Gasification of Waste From the Petroleum Industry as an Alternative to Thermal Desorption Treatment

  • Thomas Arink

Student thesis: Master's Thesis

Abstract

The petroleum industry generates a significant amount of waste in the form of drill cuttings and contaminated soil. Drill cuttings are a product of the off-shore drilling rigs and are comprised of wet soil and total petroleum hydrocarbons (TPH). Contaminated soil is generated at oil well sites as well as at on-shore refineries which also contains TPH. One of the main treatment methods currently used is thermal desorption (TD). Thermal desorption is a method where the waste material is heated to 450 oC in an anaerobic environment to release the volatile. Condensed volatile is used to partially fuel the reactor. For the thermal desorption unit dry contaminated soil is mixed with moist drill cuttings to generate a suitable mixture. By analyzing Thermo gravimetric (TGA) data of the TD feed and discharge, TPH removal appeared to be less than 50% of the initial TPH mass fraction. Since the discharged material is disposed off in landfill, the remaining TPH poses a risk to the environment. This study proposes gasification of petroleum waste as an alternative to TD. Gasification can lead to the complete removal of TPH in the petroleum waste due to the significantly higher reaction temperature. This work aims to demonstrate the technical feasibility of gasification as a treatment method for petroleum waste. It consists of three successive and complementary studies following the analysis and characterization of the petroleum waste. Firstly, the mathematical gasification model is developed representing an idealistic conversion of the petroleum waste. This zero-dimensional systematic analysis is also used to study the co-gasification of petroleum waste with a higher calorific value material. The model is based on the Gibbs energy minimization together with Lagrange multiplier; it is used to find the product species composition for different feedstock mixtures and fuel-to-air ratios. Secondly, a two-dimensional reactive flow computational fluid dynamics (CFD) model is developed in the frame work of Ansys Fluent. This model integrates the reaction kinetics into a discretized geometrical representation of a drop tube reactor. Thirdly, experiments were conducted to validate the gasification and CFD model using the ’in-house’ developed drop tube reactor (1.5m x 75mm dia.). Details of the mathematical development, results and process metrics will be presented in consideration of petroleum waste gasification.
Date of AwardMay 2015
Original languageAmerican English
SupervisorIsam Janajreh (Supervisor)

Keywords

  • Waste Management
  • Petroleum Waste
  • Waste Gasification
  • Petro-Chemical Waste
  • Contaminated Soil
  • Drill Cuttings
  • Petroleum Hydrocarbons
  • Waste Treatment
  • Thermal Desorption.

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