Oil prices boost coal tar

Press, Volume CXV, Issue 33815, 11 April 1975, Page 10

Oil prices boost coal tar

Coal tar. just 181 months ago an unwanted by-product of coal gas production, has become remarkably popular as a result of increasing prices for fuel oil. Declining sales over recent years forced the Christchurch Gas. Coal and Coke Company to burn surplus coal tar: it was impossible to give it iway. But noyv the market ■ is been recreated, and shorttge rather than surplus ippears to be the future problem. The company produces ibout 560.000 gallons of coal ar a year and has about! 150.000 gallons stored. Once, tost of the tar yvas sold tor oad surfacing, but during the 960 s there yvas almost a otal swing away from coal ar to bitumen — a by-) iroduct of oil This swing yvas eased a ■tile by Government subsides from 1973 yvhich covered bout $30,000 in transport ■sts to get surplus tar from 'hristchurch to the North' sland for roading. The dramatic change came vithin ihe last eight months.. Increasing oil nrices gave •ar an even bigger cost; advantage over bitumen'

(today bitumen at $75 a torr is almost twice the price of) coal tar) and two big Christ-' church industries have) switched to coal tar-fired; i burners. One is the Neyv Zealand) Breyveries Christchurch plant, where one boiler has been converted so far. and the: other is Feltex New Zealand. Ltd. Between them they will take 460.000 gallons of coal-1 tar fuel a year. Another likely market is rhe pool-heating equipment at Queen Elizabeth II Park. The 1 Christchurch City Council has already agreed to the) conversion of the furnaces: and contract negotiations for) the supply of the tar are) under way noyv. These changes make eco-i nomic sense — coal tar is I 22c a gallon and fuel oil prices range from 33.2 c a gal-) lon for light fuel oil to 45.3 c a gallon for thermol. There are added benefits, according to those yvbo have made the 1 switch. Cleaner air is one. Sulphur content of the coal tar averages at 0.3 per cent, compared with betyveen 3 and 4 per cent of the fuel oils. Efficiency is another. Tests, at the brewery- both on a) pilot scheme and on the: recentlv-converted boiler) show that the coal tar is as efficient as the fuel oil; when

the boiler is fully fired the! flame is even hotter than with! fuel oil. According to the brewery’s) chief engineer in Christ- 1 church (Mr F. E. Uhr) the; coai tar is proving completely, satisfactory and the breyver is using near to its quota each month. "The cost of this conver-’ sion should be offset within the first year’s savings over fuel oil,” he said. Other advantages of the syvitch include a negotiated contract for supply of the coal tar yvhich stabilises) escalating fuel costs, an assured and unrestricted sup-; ply oi the product, and the: release of 100.000 gallons of rationed fuel oil for use else-; where in the brewery, he: said. Since the conversion at the: brewery several outside firms had shown an interest,' and one Dunedin company 1 had flown three men to) Christchurch to study the installation. The coal tar is pre-heated, so it arrives in the boilers with the viscosity of light diesel and ignites at the burners. A hidden advantage of the, use of coal tar, apart from: the money saved directly by the firms which have con-; verted, is the consequent sav-. mg m overseas exchange;

needed to bring in the fuel oil it replaces. But wide-scale adoption of coal tar will be handicapped by the effect of the dot-: drums through yvhich the industry has passed When coal tar was the unwanted baby of the gas industry, it yvas being dumped and burned.. (The Hokitika Gas Company) was dumping it in an old. mine: the Oamaru Borough Council dumped it in 40gallon drums: Nelson, Blenheim, and Dunedin ran out of storage). So a lot of the potential has been wasted. More critical. however, has been the’ conversion by several gas companies to virgin naptha reformers for the production 1 Naptha is an oil product: and those companies which; have switched completely from coai to naptha gas pro- : duction are themselves at the; mercy of overseas oil prices.) Gisborne, Napier, and Timaru are all either totally or) almost totally converted to: naptha reformers, Dunedin had moved rapidly to naptha gas production, and Christchurch noyv uses naptha for about 30 per cent of its gas; production. As a result, the capability l for producing coal tar, yvhich was once present has i to soma extent disappeared,'