Q & A > Question Details
Are there any recent alkylation projects that you can comment on where mass transfer efficiency improvements showed significant reductions in required acid consumption? Also, what recent improvements have resulted in reduced water wash or caustic wash requirements?
25/06/2014 A: Amarjit Bakshi, Refining Hydrocarbon Technologies LLC, abakshi@rhtgulfcoast.com
Sulfuric Acid Alkylation :
Economic Summary
Conventional , CDAlky, RHT
Acid Cost MM $/y(1) 10.7 , 5.9 , 5.1
Utilities Cost MM $/y 14.8 , 12.3 , 10.9
Octane Value MM$/y(2) Base , 14.9 , 18.4
Total dollar advantage/y(3) Base , 22.2 , 27.9
(1) Sulfuric Acid at 125 USD/mt, 0.55/.30/20 lbs Acid/gallon alkylate produced.
(2) Octane advantage at 1.0 USD/Octane barrel
(3) Operating cost savings excluding Acid regenration
Acid Regeneration Costs have not be included.
(4) CDAlky uses packing for mixing, loading and unloading of [packing cumbersome in the reactor, needs frequent changes and under mixing pressure drop chance of collapse. Licensor describes that packing used in the mixing.
11/09/2009 A: keith bowers, B and B Consulting, kebowers47@gmail.com
The fundamental chemistry of the 'Friedel-Crafts Alkylation' reaction favors extremely high iso-butane:olefin ratio at the tertiary carbonium ion contact with the olefin molecule. This reduces the probability that 2 olefin molecules will react to form 'polymer. The reaction chemistry also favors very short 'contact time' as the initial reaction product is the iso-octane molecule, which then isomerizes to lower octane molecules if it stays in contact with the catalyst acid.
Lower reacting temperature slows the relative rate of polymerization and acid degradation, but the viscosity increase of the acid phase is detrimental to good mixing. One is attempting to achieve complete mixing at the molecular level to obtain the best possible product octane and yield. Mixing is an energy intensive process, adding a lot of entropy. There are different way to achieve the very high interfacial area desired, and each has its own characteristics that must be managed to maximize the desired results. There is no 'free-lunch', but each refinery may have different constraints and costs of the required utilities, which will impact on the different 'processes' in varying ways.
31/07/2007 A: Keng H Chung, Well Resources Inc, kengchung@hotmail.com
Would you be interested in retrofitting your alkylation unit with our IONIKYLATION? We had successfully completed the commercial trial. You can find out more in "Ionic liquid alkylation process produces high-quality gasoline", Oil & Gas Journal, Vol 104 Issue 40 Oct 23, 2006.

Let me know if you are interested. ......
24/07/2007 A: Amarjit Bakshi, Refining Hydrocarbon Technologies LLC, rhtgulfcoast@rhtgulfcoast.com
RHT-Alkylation technology provides a simple mixing device for alkylation of butylenes at low temperature. The reaction is at isothermal conditions at low temperature, which provides the advantages of high-octane product and low acid consumption. As mass transfer is provided by a simple mixing device the Capex/Opex are lower compared to any technology available.
RHT-Alkylation does not use complex internals (which are to be replaced often) simple mixing device provides adequate mass transfer for reaction to reach completion at low temperature. The acid/hydrocarbon can be separated by advance coalescer design. The auto refrigeration vapors can be absorbed in the heavy hydrocarbons making the compressor redundant. These three major improvements provide major savings in Capex/Opex also acid consumption is reduced without producing any waste, as caustic and water wash are deleted.
RHT- Alkylation provides major break through in Sulfuric Acid Alkylation Technology
22/07/2007 A: Todd Vogt, CD TECH, todd.vogt@us.abb.com
For alkylation of mixed C4 feeds using sulfuric acid, lower temperature operation offers a means for reducing acid consumption. CDAlky allows for routine operations at very low temperatures, while maintaining conventional compressor suction pressures and allowing lower reactor energy input. This is achieved with improved heat and mass transfer techniques to compensate for the challenges of liquid/liquid contact at these low temperatures. Due to the enhanced contacting performance, better selectivity is obtained, significantly lowering acid consumption and increasing alkylate octane. Because improved mass transfer is achieved without the need for a tight emulsion, acid and hydrocarbon separation is much easier. This results in a process with a reactor effluent that requires no downstream acid or alkaline water wash and is suitable for direct feed to the fractionation section.