Deposition and precipitation of paraffin wax in pipelines are major problems in the production, transfer, storage, and processing of crude oil. To prevent complete clogging, it is necessary to minimize and remove deposited wax in pipelines and tubing. Significant research has been done addressing the mechanisms of wax formation and its composition. In this review, the status of research and perspectives on the occurrence and characterization of the paraffin wax that forms in crude oil developing wells and pipelines has been critically reviewed. Several approaches for detecting paraffin wax and managing wax formation damage during oil recovery were discussed. This review also highlighted the effects of temperature and crude oil type on wax formation.

https://www.mdpi.com/1996-1073/12/6/967/pdf

Occurrence and Characterization of Paraffin Wax Formed in Developing Wells and Pipelines

Wax deposition in oil and gas pipelines is considered one of the most severe operational problems, and significant efforts have been made to prevent and remediate this flow assurance issue. Chemica...

A Critical Review of Controlling Paraffin Deposition in Production Lines Using Chemicals

Photothermal Clothing for Thermally Preserving Pipeline Transportation of Crude Oil

A review on the rheology of heavy crude oil for pipeline transportation

When crude oil is extracted out of a subterranean reservoir at high temperature and pressure, it is usually transported via a pipeline, where the crude oil experiences radical changes in its physical and chemical properties, instigating numerous complications. Among the various flow assurance problems, wax deposition and build up are among the most commonly found. However, the accurate mechanism of wax deposition is still unclear and is widely debated among researchers. The mechanism under multiphase conditions is also an ambiguity. This review covers the six wax deposition mechanisms, the challenges in multiphase flow conditions, the latest types of chemical inhibitor, and a summary of factors governing chemical inhibitor performance.

Wax formation mechanisms, wax chemical inhibitors and factors affecting chemical inhibition

Flow improvers for assured flow of crude oil in midstream pipeline - A review

The study was carried out to produce biodiesel through direct transesterification of waste avocado seed. The method involves solvent assisted in-situ alkali-catalyzed transesterification. Experiments were conducted to determine the selection of appropriate solvent, effects of catalyst, methanol quantity, temperature, time, stirring rate and co-solvent amount. This process yields biodiesel of 94.4 wt% with respect to weight of total oil content of avocado seed. The optimum parameters observed were 0.05 wt% catalyst (KOH), 1.5 g methanol, 65 °C reaction temperature, 600 rpm stirring rate, 50 min reaction time and 30 g of Tetrahydrofuran for 10 g seed. The process was scaled up to bench scale and the product biodiesel obtained was washed, dried and their fuel properties were compared with ASTM D 6751 specifications. It was found that avocado seed biodiesel exhibits exceptional oxidation stability and low temperature properties.

In-situ transesterification and process optimization of biodiesel from waste avocado seed

Production of Biodiesel Using Immobilised Rhizopus oryzae Lipase in a Microchannel Reactor

The conventional method for the production of biodiesel derived from edible and inedible oils were by extraction, refining and transesterification. Instead, transesterification can be done directly without prior extraction and refining is called in-situ transesterification. In this study, Chlorella vulgaris was subjected to in-situ transesterification and the different parameters affecting the process was analyzed. The lipid content was initially determined as 23.2 ± 2.35 wt% by Soxhlet method. The parameters like catalyst concentration, temperature, methanol weight ratio, mixing rate and moisture content were optimized. It was found that the biodiesel conversion and reaction rate are mainly affected by catalyst concentration. At 1.5 wt% of catalyst the yield of biodiesel with respect to lipid content of Chlorella vulgaris attains above 90 % at 300 g methanol (for 50 g biomass). At optimum condition it was able to achieve 93 % of esters. Thus, in-situ transesterification was simple and the biodiesel production cost was reduced.

N. Yasvanthrajan

Papers

Flow improvers for assured flow of crude oil in midstream pipeline - A review

In-situ transesterification and process optimization of biodiesel from waste avocado seed

Production of Biodiesel Using Immobilised Rhizopus oryzae Lipase in a Microchannel Reactor

In-situ transesterification of algal biomass for the production of biodiesel