Our vision and commitment

Our team is a mix of people with many years of experience exclusively in this field and the ones trained well to do the jobs.
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Subhash Dutta,
Ph.D. Founder, CTO and CEO
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SD has been a designer, program manager, hands-on experimenter, catalyst/material developer, technology developer/ adviser, professor, process engineer, modeler, programmer/coder and consultant. His balanced experience comes from positions/business with multiple O&G, E&C, Catalyst/Tech Development Companies, Academic Institutes & a Simulation Company- almost exclusively on Reactor Designs and Reaction Engineering. The Companies and Institutes he worked/ consulted for include Lummus Crest (NJ), Eka Chimie (Sweden), ALCOA (USA), Engelhard (NJ), Florida Solar Energy Center, Fluor Daniel (CA), Intevep (Venezuela), SABIC (Saudi Arabia), SimSci (CA), GTC (TX), Catalytica (CA), Technip/ Dorr Oliver(CA), ConocoPhillips (OK), Exelus (NJ), US DOD, Rentech (CO), Eltron Research & Development (CO), NJIT (NJ), FIT (FL), IIT (Delhi). He is an industry consultant in the area of process development, scale-up and commercialization, reactor design, modeling & simulation, multiphase systems and Fluidization. He co-chaired four international/ national Fluidization conferences between 1990 and 1998, and published extensively in the area of Fluidization and reaction/ reactor engineering. He is a former member of Technical Advisory Committee and Board of Directors of Particulate Solid Research Institute (PSRI). He has an extensive background and experience in coal combustion and gasification research.

A book chapter authored by him provides a detailed treatment of the effect of coal rank or type and Combustor/ gasifier operation on the product gas compositions, as well as the mechanism and kinetics of these processes. He was a lead engineer for design/development/modeling/successful scale-up of several new commercial/ ready-to-commercialize catalytic reactor systems including Lummus’ ALMA fluidized bed process for production of Maleic anhydride, a fixed bed process for acetic acid production, Syngas production for a new GTL technology and a solid acid Alkylation technology. The Lummus’ process received the Kirkpatrick honorary award for “advances in technology” in 1991. He received his Ph.D. in Chemical Engineering from the Indian Institute of Technology (IIT), and post-graduate diploma in Chemical Engineering from Tokyo Institute of Technology.

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Stephen C. Arnold,
P.E. Chief Technical Advisor
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Most of his career was at Lummus in the Technology Development Center, New Proprietary Technology, or New Technology Development Departments, and also in Chemical and Petrochemical Business Groups, with emphasis on bridging/integrating process design and development/improvement. Also advisor to international clients on related plant start-ups and operations. Was the technology leader for "ALMA" Maleic anhydride Process incorporating selective partial oxidation of n-butane with air in fluidized-bed reactor, starting from conceptual design and evaluation, through R&D, scale-up, demonstration plant, marketing, design, operating/safety procedures, commercialization, startups, customer service, troubleshooting and process + catalyst improvements. The ALMA Process development was recipient of a Kirkpatrick Honor Award for "noteworthy chemical engineering feat commercialized". The flagship plant in Ravenna, Italy received European Better Environment Award for Industry. Led startups, training of key plant personnel, performance tests at design and optimization conditions, troubleshooting and other visits at client ALMA and other petrochemical and petroleum plants in USA, Canada, Jamaica, England, Germany, Austria, Italy, Japan, Korea, and China (PRC and Taiwan). Was process Engineer at Exxon Research and Engineering (NJ) process development advisor to LKAB (Sweden) shale gasification development program, Senior Principal Development Engineer at Lummus (now CB&I NJ) and currently process development design and improvement adviser for various international clients and technologies including position with DIFREX.

