Dr. Alvin Henry Larsen, Ph.D.

 Solutia Inc., St. Louis, MO

The Design Institute for Physical Properties (DIPPR®) of the American  Institute of Chemical Engineers has become the premier cooperative physical property data effort in the United States to satisfy process engineering needs.  Celebrating its twentieth anniversary in November 1998, DIPPR® has been active longer than any other  Sponsored Research group of AIChE. The background and formation of DIPPR® are described,  highlighting the people responsible for launching DIPPR® on its path of ongoing success.

Cooperative data efforts in the United States were carried out by a wide variety  of organizations in the 1960s and 1970s. Government agencies such as the National Bureau  of Standards (NBS, later the National Institute for Standards and Technology, NIST), the  Energy Research and Development Administration, and the Environmental Protection Agency  conducted projects primarily with federal funding. Industry associations, including the  American Petroleum Institute (API), the Manufacturing Chemists Association (MCA, later the  Chemical Manufacturers Association, CMA), the Natural Gas Producers Association, Fluid  Properties Research, Inc. (FPRI), and the Energy and Power Research Institute, were  directed and funded by participating companies. Universities such as the Massachusetts Institute of Technology, the University of Houston, and Purdue University developed data  programs primarily with federal grants, and the Thermodynamics Research Laboratory (TRL)  at Washington University was supported both by federal grants and industry participants.  Simulation companies such as ChemShare and Simulation Sciences developed data banks for  their software products.

Two long-standing projects served as examples of compilations of critically evaluated data. The API Research Project 44, which began at NBS in 1942 and moved to the  Carnegie Institute of Technology (later the Carnegie-Mellon University) in 1950, developed  and published reliable property data for hydrocarbons. The MCA Research Project began as a  companion project for non- hydrocarbons at the Carnegie Institute of Technology in 1955.  Both these projects were moved to the Thermodynamics Research Center (TRC) at Texas  A&M University in 1961 and were renamed.

Other efforts around the world included the Physical Property Data Service (PPDS) of the Institution of Chemical Engineers (U.K.); the program of the Engineering  Sciences Data Unit (ESDU, later ESDU International Ltd.), supported by the National  Physical Laboratory, the National Engineering Laboratory, and other British technical  organizations; the Uhde physical property program, marketed by DECHEMA, the German  Chemical Engineering Association (Germany); the JUSE-AESOPP physical properties program,  from the Japanese Union of Scientists and Engineers (Japan); and the program of the CODATA  Task Group on Data for Industrial Chemicals (International Council of Scientific Unions).  

In preparing the third edition of "The Properties of Gases and  Liquids" in 1974, Bob Reid of the Massachusetts Institute of Technology wanted to  have a data bank of important compounds included as an appendix. He asked Union Carbide  and, later, several other companies to contribute their data.  He compared values and found many points of agreement and many errors.  As a result, Don Vredeveld of Union  Carbide suggested further cooperative efforts in physical property data.

Bob Reid then organized a meeting November 18, 1975, at the AIChE Annual Meeting  in Los Angeles to determine the level of interest in a cooperative data effort. Over 30  people attended. Don Vredeveld suggested sharing a data bank and maintaining it in  "evergreen" fashion. Howard White of the NBS Office of Standard Reference Data  (OSRD) developed a proposal for "Project Evergreen" and organized a meeting at  NBS in Gaithersburg, MD, September 21, 1976, to discuss it further and determine support  for it. No strong objections were raised, but enthusiasm for the proposal was lukewarm.  The Project Evergreen proposal was refined and presented to about 50 people at a meeting  organized by the AIChE Machine Computation Committee at the 1976 Annual Meeting, November  30, in Chicago.

Project Evergreen envisioned a data base of about a thousand  "ubiquitous" compounds, including all the properties required for process  engineering. The data base would be created with the best available data and estimates,  and made "evergreen" by continually updating it as better data and methods were  found. No experimental programs were contemplated, and maximum use would be made of existing data compilations. It was proposed that responsibility for the data base and the  data center would be assumed jointly by industry and the federal government, and that the  data center would be under the program management of OSRD. A five-year program was  proposed, with a budget of at least $100,000 per year. A wide diversity of opinions was  expressed, on issues such as scope, funding, government control, quality of results, and  response to industry needs. Additional discussion was held at the first international  conference on Fluid Properties and Phase Equilibria in the Chemical Industry, at Asilomar,  CA, in mid-January 1977.

