Homer Bhullar
Vice President, Investor Relations and Finance at Valero Energy
Thanks, Lane. For the second quarter of 2023, net income attributable to Valero stockholders was $1.9 billion or $5.40 per share compared to $4.7 billion or $11.57 per share for the second quarter of 2022. Second quarter 2022 adjusted net income attributable to Valero stockholders was $4.6 billion or $11.36 per share. The Refining segment reported $2.4 billion of operating income for the second quarter of 2023 compared to $6.2 billion for the second quarter of 2022. Adjusted operating income was $6.1 billion for the second quarter of 2022. Refining throughput volumes in the second quarter of 2023 averaged 3 million barrels per day, implying a throughput capacity utilization of 94%.
Refining cash operating expenses were $4.46 per barrel in the second quarter of 2023, lower than guidance of $4.60, primarily attributed to lower-than-expected natural gas prices. Renewable Diesel segment operating income was $440 million for the second quarter of 2023 compared to $152 million for the second quarter of 2022. Renewable Diesel sales volumes averaged 4.4 million gallons per day in the second quarter of 2023, which was 2.2 million gallons per day higher than the second quarter of 2022. The higher sales volumes in the second quarter of 2023 were due to the impact of additional volumes from the start-up of the DGD Port Arthur plant in the fourth quarter of 2022.
The Ethanol segment reported $127 million of operating income for the second quarter of 2023 compared to $101 million for the second quarter of 2022. Adjusted operating income for the second quarter of 2022 was $79 million. Ethanol production volumes averaged 4.4 million gallons per day in the second quarter of 2023 which was 582,000 gallons per day higher than the second quarter of 2022. For the second quarter of 2023, G&A expenses were $209 million and net interest expense was $148 million. Depreciation and amortization expense was $669 million, and income tax expense was $595 million for the second quarter of 2023. The effective tax rate was 22%.
Net cash provided by operating activities was $1.5 billion in the second quarter of 2023. Excluding the unfavorable change in working capital of $1.2 billion in the second quarter and the other joint venture member share of DGD's net cash provided by operating activities, excluding changes in its working capital, adjusted net cash provided by operating activities was $2.5 billion.
Regarding investing activities, we made $458 million of capital investments in the second quarter of 2023, of which $382 million was for sustaining the business, including costs for turnarounds, catalysts and regulatory compliance; and $76 million was for growing the business. Excluding capital investments attributable to the other joint venture members share of DGD, capital investments attributable to Valero were $433 million in the second quarter of 2023.
Moving to financing activities. We returned over $1.3 billion to our stockholders in the second quarter of 2023, of which $367 million was paid as dividends and $951 million was for the purchase of approximately 8.4 million shares of common stock resulting in a payout ratio of 53% of adjusted net cash provided by operating activities.
Last week, we announced a quarterly cash dividend on common stock of $1.02 per share payable on September 5, 2023, to holders of record at the close of business on August 3, 2023. With respect to our balance sheet, we ended the quarter with $9 billion of total debt, $2.3 billion of finance lease obligations and $5.1 billion of cash and cash equivalents. The debt-to-capitalization ratio net of cash and cash equivalents was 18% as of June 30, 2023. And we ended the quarter well capitalized with $5.4 billion of available liquidity, excluding cash.
Turning to guidance. We expect capital investments attributable to Valero for 2023 to be approximately $2 billion, which includes expenditures for turnarounds, catalysts and joint venture investments. About $1.5 billion of that is allocated to sustaining the business and the balance to growth. For modeling our third quarter operations, we expect Refining throughput volumes to fall within the following ranges: Gulf Coast at 1.77 million to 1.82 million barrels per day; Mid-Continent at 450,000 to 470,000 barrels per day; West Coast at 240,000 to 260,000 barrels per day; and North Atlantic at 435,000 to 455,000 barrels per day.
We expect Refining cash operating expenses in the third quarter to be approximately $4.70 per barrel. With respect to the Renewable Diesel segment, we expect sales volumes to be approximately 1.2 billion gallons in 2023. Operating expenses in 2023 should be $0.49 per gallon, which includes $0.19 per gallon for noncash costs such as depreciation and amortization. Our Ethanol segment is expected to produce 4.4 million gallons per day in the third quarter. Operating expenses should average $0.39 per gallon, which includes $0.05 per gallon for noncash costs such as depreciation and amortization.
For the third quarter, net interest expense should be about $145 million, and total depreciation and amortization expense should be approximately $690 million. For 2023, we expect G&A expenses, excluding corporate depreciation, to be approximately $925 million.
That concludes our opening remarks. [Operator Instructions].