feasibility study of bgs mavas group final › content › announcements › 10538 ›...

REPORT ENVIROS, s.r.o. – NOVEMBER 2017

UNDP ARMENIA

FEASIBILITY STUDY ON BIOGAS STATION MAVAS GROUP


QUALITY CONTROL FORM

Client: UNDP Armenia

Government bld. no.3, room 53 Republic square, 0010 Yerevan, Armenia Contact person: Diana Harutyunyan, Climate Change Program Coordinator UNDP Armenia Telephone: (+374 10) 58 39 20 (ext.14) E-mail: [email protected]

Report Name: Feasibility study on Biogas station Mavas Group

Reference number: ECZ17173

Volume number: 1 of 1

Version: Draft report

Date: 30. 11. 2017

Link to file: G:\Projects\ECZ17173_FS_UNDP Armenia biogas.docx Prepared by: ENVIROS, s.r.o.

Dykova 53/10 101 00 Praha 10 - Vinohrady IČ: 61503240, DIČ: CZ61503240

Team: Ing. Jan Pavlík Ing. Karel Pejchal

Responsible person:

Ing. Jan Pavlík Phone: (+420) 284 007 477 E-mail: [email protected]

Approved:

Ing. Jaroslav Vích CEO and Managing Director


CONTENT

MANAŽERSKÝ SOUHRN ........................................... ERROR! BOOKMARK NOT DEFINED. 1 PRVNÍ KAPITOLA .............................................. ERROR! BOOKMARK NOT DEFINED. 2 FEASIBILITY STUDY OF BIOGAS STATION ............................................................... 2

2.1 Biogas station location ......................................................................................... 2 2.2 Technical description ........................................................................................... 2 2.2.1 Description of the technological process .......................................................................... 3 2.2.2 Preparation and supply of raw materials .......................................................................... 4 2.2.3 Gas production ................................................................................................................. 4 2.2.4 Biogas cleaning ................................................................................................................ 5 2.2.5 Use of waste substrate ..................................................................................................... 5 2.2.6 Use of heat ....................................................................................................................... 6 2.2.7 Biogas station main components ..................................................................................... 6 2.3 Energy yield review ............................................................................................. 6 2.4 Project costs ........................................................................................................ 7 2.5 Economic evaluation ........................................................................................... 7 2.6 Risk and sensitivity analysis ................................................................................ 8


LIST OF FIGURES AND TABLES

Table 1: Production of waste during the year ................................................................................ 3

Table 2: Parameters of the CHP unit ............................................................................................. 6

Table 3: Inputs ............................................................................................................................... 6

Table 4: Production of biogas ........................................................................................................ 7

Table 5: Production of electricity and heat .................................................................................... 7

Table 6: Production of electricity and heat .................................................................................... 7

Table 7: Summary of the technical indicators ................................................................................ 8

Table 8: Main financial indicators .................................................................................................. 8

Table 9: Capital investment indicators ........................................................................................... 8

Table 10: Financial indicators for variable scenarios ...................................................................... 8

Location of Mavas Group (source: maps.google.com) .................................................... 2

Investment, operational costs and profit according to assumptions ................................ 9

Increased revenue from electricity sales +10% ............................................................. 10



Decrease investment costs -10% .................................................................................. 11

Decrease investment costs -10%; increased revenue from electricity sales +30% ...... 12

FEASIBILITY STUDY ON BIOGAS STATION MAVAS GROUP 1

1 INTRODUCTION

This pre-feasibility study accompanies the main study on biogas installation potential in Armenia. The aim of this report is to present theoretical solutions for installation of biogas plant with combine heat and power unit (CHP) based on the knowledge and know-how of the similar installation within the Czech Republic. Selected technologies and its economical parameters (costs, lifetime etc.) are based on expert experience of the project consultant.


2 FEASIBILITY STUDY OF BIOGAS STATION

2.1 Biogas station location

Biogas station will be located in farm Mavas Group in Greenhouse complex of 20 ha which is situated in Kotayk region, RA.

Location of Mavas Group (source: maps.google.com)

2.2 Technical description

The main area of Mavas Group operation is growing tomatoes and cucumbers in modern greenhouses.

