NutriFair 2019 Biogas Conference

Transcription

1 Biogas Innovations Large Scale Bioenergy Lab 2 Conference Fredericia, Denmark NutriFair 2019 Biogas Conference Experience from the UK to solve lignocellulosic and fibre challenges; Full-scale experience and testing of CaviMax by Mr. Owen Yeatman; Director of CaviMax

2 Cavitation technology for efficient biogas production

3 The CaviMax Family E-Pic Rotocav (2 designers, 1 x factory) Farmergy (4 sales and office staff) CaviMax sales, installation and service engineering partners working together CaviMax (2x directors) Advantage AD sector (11 engineers) Projective Non AD (20 engineers)

4 Cavitation technology for efficient biogas production Topics covered in this presentation What is CONTROLLED hydrodynamic cavitation? Hydrodynamic cavitation for disintegration of high lignin feedstocks and recalcitrant substrates CaviMax What the effects look like Benefits of cavitation for anaerobic digestion and renewable gas sector Results and observations from a years test operation in Scotland on a biomethane plant

5 What is Hydrodynamic Cavitation? (HDC) Hydrodynamic Cavitation has traditionally been known as a negative phenomenon Water hammer in pipes Cavitation and damage to pumps and ships propellers This occurs where a liquid pressure drops, and causes the liquid This is better explained in pictures

6 Cavitation Explained Vapour Pressure Curve - pressure determines the temperature that solids/liquids/gases change phase i.e. reduce atmospheric pressure by half in a vacuum flask of water, the boiling point of the water is reduced to 50oC, increase the pressure to increase the boiling point.

7 Cavitation Explained Vapour Pressure curve - control the pressure to manipulate the boiling point of liquids create the conditions for bubble formation and collapse - microjet

8 Hydrodynamic cavitation Imploding bubbles create millions of high pressure microjets in the chamber Asymmetric bubble collapse causes high pressure microjets in the liquid these project their energy into the particles in the substrate, causing collateral damage to surrounding biomass / solids

9 CaviMax The Biomass Disintegrator Inside the cavitation chamber liquids pumped at speed through a spinning rotor-stator, this creates pressure differentials in the liquid out in

10 How we harness the destructive forces of CONTROLLED Hydrodynamic Cavitation Application 1 Biomass disintegration The applications relevant to Nutrifair and The Bioenergy Conference are: 1) Increasing the performance of AD / biogas /biomethane plants

11 What can the CaviMax Biomass Disintegrator treat in the biogas plant? High lignin feedstocks agricultural residues Secondary sewage sludges Food and drink production waste Floating layers Part digested substrate, still energy in digestate The greatest biogas % increase is achieved through treating only the recalcitrant materials that are indigestible, unusable and the energy usually wasted

12 How we harness the destructive forces of CONTROLLED Hydrodynamic Cavitation - Application 2 - Liquid pig food 2) Increasing the growth rate and reducing antibiotic use in pig rearing

13 Pilot study being carried out in Italy between an innovative pig farmer, CaviMax and a reputable veterinary practice overseeing the pig health and progress. Results of the trial so far CASE STUDY Application 2 - Liquid pig food from maize silage

14 How is CaviMax harnessing the power of cavitation for the biogas industry? What problems needed overcoming? Many anaerobic digestion plants undersized to increase sales quotas Many evolutions of design, some of them dead ends Many plants built to the spreadsheet with little link to real time operating parameters Biogas plants now not achieving the returns promised Many plants are now limping along, not providing enough income to engineer out problems Changes in feedstocks allowed per tariff, reduction of energy crops, waste component now a factor Lignocellulosic and recalcitrant organic materials are problems for the AD industry Floating layers cause major headaches Lack of space to increase digestion capacity and retention time Reduction of subsidies means that only 2 new biomethane plants were built last year in the UK All of the above can be overcome by installing a CaviMax, plus a whole list of intangibles that get poor / average plants to the top of the performance spectrum, which in this industry is BIG MONEY

15 Benefits of cavitation for biogas plant operation - Reduce feedstock costs or increase biogas production - Ability to digest high lignin feed stocks utilise straw - Decrease problematic floating layer important when dealing with grass and straw (crust reduction in digester) - Increased availability of cellular juices - Acceleration of hydrolysis & the anaerobic digestion process - Reduce retention time in digester - Increased pumpability of substrate - Reduced plant downtime due to blockages - Reduction in H 2 S pollution, plant degradation & hazard

16 What do the effects/results look like? Reduced particle sizes & viscosity Sample from maize fed AD plant recirculating substrate line fed back into the same digester Before cavitation see lots of fibres and solid material left in the hand after squeezing the water out of the sample After cavitation much less left in the hand after the squeeze test

17 What do the effects look like? Cavitated sample on the right uncavitated on the left see reduced viscosity, thinner, less particles, freer flowing

18 What do the effects look like? The jar settle test, give the samples a shake and see how long the particles take to settle, left is non cavitated, middle and right, I x cavitation pass, and multiple cavitation passes Non cavitated settles straight away, cavitated small particles stay in suspension for days and weeks After many weeks the non cavitated sample turns into a floating layer, the cavitated samples are like fine silt, some particles are so small they are still in suspension Trial feedstock = paunch manure (undigested gut contents of cattle)