To handle funding and legal issues, an umbrella organization for industry participation in such a cooperative effort was considered essential. Several potential  umbrella organizations were discussed. MCA, AIChE, NBS, and API were suggested. MCA was  considered first, since its membership consisted of a wide variety of companies in the  chemical industries and since it had previously coordinated a data project at Carnegie  Institute of Technology and, later, at Texas A&M University.

At a meeting in Washington October 27, 1976, the MCA Engineering Advisory Committee appointed David Roth of Allied Chemical as chairman of a Thermophysical and  Chemical Data Ad Hoc Task Group. The Task Group was established to review the Project  Evergreen proposal, evaluate other alternatives, and recommend the level of MCA  involvement in such an endeavor.

David Roth called a meeting of the Task Group, held January 10, 1977, at Allied Chemical's offices in Morristown, NJ. The Task Group concluded that Project Evergreen had  several drawbacks which could be overcome by MCA sponsorship of the project. It later  recommended that MCA establish a permanent committee to oversee the effort. The Task Group  was superseded in April 1977 by a Subcommittee on Thermodynamic and Physical Data under  the Engineering Advisory Committee, with David Roth as chairman.

Several discussions and meetings were held in Washington under MCA auspices during 1977. The program objectives, contractor selection, and data base content were  developed in some detail. Mel Albright of Phillips Petroleum suggested an organization  similar to the Gas Processors Association (GPA) and a project funding procedure patterned  after that successfully used by GPA, in which projects were funded separately by annual  commitments of the sponsoring companies through a balloting procedure. This approach was  adopted, and Evan Buck of Union Carbide developed additional details of an organizational  structure and a funding mechanism. David Palmer of Amoco Chemicals drafted a program proposal and developed a proposal for a project to measure acetic acid-water PVT and VLE  data, and Al Larsen of Monsanto developed a proposal for a data base project (later the  Data Compilation project) and organized the program proposal for the entire effort,  including the contributions by Evan Buck and David Palmer.

Concerns regarding MCA sponsorship were raised, including use of the MCA "Special Project" format for an open-ended project, participation of non-MCA members in technical direction and funding, administrative procedures, and possible use of  OSRD as the program manager with technical direction and funding through MCA. The MCA  staff reviewed the proposal in March 1978, and would not recommend approval to the MCA  Board of Directors. The Subcommittee under David Roth then recommended that the proposal  be withdrawn from MCA consideration.

Over the same period of time, AIChE was also considered as a potential sponsor  of the cooperative physical property data effort. Steve Newman of Foster Wheeler suggested  in February 1977 that the AIChE Research Committee be involved, and later proposed a  project for preparation of a data book similar to the API Technical Data Book¾Petroleum  Refining, but oriented toward chemicals. In September 1977, in Chicago, David Palmer  discussed the MCA proposal with AIChE leadership, to explore possibilities of AIChE  sponsorship.

In October 1977, David Roth requested that an acronym be selected for a proposal to AIChE Council the following month. Over 25 acronyms were considered for the effort with  MCA, but none of them had strong support. Of course, the acronym would be derived from and  be consistent with the name of the effort. But it also had to be catchy and easy to  remember. In response to the request, Al Larsen suggested "DIPPR," from its  organization as a Design Institute of AIChE and from the need to include Physical Property  Data (or some close equivalent) in a direct way. The emphasis was to be on Data, not  Research, but "DIPPD" just didn't have a good ring to it. "DIPPR"  could be used anyway, by taking the "R" from "PRoperty." The acronym  has served well and is highly recognizable.

The proposal was presented to AIChE Council in New York in November 1977 to establish DIPPR with an organizational structure similar to that of the Design Institute  for Emergency Relief Systems (DIERS), which had recently begun. John Prados of the  University of Tennessee, a former AIChE Director, was appointed to head an ad hoc  committee to study the proposal.

