Doing AD Well:
Improving
Operational
Performance
W
ith 388
anaerobic
digestion
(AD) plants,
the industry is already
generating sufficient green
energy to power half of
the households in central
London (710,000 homes),
however, the industry is
far from reaching its full
potential. AD is a constantly
evolving, adapting
technology which is always
driving hard to reduce costs,
increase outputs, cut carbon
footprints, and to develop
new, innovative high-value
products.
Dodd, noted at our National
Conference last December,
“operational performance
underpins the economic
viability of projects,
confidence in the sector’s
health and safety record,
the quality of outputs and
the professionalisation
of standards across the
industry.” If you are to
maximise outputs, ward off
the regulators and ensure a
safe operating regime, then
the decisions made on the
type of technology used for
your AD plant will have a
fundamental impact on the
plant’s efficiency.
This year’s UK AD & Biogas
2015, which we will be
hosting at the NEC in
Birmingham on 1-2 July,
will showcase the latest
technology and services
from the AD industry to
around 3,000 visitors.
There’s plenty to showcase
as the industry comes
under increasing pressure
to improve operational
performance, manage
environmental risk and find
new ways of maximising the
process outputs.
Plants designed for one
type of feedstock do
not necessarily work
as effectively for other
varieties and so matching
the feedstock composition
of your farm to the type of
digester is vital. PROjEN’s
Process Consultant, Dr Les
Gornall, explains that “to
reduce parasitic electrical
loads and maximise gas
production, digesters need
a feedstock that is best
described as ‘good soup’;
high in organic matter
and free of contaminants.
It’s also crucial to choose
the right bacteria for the
As the Head of Operations
for Tamar Energy, Kyrone
feedstock and digester
operating temperature.
Make the microbes happy
and they will thrive. After
all, a digester is a living
organism that needs to be
attended to every day.”
Another aspect that
operators need to consider
is the need to extract the
greatest possible value
from an AD plant’s outputs.
HRS Heat Exchangers’
International Sales Manager,
Matt Hale, challenges those
AD operators who fail to
utilise the heat output from
the plant, “not using the
heat naturally generated
as part of the AD process
could be costing operators
thousands of pounds each
year, particularly if they’re
adding heat elsewhere. By
using a heat exchanger to
capture and transfer this
waste heat, a well-designed
system could recover
40 per cent of the heat
produced by the plant.” Heat
is often an under-utilised
valuable output of AD,
which can then be used for
a wide variety of purposes,
including feedstock preheating; digester heating;
pasteurisation; evaporation;
or to heat nearby buildings.
Richard Gueterbock,
Director of Clearfleau, a
company which designs
and builds on-site AD
plants, emphasises that
investing in technology
which complements your
existing business model
is most likely to maximise
your returns, “AD plants
are designed to take a
certain load and a certain
feedstock so the key thing
for us is making sure the
client operates the plant
in the way in which it was
designed. AD is a biological
process which needs to
be optimised, so careful
and effective monitoring
is fundamental.” Ensuring
that you select the right
equipment to operate
your plant at the highest
possible standard is also
essential to maintaining
investors’ confidence in
AD projects. Jelf Insurance
Brokers’ Renewable Energy
Executive, Carl Gurney,
warns that “if the industry
fails to raise its standards
then insurers, due to
claims levels, will either
apply premiums that are
unsustainable or not offer
cover at all.”
The water sector in
particular has lead the