Viet Nam experience and opportunities on biogas, biomethane and waste-to-

energy

Dr. Pham Quang Ha, Vietnam Academy of Agricultural Sciences (VAAS)

Manila, 26 June, 2019

Priority bioenergy pathways

Biogas bioenergy pathways prioritized, based on spread, relevance for decision-making, and need for further evidence:

• biogas, at household, farm and industrial levels

2

Biogas: scope of analysis

2 types/scales of systems analyzed:

• Household/ Small scale (from pig manure)

• Farm/ Large scale (also from pig manure)

3

Biogas at household level:spread and use

• There are about 3.5 M households with pig production and more than 7000 large scale pig farm (in total 28 M pig) with about 25 M tones pig manure to be treated, reused as resources.

• 500,000 + Anaerobic Digesters (ADs) in house hold levels- of which 90% operational - installed, thanks to the support of the Government and of international entities as well, e.g. SNV, ADB, WB

• In households with ADs, biogas provides most of the energy for cooking and is used for heating and lighting as well, displacing traditional biomass and fossil fuels

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Technology description

Vietnam - Large-scale biogas -SWOTStrengths

• Re-Use solid waste smartly• Reduces the use of other type of

fuel (e.g. fossil fuel, wood) and the related environmental impacts. Saving energy consumption

• Cut down energy costs through self-provision

• Increase soil quality (soil organic matter content) and fight soil depletion

• Effective use of agro-industrial waste: easy and healthy waste disposal

• Increase crop yield

Weaknesses

• Lack of technology know-how in plant management to fit the national electricity network/ grid

• High cost for collecting and transporting the feedstock

• High maintenance cost• Lack of use for heat generated to

electricity • Lack of standard for liquid use

after biogas

Opportunities

• Existence of incentives for production of renewable energy

• Building capacities• Development of new

enterprise for collecting, transporting and selling agro-industrial waste as feedstock and organic fertilizer production.

• Skilled employees for checking plant performance

• Promotion for green growth

Threats

• Possibility of accidental emissions of methane in the atmosphere

• Environmental barriers for liquid use after biogas

• Animal disease ( such as ASF, Feet and Mouth Disease)

• More GHG emission if CH4 will be burn (no use)

• Increase non point pollution if use non appropriate

• Technical barriers on by product use for crop ( heavy metal)

Vietnam - Small-scale biogas - SWOTRank Strengths Weaknesses Opportunities Threats

1Access to modern, clean cooking

energy.Stability of biogas functional

Networking to share the gas in the

communityNo use gas in excess

2Improve sanitation management

and reduced indoor air pollution

Lack of skills and knowledge in

maintenance for user

Incentives for climate change

mitigation Uncertainty of feedstock availability

in the long term

3Availability of feedstock and

improved waste disposal.Lack of seasonal stock Water pollution

4

By-products such as slurry,

digestate can be used for crops

with certain security

Low water use efficiency

5 Easy to establish Quality of biogas is poor

Technical barriers on by product use

for crop ( heavy metal)

6Save labor (e.g. in wood

collection).Animal Decease (ASF)

Parameter Unit

Amount found in sampled

wastewater of types of bio-

digester

Threshold values

for industry

waste water

established by

QCVN

40:2011/BTNMT

(Column B)

Threshold values

for waste water

from livestock

by QCVN 62-

MT:2016/BTNMT

(Column B)KT1 KT2 Composite

Ntt mg/l 265.62 218.55 188.40 50 150

Ptt mg/l 74.73 84.95 69.27 6 No regulation

TSS mg/l 4639.84 3690.85 3223.11 100 150

COD mg/l 1083.83 875.14 726.70 150 300

BOD5 mg/l 565.42 429.99 385.36 50 100

Fecal

coliform

MPN/

100 ml1948 2814 4331 5000 5000

Quality of wastewater after biogas

N, P, K concentration in Slurry and Solid from biogas

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Indicator Ntotal NH4+ P2O5 total K2O total pH

Liquid

slurry

mg/l 170-2240 130-930 56-320 100-434 1.7-8.5

% 0.017-0.22 0.013-0.093 0.0056-0.032 0.01-0.043

Solid

slurry

mg/kg 140-3800 30.8-261.7 246-620 434-3100 7.0-8.6

% 0.07-1.9 0.015-0.13 0.123-0.31 0.217-1.55

GHG emissions: comparison with the BAU case

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28.79

40.24

46.91

manure-biogas natural gas LPG

g CO2eq/MJ useful heat (for cooking)

Using biogas is achieved GHG emission saving ~ 45% and 50% in comparison to the BAU in which cooking is done by natural gas or LPG cook-stove,

respectively

LCA results for Biogas: non-GHG emissions

11

0.00

0.01

0.01

0.02

0.02

0.03

0.03

0.04

0.04

0.05

0.05

SO2 NOx CO VOCs PM10 Dust NH3

g/MJ biogas

g/MJ nat. gas

g/MJ LPG

Biogas at farm level:overview

• ADs mainly used as a waste management strategy, i.e. to reduce odor and emissions from pig manure

• Only a small fraction of the produced biogas is used (for the energy needs of the households living on the farm and its surroundings), while most of it is vented or flared, with significant GHG emissions

RECOMMENDATIONS:

• Power generation, including for injection into the grid, from agricultural and livestock residues, should be promoted

• Opportunities to further distribute biogas to local communities should be explored.

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Biogas: adoption barriers to overcome

• Inability to manufacture appliances and digesters locally

• Lack of technical skills in the private sector to install and maintain digesters

• Poorly developed biogas-based energy conversion equipment, with low heat conversion efficiency

• Lack of large appliances capable of using biogas

• Limited awareness of available digestate applications and of the related benefits

• Lack of institutional coordination among relevant national/local entities and international donors

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Biogas:key recommendation

• At national level, stronger coordination/cooperation among relevant ministries (mainly MARD, MOST, MONRE, MIT) to establish different standard on bioenergy , re-use resources and by product from agriculture

• In addition, local and provincial agencies, especially in the agricultural sector, should be engaged in decision-making related to biogas in the whole chain from animal production to by-product management with multi-purposes ( meat, gas, animal manure and slurry re-use, electric generator)

• The private sector and NGOs should be involved and consulted as well, in order to identify and share best practices, jointly mobilize resources, apply new technologies, and develop the technical workforce

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Application of microbial inoculants to treat solid waste after biogas, manure as bio-organic

fertilizer.

Thank you for your attention