19 What do the effects look like? The treatment has a visible effect smaller particles BEFORE CAVITATION AFTER CAVITATION The large particles are reduced, the smaller particles are also reduced and homogenised

20 What do the effects look like? Gross solids after water has been squeezed out, the finer particles are still in the water BEFORE CAVITATION AFTER CAVITATION

21 Effects of cavitation reduction in particle sizes > <0.5 Largest Medium Smallest Particle Size (mm) Same dry matter content, however particle sizes are redistributed Untreated Substrate Cavitated Substrate

22 Results of cavitation - increase in biogas and methane Biochemical Methane Potential (BMP) Test - STRAW Batch test results - STRAW Untreated Treated with cavitator % change Dry Matter (%) % change CH4 in biogas (%) % change Length of test (days) % change Methane per tonne of dry matter (m3) % increase Biogas per tonne of dry matter (m3) % increase methane percentage increase in cavitated sample = 68%

23 Pre-treating straw with HDC results in a viable feedstock Biochemical Methane Potential (BMP) results of straw treated with hydrodynamic cavitation Biogas per tonne of dry matter (m3) Methane per tonne of dry matter (m3) Length of test (days) CH4 in biogas (%) Dry Matter (%) Treated with cavitator Untreated methane percentage increase in cavitated sample = up 68%

24 Results of cavitation of grass = viable biogas feedstock Grass - Batch Test Results Untreated Treated with Cavitator % change Length of test (27 Days) % change Dry Matter (38.75%) % change Ch4 in Biogas % % increase H2S content (PPM) % reduction Methane per tonne of DM (m3) % increase Biogas per tonne of DM (m3) % increase Biogas per tonne of Fresh matter (m3) % increase methane in cavitated sample = 36% increase hydrogen sulphide (H2S) in cavitated sample = 59% decrease

25 700 Cavitation of grass = viable biogas feedstock Biochemical Methane Potential (BMP) results of grass treated with hydrodynamic cavitation 29% increase % increase % decrease 30% increase 100 0% change 0% change 5% increase 0 Length of test (days) Dry matter % Methane in biogas % H2S - hydrogen sulphide content (ppm) Methane per tonne of dry matter (m3) Biogas per tonne of dry matter (m3) Biogas per tonne of fresh matter (m3) Untreated Treated with cavitator

26 Where does it fit in? CaviMax positioned mid-process treating the floating layer Draw off floating layer from the top of the digester pass through CaviMax to homogenise the substrate Return cavitated substrate back to the bottom of the digester for further digestion which increases flow and bioavailability of the substrate Access the energy of undigested feedstocks

27 Traditional feedstocks Where does it fit in? CaviMax positioned to pre-treat high lignin feedstocks Primary digester High lignin feedstocks To secondary digester / end store Feed in system CaviMax Recirculate digestate to hydrate feedstock to create pumpable substrate Unlock the potential of straw, grass silage, residues

28 Where does it fit? CaviMax positioned mid-process between digesters Primary digester The CaviMax in this position will reduce particle sizes of the substrate, providing increased plant efficiencies and biogas yield Secondary digester Ideal position to treat recalcitrant materials that did not get fully utilised in the primary digester extract maximum value from your substrate energy crops / secondary sludges in waste water treatment / food and drink waste / undigested fractions of feedstocks

29 Lesson learned at the industrial scale Biomethane gas-to-grid plant in Scotland Observations: DM stayed the same Viscosity reduced 35% less parasitic load for mixers and pumps 2017 = 7/6 mixers broken 2018 = 1 mixer reached end of life The mixers were changed in pairs, and each pair was a downtime (no biogas) of 3 days = >9 days lost Emil & bride came to visit on honeymoon Challenges: Electric cable accidently broken underground by operators Pressure seals needed optimisation Feedstocks always changing so no baseline data to calculate biogas uplift The unit is being moved to a site with consistent feedstocks and base data

30 Process intensification technology Fit a CaviMax to optimise

31 The best hydrodynamic cavitaton reactor in the market The ROTOCAV is designed to MAXIMIZE THE AREA THAT GENERATES CAVITATION: compared to the other dynamic hydrodynamic cavitators of the same size on the market, the volume of ROTOCAV S cavitation can be 3-4 times more

32 CaviMax service & breakdown Time is money, our ethos is to minimise downtime, so we provide the following:- Full UK / EU coverage service and maintenance division CaviMax service & maintenance plan Remote dial in problem identification worldwide Controls and sensors readily available in most countries worldwide, easily replaceable and automatically programmed once integrated into the CaviMax system Critical spares onsite with CaviMax Training provided for onsite maintenance team Camera and audio steam from CaviMax container to UK team to help guide the onsite team

33 Thanks for listening Team CaviMax have years of experience in planning, designing, building, operating, managing and maintaining biogas / biomethane plants, come discuss your plant with us to see how we can CaviMaximise your biogas plants operation Owen Yeatman Director Matt Powell - Director Emma Greenwood Business Development Manager