NSCAConference Wednesday 28th June 2000 RSA
ROLE OF ENERGY FROM WASTE PLANTS IN THE WASTE MANAGEMENTHIERARCHY BIFFA VIEWPOINT
Peter T Jones Director
The British Economy consumes around a 164 million tonnes ofcarbon equivalent fossil fuel energy in various forms each year and disposes ofaround 130 tonnes of carbonaceous material at the end of the industrial processas solid material. Additionally the originalfossil fuel input, net of energy substitution from European sources, accountsfor around 160 million tonnes carbon equivalent gaseous emissions toatmosphere. Set in this context thereis a clear case for identifying technology and logistics solutions to mitigateinput of fusel fuel non renewablematerials by offset surplus carbon disposed of elsewhere in the system. At Macro Level the objective is to establishthe BPEO for those tradeoffs wherever net benefits occur. The mix lies between a range of logisticsand end process technologies, from landfill gas utilization through to moreesoteric technologies involving gasification, pyrolysis and mass birn. The secret lies in identifying BPEO based on shifts in futurecompositional mixes of waste arisings, geography and the extent of any stepchange breakthroughs in process technologies which are driven by scaleeconomies or improvements in conversion efficiencies.
Against this backdrop theauthor argues for a precautionary approach in terms of scale until there is afar wider appreciation of overall waste carbon flows in the economy. The backdrop of growing Governmentconfidence in the management of budgetary and fiscal drivers, coupled to theemergence of innovative public sectorfunding programmes militates against long-term commitments extending over manydecades to technologies which absorb substantial proportions of the wastestream on an indiscriminate basis.Financial risks apart such solutions tend to be over dependant on largevolume flows of raw material ingredients which, in turn, may drive outincentives to attack environmental impacts further up the supply chain at thedesign and procurement or marketing phase.
II Background drivers The carbon balance
Government, academics,industry and consumers remain on the threshold of understanding about the flowof resources through the environmental economy of GB Plc. In our publication Great Britain PLC (www.biffa.co.uk)we explored the approximate dynamic of that process and identified 600 milliontonnes of raw material flows in the economy feeding a net consumer demand ofaround 60 million tonnes. Of totalsolid material inputs carbon is the second most significant after aggregates. (Exhibits)Little is understood with regard to outflows of carbon from the economyand we are currently working with a range of academic bodies (Oxford Universityand The University of Exeter) to quantify understanding in this area. Preliminary estimates suggested around 89million tonnes of surplus carbon (Exhibit) but that figure can now revisedupwards as a result of extrapolations of agricultural arisings being revisedupwards. (Exhibit)
These figures arepresented on the basis that the Governments energy strategy needs to beformulated in the context of total available fuel feed stock, adjusted forallowances on calorific value (c.v.) and ease of access. The author suggests that by 2010 there willbe a far more routine appreciation of the opportunities for Co2 reduction(identified as the major environmental current threat) in the context of theoverall carbon mass balance. In parallel with this supply side issueunderstanding will also expand with regard to the options for carbon fixationthrough the plant eco system and even landfill.
Set in this context theformal waste hierarchy can be a clumsy tool.Discussion thus far has emphasises the prominence of end process technologiesrather then the combined impact of logistics and technologies. (Exhibit)
The second significantcaveat is that for the purposes of the current conference one must defineenergy from waste more narrowly in the context of immediate issues relatingto municipal refuse. The wider viewpoint is presented however in so far as imminent solutions to the management ofmunicipal waste streams need to be taken in the context of overall picture not the other way around. Section IIIand section IV consider each in turn.
III THE LOGISTICS/PROCESS TECHNOLOGY
The art of combined lifecycle assessment processes on end process technologies and logistics is stillat a relatively early stage (Exhibit). Difficulties in those studies arefurther compounded by the complication of intermediate handling systems forwaste between point of production in households and the final resting place particularly where intermediate handling systems such as transfer stations andMRF (material recycling facilities) are utilized (Exhibit) Underpinning both however is the importanceof the economies of scale and the need to design logistics collectioninfrastructures in the context of specific end process technologies. To do otherwise is to join the wrong horseto the wrong cart. This assessment theattraction of large scale mass burn energy from waste facilities lies in theirability to utilize the existing fleet infrastructure of mobile collectionvehicles (Exhibit) which will move material on a combined basis regardless ofits calorific value, density, level of hazard or degree of inertness. Mass burn energy from waste plants have astriking advantage over other process technologies which demand morediscrimination (and investment) in collection methodologies whether sortationand segregation occurs at the point of waste production or at an intermediatestage. The impact conundrum is thuswhether to whether to risk significant end life environmental impacts in theprocess technology or logistics infrastructure. Solutions which optimise both are naturally preferable. (Exhibit)
Based on our experienceas the UK largest industrial and commercial waste carrier (handling around 8million tonnes of industrial and commercial wastes and 4 million tonnes ofmunicipal refuse) the precautionary principal suggests that flexibility at thisearly stage should be the order of the day.