It was evident that AIChE would be very interested in serving as the umbrella organization for the proposed program, as a Design Institute, should the effort with MCA  not come to fruition. In January 1978, Stan Adler of Pullman Kellogg, Al Larsen, Steve  Newman, David Palmer, David Roth, and F. J. Van Antwerpen, Executive Director of AIChE,  were also named to the ad hoc committee, which deferred action pending the MCA decision.  Word was finally received in late April 1978 that the MCA initiative was withdrawn. The ad  hoc DIPPR® committee met a few days later in New York and moved rapidly to revise the  proposal for presentation to AIChE Council in Philadelphia June 3. At that time, Council approved formation of DIPPR®, disbanded the ad hoc committee, and asked John Prados to  chair a DIPPR® Formation Committee. He named Al Larsen, Steve Newman, David Palmer and  David Roth to the committee.

John Prados established a timetable to launch the DIPPR® organization, including publicity and solicitation for membership, an organizational meeting at the AIChE Annual  Meeting in November 1978, balloting for 1980 projects in early 1979, selection of project  investigators in Fall 1979, and beginning the second-year cycle at the 1979 Annual AIChE  Meeting. AIChE headquarters sent out over 600 letters of solicitation for DIPPR  participation over the signature of Wm. H. Corcoran, AIChE President.

During the three years it took to get the cooperative physical property data  effort organized as DIPPR®, under AIChE auspices, the proposal was refined and expanded  several times. Momentum for the effort increased with each meeting. Meetings were held in  many locations, throughout the country, converging on the organizational meeting in Miami  Beach.

The long-awaited meeting was convened in the Americana Bal Harbour Hotel in Miami Beach, November 15, 1978, at 9:00 AM. A sense of excitement and anticipation filled the air. It was also the first meeting of the DIPPR® Technical Committee. The meeting was held in two parts: (1) an open session, for all interested  people, and (2) a closed session, for representatives of DIPPR® participants only. DIPPR®  participants were defined as those companies who had paid the $500 DIPPR® dues for 1979,  but due to the short time available after the solicitation letters were sent until the  organizational meeting, companies whose representatives were confident of joining DIPPR®  were also invited to the closed session.

The open session introduced DIPPR, including objectives, organization, funding methods, schedules, and proposed projects. The closed session discussed weighting factors  for various types of companies, and elected John Prados Chairman of the Technical  Committee, with David Palmer as Vice Chairman. Project steering committees for proposed  projects, as well as the Liaison Committee and the Publicity and Recruitment Committee,  were formed by electing chairmen of the committees. These chairmen were then made  responsible to recruit their committee members from interested Technical  Representatives.  Meetings of the Technical Committee were set to be held annually,  in conjunction with AIChE Annual Meetings.

Five projects were approved for balloting to DIPPR® participants: Data Compilation, Chemicals Technical Data Book, Electrolyte Phase Equilibria, Acetic Acid-Water PVT and VLE Measurements, and Mixture Experimental Data. These projects were  balloted in early 1979 to begin work in 1980.  None of the projects were successful  on the first ballot, and all were submitted for a second ballot to all DIPPR® participants.  The Data Compilation project was then fully funded, and three other projects received  adequate funding to begin: The Data Book Project with help from NBS, and the Acetic Acid  and Mixture Properties projects with help from the Environmental Protection Agency. The  Electrolyte Phase Equilibria project failed to get enough support in 1979, but was revised  and succeeded in 1980 to begin in 1981 at NBS.

The following were elected at the organizational meeting:  Al Larsen,  Chairman, Data Compilation Project Steering Committee; Bill Seaton (Tennessee Eastman), Chairman, Pure Component Data Project Steering Committee; David Zudkevitch (Allied  Chemical), Chairman, Mixture Data Project Steering Committee; Herbert Barner (Kennecott  Copper), Chairman, Electrolyte Equilibria Project Steering Committee; Steve Newman,  Chairman, Liaison Committee; and Mac Clarke (Olin Chemicals), Chairman, Publicity and  Recruitment Committee.  The DIPPR® Administrative Committee was formed from those  elected, with John Prados Chairman and David Palmer Vice Chairman, subject to AIChE  Council approval. In September 1979, John Prados was succeeded by David Palmer as Chairman  of the Technical Committee and by David Roth as Chairman of the Administrative Committee.

During 1979, requests for proposals were prepared and distributed, contractors were selected, and preparations were made to begin project work in 1980. At a meeting of  the Data Compilation Steering Committee including the Data Book Subcommittee in  Gaithersburg, MD, October 26, 1979, Ron Danner and Tom Daubert at The Pennsylvania State  University were selected as principal investigators for the Data Compilation and Data Book  projects. Grant Wilson, Wilco Research Company (later Wiltec Research, Inc.), was selected  as the principal investigator for the Acetic Acid-Water PVT and VLE Measurements Project  by its sponsors, and Grant Wilson and John Oscarson, Brigham Young University, were  selected as investigators for separate portions of the Mixture Experimental Data project  by its sponsors. By January 1980, DIPPR was in full operation with four projects underway.

Much of the strength of DIPPR® has come from the rationale developed during its formation. This rationale includes responsiveness to industry needs, annual accountability  for funding and results, and independent projects from which DIPPR® participants can  choose.

In the late 1970s, available compilations of data did not satisfy industry needs  very well. Data were sparse for many chemicals important to industry. Even for common  chemicals, data were sparse for some important properties and temperature ranges. Some  compilations had been worked on for decades but were still incomplete. Others made heavy  use of estimation methods and left the task to the user to resolve the discrepancies  between results calculated by different methods. Most available compilations provided no  recourse to source data. Values obtained or computed from separate sources often differed  significantly. Process engineers had to locate data sources, evaluate data and estimate  missing values.

 With increasing use of computers for simulation and design calculations,  industry representatives believed that satisfying industry needs was essential and had to  be accomplished within a relatively short time frame. Data for high-volume chemicals and  chemicals important in several processes or in processes run by several companies were  needed, and had to include all the properties over all the ranges required for process  engineering. Data evaluation would be needed to select the best data and estimate reliable  values. Data specialists in sponsor companies would need recourse to source data for data  review and further evaluations.

The Data Compilation project became the "flagship" project for  DIPPR®,  with other experimental projects contributing to the Data Compilation as appropriate. In turn, the Data Compilation would identify gaps and inconsistencies in the literature requiring measurements, which would be prioritized and carried out by other DIPPR®  projects.

The DIPPR® balloting procedure gave a sense of urgency for each project to make  progress and deliver useful results every year or face the risk of not receiving adequate  funding in the next ballot cycle. Thus as projects fulfilled their objectives or were no  longer considered useful, they would be terminated by decision of the sponsors or by the  balloting procedure.  Weighting factors from 1 to 8 gave small companies the  opportunity to sponsor DIPPR® projects at low cost. All project results would be published  or made available eventually, but sponsors would enjoy exclusive use of the results for at  least a year. A summary of DIPPR® projects was recently published in the Journal of  Chemical and Engineering Data (1996, 41, 930-934), and illustrates the breadth of scope of DIPPR® projects over the years.

The independence of DIPPR® projects from each other assured that DIPPR® was working on the right things. DIPPR® participants could propose new projects at any time, to  respond to new technology needs. Some projects would be of short duration, one to three  years, while others would continue longer or indefinitely. Flexibility and relevance would  thus be maintained.

This rationale, developed during the formation of DIPPR®, has served remarkably well to provide purpose, stability, and significant results. It continues to be important  in guiding DIPPR®. But even more important are the people who have done the work to make  DIPPR® successful over the years. This includes Bob Reid, Don Vredeveld and Howard White,  whose early concepts and efforts led to the formation of DIPPR®; the Management and  Technical Representatives of DIPPR® participants, all of whom have served as volunteers;  the DIPPR® Technical Directors, Ted Selover and George Thomson, who have guided the DIPPR®  effort with enthusiasm; the AIChE staff, whose support has been crucial; and a large  number of contractors, investigators, and students, who have carried out the project work.  To recognize all their contributions, it was fitting to celebrate the anniversary of DIPPR®  in Miami Beach, twenty years to the day after its formation.