Natural gas fueled re-fuse trucks are an excellent option for operators in the Washington, D.C.-based U.S. Environmental Protection Agency's designated non-attainment communities or for those who are just concerned with doing their part to protect the environment.
Not only do engines operating on natural gas produce less emissions and reduce the country's dependence on imported oil, its cost also can be considerably less. For instance, compressed natural gas (CNG) is about 10 to 50 percent less expensive per equivalent gallon than either unleaded gasoline or diesel fuel. Like gasoline and diesel though, natural gas prices vary around the country.
Natural gas vehicles differ from more traditional trucks mainly in the manner in which their gas is stored. There are two basic systems:
* CNG which is compressed to very high pressures, typically 3,000 per-square-inch (psi) and stored in special cylinders; and
* liquid natural gas (LNG) which is super-cooled to a temperature of -260 degrees F to -270 degrees F, liquefying it.
Engines operate on CNG or LNG with equal ease. Whether stored at high pressure or low temperature, by the time the gas reaches the en-gine's combustion chamber, it has returned to its gaseous form. With ap-propriate modifications, regular gasoline or diesel engines can be retrofit-ted to operate on natural gas, and companies a-round the country currently are doing the conversions. Converted engines allow fleets with still serviceable trucks and engines to benefit from most natural gas advantages without a substantial investment in new equipment.
Since conversions can result in compromises, the best, though more expensive, approach is buying engines specifically designed to operate on natural gas. These give optimum performance and fuel economy, produce minimum emissions and have the greatest reliability and durability especially for the hours of non-stop operation in stop-and-go city traffic.
Caterpillar, Cummins, Detroit Diesel and Mack now offer natural gas engines for refuse trucks. While these engines started out as diesels, they have been optimized to run on natural gas with features such as:
* spark ignition systems (natural gas requires spark ignition versus compression ignition found in diesel engines),
* electronically-controlled turbochargers and
* "lean burn" technology with higher air-to-fuel ratios for more efficient performance and reduced emissions.
Cleaner burning also minimizes carbon buildup in the engine which translates to less maintenance. Other changes can include special catalytic converters, air/fuel mixers with an electronically-controlled governor, pistons designed specifically for natural gas and premium valve and valve inserts plus actuators, sensors, computers and controls. Done right, natural gas engines retain diesel-like performance, reliability and durability while significantly lowering nitrous oxide and particulate emissions.
Gas storage is one of the biggest choices facing operators. Storage capacity directly affects the range between fill ups. With CNG, high pressures require heavy storage tanks. Even with very large tanks, ranges still can be quite limited. The higher the compression, the greater the vehicle's range, at least theoretically.
With current technology, about the highest practical natural gas compression for on-board tanks is 3,000 psi. An increase to 3,600 psi does not really provide a great increase in storage capacity because cylinder walls have to be made thicker, resulting in reduced volume for the same external dimensions. Sufficient range for a day's work without refueling can impact the refuse truck's useful capacity.
With "fast-refill" CNG facilities sprouting up nationwide, refueling takes about the same time as filling a diesel fuel tank. "Slow-fill" systems are appropriately called "overnight" refueling since it takes five to eight hours to refill tanks.
LNG, on the other hand, offers a substantial increase in range because of the much greater gas compression that comes with liquefaction. How-ever, maintaining super-cool temperatures requires large, heavy, highly-insulated tanks which still forces compromise between vehicle range and cargo carried. Like CNG, space has to found for the tanks plus associated supports and plumbing. And, LNG refueling facilities are harder to find than CNG "stations."
As a result, CNG is the most commonly used alternative fuel and has been used for decades. Therefore, a wealth of experience has be accumulated on its safety. For example, a recent study done by Power Labs Ltd. and the Institute for Gas Technology showed an extremely low failure risk for the large number of cylinders, even under the severe conditions en-countered in natural gas vehicles. Over a 20-year period with 1.5 million cylinders in service worldwide, only 15 ruptures and 20 leaks were found. Other testing has shown that CNG tanks are as safe or safer than a gasoline tank, even when hit by a bullet or struck in a collision.
If the CNG or LPG tank should rupture, or more likely, if lines or fittings break, the danger is much like a natural gas line rupture with the same dangers and procedures. If the CNG or LPG tank is damaged, leaking or already on fire, it should be approached only by experienced personnel wearing proper protective clothing and self-contained breathing apparatus.
Because of manufacturers' rigid standards, plus expensive storage tanks and plumbing, natural gas vehicles can be significantly more expensive. Higher costs can be offset, however, by the lower fuel costs as well as by incentives from governmental agencies and manufacturer re-bates. Also of importance is the need for an excellent maintenance and inspection program. Damage to tanks should be prevented, inspections made periodically and damaged tanks replaced immediately.
Acquisitions American Disposal Services, Burr Ridge, Ill., a regional, integrated, non-hazardous solid waste services company, has purchased Liberty Disposal Inc., Johnston, R.I., and Christiansen's Inc., Sandusky, Ohio.
In addition, the company has purchased assets of Browning-Ferris Industries of Connecticut Inc., including a collection company located in southwest Connecticut and obtained an exclusive contract to operate a transfer station for the town of Stratford.
CETCO, Arlington, Heights, Ill., has acquired the minerals processing operation in Belle Fourche, S.D., of American Colloid Co., one of its sister subsidiaries under AMCOL International Corp.
Eastern Environmental Services has acquired the rights to operate a transfer station and processing facility known as "Sanitary District No. 1" in New York for 13 years. The company will receive 1.7 million annually to process approximately 100 tons of waste per day.
Republic Industries Inc., Fort Lauderdale, Fla., has acquired three solid waste companies - National Serv-All, Fort Wayne, Ind.; AAA Disposal of Nashville, Tenn.; and Elliott's Agri-Service Inc., Pineland, Texas - for an aggregate purchase price of approximately $60 million, payable in Republic common stock. The three companies combined revenue in 1996 was approximately $38 million.
Roy F. Weston Inc., West Chester, Pa., announced that it has sold the assets of its wholly-owned subsidiary Weston Interactive Inc. to AIG Consultants Inc., New York, a subsidiary of American International Group Inc., for $1.35 million. Weston Interactive develops and markets interactive mutimedia courseware addressing workplace safety and environmental issues.
Agreement Leach Co., Oshkosh, Wis., and Wagon Engineering, Kuala Lumpur, Malaysia, signed a license and technical assistance agreement under which Wagon will produce and market the Leach 2RII rear loading refuse collection body at Wagon's new Kuala Lumpur manufacturing facility.
Contracts Earth Tech, Long Beach, Calif., recently was awarded a $49 million, five-year contract, with the U.S. Environmental Protection Agency, Region IV, to provide Emergency and Rapid Response Services for removal of hazardous substances at Superfund sites in Florida, Georgia, South Carolina, North Carolina, Tennessee, Kentucky, Alabama and Mississippi.
Browning-Ferris Industries (BFI), Houston, has signed a five-year contract under which International Billing Services, El Dorado Hills, Calif., will process all BFI customer statements for North America.
Shred-Tech, Cambridge, Ontario, Canada, has been awarded a $3- million contract by Micro Metallics Corp., San Jose, Calif., to supply and install a custom-designed system to reduce computer and computer hardware for the recovery of component metals.
The city of Riverview, Mich., has awarded a multi-year contact to EMCON, San Mateo, Calif., to provide engineering services to the Riverview Land Preserve, a 285-acre solid waste disposal facility. Services include: routine landfill site support, evaluation of the landfill's airspace use, leachate and landfill gas management projects and development of a master plan for the landfill.
Fiscal Browning-Ferris Industries Inc., Houston, reported consolidated net income, before an extraordinary charge, for the quarter ending March 31 of $70,955,000, or 35 cents per share, on consolidated revenues of $1.414 billion.
Eastern Environmental Services Inc., Mt. Laurel, N.J., reported revenue for the quarter ending March 31 of $19.5 million and operating income of $2.6 million, excluding merger costs of $1.5 million, compared to $9.6 million in revenue and $16,000 in operating income for the same period in fiscal 1996.
Republic Industries Inc., Fort Lauderdale, Fla., reported that for the three months ending March 31, net income increased 133 percent to $28.9 million, or 8 cents per share, from $12.4 million, or 4 cents per share in 1996 for the same period.
USA Waste, Houston, reported financial results for the first quarter ending March 31. Net income increased 78 percent to $49.1 million, while earnings per share rose 52 percent compared to the 1996 period. Also, operating profits increased 64 percent to $88.8 million from $54.2 million.
New Division National Seal Co., Aurora, Ill., has announced the creation of its Piping and Gas Collection Systems Division. This new division offers complete systems for landfill gas recover and other HDPE pipe installations and will be headquartered in Baton Rouge, La.
Paperboard Alliance The 100% Recycled Paperboard Alliance joined with eight major packaged goods companies to participate in a high-visibility marketing campaign featuring products packaged in 100 percent recycled paperboard. The companies include: General Mills, Lever Brother Co., The Dial Corp., Martin's Potato Chips, New Mexico's Kitchen, Oceana Foods, Comet American Marketing and General Building Corp.
Patent SwapLoader, Des Moines, Iowa, a manufacturer of hook-lift hoists, has been awarded a U.S. patent for the dual-capacity of its Model SL-2418HD, a model designed for medium-duty trucks with 96" cab-to-axle.
Purchase Reko B.V. has purchased an MSS VYDAR Automated Plastic Flake Removal System for installation in its PET recycling facility in Geleen, Holland, from MSS International Inc., Nashville, Tenn.