ARCHIVE: Additional guidance from the Department for Environment, Food and Rural Affairs, and from the Welsh Assembly Government
AQ 23(04)
Amendments of PG 1/3(95) Boilers and Furnaces, 20-50 MW Net Rated Thermal Input
[THE AMENDMENTS ARE IDENTIFIED BY ITALICS IN THE NOTE BELOW]
This note amends PG1/3(95), following its second review. The note has not been republished in the new format because of the relatively few amendments and small number of regulated installations.
The amendments and new text at points 6 onwards below should be treated as statutory guidance under both section 7(11) of the Environmental Protection Act 1990 and also Regulation 37(1) of the Pollution Prevention and Control (England and Wales) Regulations 2000, SI 1973.
For the purposes of regulation under the Pollution Prevention and Control Act 1999, the schedule of activities, installations and mobile plant is contained in Schedule 1 to the Pollution Prevention and Control Regulations 2000, SI 1973 as amended. The timetable for implementation is contained in Schedule 3 to the same regulations.
Background
1. Carbon monoxide monitoring provides an additional check against poor design and maintenance and helps identify whether good combustion is occurring.
2. Low NOx burners produce an appreciable and worthwhile drop in nitrogen oxide emissions when burning gas.
3. Since PG1/3 was last revised, Directive 1999/32/EC on the Sulphur Content of Certain Liquid Fuels (SCCLF) has set dates and limits on the sulphur content of residual and gas oil burnt in Part B and other plant. Transposed by the Sulphur in Liquid Fuels (England and Wales) Regulations 2000, SI 1460, the changes have already been notified to local authorities in a letter from DETR and the National Assembly for Wales dated 22 June 2000. The dates and limits that are incorporated into PG1/3 are:
Before 1 January 2008, gas oil must contain 0.2% by mass of sulphur or less;
From 1 January 2008, gas oil must contain 0.1% by mass of sulphur or less;
From 1 January 2003, heavy fuel oil must either contain 1% by mass of sulphur or less or, when burnt, emit sulphur dioxide at a concentration of 1700mg/m3 or lower.
4. In some circumstances regulators may look in PG1/3 for advice on supplementary firing. The cross reference to PG1/4 will assist.
5. The Pollution Prevention Control (England and Wales) Regulations 2000 SI1973 (PPC Regs) contain a definition of combustion activities which differs a little from that for combustion processes in the Environmental Protection (Prescribed Processes and Substances) Regulations 1991 SI472 as amended:
- the PPC Regulations define combustion activities by the 'rated thermal input'. Previously the 'net rated thermal input' was used.
- for information, a change has been made to the aggregation rule for Part A activities. Under IPPC, all combustion appliances are added together. Previously boilers and gas turbines, for example at a combined heat and power plant, would not have been added together.
Amendments
6. Clause 2, add to the end of Clause 2
"For combined heat and power schemes (CHP) a gas turbine may be associated with a supplementary boiler. For a CHP scheme where the supplementary firing is at a net rate between 20 - 50MW, the guidance in PG1/4 (Gas turbines) Appendix 2 should be applied. For information, a CHP process description is in PG1/4, clauses 3 and 4."
7. It was proposed in a consultation paper issued by Defra on 10 December 2003 to amend the PPC Regulations. The proposal is to amend section 1.1 of Schedule 1 to the Regulations to insert the word "net" in paragraphs (a) - (c) of the Part B definitions.
Clause 4, until such time as the amendment is made, add to the end of Clause 4, a new paragraph:
"Under LAPPC, 'thermal input' is calculated similarly, except that the gross rated thermal input should be used instead of the net rated thermal input. The gross rated thermal input is larger than the net rated thermal input by the amount of heat needed to vaporise water produced by the combustion of hydrogen in the fuel (the latent heat of condensation) plus any heat added to the fuel or air before combustion. For coal and coke this makes little difference. For fuel oil the gross rated thermal input is about 5% above net rated thermal input. For natural gas, the increase is about 10%."
8. Clause 8, add to the end of Clause 8 a new paragraph:
"The first annual monitoring of carbon monoxide required by Clause 20 as amended by AQ23(04), should take place within 12 months of the publication of the AQ Note. The carbon monoxide limits in Clause 15, as amended by AQ23(04), apply from the date of first annual monitoring for carbon monoxide."
9. Clause 15i, delete the table and heading in Clause 15i and replace with the following heading and table and note.
for solid fuel firing.
|
|
plant new since 1 September 1995 mg/m3 |
Plant in operation before 1 September 1995 mg/m3 |
|
Sulphur dioxide (indigenous coal) Sulphur dioxide (non-indigenous coal) |
3000 2000 |
3000 2000 |
|
Nitrogen oxides expressed as NO2 stoker firing other firing methods |
450 650 |
500 650 |
| Carbon monoxide | 150 | 150 |
| Total particulate matter | 300 | 300 |
Boiler replacement to meet the carbon monoxide limit should not be required.
10. Clause 15ii delete the table and heading in Clause 15ii and replace with the following heading, table, and notes.
for liquid fuel (BS 2869:1998 classes E,F,G and H - residual fuels, for example heavy fuel oil
|
|
plant new since 1 September 1995 mg/m3 |
Plant in operation before 1 September 1995 mg/m3 |
| Sulphur oxides until 1.1.2003 |
3000 |
3000 |
| Sulphur oxides from 1.1.2003 |
1700 |
1700 |
| Nitrogen oxides expressed as NO2 | 450 | 600 |
| Carbon monoxide | 150 | 150 |
| Total particulate matter | 150 | 150 |
The emission concentration limit can be replaced by mass limits on sulphur in the fuel. Those limits are:
From 1st January 2003, fuel used should have a sulphur content not exceeding 1% by mass. Until then, the maximum sulphur content of fuel should be 2% by mass. It is mandatory to apply either the mass or concentration limits, to comply with the Sulphur in Certain Liquid Fuels (England and Wales)Regulations 2000 SI1460. Boiler replacement to meet the carbon monoxide limit should not be required.
11. Clause 15iii delete the table and heading in Clause 15iii and replace with the following table, heading and notes:
for liquid fuel (BS 2869:1998 class D -middle distillate fuels for example gas oil):
|
|
plant new since 1 September 1995 mg/m3 |
Plant in operation before 1 September 1995 mg/m3 |
| Nitrogen oxides expressed as NO2 | 200 | 300 |
| Carbon monoxide | 150 | 150 |
| Total particulate matter | 100 | 150 |
To comply with SI 2000/1460, fuel used from 1st January 2008 must have a sulphur content not exceeding 0.1% by mass. Until then the sulphur in fuel limit must be 0.2% by mass.
Boiler replacement to meet the carbon monoxide limit should not be required.
12. Clause 15iv delete the table and heading in Clause 15iv and replace with the following heading, table and note:
natural gas
|
|
plant new since 1 September 1995 mg/m3 |
Plant in operation before 1 September 1995 mg/m3 |
| Sulphur oxide |
35 |
35 |
| Nitrogen oxides expressed as NO2 | 140 | 200 until 1.1.2003 140 from 1.1.2003 |
| Carbon monoxide | 100 | 100 |
| Total particulate matter | 5 | 5 |
Boiler replacement to meet the carbon monoxide limit should not be required.
13. Clause 18 Add to Clause 18 between the second and third paragraphs
" In addition to the Clean Air Act 1993 and statutory nuisance
provisions, the sulphur limits in oil in Clause 15 also apply to standby
plant used for less than 100 hours per annum and fuel used during interruptions
of a gas supply"
14. Clause 20 In each of paragraphs 1, 3 and 4, immediately after the phrase 'nitrogen oxides', add "and carbon monoxide"
AEQ/Defra
6th October 2004
Page published: 07 October 2004