This is not necessarilythe message Government wishes to hear given that the clock is ticking oncommitments to the landfill directive and recycling targets. Nevertheless our natural inclination is tosuggest that it is dangerous to lock into large scale incineration EFW due tothe presence of the following key area of risk
Capital Investment is locked in for a 30 year contractterm to achieve the necessary payback
Waste composition flows have shifted considerably inthe last 10 years and can be expected to shift even more over the next 30
Producer responsibility will eventually introduce largescale material reclamation initiatives which will exit substantial tonnageflows of specific high CV materials into raw material substitution routes.Integrated Product Policy (IPP) will accelerate this process.
Government fiscal strategy will favour recycling andmaterial reuse as generally more beneficial in term of Co2 avoidance
The technology substitution effect within the EFWbasket will expand substantially in coming years (ethanol systems Iparticular)
e.commerce could impact on the redistribution of wastearisings particularly at the existing retailer stage
Target on specific industries linked to producerresponsibility could result which in tradable permit regimes which will skewwaste flows in different directions.(Exhibit)
Presentedwith such uncertainties we believe that major investment in more than a fewdozen lime scale waste incinerators could represent significant long termpotential burdens on public purse where contractual arrangements involve putor pay goes options obligations.
IV EARNINGCAPITAL ENERGY FROM WASTE- SCALE
For Biffa objections to energy from waste incineration relate primarilyto the scale of the operation not technological issuesassociated with emission control technology (unless the regulatory regime islacking). For this reason we propose that EFW/incineration is an end lifetreatment method appropriate to collection infrastructures where materialsegregation ensures the supply of high CV material otherwise useless to otherrecycling processes (Low moisture content contaminated plastics, timber, paperand fibre). Consideration of theoverall tonnage yield of these materials in the domestic waste stream (total 24million tonnes ex households) suggest a realistic yield tonnage in the regionof 7 million p.a.
This figure is based on a plot of the urban conurbation showingpopulation density of 500 per square kilometre and above (Exhibit). Relating the target yield base to thecompositional flows in domestic dustbins suggests an optimum target EFW feedstock capacity of 6-7 million tonnesp.a. (Exhibit) In practicalterms collection infrastructures will not discriminate for such materialshowever and they will therefore absorb 3 million tonnes of inert and around 5million tonnes of high moisture content food waste and the hard waste at thesame time. This places nominal capacityaround 15 million tonnes or 40 x 0.35 million tpa facilities. This number of installations are likely toinvolve a capital investment profile in the region of 3.5 4 billion slightly over the combined annual total of PFI Spend Schemes for all publicservices in 2000 /2001 of 3 billion (Exhibit)Long time commitment to capital spend levels of this order of magnitudeshould be viewed with caution given the fast developing nature of alternativetechnologies which although they require higher investment in the logisticsand collection phase can be expected to deliver greater levels of capitalspend efficiency. They will also offergreater level of flexibility by operating on considerably reduce scale.(Typically burning quality control feed stock inputs of 20,000 30,000 tpa) These newer technologies burningpreselected high CV feed stocks appear to match large scale mass burnfacilities for capital investment cost per mega watt hour of around 3- 3.5million depending on the CHPoptions. Waste Strategy 2000 lists anumber of alternatives treatment technologies
Fermentation
Anaerobic digestion
Gastrification
Feed stock substitution
SubstituteFuels plasma arc
Feedstock recycling
Based on evidence from the US fermentation appears to offer the mostpromising route to market producing ethanol as a car fuel substitute throughthe biological rather than direct birn route.The science of maximising the CV yield from particular feed stocks isdetermined by the laws of thermodynamic the assessment of financial risk is howeveris matter of managerial judgement. Theassertion that expenditure of significant capital sums in large scale, singlesolution exit options at a time when compositional mixes, technological advanceand public understanding are all in a state of flux is a matter for politicaljudgement. When they are built beprepared to justify the financial and environmental cost to the nextgeneration- for that is who is likely to pick up the tab?
We are on the threshold of understanding thecreativity and originality of changes available in supply thinking in terms ofdesign and component material substitution which will produce dramatic shiftsin the nature of the waste stream.Replacing 50 large landfill sites by 50 large EFW facilities couldstifle that enervation with substation lost opportunities for sustainabilityimprovements in the hole supply chain rather than just at the end of it.
Peter T Jones
14th June 2000
LISTOF REFERENCES:
Energyfrom Waste An environmentally acceptable waste management option
Optionsfor Waste Management October 1997
Economicaspects of Resource cycles Delft University
Optionsfor Urban Waste Management November 1998
WasteBulletin 71 March 2000
WasteManagement Magazine (US November 1999)
PinnerProductions Barriers and cars toimplementation Massachusetts Environmental Ventures Autumn 1998
Firing upfor the future Waste Management Magazine March 2000
BiffaSource Material
P N Hobson Ecology of Anairobic Digestion Society forGeneral Microbiology Publication 1981 reference0.12.147480.1
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