Portrait of Stephen C Arnold

Contributed to other development efforts at initial stages of process conceptualization, economic justification, laboratory testing and preliminary design phases. Technologies have included petroleum refining FCC (fluid catalytic cracking), catalytic reforming, hydrodesulfurization, hydrocarbon dehydrogenations (Alkanes, olefins, Ethylbenzene) ranging from no oxygen to O2 assist (for heat supply with/without other process benefits) to oxidative dehydrogenation (ODH), including close attention to flammability + energy considerations, CO2 enhanced ODH, OxyMethylation of Toluene (OMT) to styrene, Paraxylene reactions/ separations, Hydroisomerization of Alkanes to branched Alkanes in Gasoline boiling range (increase octane), selective ring opening, CO2 absorption, propylene glycol from Biodiesel byproduct glycerol, fluid-bed gasification of petroleum coke, coal and biomass.

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Suresh Vijay,
Chief System Officer
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A Software Engineer having significant experience in his field is now the team-lead of the DIFREX TECH SUITE™ SoftPack, the web version and extension programs. His experience covers various organizations in India working on various latest software technologies and frameworks like Java, Apple development (Objective C and Swift), Action Script and Blackberry Development. Developed more than 10 successful mobile and desktop applications. Some of them have more than 50k downloads.

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Jim Brenner,
Ph.D. Senior Technical Officer
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Dr. Jim Brenner has a wide range of Nanotechnology and materials characterization experience. Among his projects are development of catalysts for Hydrodesulfurization and Hydrodenitrogenation of crude oil, as well as development and characterization of novel porous materials. Dr. Brenner's capabilities include reaction testing, as well as a range of catalyst characterization methods including surface area, Chemisorption, particle size and zeta potential analysis, and electron and scanning probe microscopies. He is Nanotechnology Minor Program Chair at the Florida Institute of Technology

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Portrait of Aashish Gaurav
Aashish Gaurav,
Ph.D., Process Design & Modeling Specialist
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Brings a strong skill-set and experience in process design, modeling and simulation (gPROMS, Aspen Plus, Aspen Hysys) and cost engineering. He aspires to create a niche in the field of chemical engineering by working to identify, develop and implement integrated solutions to energy, economic and environmental challenges. He is passionate about building and managing successful and high-impact teams, and hopes to equip people in their communities, organizations or businesses to utilize the resources they possess and to optimize their capacities Sustainably. He received his Ph.D. in Chemical Engineering from the University of Waterloo.

Positions open

We are looking for CBDO (Chief Business Development Officer), Email your resume to info@difrex.com

Why us

How we do and deliver, no-risk contract, price policy
  • Our work is backed by experience, coverage and track-record unmatched in this field.
  • We use a proven, organized path toward goals that eliminates trial and error and uncertainties that slow down many reactor projects.
  • We provide performance guarantee on any reactor we design, fix or revamp.
  • We are also hands-on people ready for tests and all experimental work including catalyst/ feed preparation, unit building and operation.
  • We work on reactors and reaction systems of any kind, scale or complexity, including those involving undefined /difficult-to-define chemistry of coal, biomass and petroleum.
  • We work on both catalytic and non-catalytic gas-solids reactors and with/ without solids undergoing both physical and chemical changes.
  • We discriminate between alternate reactor concepts quickly and recommend the best - prior to decision-making process.
  • We provide robust stand-alone reactor models that are yet portable, simple and easy-to-use Company-wide and by decision makers.
  • Our customer service continues beyond the completion of proposed jobs.
  • We continuously upgrade models and reaction, kinetics and property database that are available as a part of the customer service.
  • Our models can be upgraded to include further details and sophistications as necessary.
  • We provide in-depth analysis and make smart software and figures handy to help in head start and confident business decision on reactors.
  • Our ‘no-oops’ development and design are geared to address all anticipated problems prior to demonstration/ pilot plant campaigns that substantially reduces cost, delay and failure of traditional process development efforts.
  • We perform gap analysis to prioritize the areas according to the effort needed for a specific job at hand. We do what-if analysis to determine what may go wrong after a reactor is in operation, and its safety and emissions. We do so-what analysis to establish the process economics.
  • We provide the most comprehensive reactor solution including running bench/pilot scale experimental programs and building robust models.
  • We conduct techno-economic feasibility study and deliver BED package.

