Converting the methane to ethylene in the pulsed compression reactor poses a more cost-effective and environmentally friendly alternative compared to conventional ethylene production.
Projects

COMPACT – Pulsed Compression II

Ethylene production by compressive activation of methane.

Goal

The goal of this project is to produce ethylene from methane using pulsed compression technology and to determine the feasibility for industrial applications.

Motivation

There is a high demand for cleaner carbon sources and fewer CO2 emissions. The pulsed compression technology saves energy and emissions compared to conventional ethylene production by using nearly adiabatic compression. This is done in order to reach the necessary and extremely high temperatures for cracking of methane. It also reduces emissions by using natural gas as a feed stock instead of naphtha. Along with the highly valuable ethylene also hydrogen is produced. A big advantage can be the localized production of liquid fuels near remote gas fields.

Approach

The chemistry of methane cracking is investigated in the so called single shot reactor (SSR). The SSR is build in such a way that only one compression and expansion cycle is produced. The temperature and pressure in the gas can rise up to respectively 800 to ~1800 K and 50 to ~700 bar creating unique and extreme circumstances. By doing research on different conditions the most optimal operating windows are identified. Based on these investigations a design is proposed for the continuous reactor that is scalable and ready for use in industry.

Principle

A single compression is initiated by releasing an amount of pressurized nitrogen underneath the piston as shown in the figure. During such a compression the temperature and pressure in the reactant chamber where methane is present rise quickly. This enables the reaction towards ethane and ethylene. However, the reaction mixture is also quickly quenched (up to 10^7 K/s), because the piston is free and moves back down again. This effect causes the reaction mixture to ‘freeze’ the products and prevent further decomposition towards carbon soot.

Schematic view of the PCR principle

Objectives

  • To study and further develop the pulsed compression reactor for the highly endothermic and high temperature conversion of methane to ethylene up to and including TRL 6.
  • To carry out all investigations and preparations and to collect all information, necessary to enable a justified decision whether investigations and developments to prove TRL 7 of the technology should be entered.

Project activities

  • Research on methane chemistry
  • Research on suppressing coke formation
  • Research on best operating conditions for maximizing yield
  • Research on most optimal continuous design
  • Research on energy efficient configurations for an industrial sized plant