Good afternoon, and welcome to the NewMarket Corporation Conference Call and Webcast to review Fourth Quarter and Full-Year Financial Results. At this time, all participants are placed on a listen-only mode. It is now my pleasure to turn the floor over to your host, Mr. Bill Skrobacz. Sir, the floor is yours..
Thank you, Ali, and thanks to everyone for joining me this afternoon. Let me apologize in advance if I need to mute the audio for a few seconds during the call, as I'm recovering from a cough. As a reminder, some of the statements made during the conference call may be forward looking.
Relevant factors that could cause actual results to differ materially from those forward-looking statements are contained in our earnings release and in our SEC filings, including our most recent Form 10-K. During the call, we will also discuss the non-GAAP financial measures included in our earnings release.
The earnings release, which can be found on our website, includes a reconciliation of the non-GAAP financial measures to the comparable GAAP financial measures. We intend to file our 2022 10-K towards the end of February. It will contain significantly more details on the operations and performance of our company. Please review it.
I will be referring to the data that was included in last night's release. Net income for the fourth quarter of 2022 was $91 million or $9.26 per share. Net income for the year was $280 million or $27.77 per share compared to net income of $191 million or $17.71 per share for the full year 2021.
Petroleum additives sales for the fourth quarter were $680 million and reached $2.8 billion for 2022 compared to $2.3 billion for 2021. Petroleum additives operating profit for the quarter was $117 million. And for 2022, it was $378 million compared to $281 million for 2021.
For the year, the operating profit increase was mainly due to increased selling prices, partially offset by higher raw material and operating costs. Shipments decreased 2.9% between full periods, primarily due to decreases in lubricant additives shipments.
Supply chain disruptions and new sanctions introduced during 2022 as a result of the Russia-Ukraine war were the primary contributors to the decline in shipment. During the year, working capital increased $204 million.
We funded capital expenditures of $56 million and returned $292 million to our shareholders through dividends of $84 million and share repurchases of $208 million. We ended the year with a healthy balance sheet and with a net debt to EBITDA at 2 times.
As we have stated before, we are comfortable maintaining the net debt-to-EBITDA in the 1.5 times to 2 times range. And at times, we may go outside that range. In 2023, we expect to see capital investment in the $70 million to $80 million range.
The last three years have been characterized by unprecedented factors, including the impact of the COVID-19 pandemic, worldwide supply chain disruptions, inflation and war. Accordingly, we believe that it is useful to compare our '22 results to 2019, the last full year before these factors.
Petroleum additives sales in 2022 were $578 million higher than in 2019, an increase of 26%. Petroleum additives operating profit in 2022 was $19 million higher, an increase of 5% over 2019, and shipments in 2022 were 2.8% higher than 2019. Petroleum additives operating margin for '22 was 13.7% versus 16.5% in 2019.
We're pleased by the performance of our petroleum additives business in 2022 and the work done by our team to navigate through the many challenges of the past three years.
While our efforts to resolve supply chain issues to better meet our customers' growing needs have shown improvement, we are still challenged by the inflationary environment and rising operating costs that we expect to continue into 2023. Margin recovery and cost control will remain priorities throughout 2023.
We want to thank our dedicated employees for their commitment to our business and to serving our customers. We continue to make decisions to promote long-term value for our shareholders and customers, and we remain focused on our long-term objectives.
We believe the fundamentals in how we run our business, a long term view, safety first culture, customer focused solutions, technology driven product offerings and world class supply chain capability will continue to be beneficial for all our stakeholders. Ali, that concludes our planned comments. We are available for questions via e-mail or by phone.
So please feel free to contact me directly. Thank you all again, and we will talk to you the next quarter..
Thank you. This does conclude today's conference call. You may disconnect your lines at this time, and have a wonderful day. We thank you for your participation..