Application of Waste Energy Utilization Techniques in

Aplinkos tyrimai, inžinerija ir vadyba, 2006.Nr.1(35), P.32-42 Environmental research, engineering and management, 2006.No.1(35), P.32-42

ISSN 1392-1649

Application of Waste Energy Utilization Techniques in Lithuanian Industry Irina Kliopova, Jurgis Kazimieras Staniškis Kaunas University of Technology, Institute of Environmental Engineering

(received in January, 2006; accepted in February, 2006) The use of waste energy resources could be evaluated as a potential which allows adding or partially replacing importable primary energy in all Baltic States. Currently, only in Lithuania about 4 TWh/y of heat energy are wasted to the environment by industrial processes. The evaluation of the possibilities of waste energy utilization in industrial companies was carried out. The possibilities of the development of cleaner production (CP) techniques with the purpose to increase the efficiency of energy consumption in production processes were analyzed. The database “The implementation of Cleaner Production in Lithuania” was created and used for this purpose. It was determined that the implementation of CP methods in Lithuanian companies allowed saving 72.1 GWh/y heat energy, mainly (89%) by applying waste energy utilization techniques. Key words: waste energy, utilization techniques, Cleaner Production, energy saving, efficiency of energy consumption.

1.

Introduction

According to the National Energy Strategy of Lithuania (2002), one of the main strategic goals of the Lithuanian energy sector is to achieve that the share of local energy resources in the primary energy balance would be 12% in 2010, i.e. close to the requirements of the EU directives [1]. Step by step Lithuania follows this obligation. For example, currently bio-fuel (wood, straw, municipal wastes, etc.) is used in 200 boiler-houses (with approx. 416 MW of total installed capacity) in Lithuania [2]. In the overall primary energy balance for 2004, the share of local, renewable and waste energy sources (excluding local oil resources) in Lithuania makes approx. 10%. In accordance with the evaluation of the energy sector development in Lithuania and other EU countries, the share of renewable energy sources in the total energy balance in Lithuania exceeds the EU average by 30% [3]. But, it was evaluated that Lithuania has approx. 2 mil. toe of unutilized renewable energy potential, of which waste energy recourses come to about 17% [4]. This question is very important for the other neighboring Baltic States too. Some key indicators in the energy area for 2003 in these countries are presented in Table 1. A comparison of these data

shows that final energy consumption per GDP unit in Latvia is more than in Lithuania by approx. 23%, and in Estonia - by 26% (2003) [5]. The Baltic energy strategy was signed by representatives of the Committees of Energy in Lithuania, Latvia and Estonia on the improvement of co-operation in the energy sector among these countries. Energy efficiency is one of the main instruments to fulfill the general objectives of the strategy [6]. 2.

Increasing the efficiency of energy consumption in production processes

The Baltic States inherited an economy characterized by an irrational use of energy resources (too much energy is used for the production of GDP unit), and the modernization requires heavy investments. That is one of the main weak points of the energy sector in the Baltic States today. For example, final energy consumption per GDP unit in Lithuania exceeds the EU average by approx. 16% [5]. It has been evaluated that yearly about 4 TWh of heat energy are wasted to the environment during

Application of Waste Energy Utilization Techniques in Lithuanian Industry

pollution or to minimize it comprises the core of the CP concept [8]. Wastewater, air emissions and energy losses (for example, with warm wastewater or exhaust gas) are inevitable during production (see Fig. 1). Currently, such CP innovation as recycling systems is implemented more and more often (reuse of lowquality raw materials, waste, subproducts, and wastewater in the same process or in other company’s production processes). The implementation of waste energy reuse (recycle, utilization) technologies is an essential environmental and thus economic task for all production companies.

production process in Lithuania. Only about 0.92 TWh of waste heat energy is reused due to environmental activity of some production companies [7]. The solution of the problems of the ineffective use of energy resources becomes one of the essential elements of the sustainable industrial development. Implementation of techniques for the effective use of energy in the production processes is one of the main directions of the Revised and Innovated National Program for Increasing the Efficiency of Energy Consumption in Lithuania (2001). Continuous application of prevention strategy for processes and products with the purpose to save natural resources, all types of energy, to eliminate Table 1.