Mavas Group LLC” is one of the largest producers of fresh vegetables and fruits. Greenhouse complex of 20 ha is situated in Kotayk region, RA. Company’s is based on modern technologies, which are up to the international standards. The greenhouses are equipped with the latest innovative European constructions mainly imported from the Netherlands.


The annual production of green waste is 2 610 tons. During the year the amount of waste varies, it is not constant. See table below.

Production of waste during the year

Month Waste (tons)

January 210

February 210

Marc 210

April 300

May 350

June 320

July 170

August 70

September 100

October 250

November 210

December 210

Total 2 610

Therefore, it is necessary to build a waste stack in order to be able to supply equally the feedstock of the bioreactor.

The structure of the biogas facility will include the following equipment: Waste stack Loading reservoir; Bioreactor; Tank for separated substrate; Separator; Pumping station; Supply container for dry raw materials; Cogeneration unit; Biogas filter; Transformer substation;

2.2.1 Description of the technological process

The planned capacity of the power generated by the biogas plant is up to 64 kWe and the total thermal power is 87 kWh. Heat and electricity will be generated by burning biogas in internal combustion engine. Biogas will be produced by anaerobic processing method (in the oxygen-free environment) from green waste from tomato and cucumber cultivation and cattle slurry.

Biogas production is performed in anaerobic systems. This is a controlled process of biogas production from different types of anaerobic microorganisms the composition of which depends on the materials forming them as well as from рН, the temperature and influences of methane formation process. According to the current knowledge four successive respectively parallel running biochemical processes are recognized which lead to anaerobic decomposition of organic matter:


Hydrolysis – During hydrolysis biopolymers are decomposed to monomeric building blocks or other dissolvable basic products. Fats decompose to fatty acids, carbon hydrates as for example polysaccharides are transformed in monosaccharides or oligosaccharides and the proteins in pectins, respectively to amino acids, i.e. the biopolymers in long chains are converted in short chains. Catalysts of these reactions are certain anaerobic microorganisms, which act as reagents hydrolyzing the exoenzymes.

Acidogenesis – Within the acidogenesis /or fermentation/, which starts immediately after the hydrolysis, simple monomers are converted into fatty and carbon acids, as for example butyric, propionic and acetic acid, then in lower alcohols - ethanol. When this transformation occurs, first the selected anaerobic microorganisms receive the necessary energy. In this process 20% of the whole volume is acetic acid.

Acetogenesis – A biological reaction where the lower fatty and carbon acids as well as the lower alcohols are converted in acetic acid.

Methanogenesis – A biological reaction where the acetic acids are converted in methane.

Biogas is produced in bioreactors with the support of a constant substrate temperature (about 38 – 42°C), by mixed substrate, in the absence of oxygen. During fermentation in a bioreactor, biogas is collected under a double-membrane dome into which air is blown to support the shape of the dome and thereby to support biogas pressure. In bioreactors, about 36 m3/hour (311 642 m3/year) of biogas will be produced. In order for the biogas production process to take place, it is necessary to maintain a constant temperature in the bioreactor (about 40 °C). The substrate in the bioreactor is heated by the waste heat of the generator (the heat exchanger is supplied to the generator). The feed temperature is controlled by a three-way valve.

At the bioreactor, a heat distribution unit is installed. Heat distribution unit comprises: the collector; capacity expansion; control valves.

Green waste will be diluted by beef slurry and liquid digestate.

2.2.2 Preparation and supply of raw materials

Green waste will be used as a raw material for the production of biogas in the biogas reactor. Loading and unloading works will be carried out with the help of a front loader.

Green waste is brought from the stack. With the help of a front loader, it is loaded into the raw material supply unit, from where it is fed through the screw conveyor to the crusher. After grinding, the inputs are inserted via a screw conveyor into the bioreactor.

Substrate from the bioreactor and beef slurry are delivered to bioreactors by means of a screw pump.

The appropriate space for these operation is available in Mavas, generally approx.. 500m2 is necessary for this technological step.

