Refused Derived Fuel Technical and economic viability

Pedro Miguel de Oliveira Caracol

Master Thesis in Civil Engineering

Extended Abstract

Jury

President: Professor Doutor António Alexandre Trigo Teixeira

Supervisor: Professor Doutor João de Quinhones Levy

Member: Engenheiro Artur João Lopes Cabeças

Member: Engenheira Filipa Maria Santos Ferreira

Junho 2016

1

1. Research justification and methodology

This dissertation aims to clarify the principal factors regarding on the Refuse Derived Fuel (RDF)

production methodology by the company ProResi, as well as its route to the cement industry

and respective energy recovery by Cimpor.

Seek to identify the added value of the RDF production given the legislative framework, the

characterization of their properties and existing infrastructures. Its use must be evaluated from

two perspectives, obtaining an alternative fuel and, at the same time minimize landfilling and

improve waste management hierarchy.

It’s described the RDF production process by the waste management operator, and

downstream, by the cement industry, the viability of its co-processing according with existing

technologies for waste recovery. It is intended, through this work, aid the entrepreneur’s

decision process concerning the business sustainability.

Solid waste issue may be evaluated as a management problem which requires developing

collection, transportation and disposal practices for wastes; raising awareness among local

authorities and public. (Sarc, 2013)

The cement industry increasingly uses a variety of alternative fuels which are typically derived

from waste whit the goal to reduce their consumption of conventional fossil fuels while at the

same time help to avoid conventional disposal of the waste materials through land-filling or

incineration. (Gallardo, 2014)

In addition to these direct effects, the utilization of alternative fuels by the cement industry

typically results in GHG emission reductions at landfills and incineration plants where these

wastes would, otherwise, be disposed. These indirect emission reductions can be equal, higher

or lower than the direct CO2 emissions from alternative fuels combustion at the cement plant,

depending on the type of waste and the displaced disposal path. The combination of direct

emissions impacts, indirect emission reductions, and resource efficiency makes the substitution

of alternative fuels for conventional fossil fuels an effective way to reduce global GHG emissions

RDF is an alternative solid fuel, which is derived from recyclable materials municipal or industrial

solid wastes, such as plastics or from materials that are hard to recycle after decomposing.

Refuse-derived fuel typically consists of pelletized or fluffy MSW that remains after the removal

of noncombustible materials such as ferrous materials, glass, grit, and other noncombustible

materials. The remaining material is then called RDF and used in clinker production as a

secondary fuel. However, the environmental concerns of incineration also apply to RDF

combustion facilities. The limit values for some pollutants are the same for cement and

combustion plants. There are significant differences with respect to some pollutants. (Gascoyne,

2010)

2

2. Definition

Refuse derived fuels cover a wide range of waste materials which have been processed to fulfil

guideline, regulatory or industry specifications mainly to achieve a high NET Calorific Value

(NCV). RDF include residues from MSW recycling, industrial/trade waste, sewage sludge,

industrial hazardous waste and biomass waste. (BREF, 2006)

The term ‘Refuse Derived Fuel (RDF)’ in English speaking countries usually refers to the

segregated high calorific fraction of processed MSW. Other terms are used for MSW derived

fuels such as Recovered Fuel, Packaging Derived Fuel , Paper and Plastic Fraction and Processed

Engineered Fuel

3. RDF Classification

Classification is applied to put any RDF in a “cell” and to give a global view on all existing RDF s̀.

There is a hidden, but still a major contribution of classification to a high level of protection to

the environment. Because each RDF can now be classified, it will become very clear at a quick

glance which SRF has indeed poor environmental properties and may need special raw-gas

cleaning technology. The following three properties where choosen to quickly describe (or

classify) a RDF: (CEN/TR 14745:2003)

Net Calorific Value (NCV) NCV is an indicator of the market value of RDF. NCV also

indirectly gives an impression what type of SRF is involved. NCV is the most important

property of SRF as it describes its value as a fuel.

Chlorine (Cl) Chlorine is unwanted in SRF as it contributes to corrosion. High chlorine

content will lower the market value.

