to enhance the performance of polymeric pour point depressants (PPDs). Based on the specific layered structure and favorable cationic exchange characteristics of nano-clay particles in the presence of charged organic compounds, an original hydrophilic nano-clay is first modified by octadecyl trimethyl ammonium chloride (OTAC) and then by polyoctadecylacrylate (POA). The modified nano-clay serves as an effective nanocomposite PPD. Compared to an identical content of POA, addition of POA/clay nanocomposite PPD to Changqing waxy crude oil improves the rheological properties while elevating the wax appearance temperature of the oil. Polarized microscope observation shows that POA/clay nanocomposites provide wax nucleation sites upon which wax molecules assemble and precipitate. Addition of POA/clay nanocomposite PPD results in larger and more compact crystal morphology, thus inhibiting the formation of a network structure, and further improving rheological properties of waxy crude oil.