2.2.3 Gas production

Biogas is produced in bioreactor with the support of a constant temperature (about 38 - 42°С), pH 7-8, and mixing of the substrate in an oxygen-free environment, for this purposes, the heating tubes of the bioreactor are installed inside the structure.


The biogas is collected under a dome of double membranes between which air is supplied to support the shape of the dome and thereby to support the biogas pressure.

The estimated biogas productivity in bioreactor is about 36 Nm3/hour.

Biogas through pipes is fed into the module for biogas preparation and treatment. To raise the biogas pressure, a compressor is placed in front of the biogas treatment preparation module, which raises the pressure from 1.5 mbar to 100mbar. Filtering material in the biogas treatment preparation module is activated coal. After filtration, biogas is fed to the cogeneration unit.

Biogas is not stored on site. A small reserve amount of biogas is stored under the domes. In the event of generator failure or excessive biogas production, surpluses are flared.

2.2.4 Biogas cleaning

The main constituents of biogas are methane (about 54%), carbon dioxide (about 39%), oxygen (up to 4%), hydrogen sulphide (up to 0.01%), ammonia (up to 0.0001%), hydrogen (up to 0.0001%). Hydrogen then burns and turns into water. About 50% of ammonia precipitates in a place with a condensate in the cooler.

During the production of biogas, hydrogen sulphide is released in the bioreactor. The content of hydrogen sulphide in biogas when fed to the cogeneration plant should not exceed 200 ppm. Excess of hydrogen sulphide content in biogas promotes increased wear of the cogeneration unit engine. The content of hydrogen sulphide in biogas can reach up to 1000 ppm. To eliminate the above-listed circumstances, the amount of sulphur compounds in biogas is reduced by a supply of oxygen to the dome of the bioreactor. An air is supplied under the dome of the bioreactor in an amount such that the oxygen content in the biogas does not exceed 4% of the biogas volume. This amount of oxygen allows, without disturbing the main process, the multiple bacteria to surface the substrate and absorb hydrogen sulphide. Significant reduction in hydrogen sulphide is achieved at this stage.

Cleaning of biogas in the activated carbon filter before entering the unit is done in the biogas preparation block, which consists of:

cooling block (with the condensation of moisture from biogas);

heat exchanger for biogas (biogas is cooled and further dried);

compressor, which raises biogas pressure up to 150 mbar;

cleaning biogas in a filter with activated carbon;

the biogas meter.

2.2.5 Use of waste substrate

After fermentation, the spent substrate, which is equal in quality to the high-quality fertilizer, is pumped to the separator by pump. The screw-type separator separates the dry part, and the separated substrate is brought to the reservoir of the separated substrate by gravity. The separated liquid mass is pumped to the storage tanks of the substrate by means of installed pumps. The separated dry mass is poured into the storage area of the separated dry part from where it is transported for further storage to the existing storage areas. Liquid digestate, which is also considered as nutrient-rich wastewater is reused to dilute the new manure input for the biogas production and not used substrate is stored as a fertilizer.


2.2.6 Use of heat

Full utilization of produced heat is assumed. A part of the heat will be used for heating of the biogas plant technology and the rest will be used for heating greenhouses.

2.2.7 Biogas station main components

The biogas station main components are:

Green waste store stack – open concrete stack

Slurry storage tank – circular reinforced concrete tank

Bioreactor – circular reinforced concrete tank with an internal diameter of 12 m. The depth of the tank is 5 m. The tank is insulated. The useful volume is 452 m3.

Storage tank of substrate – circular reinforced concrete tank with internal diameter of 26 m. The depth of the tank is 7 m. The useful volume is 3 184 m3.

CHP unit – cogeneration unit MGM 70, producer Motorgas. The unit consists of a motor generator module, module technology and exhaust silencer. The unit is designed to run on biogas and in parallel operation with the network 400V/50Hz. The hot water circuit is adapted to the hot water gradient of 90/70°C.

Parameters of the CHP unit

Parameter Unit Value

Energy input kW 179

Gas volume Nm3/h 33,2

Electrical output kW 64

Electrical efficiency % 35,8

Heat output kW 87

Heat efficiency % 48,6

2.3 Energy yield review

The basic input raw material will be green waste from growing tomatoes and cucumbers. To improve the process of biogas production will be added cow manure/slurry. The digestate will be used to dilute the inputs.