Some key indicators in energy area of Baltic States, 2003

Indicators Primary Energy Supply (TPES), ktoe Final Energy Consumption, ktoe Final Energy Consumption in Industry, ktoe Net Import Share in Energy Balance, % Population, thous. GDP1, bn. PPC2 (preliminary data) Comparative Data

Lithuania 8985 4951 1579

Latvia 4623 3858 706

Estonia 5161 2790 650

42.7 3454 33.50

68.3 2320 20.18

27.5 1354 13.95

8.70 1.99 1.66 191.18 43.09

10.30 3.81 2.06 200 11.97

GDP, thous. PPC / cap. 9.70 Primary Energy, toe/cap. 2.60 Final Energy, toe/cap. 1.43 Final Energy, ktoe/GDP bn. PPC 147.79 8.38 REP / TPES, % (2002) 1 2 Notes: GDP – General Domestic Product (bn. PPS); PPC – purchasing power standards.

Inputs:

Outputs:

Raw materials

Products Sub products

Additional materials

Solid waste

Production process

Water Hot water

Wastewater Elimination / emission

Supply/ feed

Heat energy

Air emissions Warm waste water

Recycling Fig. 1.

Typical production process

innovations in 80 companies from different Lithuanian sectors of economy since 1993. These CP projects were evaluated and implemented while implementing various CP, CP financing, Environmental Management Systems (EMS), Integrated Pollution Prevention and Control (IPPC) implementation programs organized by the Institute of Environmental Engineering (APINI) in Lithuania. The database is widely used: to begin with the search of the optimal technical decision, identification of environmental indicators of different technological processes, data systematization, search of financial sources, up to information used as a methodical

When solving environmental problems related to the use of systematic methodology for the evaluation of CP techniques, it’s necessary to identify the reasons for waste energy generation, or, in other words, the general causes for waste energy generation before the analysis of the possibilities to use these resources. The database “The implementation of Cleaner Production in Lithuania” was used for this purpose [9]. This database was created with the aid of Microsoft Assess 2000 program in 2002 and is annually renewed. Currently, this database presents the technical, environmental, economical and financial information on 175 implemented CP 33

I. Kliopova, J.K. Staniškis

prevention methods (Table 3) shows that process optimization has more possibilities in energy saving. The results of the environmental improvement in 80 Lithuanian production companies (inc. energy production) in energy area since 1993 are as follows: electricity saving about 33.8 GWh/y, heat energy saving 72.1 GWh/y, energy production from local renewable resources increased by 12.7 GWh/y. Energy saving due to implementation of CP techniques makes about 0.6% of total energy consumption in the Lithuanian industrial sector [5]. On evaluating the main reasons for energy loss generation (Table 2) and the possibilities of implementation of CP innovations for increasing energy efficiency (Table 3), it is possible to suggest the hierarchy of prevention methods in the energy environmental sector (Fig.2).

material for training. The possibility of data analysis is one the main advantages of the created database. Thus, using the database, the following steps of analysis were carried out: 1) analysis of the possible causes of an inefficient use of energy and waste energy generation in different production processes, 2) identification of the development possibilities of CP methods for the increasing energy use efficiency in Lithuania, and 3) analysis of waste energy utilization possibilities. The first analysis (Table 2) revealed that the most of energy losses in production companies are produced while supplying energy to the technological processes and in these processes due to old and worn out pipes, technologies, equipment, control systems [7]. A more detailed analysis of the applied Table 2.

Possible causes for energy loss generation in production process

Determination of causes

Description

Technology level

Improper choice of production technology; lack of information about new technologies or materials Old and worn out equipment; unfitted choice of equipment capacity; heat losses in pipelines Ineffective operation or absence of process control equipment, for example, absence of measurement equipments, controllers, etc. Lack of information systems; ineffective management planning; lack of competence; absence of EMS Absence of heat insulation, unusual use of construction materials; heat loss with cooling water, condensate, warm air, wastewater, with air emissions Low-quality input flow (raw materials, steam); product specification; unusual waste utilization

Technical status equipment Level of process control

of

Management planning and information systems Loss of waste energy Other possible causes

Table 3.

Increase of energy consumption efficiency by implementing Cleaner Production in Lithuanian industry

Widely applied CP methods Good housekeeping Input substitution Process optimization Technology modification Onsite recycling

Description Implementation of proper energy management system, etc. Substitution of renewable or longer usable materials and energy resources for existing inputs Realization of optimal operating conditions by implementation of process control, flow separation, heat recovery, recycling, etc. Redesigning or replacement of existing technologies or equipment in order to reduce material and energy consumption Recovery of lost raw materials or energy from waste streams and reuse in other technological processes of the company Total:

Number of implemented CP projects 16

Electricity saving, MWh/y

Heat energy saving, MWh/y 4115

Energy production from local renewable resources, MWh/y

7

449

102

12682

92

22450

50018

37

7191

4706

17

3730

13191

169

33820

72132

A good energy saving effect is achieved by relatively small investments during implementation of the first three prevention methods. For example, reconstruction of the steam supply system in the biggest Lithuanian yarn production company (replacement of manually controlled valves by automatic ones, installation of a new system of steam

12682

reduction, replacement of ineffective steam pressure regulators, and steam traps) allows saving 11% from the total heat energy consumption. The investments repaid after 1.5 years [9]. The reconstruction of pressed air supply in a deflection systems production company (implementation of new local compressors in separate 34


departments instead of one, old and ineffective) allows minimizing electricity consumption in the

pressed air production department by 37%. This project’s pay-back period is 8 months [10]. Input substitution

Prevention methods

The optimization of energy supply systems Optimization of production process Technology modification

Waste energy utilization Energy recovery from production waste (waste-to-energy)

Fig.2.

Hierarchy of applied CP methods in energy environmental sector

renovation. But the investments in new technologies are often larger. That influences the pay-back period: 51% of such innovations are paid back within 2–3 years, 8.5% - within more than 3 years [10]. For example, the implementation of the Spiral Freezer system (extremely fast freezing) in the deep-frozen products production department allows saving about 280 MWh/y of electricity, i.e. 21% of the total electricity consumption in the company. The pay-back period of the new freezing technology is 3.5 years. Another example is the modernization of waste water treatment plants in galvanic company, which allows saving on the process level about 75% of electricity with the pay-back period 3.5 years. There are a lot of examples of energy recovery from production waste implemented in EU countries [11, 12], which are evaluated and step by step introduced in Lithuania, for example, energy recovery from production waste in wood treatment, furniture production and stockbreeding processes. There the generated waste becomes a bio-fuel for energy production. The major part of this energy is reused in the processes, and the other part is supplied for district heating.

The renovation of 250 m of the thermal route in a small town allows eliminating heat energy losses and thus saving 50 MWh/y of heat energy (2% of the total production in the boiler house of a heat energy supply company). The pay-back period of this CP project was approx. 1.5 years. The implementation of a new wood-fired boiler with a capacity 0.5 MW and 80% of efficiency instead of a fuel-oil-fired boiler with a capacity 1.5 MW and 75% of efficiency in a heat energy production company allows producing 850 MWh/y of heat energy from local renewable resources with a less environmental impact. The investments repaid after 2.9 years. The implementation of a new wood-waste-fired water heating boiler with a capacity 2.5 MW in a furniture company instead of the old ineffective gasfired boiler with a capacity 6.4 MW allows producing 3500 MWh/y of heat energy using wood wastes generated during furniture production, and saving 364 MWh/y of electricity (approx. 36% of the total electricity consumption within the company). The project’s pay-back period is 3 years. The optimization of technological process with the purpose to minimize energy consumption is one of the most frequently applied CP methods. The results of the evaluation of environmental efficiency show that the process optimization allows minimizing electricity consumption for a production unit by 18%, and heat energy consumption by 9% [10]. For example, optimization of the conditioning system (replacement of the ineffective equipment of the control system, installation of four new local cooling machines and two compressors instead of old ones, etc.) in the biggest Lithuanian textile company allows an annual saving of about 8000 MWh of electricity and 116 MWh of heat energy. Thus energy consumption for 1 m2 of cotton fabric (MJ/m2) was reduced down to the European level (from 18.1 to 15.2 MJ/m2). The investments repaid after 1.7 years. Impressive results in energy saving are achieved by technology modernization or equipment

3.

Waste energy processes

utilization

in

production

Analysis of applying waste energy utilization techniques in different sectors of economy identifies more possibilities in electricity and heat energy saving and pollution prevention. The waste energy utilization techniques widely applied in Lithuanian industry are presented in Table 4. One very important technique co-production of heat and power in power-stations may be introduced there [11]. But, on the whole, these projects in Lithuanian power plants are in the process of implementation; therefore, there are no suitable data on the cogeneration enough for the analysis.

35


Table 4.