Our work is backed by experience, coverage and track-record unmatched in the field.

No-risk contract: We offer guarantees* on our products, services and solutions.
*Conditions apply
Upfront pricing: All work is done on upfront, lump-sum pricing negotiated in advance. A list of standard/ routine products and services is also posted. Payment terms and conditions are negotiable.
  1. Book Chapter ‘Kinetics of Coal Pyrolysis and Gasification Reactions’, Ch.2 “Coal Conversion Technology”, Addison-Wesley Publishing Company, 1979; Co-author C. Y. Wen, West Virginia University
  2. “A Portable Microreactor System to Synthesize Hydrogen Peroxide”, PI, DOD project awarded, 2006
  3. “Gaseous, Liquid and Gelled Propellant Hypergolic Reaction Mechanisms”, PI, DOD project awarded, 2006
  4. “Microchannel Reactor for Direct Production of JP-8 Fuel”, PI, DOD project awarded, 2007
  5. “Commercial Microchannel Reactor for Jet Fuel Production’, PI, Rentech project, 2008
  6. “Build Robust Reactor Models”, CEP, 96(10), p. 37, October 2000.
  7. “Supermodeling Reactors for Profitability”, Chem. Engg., 107(6), p. 72, 2000
  8. “Modernize Process Reactors”, Hydrocarbon Processing, November, 1999, p.91
  9. “Overhaul Process Reactors”, Hydrocarbon Processing, September 1999, p. 43
  10. “General Reactor Model Improves HPI Applications”, Hydrocarbon Processing, July 1999, p. 45
  11. “Circulating Versus Bubbling Fluidized Bed for Hot Gas Desulfurization by Zinc Titanate”, “Circulating Fluidized Bed Technology V”, Proc. 5th Int. Circulating Fluidized Bed Conf., Beijing, PRC, May, 1996, p. pr-7
  12. “Reactor Model: Usefulness of A Lesser Known Tool In Process Plants”, paper presented at the SABIC Tech. Meeting, May, 1996
  13. “Fluidized and Moving Bed Desulfurization by Zinc Titanate”, AIChE Symp. Ser., 301 (90), p. 157, 1994
  14. “Alternate Reactor Concepts for Oxidative Coupling of Methane”, “Fluidization VII”, ed. Potter and Nicklin, Proc. 7th Int. Fluidization Conf., Brisbane, Australia, May, 1992, p. 445
  15. “An Experimental Investigation on the Effectiveness Of Baffles in Breaking Bubbles in Fluid Beds”, J. Chem. Engg. Japan, 25 (3), p. 345, 1992
  16. “Gaining The Competitive Edge: Translating Science and Engineering into Marketable Products”, paper presented at the AIChE Annual Meeting, Los Angeles, Nov., 1991
  17. “A Novel CFB Application: A Chemical Compressor”, “Circulating Fluidized Bed Technology III”, ed. Basu, Horio and Hasatani, Proc. 3rd Int. Circulating Fluidized Bed Conf., Nagoya, Japan, Oct., 1990, p. 465
  18. “A Novel Circulating Bed Metal Hydride Compressor”, paper presented at the 8th World Hydrogen Conf., Honolulu, Hawaii, 1989
  19. “Circulating Fluid Bed Reactor Model Developed for FCC/ART Catalyst Regenerator”, “Fluidization VI”, ed. Grace, Shemilt and Bergougnou, Proc. 6th Int. Fluidization Conf., Banff, Canada, May, 1989, p.9
  20. “Unified Model Applied To The Scale-up of Catalytic Fluid Bed Reactors of Commercial Importance”, “Fluidization VI”, ed. Grace, Shemilt and Bergougnou, Proc. 6th Int. Fluidization Conf., Banff, Canada, May, 1989, p.311
  21. “Economic Assessment of Advanced Electrolytic Hydrogen Production”, Int. J. Hydrogen Energy, 15 (6), 387, 1990
