Supplemental Balance Sheet Information

12 Months Ended

Dec. 31, 2023

Balance Sheet Related Disclosures [Abstract]

SUPPLEMENTAL BALANCE SHEET INFORMATION

Components of "Intangibles and other assets, net" at December 31, 2023 and 2022 were as follows:


	2023		2022
Catalyst and turnaround costs	$	701	$	1,108
Other intangible assets	55		154
Other	1,283		1,152
	$	2,039	$	2,414

Other intangible assets consist of technology-based assets.

Amortization expense, included in "Depreciation and amortization" on the Partnership's Consolidated Statements of Operations includes amortization of intangible assets, turnaround expenses, and deferred charges. Aggregate amortization expense was $5,006, $5,713, and $4,085, for the years ended December 31, 2023, 2022 and 2021, respectively.

Estimated amortization expense for the years subsequent to December 31, 2023 are as follows: 2024 - $6,087; 2025 - $593; 2026 - $1; 2027 - $0; 2028 - $0; subsequent years - $0.

Components of "Other accrued liabilities" at December 31, 2023 and 2022 were as follows:


	2023		2022
Accrued interest	$	17,956	$	15,131
Asset retirement obligations	25		298
Property and other taxes payable	4,348		4,562
Accrued payroll	4,136		3,504
Operating lease liabilities	14,901		9,084
Other	133		495
	$	41,499	$	33,074

The schedule below summarizes the changes in our asset retirement obligations:


	Year Ended December 31,
	2023		2022
	(In thousands)

Beginning asset retirement obligations	$	4,992	$	9,072
Revisions to existing liabilities 1	—		—
Accretion expense	191		381
Liabilities settled	(1)		(4,461)
Ending asset retirement obligations	5,182		4,992
Current portion of asset retirement obligations 2	(25)		(298)
Long-term portion of asset retirement obligations 3	$	5,157	$	4,694

1 Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, discount rates, and the estimated remaining useful life of the assets.

2 The current portion of asset retirement obligations is included in "Other current liabilities" on the Partnership's Consolidated Balance Sheets.

3 The non-current portion of asset retirement obligations is included in "Other long-term obligations" on the Partnership's Consolidated Balance Sheets.