Most investors know Phillips 66 (PSX 1.26%) as one of America's largest oil refiners. The company currently operates 11 facilities in the country, making it an essential supplier of refined products. However, what many investors might not realize is that refining is just one part of Phillips 66's story.

No. 1: Its history dates back to 1875, not 2012

The current version of Phillips 66 started in 2012 when oil giant ConocoPhillips (COP -0.75%) spun it off. Its predecessor, though, dates back to 1875, when Isaac Blake started the Continental Oil and Transportation Co. to sell kerosene in San Francisco. Meanwhile, Phillips Petroleum Company got its start in 1917 when Frank and L.E. Phillips started the company in Oklahoma. Conoco eventually merged with Phillips in 2002 in a deal that created the sixth-largest publicly traded oil company in the world. However, it spun off its refining and marketing business a decade later so it could concentrate on growing its exploration and production business.

Refinery at twilight with a beautiful sky.

Image source: Getty Images.

No. 2: It's much more than just a refining company

Phillips 66 currently has the capacity to refine 2.2 million barrels of oil per day in both the U.S. and Europe, making it the second-largest independent refiner behind Valero Energy (NYSE: VLO), which controls 3.1 million barrels per day of capacity. That said, while refining is its biggest moneymaker, Phillips 66 operates three other important segments: chemicals, midstream, and marketing and specialties.

The chemicals segment consists of its CPChem joint venture that it co-owns with oil giant Chevron (NYSE: CVX). It's currently the world's largest producer of high-density polyethylene, which is used to make plastic bottles among other things. Meanwhile, the company's midstream business gathers, processes, transports, fractionates, and markets natural gas and NGLs, and carries crude to its refineries. Phillips 66 owns some of these assets on its balance sheet, with the rest owned by its MLPs, DCP Midstream Partners (NYSE: DCP) and Phillips 66 Partners (NYSE: PSXP). Finally, the marketing and specialties business, among other things, operates the largest branded aviation fuel business in the U.S.

No. 3: Warren Buffett is its biggest investor

Warren Buffett's Berkshire Hathaway (BRK.A 1.66%) (BRK.B 1.35%) owns large chunks of several well-known companies, including Phillips 66. Overall, Berkshire Hathaway owns more than 80 million shares, currently valued at more than $6 billion, which is its seventh largest stock holding. That's good for a 15.6% stake in the Phillips 66, making Buffett's company the top shareholder.

No. 4: It set the world record in organic solar cell efficiency

While its core business focuses on turning fossil fuels into higher-valued products, Phillips 66 is working on products and projects in the renewable energy sector. One of those products is a polymer-based single junction organic photovoltaic (OPV) cell for the solar industry. Last year, its OPV set a new record for efficiency at 11.84%. The solar cells use propriety state-of-the-art polymers developed by Phillips 66. While not commercialized just yet, this technology has the potential to decrease the cost of producing solar power dramatically and could put it on par with conventional technologies.

Solar panels absorbing the suns energy on hot summer day.

Image source: Getty Images.

No. 5: It has returned more than $14 billion in cash to investors since 2012

Phillips 66's current portfolio of energy manufacturing and logistics assets generate gobs of cash flow each year. While the company invests a significant portion of that money back into its business to maintain its operations and grow its asset base, it still has plenty of cash left over each year, which it uses to repurchase shares and pay a growing dividend. Overall, it has increased the dividend seven times since gaining its independence from ConocoPhillips, growing the payout by a remarkable 30% compound annual growth rate. On top of that, it has repurchased more than 100 million shares of stock, which has reduced its outstanding share count by almost 18%. Add it up and the company has returned more than $14 billion in cash to investors over the past five years.

Investor takeaway

It's important that investors know that Phillips 66 is so much more than just an oil refiner. In fact, its diversified business model is a key reason why superinvestor Warren Buffett owns such a significant stake in the company and why it has returned billions in cash to investors over the years. That diversification should enable the company to continue to thrive in future years even as the world begins its slow transition away from fossil fuels.