  22. “Technology Assessment of Advanced Electrolytic Hydrogen Production”, Int. J. Hydrogen Energy, 15 (6), 379, 1990
  23. “A Novel Metal Hydride Compressor Concept”, Florida Solar Energy Report No. FSEC-CR-233-88 prepared for DOE, Oct. 1988
  24. “Utilization of Hydrogen for Power Applications”, Florida Solar Energy Report No. FSEC-CR-225-88 prepared for DOE, Sept. 1988
  25. “Storage of Hydrogen In Gaseous, Liquid and Solid Forms”, Florida Solar Energy Report No. FSEC-CR-204-88, DOE, June 1988
  26. “Electrolytic Hydrogen Production Technology”, Florida Solar Energy Report No. FSEC-CR-188-87 prepared for DOE, Dec. 1987
  27. “A Unified Approach To The Modeling of Catalytic Fluidized Bed Reactors”, Proc. World Cong. III Chem. Reaction Engg., Tokyo, 1986, p. 287
  28. “Scale-Up of A Commercial Catalytic Fluid Bed Reactor Involving Complex Kinetics”, Inst. Chem. Engg. Symp. Ser. 87, p. 517, 1984
  29. “Measurement of Bubble Characteristics By Optical Probe”, paper presented at the AIChE meeting, Chicago, Nov., 1980
  30. “Experimental Investigation on A Fast and Exothermic Solid-Liquid Reaction System”, Chem. Engg. Science, Chemical Reaction Engineering, 1, 1980
  31. “A Simple Probe for Fluidized Bed Measurements”, Cana. J. Chem. Engg., 57, p. 115, 1979
  32. “Dead-zone Heights near The Grids of Fluidized Beds”, ‘Fluidization’, Cambridge University Press, p. 32, 1978
  33. “Solid-Gas Reactions in Coal Conversion Processes”, ‘Coal Processing Technology’, CEP Tech. Manual, IV, p. 40, 1978
  34. “Reactivity of Coal and Char: Part I – In Carbon Dioxide Atmosphere”, I&EC Process Design & Development, 16, p.20, 1977
  35. “Reactivity of Coal and Char: Part II – In Oxygen-Nitrogen Atmosphere”, I&EC Process Design & Development, 16, p.31, 1977
  36. “Research Needs for Analysis, Design and Scale-up of Fluidized Bed Reactors”, AIChE Symp. Ser., 73 (161), p.1, 1977
  37. “Mechanism and Kinetics of Sulfation of Iron Pyrite under Pressure”, I&EC Process Design & Development, 14, p. 242, 1975
  38. “Reaction Rates of Coals and Chars with Carbon Dioxide”, report submitted to the Energy Research and Development Admin., Morgantown, WV, 1975
  39. “Analysis of Rates of Oxidation of Coal Chars”, paper presented at the Combustion Institute meeting, Palo Alto, CA, 1975
  40. “Kinetics of Drying and Decomposition of Calcium Hydroxide”, Chem. Engg. Sci., 29, p. 2000, 1974
  41. “Production of Ammonium Sulfate from Iron Pyrite”, I&EC Process Design and Development, 13, p. 215, 1974
Other References
  1. Chhetri, A. B. et al. “Non-edible Plant Oils as New Sources for Biodiesel Production”, Int. J. Mol. Sci., 9, p.169, 2008
  2. Mahfud, F. H., “Exploratory Studies on Fast Pyrolysis Oil Upgrades”, Doctoral Thesis, Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit Groningen, Nov. 2007
  3. “Thermal Methods of Municipal Waste Treatment”, A Biffaward Programme on Sustainable Waste Management, www.capenhurst.com, 2003
  4. Leibold, H. et al. “Hot Gas Cleanup R&D at Forschungszentrum Karlsruhe”, IEA Bioenergy Agreement 2004-2006, Task 33: Thermal Gasification of Biomass, June 12-14, 2006