Licensed Processes

Natural Detergent Alcohols (NDA)

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Introduction

JM Davy have licensed the greatest number of plants worldwide for the production of natural detergent alcohols (NDA), also known as fatty alcohols.

Our process is designed with an esterification step prior to hydrogenolysis. This achieves greater efficiency, ease of operation and product quality as well as allowing use of lower-cost materials of construction for the hydrogenolysis and refining sections.

Process Flowsheet

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nda-ester-ro nda-hydro-ro nda-refining-ro nda-ro-esterification nda-ro-hydro red-panel
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Key Reactions

NDA synthesis proceeds by the following overall reaction:

Process Description

Fatty alcohols are produced in two stages: esterification of a fatty acid feed to form methyl esters, followed by vapour-phase hydrogenolysis to convert the methyl ester intermediate to a crude NDA product mix of various chain lengths.

The purpose of the esterification step is to produce a non-acidic intermediate – the methyl ester – which allows lower-cost carbon steel material selection in hydrogenolysis.

In addition, our esterification reaction system removes the reaction water produced prior to hydrogenolysis, which enhances process efficiency.

Process feedstock

The Davy NDA process can convert short chain (C8/C10), medium chain (C12/C14) or long chain (C16/C18) fatty acids to their equivalent alcohols. The process feedstock comprises fatty acids predominantly derived from palm kernel or coconut oils that have been distilled and fractionated into these different cuts.

Plants are normally optimised for C12/C14 processing to meet predominant market demand, but different cuts can be processed on a campaign or continuous basis. The Davy process is also tolerant of loose cuts, for example the C12/C14 feed may typically contain up to 10% C16.

Esterification

The pre-heated liquid fatty acid feeds to the top of the esterification reaction column, in which it reacts with methanol to form its equivalent fatty acid methyl ester (FAME):

The reaction proceeds in the presence of a proprietary solid catalyst, achieving almost complete conversion to the methyl ester intermediate.

Water produced in the esterification reaction is stripped from the methyl ester by excess methanol vapour and taken overhead of the reaction column.

The methyl ester then feeds directly to hydrogenolysis without any further process steps.

Hydrogenolysis

Ester hydrogenolysis proceeds in the vapour phase at low pressure, over a fixed bed of chrome-free copper catalyst, producing a crude fatty alcohol product stream and methanol:

This methanol produced by the hydrogenolysis reaction is recycled back to the esterification stage to minimise the requirement for methanol make-up.

Refining

Crude fatty alcohol is refined to produce high-quality product in a single distillation column.

Subsequent polishing converts any residual carbonyls (principally aldehydes) in the product to alcohols.

Other intermediates and by-products are recycled for re-use in the process or used as fuel.

+Process option: different feeds

+Process option: different fatty acid cuts

+Process option: hydrogen generation

The JM Davy Advantage

JM Davy’s use of esterification prior to hydrogenolysis has transformed fatty alcohol production. The benefits of this innovation are numerous, from reduced capital costs to milder, safer operating conditions and improved conversion.

The main process advantages are highlighted below. For more detailed benefits related to our technology, go to our esterification and hydrogenolysis pages.

+Process flexibility:

  • Our NDA process converts short chain (C8/C10), medium chain (C12/C14) and long chain (C16/C18) fatty acid feedstocks to their equivalent alcohols.
  • Additionally, our process can operate without the esterification step, instead taking a methyl ester feed directly to hydrogenolysis. We can therefore produce fatty alcohols from an acid or ester feed, or a combination of acid and ester feed, in the same plant.

+Simplified catalysis, process efficiency:

  • The esterification and hydrogenolysis catalysts remain in their respective reaction vessels, eliminating the need for catalyst separation and neutralisation at any stage of the process.
  • The esterification catalyst can also be changed at 100% load without any downtime or loss of production.

+Low material and equipment costs:

  • The esterification step neutralises the acidic feed. This enables the hydrogenolysis and refining systems to be made of inexpensive carbon steel.

+Low-cost, higher-performance catalyst:

  • The non-acidic hydrogenolysis environment also allows use of a base-metal catalyst instead of a high-grade precious metal catalyst.  This delivers superior performance at lower cost.

+Net savings over conventional processes:

  • The combined savings of cheaper construction materials and catalysts more than compensate for the cost of the added esterification step.
Core Technologies & Related Processes

Explore the core technologies that underpin the Davy NDA process:

JM Davy also employs esterification and hydrogenolysis in our world-class butanediol (BDO) and n-methyl-2-pyrrolidone (NMP) processes.  Click on the panels below to learn more:

We also produce biodiesel using a process derived from our NDA and BDO flowsheets:


Core Technologies

Explore the core technologies that underpin the Davy NDA process:


Related Processes

JM Davy also employs esterification and hydrogenolysis in our world-class butanediol (BDO) and n-methyl-2-pyrrolidone (NMP) processes.  Click on the panels below to learn more:

We also produce biodiesel using a process derived from our NDA and BDO flowsheets: