Harold A. Sorgenti, 84, of Philadelphia and Palm Beach, Fla., a chemical engineer and inventor who became a leader in Philadelphia's business and civic communities, died Wednesday, July 11, of heart failure at Penn Hospice at Rittenhouse.

Mr. Sorgenti began his career in 1959 as a research engineer for Arco Chemical Co., a subsidiary of the Atlantic Richfield Co. He obtained 16 patents for various chemical processes in the research and development department.

He proved his mettle by moving into the corporate areas of technology and then planning and strategic development, said Fred Rullo, who worked for Mr. Sorgenti. After serving in various American cities, he returned to Philadelphia in 1976 as a senior vice president.

"Intellectually, he was brilliant," Rullo said. "He had boundless energy, he was a great leader, and he had a great feel for the business world."

In 1979, Mr. Sorgenti became president and CEO of Arco Chemical, and over the next 12 years he headed a transformation that resulted in the splitting of the company into two corporate entities — Lyondell Petrochemical, which became LyondellBasell, and Arco Chemical.

In 1991, Mr. Sorgenti retired. Coincidentally, Rullo had left another corporate post in Connecticut, so both were at loose ends.

"Hal called me and said, 'Listen, why don't we do something for fun? Let's start up a little chemical company. If it doesn't work out, so what? If it does, we'll give it to the kids.' I was the marketing side, and Hal was the technology and financial side."

The men founded Freedom Chemical Co., a firm that made products for the personal care, food, beverage, textile and pharmaceutical industries. At first, it was just the two of them with an administrative assistant.

"We worked our tails off. There was a lot of heavy lifting," Rullo said. "I have to say I was fortunate to work with him. He had a lot of name recognition, and that helped us incredibly."

The men began acquiring other small chemical companies. In 1998, when sales reached $350 million, BFGoodrich purchased Freedom Chemicals for $375 million.

After the company was sold, the two were viewed as models for corporate executives who successfully made the transition to entrepreneurship, Rullo said.

A major pillar of Mr. Sorgenti's life was volunteer work. While at Arco Chemical, he came to see that civic involvement was an important part of the firm's culture and philosophy, and took that to heart.

In 1983, he was serving on the boards of the Academy of Music, Philadelphia College of Art, St. Joseph's University, Pennsylvania Academy of the Fine Arts, Philadelphia Orchestra, and the United Way of Southeastern Pennsylvania.

''Almost everybody in my management group is on one or two boards,'' he said then. ''We expect it. Not only is it important to the community, but it's a growing experience. You [mix] with so many different sorts of people.''

Mr. Sorgenti created EMSCO Scientific Enterprises in West Philadelphia, a minority-owned provider of bottles, beakers, flasks, and disposable coveralls to laboratories throughout the region.

He not only thought up the idea, but also wrote letters to the chief executives of 20 large local firms, asking them to pledge making a certain percentage of their purchases from the new company.

Such action was necessary, Mr. Sorgenti wrote, "to reverse some of the unsettling trends that plague our cities.''

Mr. Sorgenti's efforts were recognized in 1985 when the Chamber of Commerce and the Penjerdel Council, an association that studies and makes recommendations on regional economic issues, gave him the William Penn Award for outstanding leadership, the business community's most prestigious prize.

Other honors included the Commendatore Medal (for service to the Republic of Italy), the Franklin Institute Phillip H. Ward Medal, the Martin Luther King Association Award for Corporate Justice, the Chemical Market Research Honor Award, and the Drexel University Business Leader of the Year Award.

He received honorary degrees from Chestnut Hill College and Ohio State, St. Joseph's, Villanova, and Drexel Universities.

Born in Brooklyn, Mr. Sorgenti graduated from Bay Ridge High School there. He earned a bachelor's degree from City College of New York and a master's degree from Ohio State, both in chemical engineering.

Mr. Sorgenti was a collector of African American art and donated much of it to the Academy of the Fine Arts.

He was devoted to his family, with whom he enjoyed leisure time in Florida and in Avalon, N.J.

He is survived by his wife of 56 years, Ann R. Sorgenti; daughters Elizabeth Sorgenti Paterno and Lucille Sorgenti; four grandchildren; and many nieces and nephews.

A visitation from 9:30 to 11 a.m. Wednesday, July 18, will be followed by an 11 a.m. Funeral Mass at St. John Neumann Catholic Church, 380 Highland Lane, Bryn Mawr.

Interment will be at Calvary Cemetery in West Conshohocken.

Memorial contributions can be made to Trustees of the University of Pennsylvania, Penn Medicine Hospice, Penn Medicine Development Office, 3535 Market St., Suite 750, Philadelphia, Pa. 19104.