Air Abatement System Efficiency Improvement

Project Summary

The Corporation in this study is a manufacturer of numerous molded and fabricated foam products. The fabrication of expanded polystyrene (EPS) produces pentane as a byproduct, which is a volatile organic compound (VOC). This chemical must be removed prior to being exhausted to the atmosphere, by means of a Regenerative Thermal Oxidizer (RTO). The RTO must operate continuously to maintain abatement of the pentane in the curing process.

The facility makes foam products during from 7:00 AM to 11:00 PM, allowing them to cure overnight. The regenerative thermal oxidizer runs in the mold machine and bag rooms during the day, at a rate of 9,000 CFM to serve production, but is turned down to 5,000 CFM at night to serve only the bag room. Testing was performed on the RTO with four feet of ceramic media that showed heat recovery efficiency of 89%, at an average of 8,700 CFM during production.

Energy Engineers audited the facility and concluded that design improvements can allow the efficiency to reach 96%. Metal-to-metal poppet valve seals are currently sealing the manifold, however they require added pneumatic air to seal the manifold properly. This pneumatic air can leak into the manifold, and must be heated to operating temperature. Replacing these with metal-to-silicone seals will eliminate the need to add and heat pneumatic air.

A second update consisted of adding ceramic media to the RTO. Ceramic media will recover more heat from the exhaust gas so that it will be used again to heat the incoming emission stream. There were originally four feet of ceramic media, by adding one foot the heat recovery effectiveness can be increased resulting in a reduction of natural gas consumption. Based on the measured results in both the production and non production operation, the improvements resulted in a retrofit thermal energy recovery of 94.3%.

The total project cost was $138,000 with a Lockheed Martin Energy paid an incentive of $59,806. The energy savings was 59,806 therms annually, corresponding to a cost energy savings of $48,508 a year. These savings make a simple payback of only 1.6 years!

Project Team

PGE Logo
Program Pacific Gas and
Electric Company
Lockheed Martin Logo
Lockheed Martin Energy
Heavy Industry Energy Efficiency

Goals

Increase the energy efficiency of the facility's regenerative thermal oxidizer

Strategies

Replace metal-to-metal poppet valves with metal-to-silicone and add one foot of ceramic media

Benefits

Decrease in energy loss

Energy Savings

59,806 therms annually

Equipment Installed

(1) Metal-to-Silicone poppet valve One foot of ceramic media

Financial Analysis Total Project Cost

$138,000

LM Paid Incentive

$59,806

Energy Cost Savings

$48,508

Simple Payback

1.6 years

It is our objective to assist PG&E heavy industry customers in:

Improve product quality and production rate
Identify process-focused energy efficiency improvements and other opportunities
Facilitate electricity and natural-gas energy efficiency equipment and demand reduction upgrades
 
Reduce operating costs per unit of product
Reduce waste, pollutants, and Green House Gas emissions
 

Increased production efficiency = Lower production costs = Increased profits