Reference number  
DRS 407-3: 2019  
© RSB 2019  
 
 
 RWANDA 
STANDARD  DRS 
407-3 
First e dition  
2019  - xx-xx 
 
Emission limits — Specification — 
Part 3:  
Thermal power thermal thermal plants  
  DRS 407-3: 2019  
©RSB 2019  - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB2019  
All rights reserved. Unless  otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce thi s document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS 407-3: 2019  
iii                ©RSB2019 - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  2 
2 Normative references  ................................ ................................ ................................ ...................  2 
3 Terms and definitions  ................................ ................................ ................................ ..................  2 
4 Requirements  ................................ ................................ ................................ ................................  4 
5 Test methods  ................................ ................................ ................................ ..............................  10 
 DRS 407-3: 2019  
©RSB 2019  - All rights reserved                  iv 
 Foreword  
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards adopted 
by Technical committ ees are ratifie d by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 407-3 was prepared by  joint Technical Committee RSB/TC 23 (Road Vehicle s) and RSB/TC 41  
(Environmental Protection) . 
DRS 407 consists of the following parts, under the general title Emission limits — specification : 
 Part 1: Road vehicles  
 Part 2: Non-road mobile machine ry 
Part 3: Thermal power thermal thermal plants  
Committee membership  
The following organizations were represented on the Joint Technical Committee on Road v ehicle  (RSB/TC 23) 
and Environmental Protection (RSB/TC 41)  in the preparation of this standard.  
Akagera Motors  
Energy Development Corporation Ltd (EDCL)  
Integrated Poly technic Regional College (IPRC) Kigali  
Metropole Motors  
Ministry of Environment (MoE)  
Ministry of Infrastructure (MININFRA)  
Ministry of Trade and Industry (MINICOM)  
PurePro® Ltd  
Real Contractors Ltd  
Rwanda Environment Management Company (RWEMACO)  DRS 407-3: 2019  
v                ©RSB2019 - All rights reserved  
 Rwanda Garages Association (RGA)  
Rwanda National Police (RNP)  
Rwanda Transport Development Agency (RTDA)  
Rwanda Utility Regulatory Agency (RURA)  
SAR Motor s 
Standards for Sustainability (SfS)  
Sulfo Industries Rwanda  
TUMECO Garage  
University of Rwanda - College of Science and Technology (UR - CST)  
Rwanda Standards Board (RSB) – Secretariat  
 DRS 407-3: 2019  
©RSB 2019  - All rights reserved                  2 
 Emission limits — Specification  — Part 3:  Thermal power thermal 
thermal plants  
1 Scope  
This Draft Rwanda Standard specifies requirements for  emission  limits  and test methods  for thermal power 
thermal thermal plants . 
2 Normative references  
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document. For dated references, only the edition cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) ap plies.  
ISO 7996,  Ambient air — Determination of the mass concentration of nitrogen oxides — 
Chemiluminescence method  
ISO 4224, Ambient air — Determination of carbon monoxide — Non-dispersive infrared spectrometric 
method  
ISO 8186, Ambient air — Determinati on of the mass concentration of carbon monoxide — Gas 
chromatographic method  
ISO 4221, Air quality — Determination of mass concentration of sulphur dioxide in ambient air — Thorin 
spectrophotometric method  
ISO 12141, Stationary source emissions — Determina tion of mass concentration of particulate matter (dust) 
at low concentrations — Manual gravimetric method  
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions apply . 
3.1 
emission  
discharge of substances from a power plant into the atmosphere  DRS 407-3: 2019  
3                ©RSB2019 - All rights reserved  
 3.2 
emission limit value  
permissible quantity of a substance contained in the waste gases from a power plant which may be 
discharged into the air during a given period  
NOTE  It is calculated in t erms of mass per volume of the waste gases expressed in mg/Nm3, assuming oxygen  
content by volume in the waste gas of 15 % for all thermal thermal plants  and fuels and fuel types except for boilers 
(3 % O 2 for gaseous and liquid fuels, 6  % for solid fuels) . 
3.3 
fuel 
any material capable of releasing energy by combustion or by  chemical or physical reaction  
3.4 
gas turbine  
machine which converts thermal energy into mechanical work; it consists of one or several rotating 
compressors, a thermal device(s) which heats the working fluid, one or several turbines, a control system 
and essential auxiliary equipment. Any heat exchangers (excluding waste exhaust heat recovery 
exchangers) in the main working fluid circuit are considere d to be part of the gas turbine  
3.5 
engine  
machine delivering  shaft power by the conversion of fuel chemical energy into mechanical work during 
combustion  
3.6 
gas engine  
internal combustion engine which operates according to the Otto cycle and uses spark ignition to burn fuel  
3.7 
diesel engine  
internal combustion engine which operates according to the Diesel cycle and uses compression ignition to 
burn fuel  DRS 407-3: 2019  
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 3.8 
natural gas  
complex gaseous mixture of hydrocarbons, primarily methane, but generally includes ethane, propane and 
higher hydrocar bons, and some non -combustible gases such as nitrogen and carbon dioxide  
NOTE Natural gas can also contain components or containments such as sulfur compounds and/or other chemical 
species . 
3.9 
solid fuel  
any form of  solid substance that is burnt to releas e heat or energ y such as coal, peat or biomass  
3.10 
liquid fuel  
any form of  liquid substance that is burnt to release heat or energy such as heavy fuel oil, light fuel oil, 
crude oil, emulsified fuels or liquid bio fuels  
3.11 
gaseous fuel  
any form of gaseo us substance  that is burnt to release heat  or energy such as natural gas  
4 Requirements  
The following stack emission limit apply  to the different  types of power thermal thermal plants  as outlined 
in Table 1, Table 2 and  
Table  3. 
 DRS 407-3: 2019  
©RSB 2019  - All rights reserved                  2 
 Table 1 — Emission limits for power thermal thermal plants  above 50mwth (in mg/ Nm3 or as indicated) under reference conditions of 
273.15 ºK and 101.3 kPa 
Combustion 
technology/Fuel  Particulate Matter 
(dust) Sulphur dioxide (SO 2) Nitrogen  
Oxides (NO x) Carbon monoxide (CO)  
Reciprocating engine  
 