Inputs

Input Amount (t/a) Dry matter content (%)

Organic materials (%)

Biogas (m3/a)

Green waste 2 610 30 88 275 616

Cow slurry/manure 1 000 5 85 15 938

Digestate 3 000 6 45 20 088


Total 6 610 15 311 642

Production of biogas

Parameter Unit Volume

Biogas per year Nm3 311 642

Biogas per hour Nm3 35,6

Energy in biogas kW 192

Expected electricity and heat production of the biogas plant during average year is presented in the table below.

Production of electricity and heat


Electricity generation MWh/a 550

Own electricity consumption MWh/a 13

Electricity supplied to the grid MWh/a 537

Heat generation MWh/a 749

Own heat consumption - BGS MWh/a 188

Heat for heating greenhouses MWh/a 561

2.4 Project costs

The following table shows the estimated investment costs. These costs depend on a number of factors. It is based not only on the size of the equipment and on the installed technology but also, on whether the construction is realized by self-help or supply and on the share of self-help work.

Production of electricity and heat

Parameter Price (EUR) Share

Building part 131 625 45%

Technological equipment 58 500 20%

Cogeneration unit 87 750 30%

Other investment costs 14 625 5%

Total 292 500 100%

2.5 Economic evaluation

The capital investment decision indicators (IRR, NPV and simple payback period) are calculated based on the project cash flow before financing. 20 years were taken as a period for the analysis. The discount rate was set to 8% for the purposes of economic indicators calculation in the sensitivity analysis.


The total investment costs together with the energy, fuel, operational, labour and other costs and revenues were used for calculation of simple payback period. The following tables summarize technical and financial indicators of the renewable energy project.

Summary of the technical indicators


Electrical capacity kW 64

Heat capacity kW 87

Heat in biogas kW 192

Electricity supplied to the grid MWh/a 537

Heat for heating greenhouses MWh/a 561

Main financial indicators


Investment costs EUR 292 500

Lifetime year 20

Discount rate % 8

Feed in tariff EUR/MWh 75,48

Price of natural gas EUR/m3 0,2286

Used exchange rate 565 AMD/EUR. Feed in tariff 42,645 AMD/kWh.

Capital investment indicators


Investment costs EUR 292 500

IRR % 4

NPV EUR - 69 574

Simple payback period year 12,9

Real payback period year 41

2.6 Risk and sensitivity analysis

In order to test the robustness of the project’s financial results, several sensitivity scenarios were developed. The following cases include various levels of increase of investment costs (by 10%), increase of revenues (by 10%, 20% and 30%).

The following table summarizes the results of the sensitivity analysis.

Financial indicators for variable scenarios

Scenario NPV (EUR) IRR (%) Real payback period (year)


Investment, operational costs and profit according to assumptions -69 574,42 4,2 41,0

Increased revenue from electricity sales +10% -29 806,56 6,3 27,0

Increased revenue from electricity sales +20% 9 961,31 8,2 18,5

Increased revenue from electricity sales +30% 49 729,17 10,0 14,5

Decrease investment costs -10% -40 324,42 5,5 34,1

Decrease investment costs -10%; increased revenue from electricity sales +30% 78 979,17 11,6 12,0

Investment, operational costs and profit according to assumptions


Increased revenue from electricity sales +10%




Decrease investment costs -10%


Decrease investment costs -10%; increased revenue from electricity sales +30%


3 PICTURES

Foto 1: View on Mavas area

Foto 2: Mavas greenhouses


Foto 3: Available waste

Foto 4: High-tech greenhouse

ENVIROS, s.r.o.

Dykova 53/10, 101 00 Praha 10-Vinohrady Česká republika

IČ: 61503240, DIČ: CZ61503240 Společnost vedená u Městského soudu v Praze,

oddíl C, vložka 31001

Tel.: +420 284 007 498 Fax: +420 284 861 245

E-mail: [email protected]

www.enviros.cz

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