Mercury (Hg), an RDF environmental quality indicator because of its high volatility

Per property SRF can be classified according to the following table 1.

Table 1 - RDF Classification

3

4. Processing methods and production

RDF manufacturing process steps are, in the most of the cases, separating at source, sorting or

mechanical separation, size reduction (shredding, chipping and milling), separation and

screening, blending, drying and pelletizing. MSW is first treated in a pre-shredder followed by

magnetic separator. It is then sent to a ballistic separator to separate the low calorific value

wastes. The rest of the waste material is screened to remove the recyclable fractions (e.g.

metals), the inert fractions (e.g. glass) and the fine wet putrescible fractions (e.g. food) prior to

pulverization of the material. The metal free part is sent to fine (final) crushers for reduction to

an appropriate size used in cement factories. Calorific value of RDF is about 4000 kcal/kg. The

reason for high calorific value is due to the presence of plastic, paper or cardboard in RDF. In

addition RDF also contains high biomass value. However, it depends on the nature of municipal

waste and the organic or combustible content which is also related to the standard of living and

consumption habits. (Kara, 2012)

5. System Analysis

ProResi

The non-hazardous industrial waste (NHIW) management represents the ProResi’s main activity

which can be sent to landfill or to RDF processing unit depending on their origin and type. The

landfill and the RDF production line work complementary allowing to expand the activity of the

final destination / disposer to final destination / disposal or recovery. The non -hazardous

industrial waste fractions which are liable of valorization are sent to the RDF processing line,

which allows the reduction of landfill operating costs and occupied volume, the savings in waste

management tax and the use of sanitary landfill only for the “rest fraction” in a “Carbon Neutral

Landfill” perspective.

The NHIW data were collected and analyzed during January and September of 2015 for the

chlorine content, moisture content and low calorific value, characteristics that define the quality

of the CDR and respective feasibility of its using in the cement industry co-processing.

The figure 1 expresses the chlorine content variation. The average of the samples taken on dry

basis, was set at 0.92%. This high chlorine content value is explained by the fact that much of

the chlorine contamination sources are present in NHIW samples.

4

According Cimpor source, the cement industry favors a CDR with moisture content up to 20%

which is one of the main parameters that prevents a higher replacement rate of fossil fuels. A

high moisture content RDF may compromise the efficiency of the combustion process, caus ing

a drastic temperature reduction inside the furnace, which must has to be constant and

approximately 2000 ° C.

Regarding the moisture content and low calorific value, we can notice its inverse retation. The

figure 2 and 3 expresses the variation of these two parameters. It was obtainded the average

value 19,4 Mj/kg for the LCV and 17,3% for the moisture content.

AVE

In order to determine the feasibility of processing RDF from municipal waste (MW) and

compares it with the CDR from NHIW, were made available by AVE samples collected between

January and June of 2015.

The figure 4 expresses the chlorine content variation. The average of the samples taken on dry

basis, was set at 0.83%.

Figure 1 - RDF Chlorine content variation from NHIW

Figure 2 - RDF moisture content variation from NHIW Figure 3 - RDF NCV content variation from NHIW

5

The moisture content average obtained was 39.0%, substantially higher than the value

obtained for the same feature for RDF prepared from the NHIW (17.30%). This moisture

content obtained in the RDF samples from MW is explained by the high amounts of

biodegradable waste present in MW, which leads to a difficult self -sustaining combustion and,

consequently, to power recovery efficiency limited by LCV.

The figure 5 and 6 represents the RDF from MW variation in order to moisture content and

LCV, respectively. As expected, due to higher moisture contents when compared to RDF

derived from NHIW was obtained a lower LCV, registering an average value of 12 MJ / kg.

The price variation of RDF from NHIW and MW according to the prices table 2014 are shown in

figures 7 and 8. The price average obtained for the CDR sales price originating in NHIW and

MW was 18€ / ton and 3.9€ / ton, respectively.

Figure 4 - RDF Chlorine content variation from MW

Figure 6 - RDF NCV variation from NHIW Figure 5 - RDF Moisture content variation from MW

6

On the national scene, due to an absence of a regulate RDF market, the evolution of its price is

dependent on the consumer willingness. It becomes necessary to evaluate not only the benefits

inherent to the RDF receiving industry and the price that they’re willing to pay in order to use it

in partial substitution of fossil fuels, as well as advantages for the producer.

Based on ProREsi input output stream and admitting the following assumptions:

5% increase of the material that can be sent to CDR production line per year

Constant value sales of € 18 / ton CDR, which is equivalent to the value obtained in the the same company study of case.

Table 24 expresses the recovered materials commercial value, allowing calculate the earnings

through these materials.

Table 2 - Commercial value of recyclable. (Source: http://www.indexmundi.com/commodities/)

Month Price

Aluminum (€m3/Ton)

Price Rubber

(Euro/kg)

Price Wood

(€m3/Ton)

Variation Aluminum

Variation Rubber

Variation Wood

Jun-15 1,505.24 1,64 780.39 - - -

Jul-15 1,491.73 1,51 796.13 -0.90 % -8.57 % 2.02 %

Aug 2015 1,390.19 1,45 785.73 -6.81 % -14.50 % -1.31 %

Sep 2015 1,416.21 1,37 779.56 1.87 % -8.36 % -0.79 %

Oct 2015 1,350.80 1,37 779.40 -4.62 % -0.88 % -0.02 %

Nov-15 1,365.57 1,36 814.01 1.09 % -1.86 % 4.44 %

Dec 2015 1,376.60 1,36 804.52 0.81 % 0.88 % -1.17 %

Figure 7 – NHIW RDF Price variation Figure 8 - MW RDF Price variation

7

Table 25 represents, in function of the amount of waste received and which are likely to be sent

to RDF production line, the revenues from its sales and recovered recyclable material, as well.

Table 3 - Benefits from RDF and Recyclable sales

Year RDF input stream (t)

RDF input stream

benefits (€/t)

RDF output stream (t)

Output stream

benefits CDR (€/t)

Recyclable material

benefits (€/t)

2014 12 301 615 050 9 722 174 996 439 379 2015 12 916 645 803 10 694 192 496 461 348

2016 13 562 678 093 11 764 211 745 484 415

2017 14 240 711 997 12 940 232 920 508 636 2018 14 952 747 597 14 234 256 212 534 068

2019 15 700 784 977 15 657 281 833 560 771 2020 16 485 824 226 17 223 310 016 588 810

At the same time, the spared costs related to the waste management tax, according to the

variation expected by 2020, are expressed at Table 26.

Table 4 - Avoided costs associated with Waste Management Tax

Ano Amount of waste spared

from landfill (t)

waste management tax

(€/t) Spared cost (€)

2014 12301 4,27 52 525,2

2015 12916 5,5 71 038,2 2016 13562 6,6 89 508,2

2017 14240 7,7 109 647,6

2018 14952 8,8 131 577,1 2019 15700 9,9 155 425,4

2020 16485 11 181 329,7

According to the assumptions considered, the revenues from RDF production line installation

related to its direct sales and recyclables could reach the year 2020, about 898,826€. Adding to

these revenues, it can be spared through the coasts associated whit the waste management tax

in the year of 2020, according to the expected tax variation at PERSU 2020, about € 181,329.

Thus, the implementation of a CDR production line presents an opportunity in terms of resource

management.

Consequently, there is still considering the advantages relating to:

• Landfill occupied volume reduction;

• Landfill Reduced operating costs.

8

To the RDF client, it is assumed that the annual average characteristics of received fuel

correspond to NCV 12.6 MJ / Kg and 31.82 to petcoke MJ / kg, according to Cimpor source. The

quocient NCVRDF / NCVPetcoke translates the relationship between the respective PCI and assumes

the value 0.39.

