Licensed Processes

Gas-to-Liquids (GTL)

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Introduction

This world-leading GTL technology is the culmination of a continuing long-term collaboration between JM Davy and BP.

Our novel GTL process centres on proprietary Fischer Tropsch (FT) technology, which produces high-purity paraffins using fixed-bed catalysis. The feed for the FT conversion is synthesis gas (syngas – CO, CO2 & H2), which can be derived from natural gas, or from gasified coal, biomass or petcoke.

A proprietary hydrocracking process delivers quality synthetic liquid crude products for the production of high-grade transport fuels, naphtha and base oils.

Process Flowsheet

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GTL flowsheetBASE_MOB1900
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Key Reactions

The Fischer Tropsch process reacts carbon monoxide (CO) and hydrogen (H2) from syngas to produce the core paraffin product as follows:

Process Description

Our gas-to-liquids (GTL) process comprises three main steps: firstly, syngas generation; secondly, conversion of CO and H2 to a mixture of long-chain alkanes (or paraffins) by our fixed bed Fischer Tropsch (FT) process; and finally upgrading the paraffin mixture to a specific range of liquid fuels by hydrocracking and distillation.

Process feedstock

Syngas can be produced by reforming natural gas or by the gasification of biomass, petcoke or coal.

JM Davy’s technologies focus on syngas production by reforming natural gas. We offer various reforming technologies, including auto-thermal reforming (ATR) and steam-methane reforming (SMR). We also offer a compact reformer which features reduced weight and footprint.

Reforming

When syngas is obtained by reforming natural gas, methane and steam react in a process otherwise known as steam reforming, which may be summarised as follows:

Fischer Tropsch conversion:

Purified syngas is converted in a series of proprietary Fischer Tropsch reactors, each of which consist of multiple single-pass reaction tubes containing fixed beds of a proprietary catalyst.

Flowing downward through the tubes, the hydrogen and carbon monoxide react, creating mainly linear paraffinic hydrocarbon chains of various lengths, plus water:

After separation, the final products from the FT process are a heavier ‘wax’ stream (nC20 – nC100+), which is a solid at room temperature, and a lighter liquid stream (nC5 – nC25), which forms a majority of the paraffin product.

The reaction water is removed as a separate stream.

The catalyst’s selectivity achieves high product purity and there is no need to top up or regenerate the catalyst once installed. There is no catalyst attrition and therefore no particulate contamination of the wax.

Upgrading

Mild hydrocracking upgrades the paraffins to a synthetic crude mixture. This is achieved using a commercially produced catalyst in a proprietary reactor design that is specifically tailored to process our FT products.

The upgrading process typically yields (by weight) 80% middle distillate – predominantly diesel – and 20% naphtha. Any unconverted wax is recycled to extinction.

Distillation then separates the final products.

+Process option: feedstock and capacities

+Process option: product variation

The JM Davy Advantage

Our unique reforming, FT and upgrading technologies put our GTL process at the forefront of productivity, efficiency and product quality. Learn more about the advantages offered by this process here:

+Excellent product purity and performance:

  • Our FT diesel has undergone extensive engine testing to assess its blending qualities and end-product performance characteristics.
  • Our FT diesel has successfully passed all of the standard industry tests (for example chemical fuel properties, emissions, performance) using a range of different fuel mixtures.
  • We have also seen a reduction in carbon monoxide and other hydrocarbon emissions versus conventional-refinery produced fuels.

+Simple metallurgy, simple construction:

  • Our FT converter design requires no exotic metallurgy and is easily fabricated.

+Flexible feedstocks:

  • The JM Davy/BP fixed-bed FT process can operate with purified syngas from a variety of hydrocarbon feedstocks, whether produced from natural gas, coal, petroleum coke, oil residues or biomass.
  • JM Davy offers a range of technologies for reforming natural gas to syngas which includes:

+Simple water balance and low-waste water emissions:

  • The water produced by the FT process contains low levels of dissolved gases and traces of light hydrocarbons which require no special waste water treatment.
  • When a Davy steam reformer is used to produce the process syngas, the water can be recycled to the reformer to recover the hydrocarbons back into the process.
  • This reduces overall feedstock demand and minimises the hydrocarbon load on the plant effluent treatment facility.

+Proven and reliable hardware:

  • Conventional multi-tubular FT converters provide a robust process.
  • Multiple FT converter fabricators worldwide who are familiar with manufacturing similar reactors for other JM Davy-related technologies (with over 60 mtpa of existing petrochemicals capacity using this type of reactor design).

+No moving parts, simple process, high operational reliability:

  • Unlike slurry processes, our FT converters have no moving parts.
  • The catalyst in the process is static, so there is no need for catalyst addition or separation.
  • Catalyst at any given point in the converter runs at constant conditions.
  • Reliable ‘once-through’ design.
Core Technologies

Explore our fixed-bed FT process in more detail here:

JM Davy offer a wide range of technologies for reforming natural gas to syngas feed for our FT process. Learn more here:


Core Technologies

Explore our fixed-bed FT process in more detail here:

JM Davy offer a wide range of technologies for reforming natural gas to syngas feed for our FT process. Learn more here: