LOW SULPHUR INDUSTRIAL FUELS:

Source, Use and Pollution Minimisation

Haycock AJ (MA Geographical & Environmental Sciences)

Heating fuels provide the required energy for various industrial processes; liquid fuels having significant advantages over electricity or solid fuels. These include: abundant availability, wide variety of fuels and suppliers, assists with waste minimisation, is suitable for most applications and is cost effective (Scholtz, 2002). Oils provide radiance or luminosity essential for many industrial processes, which may not be obtained from gas or coal. Fuels of high viscosity and with impurities such as ash and water are usually cheaper but more expensive in maintenance costs of equipment than low viscosity, low ash fuels. Heavy fuel oils (HFO-residue remaining after distillation of crude oil) have been the traditional choice of Industry in generation of power and steam due to their low cost. Heavy fuel oils contain ash of usually <0.2% and sulphur of ~3.5%. The high viscosity of HFO requires it to be stored in heated tanks and reticulation systems (FFS Refiners, 2000). The most significant environmental concern from the combustion of these heavy fuel oils and coal is the amount of sulphur dioxide and nitrous oxides produced. Sulphur dioxide, if combined with moisture or rainwater, produces sulphur acids which impact negatively on health (asthma, bronchial irritation) and the environment in the form of acid rain (sulphur dioxide and nitrogen oxides) which destroys vegetation, leads to acidification of lakes, and contributes to the decay of buildings.

LEGISLATION
The Atmospheric Pollution Prevention Act of 1965 sets guidelines on pollution levels which industries are not permitted to exceed. However, the lack of Air Pollution Control Officers has resulted in unchecked emissions for many years. The guidelines are voluntary and as such are not enforceable in court (Carnie, 2002). The Department of Environmental Affairs and Tourism (DEAT) have noted that industrial areas have the highest pollution levels (SO2, particulates and oxides of nitrogen), with 80% of air pollution being generated from the combustion of coal, heavy fuel oil and other fuels (GN 1387 GG 22941- 2001). In light of these and other findings, the Department has identified SO2 as a first priority pollutant and has subsequently issued in December 2001 revised guidelines for sulphur dioxide in terms of the Atmospheric Pollution Prevention Act (GN 1387, GG 22941-2001). The revised recommended annual average maximum allowable concentration of ambient SO2 is 0.019ppm; previously the guideline was 0.03ppm. This is a significant reduction in permissible SO2 .

One of the main thrusts of the National Air Quality Management Bill (Draft 6.0-2002) is setting of ambient standards for air quality management and permissible amounts / concentrations of substances for different areas (NAQMB, 2002 Draft). These set standards will be legally enforceable. Focus areas of the Bill include: air pollution on a local, regional, national and global scale and consideration of vehicle emissions, emissions from industrial activities, acid rain and noise. Emphasis is being placed on identification, and reduction / elimination of priority pollutants such as sulphur dioxide. Durban South has been identified as a “hot spot “and has been targeted as a pilot project for the testing and development of strategies for dealing with air pollution hot spots, as well as for regionally-based laws which will be given to other hot spot areas such as Secunda and Sasolburg (Carnie, 2002).

LOCAL INITIATIVES
In Durban South there is presently a significant push being placed on phasing out of so-called ”Dirty Fuels” as it is claimed that coal and heavy furnace oils with high sulphur contents contribute to high levels of SO2 and particulate matter in the atmosphere (Mahema, 2002). DEAT has proposed various targets and time frames for the phasing out of heavy fuels over a four-year period. One of their main targets is to have sulphur in fuel of <1% or the equivalent reduction in SO2, which could be achieved through fuel switching and/or alternative fuels (Mahema, 2002). Monitoring sites in Durban have shown non-compliance with the daily average interim sulphur dioxide guideline at all Durban sites. For example, the Southern Sewage Works site recorded an exceedance of the annual average guideline (Burger & Scorgie, 2002). In light of this, the Durban Multipoint Plan aims to develop an air quality management plan, phase out “Dirty Fuels”, undertake health risk assessments and epidemiological studies, as well as set air quality standards and so forth (Chetty, 2002). A number of alternative fuels have been proposed to reduce SO2 including: gas, low sulphur coal, bio-diesel and low sulphur furnace oils. There are pros and cons to each of these proposed alternatives, however if industry used low sulphur fuels this would reduce SO2 in Durban South and in other areas. This however may have a significant economic impact on business competitiveness in these areas, which may lead to economic collapse and resultant labour migration. This obviously would be counter-productive.

FFS REFINERS LOW SULPHUR FUELS -
A REALISTIC AND POSITIVE ALTERNATIVE?

FFS Refiners is a national, entirely South African-owned, hydrocarbon refining company with the capability of handling unconventional fuels, and of processing used and residual materials into quality marketable fuels. The company has six processing facilities throughout the country, a number of smaller depots and a comprehensive transport network. As well as processing 800 000 tons of tars and oils each year, the group also receives significant volumes of conventional fuels from the major oil refineries for blending and direct marketing.

Currently, FFS Refiners’ Cape Town Branch receives more than 90% of the used oils generated in the Western Cape region and processes these into high-quality, low-sulphur fuels for industry. Methods used by FFS to recover used oils are believed to be the most advanced in the world and maximise resource recovery, final product quality and minimise waste. In 1992, FFS Refiners began to provide Low Sulphur Oil (LSO) into the industrial fuels market. It is produced by blending conventional heavy fuels with low sulphur material, which is derived from South African synthetic oil manufacturers and recovered hydrocarbons. LSO has a sulphur content average of 1.5 % compared to the traditional fuel choice for industry, namely Heavy Fuel Oil (HFO) which has a sulphur content of ~3.5% or higher (Table 1). LSO has the emissivity critical to many industrial applications with half the sulphur content.

Characteristics	Heavy-Fuel Oil 150	Low Sulphur Oil
Viscosity	150 cSt @ 50oC	100cSt @ 50oC
Density	0.99 kg/l	0.92 kg/l
Flashpoint	>100oC	>100oC
Sulphur	<3.5%	<2.0%
Energy value	43 365 kJ/kg	44 200kJ/kg
Cost	Moderate	Moderate

Table 1: Comparison of HFO and LSO (FFS Refiners, 2000)

FFS Cape Town supplies ~8 000 tons and FFS Durban supplies ~2 000 tons of Low Sulphur Fuel (LSO) into the industrial fuels market each month. FFS is thus responsible on a monthly basis for preventing the emission of approximately 320 tons of sulphur dioxide into the Cape Town atmosphere and approximately 80 tons into Durban’s atmosphere by providing a more environmentally acceptable alternative to Heavy Fuel Oil.

References
Adoption of Revised Guidelines for Sulphur Dioxide in terms of the Atmospheric Pollution Prevention Act of 1965, GN 1387 GG 22941 21st December 2001.

Burger, L Dr & Scorgie, Y (2002) Air Quality Legislation-Potential for Non-Compliance cited in Workshop proceedings “Progress regarding air quality legislation in South Africa: Implications for stakeholders ”NACA 19th July 2002.

Carnie, T (2002) Time for Industry to clean up its act, Sunday Tribune 16th June 2002.

Chetty, S (2002) South Durban Basin Multipoint Plan. Presentation at workshop on “Phasing out of dirty fuels in Durban South Basin” workshop on 17th September 2002.

FFS Refiners, (2000) Heating Fuel Handbook.

Mahema, T.S (2002) Phasing Out of Dirty Fuels. Department of Environmental Affairs & Tourism. Presentation at workshop on “Phasing out of dirty fuels in Durban South Basin” workshop on 17th September 2002.

National Air Quality Management Bill Draft 6.0 March 2002.

Scholtz, P (2002) Low Sulphur Industrial Fuel Oils. Presentation at workshop on “Phasing out of dirty fuels in Durban South Basin” workshop on 17th September 2002.