The RDF evaluation price which the consumer is willing to pay for this alternative fuel depends

on the petcoke variation price, as well as the operating and investment costs, can be determined

by the following equation:

RDF price (€/t) = FFP (€/t) x 0,39 – OIC (€/t)

• FFP represents the fossil fuel price, in this case, it’s considered the petcoque price

• OIC reflects the operating and investment costs resulting from technical adaptation to

RDF use, equipment maintenance costs, waste co-incineration rate and investment amortization in infrastructure that consumer organizations are willing to pay.

• The constant 0,39 expresses the relation between NCV RDF/ NCVPetcoque

The RDF price indexed to fossil fuel price is shown in Table XXX and was calculated assuming the

following assumptions:

• OIC is perspective to be reduced 45% in 2014, considering the CIMPOR case of study of. The value referent to the year 2010 is the sum of this variable from co-processing activity

beginning up to that year;

• An increase of 25% over the previous year referent to the amount of received RDF by Cimpor, from 2014

• The petcoque price range was estimated for the years 2015, + 5.1%, which is equivalent

to the change recorded in 2014.

Table 5 - RDF price indexed to fossil fuel price

Ano

Thermal substitution

rate (%)

Investment (k€)

RDF received (t)

OIC (€/t)

Petcoque (€/t)

RDF Price (€/t)

2010 7 9260 4745,27 1951,41 91,40 -1915,77

2011 10 - 5411,53

2012 12 4850 5507,62 880,59 87,78 -846,36

2013 17 - 6884,53

2014 18 3210 8605,66 373,01 50,82 -353,19

2015 23 1125 10757,07 104,44 53,59 -83,54

2016 25 393 13446,34 29,24 56,33 -7,27

2017 27 137 16807,92 8,188 59,20 14,89

2018 29 48 21009,90 2,29 62,22 21,97

2019 31 17 26262,38 0,64 65,39 24,86

2020 33 6 32827,97 0,17 68,72 26,62

9

Despite the volatility of the petrol price its derivatives, according to the assumptions used, the

RDF is a fuel about to become profitable for the cement industry as the main technical

adaptations that enable its use in coincineration have been made and it is expected that they

are significantly lower in the coming years. This investment was made with the aim, not only to

get a fuel that meets the energy needs of the cement industry, as well as following the strategic

guidelines set out in PERSU 2020, which took into account the energy and environmental

policies.

6. Conclusions

This thesis, which analyzes the technical and economic viability of the RDF, concluded that a high

RDF fraction from MW still does not provide a quality such that its co-processing, mainly due to

its high moisture content and poor fractionation of the various components of these wastes at

source. This is the main difficulty that waste management operators face trying to increase the

productive efficiency of the plant and become progressively more competitive on the fuel

market by obtaining a homogeneous product with high net calorific value.

It is concluded that RDF produced from NHIW presents the conditions of admissibility imposed

by the cement industry and its selling price is about 18 € per tonne. This value will become

increasingly more rentable due, not only to the expected heat exchange rate increase, which

will enable the use of a higher percentage of alternative fuel as well as the reduction of operating

and investment costs.

It is also concluded that an important measure that encourages the landfill deflection of some

possible fractions that can be recycled or energetically recovered is the waste management rate

increase as already happens in some European countries and which has proved as a good RDF

promoter mechanism. For ProResi case study perspective a reduction of costs associated with

waste management tax about € 181,329 for the year 2020.

7. References

BREF. (2006). Waste Treatments Industries. Sevilha: European comission joint research center.

Gallardo, A. (2014). Analysis of refuse-derived fuel from the municipal solid waste reject.

Elsevier, 1-8.

Gascoyne, A. (2010). Trends and drivers in SRF production and use across Europe. Londres:

Congreso "Energy from Waste".

Kara, M. (2012). Environmental and economic advantages associated with the use of RDF in.

Elsevier, 21-28.

10

Roos, H. (2007). Advanced processing of municipal solid waste for the production of high-grade

quality fuels. Sardenha: Eleventh International Waste Management .

Sarc, R. (2013). Production, quality and quality assurance of Refuse Derived Fuels (RDFs).

Elsevier, 1825-1834.