Homer Bhullar
Vice President of Investor Relaions and Finance at Valero Energy
Thanks, Joe. For the second quarter of 2022, net income attributable to Valero stockholders was $4.7 billion or $11.57 per share compared to $162 million or $0.39 per share for the second quarter of 2021. Adjusted net income attributable to Valero stockholders was $4.6 billion or $11.36 per share for the second quarter of 2022 compared to $260 million or $0.63 per share for the second quarter of 2021. For reconciliations to adjusted amounts, please refer to the earnings release and the accompanying financial tables.
The refining segment reported $6.2 billion of operating income for the second quarter of 2022 compared to $349 million for the second quarter of 2021. Adjusted operating income was $6.1 billion for the second quarter of 2022 compared to $442 million for the second quarter of 2021. Refining throughput volumes in the second quarter of 2022 averaged three million barrels per day, which was 127,000 barrels per day higher than the second quarter of 2021.
Throughput capacity utilization was 94% in the second quarter of 2022 compared to 90% in the second quarter of 2021. Refining cash operating expenses of $5.20 per barrel in the second quarter of 2022 were $1.07 per barrel higher than the second quarter of 2021, primarily attributed to higher natural gas prices. Renewable diesel segment operating income was $152 million for the second quarter of 2022 compared to $248 million for the second quarter of 2021.
Renewable diesel sales volumes averaged 2.2 million gallons per day in the second quarter of 2022, which was 1.3 million gallons per day higher than the second quarter of 2021. The higher sales volumes were attributed to DGD 2's operations, which started up in the fourth quarter of 2021. The ethanol segment reported $101 million of operating income for the second quarter of 2022 compared to $99 million for the second quarter of 2021.
Adjusted operating income, which primarily excludes the gain from the sale of our Jefferson ethanol plant, whose operations were idled in 2020 was $79 million for the second quarter of 2022. Ethanol production volumes averaged 3.9 million gallons per day in the second quarter of 2022. For the second quarter of 2022, G&A expenses were $233 million and net interest expense was $142 million. Depreciation and amortization expense was $602 million and income tax expense was $1.3 billion for the second quarter of 2022. The effective tax rate was 22%.
Net cash provided by operating activities was $5.8 billion in the second quarter of 2022. Excluding the favorable impact from the change in working capital of $594 million, and the other joint venture members 50% share of DGD's net cash provided by operating activities, excluding changes in DGD's working capital, adjusted net cash provided by operating activities was $5.2 billion. With regard to investing activities, we made $653 million of capital investments in the second quarter of 2022, of which $298 million was for sustaining the business, including costs for turnarounds, catalysts and regulatory compliance and $355 million was for growing the business.
Excluding capital investments attributable to the other joint venture members 50% share of DGD, and those related to other variable interest entities, capital investments attributable to Valero were $524 million in the second quarter of 2022. Moving to financing activities. Earlier this month, our Board of Directors approved a regular quarterly common stock dividend of $0.98 per share payable on September one to holders of record on August 4.
We returned 42% of adjusted net cash provided by operating activities to our stockholders through dividends and stock buybacks in the quarter, which is at the low end of our annual 40% to 50% target payout ratio. With respect to our balance sheet, we completed another debt reduction transaction in the second quarter that reduced Valero's debt by $300 million. As Joe already noted, this transaction, combined with the debt reduction and refinancing transactions completed in the second half of 2021 and the first quarter of 2022, have collectively reduced Valero's debt by $2.3 billion.
We ended the quarter with $10.9 billion of total debt, $2 billion of finance lease obligations and $5.4 billion of cash and cash equivalents. The debt-to-capitalization ratio, net of cash and cash equivalents. Was 25%, down from the pandemic high of 40% at the end of March 2021, which was largely the result of the debt incurred during the height of the COVID-19 pandemic.
And we ended the quarter well capitalized with $4.6 billion of available liquidity, excluding cash. Turning to guidance. We expect capital investments attributable to Valero for 2022 to be approximately $2 billion, which includes expenditures for turnarounds, catalysts and joint venture investments. About 60% of that amount is allocated to sustaining the business and 40% to growth. About half of the growth capital in 2022 is allocated to expanding our low carbon fuels businesses.
For modeling our third quarter operations, we expect refining throughput volumes to fall within the following ranges: Gulf Coast at 1.72 million to 1.77 million barrels per day; Mid-Continent at 420,000 to 440,000 barrels per day; West Coast at 255,000 to 275,000 barrels per day; and North Atlantic at 445,000 to 465,000 barrels per day. We expect refining cash operating expenses in the third quarter to be approximately $5.40 per barrel, which is higher than the second quarter, primarily due to higher energy costs.
With respect to the renewable diesel segment, we expect sales volumes to be approximately 750 million gallons in 2022 with the anticipated start-up of DGD three in the fourth quarter. Operating expenses in 2022 should be $0.45 per gallon, which includes $0.15 per gallon for noncash costs such as depreciation and amortization. Our ethanol segment is expected to produce 3.9 million gallons per day in the third quarter.
Operating expenses should average $0.50 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 $140 million and total depreciation and amortization expense should be approximately $640 million.
For 2022, we expect G&A expenses, excluding corporate depreciation, to be approximately $870 million. That concludes our opening remarks. Before we open the call to questions, we again respectfully request that callers adhere to our protocol of limiting each turn in the Q&A to two questions. If you have more than two questions, please rejoin the queue as time permits.
Please respect this request to ensure other callers have time to ask their questions.