Natural Gas  30  N/Aa 75 100 
Liquid fuel, 50 -100MWthb  30  400 450 
 100 
Liquid fuel, 100 -
300MWthb   250 200 100 
Liquid fuel, >300MWth  30 200 150 100 
Bio-fuels/gaseous fuels 
other than natural gas  30 
 
 N/A 200 - 
Combustion Turbine  
 
Natural gas (all turbine 
types of unit > 50  MWth)  N/A N/A 50 100 
Fuels other than natural 
gas  (Unit > 50MWth)  30 400 ( for Low calorific gases 
from coke oven)  
200 (for Low calorific gases 
from blast furnace)  
5 (Liquefied gas)  
35 (in general)  200 100 DRS 407-3: 2019  
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 Other gaseous fuels  30  400 ( for Low calorific gases 
from coke oven)  
200 ( for Low calorific gases 
from blast furnace)  
5 (Liquefied gas)  
35 (in general)  120 N/A 
Boiler  
Natural gas  30 35 100 100 
Other gases   400 (for Low calorific gases 
from coke oven)  
200 ( for Low calorific gases 
from blast furnace)  
5 (Liquefied gas)  200 N/A 
Liquid fuels (Plant >50 
MWth to <100 MWth)  30 400 ( for Low calorific gases 
from coke oven)  
200 ( for Low calorific gases 
from blast furnace)  
5 (Liquefied gas)  450 100 
Liquid fuels (Plant 100 -
300 MWth)  30  250 200 100 
Liquid fuels (plant >300   200 150 100 
Solid fuels (Plant 50 - 100 
MWth)  30  400  300 100 
Solid fuels (Plant 100 - 
300 MWth)  30 250 200 100 
Solid fuels (Plant >300  
MWth)  30 200  200 100 DRS 407-3: 2019  
©RSB 2019  - All rights reserved                  4 
 a N/A = not appl icable (no emissions guideline)  
 
b MWth = Megawatt thermal is the heat input on Higher Heating Value (HHV) basis 
 
NOTE All emission limit values shall be calculated after  correction for the water vapour content of the waste gases and at a standardised O 2 
content of 6  % for solid fuels, 3  % for combustion thermal thermal plants , other than gas turbines and gas engines using liquid and gaseous fuels 
and 15  % for gas turbines  and gas engines . 
Table 2 — Emission limits for power thermal thermal plants  below 50  MWth (in mg/Nm3 or as indicated) under reference conditions of 
273.15 ºK and 101.3 KPa  
Combustion 
technology/Fuel  Particulate Matter (PM) 
(dust) Sulphur dioxide (SOx)  Nitrogen  
Oxides (NO X) Carbon monoxide (CO)  
Reciprocating engine  
 
Natural gas N/A N/Aa 95 
190 (Dual fuel engines in gas 
mode)  100 
Liquid fuel, 1 -5 MWthb N/A N/A 190 
225  (Dual fuel engines in liquid 
mode)  100 
Liquid fuel, 5 -20 MWth  N/A N/A 190 
225 (Diesel Engines)  100 
Liquid Fuels, 20 – 50 
MWth  N/A N/A 
 225 100 
Liquid fuels other than 
gas oil, 1 -5 MWth  20 120 
590 (Diesel Engines)  190    100 DRS 407-3: 2019  
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 Liquid fuels other than 
gas oil , 5 – 20 MWth  
 10 120 
590 (Diesel engines)  225 100 
Liquid fuels other than 
gas oil, 20 -  50 MWth  10 120 
590 (Diesel engines)  225 100 
gaseo us fuels other than 
natural gas  10 
 15 
40 (biogas)  190 
225 (Dual fuel engines in liquid 
mode)  N/A 
Gas turbine  
Natural gas (all turbine 
types )  N/A N/A 50  100 
Gaseous fuels other than 
natural gas  N/A 15 
40 (Biogas)  190 N/A 
Liquid fuels other than 
gas oil  20 120 
590 (diesel engines)  75 N/A 
Gas oil  N/A N/A 75 100 
Boiler  
Natural gas N/A N/A 100 100 
Other gaseous fuels  N/A 35 
100 (Biogas)  200 
 N/A 
Liquid fuels (Plant 1 MWth 
to <5 MWth)  N/A N/A 200 100 
Liquid fuels (Plant 5 -50 
MWth)  N/A N/A 200 100 
Liquid fuels other than 
gas oil  50 350 300 N/A DRS 407-3: 2019  
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 Solid fuels (Plant 1 - 5 
MWth)  50 400  500 100 
Solid fuels (Plant 5 - 50 
MWth)  20 400 300 100 
a N/A = not applicable (no emissions guideline)  
b MWth = Megawatt thermal is the heat input on Higher Heating Value (HHV) basis  
NOTE All emission limit values shall be calculated after correction for the water vapour content of the waste gases and at a stand ardised O 2 content of 6  % for 
solid fuels, 3  % for combustion thermal thermal plants , other than gas turbines and gas engines using liquid and gaseous fuels and 15% for gas turbines and gas 
engines  
Table 3 — Emission limits for existing power thermal thermal plants  below 100  MWth  
Combustion 
technology/Fuel  Particulate Matter 
(PM) (Dust)  Sulphur dioxide (SOx)  Nitrogen  
Oxides (NOX)  Carbon monoxide (CO)  
Reciprocating engine  
  
Natural gas  N/A N/A 190 
380 (Dual fuel engines  in gas 
mode)  175 
Liquid fuel, 1 -5MWthb N/A N/A 250 
1850  (Engines constructed 
before 2006 and dual fuel 
engines)  175 
Liquid fuel, 5 -20 MWthb N/A N/A 225 175 DRS 407-3: 2019  
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Liquid fuel, 20 -50MWthb N/A N/A 190 
 175 
Liquid fuels , 50 – 100 
MWth  Not to exceed 250 
(Daily Average)  850 450 250 
Liquid fuels other than 
gas oil  below 5 MWth  10 
 
 120 250 N/A 
Liquid fuels other than 
gas oil (5 – 20 MWth  20 120 225 N/A 
Liquid fuels other than 
gas oil  20- 50  MWth  10 120 190 N/A 
Liquid fuels other than 
Gas oil (Plant 50 -
100MWth )  Not to exceed 250 
(Daily Average)  850 450 250 
Gaseous fuels other than 
natural gas ( thermal 
plants  below 50 Mwth ) 10 15 
60 (Biogas ) 250 N/A 
Gaseous fuels other than 
natural gas ( thermal 
plants  50 - 100 Mwth )  Not exceeding 250 
(daily Average)  35 
800 (Low calorific gases from 
gasification of refinery 
residues,  300 250 DRS 407-3: 2019  
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 coke oven gas, blast -furnace 
gas) 
Combustion turbine  
 
Natural gas (all turbine 
types of Unit below 
50MWth  N/A N/A 150 175 
Natural gas (all turbine 
types of Unit 50 - 
100MWth  N/A 35 75 250 
Gaseous fuels other than 
Natural gas ( thermal 
plants  below 50MWth)  N/A 15 
60 (Biogas)  200 N/A 
Gaseous fuels other than 
Natural gas (thermal 
plants  50 – 100 MWth)  N/A 35 
800 (Low calorific gases from 
gasification of refinery 
residues,  
coke oven gas, blast -furnace 
gas) 120 250 
Liquid fuels other than 
gas oil ( thermal plants  
below 50 MWth)  10 120 200 N/A 
Gas oil  (thermal plants  
50 – 100 MWth) Not exceeding 250 
( Daily Average)  850 
 450 175 
Boiler   
Natural g as N/A N/A 200 175 DRS 407-3: 2019  
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 Other gaseous fuels 
( 1- 5 MWth ) N/A 200 250 
 N/A 
Other g aseous fuels 5 
– 20 MWth ) N/A 35 250 N/A 
Other gaseous fuels 
(20 - 50 MWth)  N/A 35 250 N/A 
Other gaseous fuels 
(thermal pl ant 50 -100 
MWth)  Not exceeding 250  35 
800 (Low calorific gases 
from gasification of refinery 
residues,  
coke oven gas, blast -
furnace gas)  300 250 
Gas oil ( thermal plant 
below 50 MWth 
MWth)  N/A N/A 200 175 
Gas oil ( thermal plants  
50-100 MWth)  Not to exceed 250  
(daily Average)  850 450 250 
Liquid fuels other than 
gas oil (plant 1 - 5 
MWth )  50 350 650 N/A 
Liquid fuels other than 
gas oil (plant 5 -20 
MWth)  50 350 650 N/A 
Liquid fuels other than 
gas oil (plant 20 – 50 
MWth )  30 350 650 250 DRS 407-3: 2019  
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 Liquid fuels other than 
gas oil (Plant 50 – 100 
MWth)  Not to exceed 250 
(Daily Average)  850 450 250 
Solid fuels (Plant 1 
MWth – 5 MWth)  30  1100  
200 (b iomass)  650 175 
Solid fuels ( thermal 
plant 5  MWth  – 20 
MWth)  50 1100  
200 (b iomass)  650 175 
Solid fuels  (thermal 
plants  20-50 MWth)  50 400 650 175 
Solid fuels ( thermal 
plants  50 – 100 MWth)  Not to exceed 250 
(daily average)  850 600 250 
a N/A = not applicable (no emissions guideline);  
b MWth = Megawatt thermal is the heat input on Higher Heating Value (HHV) basis 
NOTE All emission limit values shall be calculated at a temperature of 273,15 K, a pressure of 101,3 kPa and after correction for the water vapour 
content of the waste gases and at a standardised O 2 content of 6  % for solid fuels, 3% for combustion thermal thermal plants , other than gas turbines 
and gas engines using liquid and gaseous fuels and 15  % for gas turbines and gas engines . 
5 Test methods  
The testing of the various pollutants shall be carried out according to the test meth ods outlined in the table be low: 
 DRS 407-3: 2019  
11                ©RSB2019 - All rights reserved  
 Pollutant  Test m ethod  
Particulate Matter ( dust) ISO 12141  
Sulphur oxides (SO x) ISO 4221  
Nitrogen o xides (NO x) ISO 7996  
Carbon m onoxide (CO)  ISO 4224 and  
ISO 8186  DRS 407-3: 2019  
1                ©RSB2019 - All rights reserved  
 Bibliography  
[1] 2016 IFC Environmental, Health and Safety Guidelines: Thermal Power Thermal thermal plants , 2008  
 
[2] IFC Environmental, Health and Safety Guidelines. Air Emissions and Ambient Air Quality, 2007  
 
[3] Directive (EU) 2015/2193 of the European Parliament and of the Council of 25 November 2015 on the 
limitation of emissions of certain pollutants into the air from medium combustion thermal thermal plants  
 
[4] Directive 2001/80/EC of the European Parliament and of the Council of 23 October 2001 on the limitation 
of emissions of certain pollutants into the air from large combustion thermal thermal plants  
 
[5] Directive 2010/75/EU of the Europea n Parliament and of the Council  of 24 November 2010  on industrial 
emissions (integrated pollution prevention and control)  
 
[6] RS EAS 751/2010 Air quality — Specification  
 
[7] ISO 554, Atmospheric conditions for testing  
 
[8] ISO 7934, Air Quality — Sampling and test methods — Stationary source emissions — Determination 
of the mass concentration of sulphur dioxide — Hydrogen peroxide/barium perchlorate/Thorin method  
 
[9] ISO 12039, Air Quality — Sampling and test methods — Determination of carbon monoxide carbon 
dioxide and oxygen — Performance characteristics and calibra tion of automated measuring systems  
 
[10] ISO 11564, Air Quality — Sampling and test methods — Determination of the mass concentration of 
nitrogen oxides — Naphthyethediamine photometric method  
 
[11] ISO 9096, Air Quality — Sampling and test methods — Stationary source emissions — Manual 
determination of mass concentration of particulate matter  
 DRS 407-3: 2019  
ICS 13.040.50  
 
 
©RSB 2019  - All right s reserved