Waste energy utilization in Lithuanian industry (1995–2005)

Sectors of economy, in which waste Heat energy Electricity Investments, energy utilization projects were saving, saving, MWh/y EUR implemented MWh/y Heat energy regeneration from wastewater (heat exchanger, heat pump) Textile industry 33913 -29 760506 Heat energy regeneration from condensate (heat pump, heater) Textile industry 6349 282380 Heat energy utilization from exhaust air and use for technological process (economizer) Heat energy production 543 34754 Heat energy from wastewater reuse for water or room heating (coil pipe system) Textile industry 782 13265 Hot (warm) water recycling or collection and reuse in other company’s processes Manufacture of metal products 320 -15 11237

Savings, EUR/y

Pay-back period, y (average)

738080

1

169840

1.9

15930

2.18

20954

0.7

20270

Manufacture of food and drinks 67 3504 3018 Rinsing (washing) wastewater recycling Manufacture of food and drinks 349 -35 70957 105480 Textile industry 1618 4 58214 52132 Transport and storage 1500 7 14481 14481 Wastewater after cooling processes reused in other company’s processes Textile industry 2179 96055 108075 Leather industry 334 2462 16780 Heat energy recuperation (collection and direction (turning) back to the same technological process) Textile industry 700 260658 173772 Heat energy utilization from technological process and use in other processes Manufacture of electrical machinery 3047 200156 100761 apparatus, appliances and supplies Manufacture of metal products 800 146 52132 23170 Manufacture of glass products 6513 214898 100015 Exhaust air cleaning and returning to the production departments Furniture production 2890 1612 570132 207930 Manufacture of chemicals and Chemical 848 278035 96689 products Manufacture of measuring and 2750 -799 159291 62124 controlling equipment Total: 65502 MWh 891 MWh 3.08 mill. 2.03 mill. EUR EUR/y

0.7 1.2 1.5 1.1 1 0.8 0.14 1.5 2 2.3 2.14 2.72 2.9 2.56 1.5 y

resources, but also obtaining other environmental effects. For example, implementation of waste energy utilization innovations presented in Table 4 decreases water consumption by 260 thous. m3/y, waste water volume by 253 thous. m3/y, waste by 2 thous. t/y, raw and additional material consumption by 722 t/y. 3) One of the most important issues could be solved by implementation of various waste energy utilization techniques, such us minimization of air emissions, inc. CO2 emissions generating the greenhouse effect. Currently, in Lithuania 83.6% of heat energy is produced by burning natural gas [5]. CO2 emission factor for natural gas typical of Lithuania is 56.1 t CO2/TJ [13]. On an average, the efficiency of Lithuanian gas-fired boilers is 91% [2]. The heating value of natural gas is about 33.47 TJ/Mnm³ [13]. In case of heat energy saving amounting to 65502 MWh/y, CO2 emissions decrease by 14464 t/y. Also, NOx emissions decrease by 26 t/y, and CO emissions by 65 t/y. The method for evaluating emissions from combustion plants, approved by the Lithuanian Ministry of Environmental protection, was used for the evaluation of NOx and CO emissions.

The main directions of the waste energy utilization in the production process were identified: 1) Waste energy resources could be used in the same technological process (for example, regeneration of heat energy from hot wastewater in a textile company finishing department (Case 1); hot exhaust air recuperation in the textile company’s drying processes; exhaust air cleaning and returning to the furniture production departments (Case 2)), in other production processes (for example, utilization of heat energy from the condensate formed in steam supply pipelines for extra heating of the textile company dyeing department), for the district heating (for example, waste heat energy utilization from glass production company for district heating of a nearest town (Case 3)). Therefore, currently, the EU is the World leader in the field of development of energy production from renewable and waste energy resources [12]. In 2005, new goals for 2020 were suggested in the EU: to expand heat energy production from renewable and waste energy recourses up to 25%, electricity – up to 33%. 2) Implementation of waste energy utilization innovations allows not only saving energy 36


Case 1. Heat recovery from wastewater and condensate in a textile company (cotton fabric production) Technical solution: Wastewater with the average temperature of 75 0C is collected to the wastewater tank after the rinsing and dyeing processes (see Fig.3). The pump P transports wastewater through a heat exchanger for the soft water primary heating up to 66 0C. The whole system consists of a wastewater tank, pump P, two heat exchangers with open pipes (WT1, WT2), electrical control system with level control, and WT3 condenser using heat energy from the condensate for further water heating from 66 0C to 78 0C. Environmental benefit: The result of analysis of heat energy consumption within the company before and after project implementation is presented in Fig.6. In 1999, the volume of textile after finishing pre-treatment increased by 15% in comparison with 1997, and steam consumption increased only by 2.5%. The implementation of the heat recovering system allows saving 7.73 GWh/y of heat energy. It constitutes 23% of the total steam consumption at the textile company’s rinsing and dyeing departments and 7.8% of the total steam consumption within the company. Energy consumption for the production of one unit (m2) of cotton fabric in this company decreased from 18.55 MJ/m2 to 16.18 MJ/m2 (EU level -14.1MJ/ m2 [9]) Economic effect: CP investments - 312000 EUR. Savings due to reduction of environmental cost – 180200 EUR/y. Pay-back period – 1.7 years.

After implementation of waste energy techniques

Before CP

Soft water supply line

Soft water supply line

780C

Warm water to finishing department Finishing department 380C Wastewater from finishing department

290C

Steam 1050C

WT2 WT3

Steam supply line WT1

Condensate

0

66 C

Wastewater (750C) to sewerage 750C

Wastewater tank Fig. 3.

P1

Principle scheme of heat recovery from wastewater and condensate (Case 1)

110

Steam consumption, GWh/y

GWh/y

25 Textile after finishing pretreatment, mill.m2/y

108

22

106

16

102 100

18.7 98.86

16.9

98

15

96.31

96

96.37

10

94 92 90

5 1996

Fig. 4.

1997

1998

Heat and energy consumption in a company (Case 1) Note. 1998 – implementation of waste energy utilization techniques

37

1999

Mill. m 2/y

20

104


Case 2. Exhaust air cleaning and returning to the furniture production departments Problem identification: The existing solid part cleaning system, which consists of a cyclone and a wet cleaning scrubber, was outworn and inefficient. More than 10% of wood dusts were emitted to the environment. Besides, it consumed a lot of energy and water; wastewater with wood dusts (up to 720 m3/y) required costly treatment; heat energy losses were generated with exhaust air. Problem solution: It was decided to replace the existing wood dust wet cleaning system by a fabric filter (dry cleaning) with a capacity more than 99% and with exhaust air returning to the production department. Environmental benefit: The implementation of this CP project allows saving electricity consumption by 520 MWh/y, and water consumption by 10000 m3/y. The volume of solid particles in exhaust air was decreased by 50 t/y. Wastewater with wood dust was eliminated. 1512 MWh/y of heat energy is saving by the implementation of a cleaned exhaust air returning system. Air emissions during this heat energy volume production decreased by 9.6 t/y (CO – 6.5 t/y, NOx – 0.68 t/y, solid. part. – 2.4 t/y), because 748 t/y of wood wastes aren’t combusted in the company’s boiler house. Economic effect: This waste energy utilization innovation allows saving for the company approx. 102000 EUR/y. Total cost for the implementation was 246000 EUR. Pay-back period – 2.4 years.

Case 3. Heat energy utilization from glass production for district heating of nearest township Problem identification: During the period 1992–2000, about 6.5 GWh/y of waste energy was utilized during glass production (exhaust air reached 480 0C). This waste energy was used for the company’s needs. The efficiency of the existing utilization system wasn’t exceeding 45%. The major part of heat energy was lost. Technical solution: The implementation of a new waste energy utilization system allows supplying about 6500 MWh/y of heat energy to district heating of the nearest small town. Environmental benefit: 2000–2004: in case of saving 6500 MWh/y of heat energy, air emissions during heat energy production in an oil-fired boiler house decreases by approx. 2000 t/y , incl. CO2 – 1970 t/y. Since 2004, air emissions during heat energy production in the gas-fired boiler house decreases by 1450 t/y, incl. CO2 – 1435 t/y. Economic effect: The project incomes in 2000 were 100000 EUR, presently, they increased up to 350 000 EUR/y. The total cost of implementation was 215000 EUR. The investments repaid after 2.15 years.

4)

5)

Implementation of waste energy utilization innovations allows obtaining not only environmental (decreasing fuel consumption and air emissions), but also economical effects (see Table 4). 1.5 years is the average pay-back period of such innovations. It depends on several factors: first and foremost, on the company’s size, the volume of accumulated energy, the originality of innovation, etc. For example, it was estimated that the pay-back period of the implementation of heat exchangers (Case 1) in smaller textile enterprises with a less waste water volume pays off after 3–4 years. Another notice: the price of designing a heat exchanger from Case 1 makes more than 35% of the total CP investment. In 2001, this textile company implemented a new CP project – heat energy recovery from wastewater of the bleaching department. The investments for a similar wastewater volume and temperature were twice less.

38

Some of the production companies are selling waste energy to energy production and supply companies. So, in Lithuania during 2004 the following significant heat energy volumes were bought by thermal / heat power stations from independent producers (production companies): 16% in Panevėžys region, 62% in Plungė town, 31% in Klaipėda region [14]. Figure 5 presents the information about the existing competition in Lithuanian district heating area among heat energy producers. 2.2 TWh of heat energy was produced from local renewable recourses [2], inc. waste energy (heat energy utilization from technological process in glass production company “Panevėžio stiklas” and the chemicals plan “Lifosa”). The heat energy price for users from, for example, Panevėžys and Klaipėda region are cut below (from 4 up to 36%) than from other regions where only classic fuel is used for energy production [14].


During 2004, these Lithuanian energy production and supply companies bought about 2.2 TWh of heat energy produced by production companies. It makes 20% of the total heat energy volume supplied to Lithuanian district heating

JSC “Klaipėdos energija”

JSC “Panevėžio energija”

“Plungės šilumos tinklai” Ltd.

“Pajūrio mediena” Ltd. (Planed sawnwood production); “Geoterma” Ltd. (Geothermal energy production); JSC “Izobara” (Heating systems and appliances); JSC “Klaipėdos baldai” (Furniture production)

“Plungės bioenergija” Ltd. (Heat energy production using bio-fuel)

“Vilniaus energija” Ltd.

JSC “Lifosa” * (Chemical Plant); JSC “Simega” (Fences, garden furniture and equipment); JSC “Panevėžio stiklas”* (Glassware production)

JSC “Grigiškės” (Paper plant)

*Waste energy utilization from production process Fig. 5.

6)

Independent heat energy producers in Lithuania

The average price of produced energy characterizes best the economical efficiency of energy production technique. The difference between heat energy prices in Lithuania, depending on fuel, is presented in Fig. 6. This investigation was carried by evaluated low heating values of different fuels [13] widely used in Lithuania and the average price of district heating [12, 14]. It shows the economic

180

advantage of all renewable energy resources. For example, such waste energy utilization technique as heat pump (which uses sun or technological process energy accumulated in air or in water) was taken for economic evaluation. For producing one unit of heat energy, a heat pump uses approx. 0.75 units of accumulated energy from exhausted air or waste water and only 0.25 units of electricity. %

%

7

Euro cents/kWh

160

6

140

100%

100 80

4 3

60

2

34%

40

Euro cents / kWh

5

120

1

20 0

0 Wood waste

Waste energy (heat pump)

Peat

Natural gas

Coal

Electricity

District heating

Fuel types

Fig. 6.

7)

8)

Distribution of heat energy prices in dependence on used fuel and in comparison with price of district heating. (Note. 100% - district heating (3.8 Euro cents/kWh))

The production volume doesn’t decrease during the implementation of waste energy utilization technologies, because it’s not necessary to stop production. The major part of savings is made due to reduction of environmental costs (of the used material, energy, water and pollution). It allows increasing the company’s level of environmental performance and decreasing the price of the manufacturing. Therefore, for implementation of

such innovations, it’s possible to get a NEFCO (Nordic Environment Financial Corporation) credit on favorable terms. For these purposes, the NEFCO established a special Revolving Fund to finance CP investments and started their activities in Lithuania in 1998 [15]. During this period, the NEFCO financed 25 CP projects on favorable terms: 6 projects – in the area of waste energy utilization, 9 – process optimization, 7 – technology modification, and 3 - in the area of 39


energy recovery from production waste and waste recovery. 4.

Economic: The economic efficiency of waste energy utilization techniques for production companies is very obvious: • investments to these projects pay-backs during 1.5 years (on average); • 87% of the economic savings are made due to reduction of direct process costs (material, energy, water and pollution); • investments to implementation could be obtained from various sources: environmental founds, EU programs and the Structural Fund, NEFCO, etc.

Conclusions

Using Cleaner Production methodology [8, 9], the main causes of the inefficient use of energy in production processes were analyzed. Loss of waste energy, a low level of process control, the poor technical status of equipment influence one of the key indicators of country economy, which is final energy consumption per GDP Unit. This indicator in Lithuania exceeds the EU average by approx. 16%. The possibilities of the development of Cleaner Production methods for increasing energy use efficiency in the production process were identified. Energy saving due to implementation of such CP techniques as input substitution, process optimization, technology modification, onsite recycling in 80 Lithuanian production companies makes about 0.6% of total energy consumption in the Lithuanian industrial sector (2003). As a result of this analysis, a hierarchy of the techniques for environmental improving in energy area using pollution prevention strategy was suggested. Usage of renewable and waste energy recourses leads to reduction of environmental impact, solving the problem of CO2 emission generating greenhouse effect, with minimization of dependence of costly imported fuel and saving energy resources. The main aspects of the application of waste energy utilization in production processes were determined to be as follows: Social: • increasing effective utilization of local, renewable and waste energy resources, thus increasing energy supply stability in Lithuania is one of the main directions of the National Energy Efficiency Program [4]; • the price of heat energy used waste energy from technological processes exceeds only the price of heat energy, produced from bio-fuel and is less than the average price of district heating by approx. 66%; • the increasing competition between Lithuanian heat energy producers and suppliers due to appearance of the new market of heat energy production from renewable and waste energy resources creates preconditions for decreasing heat energy prices.

Environmental: The implementation of waste energy utilization techniques increases the companies’ level of environmental performance in such environmental sectors as energy, water and waste water, air pollution, incl. reduction of CO2 emissions, etc. Therefore, this pollution prevention method received one of the BAT (the Best Available Techniques) in the EU for many branches of industry, for example, textile, combustion plants, chemical plants, furniture, stockbreeding, etc. [16]. Waste energy utilization helps the production companies with installations listed in Annex 1 of the IPPC (Integrated Pollution Prevention and Control) directive to achieve the BAT level in the energy environmental sector and, hereby, receive IPPC permits for the activity after 31st of October 2007. References 1. 2. 3. 4. 5.

6. 7.

Technical: • there are a lot of waste energy utilization techniques for production processes from different industrial sectors, a lot of methods of waste energy reuse: not only reuse in the technological processes, but, also, for example, for the district heating of nearest residential areas; • the market of waste energy utilization techniques in Lithuania is increasing, especially in textile, furniture industries and in energy production.

8. 9. 10.

40

National Energy Strategy, Lithuania; October 2002. Internet site: http://www3.lrs.lt/cgibin/preps2?Condition1=197078&Condition2. The results of the activity of Lithuanian District Heating Association 2005. Internet site: http://www.lsta.lt/content/blogcategory/49/58/. Eurostat, Energy and Environmental Statistics 2002, Brussels. National Energy Efficiency Program, Lithuania 2001. Internet site: http://www.ena.lt/en/main_veikla_vartojimas.htm. Juška A., Miškinis V. Energy in Lithuania. Kaunas: Lithuanian Energy Institute; 2004. ISBN 9986-49283-1. Internet site: http://www.ukmin.lt/lt/energetika/informacija/doc/lei _2004.pdf. Baltic Council of Ministers. Baltic Energy Strategy 1999. Internet site: http://www.ena.lt/pdfai/BES.pdf. Kliopova I. Possibilities of waste energy utilization in Lithuanian industrial companies. Chemical Engineering Transaction 2005; 7: 145-150. Staniškis J., Stasiškienė Ž., Kliopova I. Cleaner Production: systematic approach. Monograph. Kaunas: Technologija, 2002; ISBN 9955-09-312-9. Kliopova I. Cleaner production in Lithuanian Textile Industry. Environmental research, engineering and management 2000; 3(13): 42-51. Kliopova I. Cleaner Production through Process Control: analysis, methods and implementation. PhD thesis. Kaunas Technological University; 2002 [in Lithuanian].


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Korhonen J. A material and energy flow model for co-production of heat and power. Journal of Cleaner Production; 2002; 10: 537-544. Adomavičius V., Jaronis E.. The possibilities of power provision of home. The Academy of Applied Sciences of Lithuania; 2005. Internet site:http://gstudija.tinklapis.lt/ltma/straipsnis3.htm [in Lithuanian]. Lithuanian National Allocation Plan for Greenhouse Gas Emission Allowance for the period 2005-2007. Internet site: http://www.ekostrategija.lt/images/adm_source/Lietu vos%20NAP.doc [in Lithuanian]. Lukoševičius V., Katinas K. New pricing policy in the Lithuanian district heating sector. Thermal technology; 2004; 4: 3-5 [in Lithuanian]. Staniškis J., Stasiškienė Ž. Promotion of cleaner production investments: international experience. Journal of Cleaner Production; 2003; 11: 619–628. Activities of the European Integrated Pollution Prevention and Control Bureau. Reference Documents on Best Available Techniques. Internet site: http://eippcb.jrc.es/pages/FActivities.htm.

Dr. Irina Kliopova, lecturer at the Institute of Environmental Engineering, Kaunas University of Technology. Main research areas: Cleaner Production; Integrated Pollution Prevention and Control (IPPC), energy efficiency Address: Teatro str. 8 – 16, LT-03107 Vilnius, Lithuania Tel./fax: +370-5-2649174 E-mail: [email protected] Prof. Dr. hab. Jurgis Staniškis, director of the Institute of Environmental Engineering, Kaunas University of Technology Main research areas: sustainable development, environmental management, cleaner production, financial engineering, integrated waste management Address: K. Donelaičio str. 20-309, LT-44239 Kaunas, Lithuania Tel.: +370-37-300760 Fax: +370-37-209372 E-mail: [email protected]

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Atliekų energijos išteklių panaudojimo galimybės Lietuvos pramonėje Irina Kliopova, Jurgis Kazimieras Staniškis KTU Aplinkos inžinerijos institutas

(gauta 2006 m. sausio mėn.; atiduota spaudai 2006 m. vasario mėn.)

Lietuvos Nacionalinėje Energetikos strategijoje siekiama, kad vietinių atsinaujinančių ir atliekų energijos išteklių būtų sunaudojama apie 2 mln. tne (iš jų atliekinių išteklių – 430 tūkst. tne) per metus. Įvertinta, kad, pramonės įmonėse pasitelkus atliekų energijos išteklius, techniniu ir ekonominiu pažiūriu galima būtų produktyviai vartoti apie 4 TWh į aplinką šalinamos šilumos. Šiuo metu šalies įmonėse įvairiomis techninėmis priemonėmis sunaudojama tik apie 23 proc. į aplinką šalinamos šilumos. Mažiausiai naudojama atliekų energijos išteklių, susidarančių šalies energetikos ir nuotekų valymo įmonėse. Neefektyvaus energijos naudojimo, atliekų energijos praradimo problemos aktualios ir kitoms Baltijos šalims. Baltijos šalių 2003 metų energetinių rodiklių palyginimo rezultatai parodė, kad vienas iš svarbesnių energetinių ir ekonominių rodiklių – galutinės energijos sąnaudos bendrojo vidaus produkto (BVP) vienetui Lietuvoje 23 proc. mažesnis negu Latvijoje ir 26 proc.– negu Estijoje. Remiantis sukurta švaresnės gamybos diegimo Lietuvoje duomenų baze, kuri apima techninę, aplinkos apsaugos, ekonominę ir finansinę informaciją apie įdiegtas 175 prevencines inovacijas 80 įvairių sektorių pramonės įmonėse, buvo atliktas tyrimas, kurio metu išanalizuotos: • neefektyvaus energijos naudojimo ir energijos nuostolių įvairiuose gamybos procesuose susidarymo priežastys; • švaresnės gamybos metodų diegimo, siekiant efektyviai naudoti energiją, galimybės; • atliekų energijos išteklių sunaudojimo Lietuvos pramonės technologiniuose procesuose galimybės. Straipsnyje pateikti apibendrinantys analizių rezultatai; pasiūlyta ŠG strategijos taikymo energijos aplinkos apsaugos srityje hierarchija; įvertintas įvairiuose Lietuvos ūkio sektoriuose įdiegtų atliekų energijos sunaudojimo inovacijų ekonominis efektyvumas bei aplinkos apsaugos nauda; pateikti tekstilės, baldų ir stiklo pramonėje plačiau diegiamų atliekų energijos išteklių naudojimo pavyzdžiai. Tyrimo rezultatai parodė, kad atliekų energijos išteklių pasirinkimo galimybės Lietuvos pramonėje yra perspektyvios tiek techniniu ir ekonominiu, tiek ir socialiniu požiūriu. Visu pirmą, atliekų energijos pasitelkimas gerina įmonės aplinkos apsaugos veiksmingumą energijos, vandens ir nuotekų bei oro taršos sektoriuose. Tai labai palengvina įmonei įgyvendinti Taršos integruotos prevencijos ir kontrolės (TIPK) direktyvos reikalavimus ir atitiktį geriausiam prieinamam gamybos būdui (GPGB). Ekonominiu požiūriu atliekų energijos išteklių pasirinkimo gamybiniuose procesuose inovacijos ypač efektyvios: jų atsipirkimo trukmė vidutiniškai neviršija 1,5 metų, o 87% visų sutaupymų sudaro tiesioginiai gamybos kaštai. Socialiniu požiūriu atliekų energijos išteklių pasitelkimo inovacijos gerina energijos tiekimo stabilumą šalyje, didina konkurenciją tarp energijos tiekėjų ir kartu mažina energijos kainą. Priklausomai nuo plačiau naudojamo Lietuvoje kuro rūšies buvo palyginta gaminamos šilumos energijos kaina. Po medienos atliekų deginimo įrenginių ekonominiu požiūriu efektyviausiai šilumos energija gaminama, taikant įvairius atliekų energijos pasirinkimo metodus (pvz., šilumos siurblius, šilumokaičius).

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