Environmental Health & Safety

Eastman Chemical Earns Sustainability Recognition

Two groups honor broad-based efforts at the company

By Chemical Processing Staff

Eastman Chemical Co. faired well in the 2011 Southeastern Corporate Sustainability Rankings compiled by GreenBusiness WORKS. The Kingsport, Tenn.-based company placed 10th in the overall rankings and 2nd in the state of Tennessee.  The rankings spotlight publicly traded companies headquartered in Georgia, Florida, South Carolina, Alabama, North Carolina and Tennessee.

A total of 48 eligible companies were evaluated on three performance dimensions: environmental, social and governance. Each dimension consists of five key performance indicators with a total of 175 underlying quantitative and qualitative performance metrics.

Environmental performance indicators include waste, energy, water, emissions, and risk mitigation. Social performance indicators are product responsibility, community, human rights, diversity and opportunity, and employment quality.  Governance performance indicators comprise board functions, board structure, compensation, vision and strategy, and shareholder rights.

The rankings represent the latest recognition Eastman has attained for its commitment to environmental performance. The company also has garnered awards from the American Chemistry Council (ACC).

As part of the Responsible Care program, the ACC honors specific projects that significantly reduce energy consumption and greenhouse gas emissions. Eastman received six of the 48 awards presented to 17 member companies.

Eastman has reduced greenhouse gas intensity 27% over the last 10 years and energy intensity by 38% over 15 years, it says. For 2010, Eastman cut energy intensity another 6%, with energy savings of 3 million MMBTUs and 275,000 fewer tons of greenhouse gas emissions.

Eastman's six awards were for "Significant Improvement in Manufacturing," which recognizes companies that improve energy efficiency in their manufacturing operations through technical innovations, creative projects or implementation of novel or established procedures or actions.

Eastman's Kingsport, Tenn., site received five awards:

Recovery of steam leak-off. Six Sigma techniques were used to recover 15 psi steam leak-off from shaft seals on turbo generators in a powerhouse. New construction and use of an abandoned recovery system resulted in the recovery of the 15 psi steam for an annual energy savings of 44,391 MMBTU and an annual reduction in greenhouse gas emissions of 4,661 tons annually.

Improvements in boiler feedwater exchanger. The boiler feedwater stage heaters at a powerhouse were found to be operating at reduced efficiency due to material wear in the heat exchangers,  resulting in the boiler feed water bypassing the stage heater. A monitoring program compared temperatures of the boiler feedwater exiting the stageheater with a desired value. As a result, the stage heaters were returned to optimum efficiency and the temperature of the boiler feedwater was increased. This decreased the heat input required during steam generation and increased topping power from the generators leading to an annual energy savings of 180,456 MMBTU and an annual greenhouse gas emissions reduction of 17,330 tons.

Improvements in distillation columns. The combined use of a new distillation column and the replacement of an existing column with a new, more efficient design led to lower reflux rates, improved control, and greater energy efficiency while maintaining production.  The new column  that incorporated energy efficiency improvements was started up when the existing column was shut down to replace sieve trays with high-efficiency distillation trays and optimize tray spacing for greater efficiency. This resulted in annual energy savings of 44,150 MMBTU and an annual greenhouse gas emissions reduction of 4,635 tons.

Reduced ester still heat usage. An ester still was previously heated with 600-psig steam that was modulated through a valve to a lower pressure. Experiments with the still revealed that the column could be heated from an existing 100-psig steam header with decreased energy use and increased controllability. The heater was repiped to take the steam from this header and drain to a lower pressure condensate header. This resulted in annual energy savings of 81,000 MMBTUs and an annual greenhouse gas emissions reduction of 8,500 tons.

Reduction of natural gas usage in three heat transfer material furnaces used to provide heat for DMT (dimethyl terephthalate) production.   A new control strategy was implemented that automatically shifts load from less efficient furnaces to more efficient ones so that the overall heat duty required is provided at maximum efficiency, reducing natural gas consumption. Compared to 2008, natural gas consumption has been reduced by 80 scf per MMBTU of heat delivered to the process, with a savings of 35,393 kscf in 2010 or 6.3% of the total gas usage.  This converts to an annual savings of 36,455 MMBTUs and 1922 tons of green house gas. 

Eastman's Longview, Texas, site received one award:

Improvement of steam turbine discharge. As two large steam turbines discharge into an existing 160-psig steam system and their compressors foul, their steam load increases to maintain operating horsepower.  The ability of the existing 20-inch diameter steam lines to export additional steam was limited, causing higher discharge pressure and incremental operating cost increases over the five years between plant shutdowns.  Adding an additional steam line to maintain a constant 175-psig steam discharge pressure resulted in lower 1,500-psig steam demand, an annual savings of 34,000 MMBTUs and 2,250 tons of greenhouse gas emissions.